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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
// There are three kinds of samples done by the profiler.
//
// - A "periodic" sample is the most complex kind. It is done in response to a
// timer while the profiler is active. It involves writing a stack trace plus
// a variety of other values (memory measurements, responsiveness
// measurements, etc.) into the main ProfileBuffer. The sampling is done from
// off-thread, and so SuspendAndSampleAndResumeThread() is used to get the
// register values.
//
// - A "synchronous" sample is a simpler kind. It is done in response to an API
// call (profiler_get_backtrace()). It involves writing a stack trace and
// little else into a temporary ProfileBuffer, and wrapping that up in a
// ProfilerBacktrace that can be subsequently used in a marker. The sampling
// is done on-thread, and so REGISTERS_SYNC_POPULATE() is used to get the
// register values.
//
// - A "backtrace" sample is the simplest kind. It is done in response to an
// API call (profiler_suspend_and_sample_thread()). It involves getting a
// stack trace via a ProfilerStackCollector; it does not write to a
// ProfileBuffer. The sampling is done from off-thread, and so uses
// SuspendAndSampleAndResumeThread() to get the register values.
#include "platform.h"
#include <algorithm>
#include <errno.h>
#include <fstream>
#include <ostream>
#include <set>
#include <sstream>
#include <string_view>
// #include "memory_hooks.h"
#include "mozilla/ArrayUtils.h"
#include "mozilla/AutoProfilerLabel.h"
#include "mozilla/BaseAndGeckoProfilerDetail.h"
#include "mozilla/BaseProfilerDetail.h"
#include "mozilla/DoubleConversion.h"
#include "mozilla/Printf.h"
#include "mozilla/ProfilerBufferSize.h"
#include "mozilla/ProfileBufferChunkManagerSingle.h"
#include "mozilla/ProfileBufferChunkManagerWithLocalLimit.h"
#include "mozilla/ProfileChunkedBuffer.h"
#include "mozilla/Services.h"
#include "mozilla/Span.h"
#include "mozilla/StackWalk.h"
#ifdef XP_WIN
# include "mozilla/StackWalkThread.h"
# include "mozilla/WindowsStackWalkInitialization.h"
#endif
#include "mozilla/StaticPtr.h"
#include "mozilla/ThreadLocal.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/Vector.h"
#include "prdtoa.h"
#include "prtime.h"
#include "BaseProfiler.h"
#include "BaseProfilingCategory.h"
#include "PageInformation.h"
#include "ProfiledThreadData.h"
#include "ProfilerBacktrace.h"
#include "ProfileBuffer.h"
#include "RegisteredThread.h"
#include "BaseProfilerSharedLibraries.h"
#include "ThreadInfo.h"
#include "VTuneProfiler.h"
// Win32 builds always have frame pointers, so FramePointerStackWalk() always
// works.
#if defined(GP_PLAT_x86_windows)
# define HAVE_NATIVE_UNWIND
# define USE_FRAME_POINTER_STACK_WALK
#endif
// Win64 builds always omit frame pointers, so we use the slower
// MozStackWalk(), which works in that case.
#if defined(GP_PLAT_amd64_windows)
# define HAVE_NATIVE_UNWIND
# define USE_MOZ_STACK_WALK
#endif
// AArch64 Win64 doesn't seem to use frame pointers, so we use the slower
// MozStackWalk().
#if defined(GP_PLAT_arm64_windows)
# define HAVE_NATIVE_UNWIND
# define USE_MOZ_STACK_WALK
#endif
// Mac builds use FramePointerStackWalk(). Even if we build without
// frame pointers, we'll still get useful stacks in system libraries
// because those always have frame pointers.
// We don't use MozStackWalk() on Mac.
#if defined(GP_OS_darwin)
# define HAVE_NATIVE_UNWIND
# define USE_FRAME_POINTER_STACK_WALK
#endif
// No stack-walking in baseprofiler on linux, android, bsd.
// APIs now make it easier to capture backtraces from the Base Profiler, which
// is currently not supported on these platform, and would lead to a MOZ_CRASH
#if 0
// Android builds use the ARM Exception Handling ABI to unwind.
# if defined(GP_PLAT_arm_linux) || defined(GP_PLAT_arm_android)
# define HAVE_NATIVE_UNWIND
# define USE_EHABI_STACKWALK
# include "EHABIStackWalk.h"
# endif
// Linux/BSD builds use LUL, which uses DWARF info to unwind stacks.
# if defined(GP_PLAT_amd64_linux) || defined(GP_PLAT_x86_linux) || \
defined(GP_PLAT_amd64_android) || defined(GP_PLAT_x86_android) || \
defined(GP_PLAT_mips64_linux) || defined(GP_PLAT_arm64_linux) || \
defined(GP_PLAT_arm64_android) || defined(GP_PLAT_amd64_freebsd) || \
defined(GP_PLAT_arm64_freebsd)
# define HAVE_NATIVE_UNWIND
# define USE_LUL_STACKWALK
# include "lul/LulMain.h"
# include "lul/platform-linux-lul.h"
// On linux we use LUL for periodic samples and synchronous samples, but we use
// FramePointerStackWalk for backtrace samples when MOZ_PROFILING is enabled.
// (See the comment at the top of the file for a definition of
// periodic/synchronous/backtrace.).
//
// FramePointerStackWalk can produce incomplete stacks when the current entry is
// in a shared library without framepointers, however LUL can take a long time
// to initialize, which is undesirable for consumers of
// profiler_suspend_and_sample_thread like the Background Hang Reporter.
# if defined(MOZ_PROFILING)
# define USE_FRAME_POINTER_STACK_WALK
# endif
# endif
#endif
// We can only stackwalk without expensive initialization on platforms which
// support FramePointerStackWalk or MozStackWalk. LUL Stackwalking requires
// initializing LUL, and EHABIStackWalk requires initializing EHABI, both of
// which can be expensive.
#if defined(USE_FRAME_POINTER_STACK_WALK) || defined(USE_MOZ_STACK_WALK)
# define HAVE_FASTINIT_NATIVE_UNWIND
#endif
#ifdef MOZ_VALGRIND
# include <valgrind/memcheck.h>
#else
# define VALGRIND_MAKE_MEM_DEFINED(_addr, _len) ((void)0)
#endif
#if defined(GP_OS_linux) || defined(GP_OS_android) || defined(GP_OS_freebsd)
# include <ucontext.h>
#endif
namespace mozilla {
namespace baseprofiler {
using detail::RacyFeatures;
bool LogTest(int aLevelToTest) {
static const int maxLevel = getenv("MOZ_BASE_PROFILER_VERBOSE_LOGGING") ? 5
: getenv("MOZ_BASE_PROFILER_DEBUG_LOGGING") ? 4
: getenv("MOZ_BASE_PROFILER_LOGGING") ? 3
: 0;
return aLevelToTest <= maxLevel;
}
void PrintToConsole(const char* aFmt, ...) {
va_list args;
va_start(args, aFmt);
#if defined(ANDROID)
__android_log_vprint(ANDROID_LOG_INFO, "Gecko", aFmt, args);
#else
vfprintf(stderr, aFmt, args);
#endif
va_end(args);
}
ProfileChunkedBuffer& profiler_get_core_buffer() {
// This needs its own mutex, because it is used concurrently from functions
// guarded by gPSMutex as well as others without safety (e.g.,
// profiler_add_marker). It is *not* used inside the critical section of the
// sampler, because mutexes cannot be used there.
static ProfileChunkedBuffer sProfileChunkedBuffer{
ProfileChunkedBuffer::ThreadSafety::WithMutex};
return sProfileChunkedBuffer;
}
Atomic<int, MemoryOrdering::Relaxed> gSkipSampling;
constexpr static bool ValidateFeatures() {
int expectedFeatureNumber = 0;
// Feature numbers should start at 0 and increase by 1 each.
#define CHECK_FEATURE(n_, str_, Name_, desc_) \
if ((n_) != expectedFeatureNumber) { \
return false; \
} \
++expectedFeatureNumber;
BASE_PROFILER_FOR_EACH_FEATURE(CHECK_FEATURE)
#undef CHECK_FEATURE
return true;
}
static_assert(ValidateFeatures(), "Feature list is invalid");
// Return all features that are available on this platform.
static uint32_t AvailableFeatures() {
uint32_t features = 0;
#define ADD_FEATURE(n_, str_, Name_, desc_) \
ProfilerFeature::Set##Name_(features);
// Add all the possible features.
BASE_PROFILER_FOR_EACH_FEATURE(ADD_FEATURE)
#undef ADD_FEATURE
// Now remove features not supported on this platform/configuration.
ProfilerFeature::ClearJava(features);
ProfilerFeature::ClearJS(features);
ProfilerFeature::ClearScreenshots(features);
#if !defined(HAVE_NATIVE_UNWIND)
ProfilerFeature::ClearStackWalk(features);
#endif
#if !defined(GP_OS_windows)
ProfilerFeature::ClearNoTimerResolutionChange(features);
#endif
return features;
}
// Default features common to all contexts (even if not available).
static constexpr uint32_t DefaultFeatures() {
return ProfilerFeature::Java | ProfilerFeature::JS |
ProfilerFeature::StackWalk | ProfilerFeature::CPUUtilization |
ProfilerFeature::ProcessCPU;
}
// Extra default features when MOZ_PROFILER_STARTUP is set (even if not
// available).
static constexpr uint32_t StartupExtraDefaultFeatures() {
// Enable mainthreadio by default for startup profiles as startup is heavy on
// I/O operations, and main thread I/O is really important to see there.
return ProfilerFeature::MainThreadIO | ProfilerFeature::IPCMessages;
}
// The auto-lock/unlock mutex that guards accesses to CorePS and ActivePS.
// Use `PSAutoLock lock;` to take the lock until the end of the enclosing block.
// External profilers may use this same lock for their own data, but as the lock
// is non-recursive, *only* `f(PSLockRef, ...)` functions below should be
// called, to avoid double-locking.
class MOZ_RAII PSAutoLock {
public:
PSAutoLock() : mLock(gPSMutex) {}
PSAutoLock(const PSAutoLock&) = delete;
void operator=(const PSAutoLock&) = delete;
[[nodiscard]] static bool IsLockedOnCurrentThread() {
return gPSMutex.IsLockedOnCurrentThread();
}
private:
static detail::BaseProfilerMutex gPSMutex;
detail::BaseProfilerAutoLock mLock;
};
MOZ_RUNINIT detail::BaseProfilerMutex PSAutoLock::gPSMutex{
"Base Profiler mutex"};
// Only functions that take a PSLockRef arg can access CorePS's and ActivePS's
// fields.
typedef const PSAutoLock& PSLockRef;
#define PS_GET(type_, name_) \
static type_ name_(PSLockRef) { \
MOZ_ASSERT(sInstance); \
return sInstance->m##name_; \
}
#define PS_GET_LOCKLESS(type_, name_) \
static type_ name_() { \
MOZ_ASSERT(sInstance); \
return sInstance->m##name_; \
}
#define PS_GET_AND_SET(type_, name_) \
PS_GET(type_, name_) \
static void Set##name_(PSLockRef, type_ a##name_) { \
MOZ_ASSERT(sInstance); \
sInstance->m##name_ = a##name_; \
}
// All functions in this file can run on multiple threads unless they have an
// NS_IsMainThread() assertion.
// This class contains the profiler's core global state, i.e. that which is
// valid even when the profiler is not active. Most profile operations can't do
// anything useful when this class is not instantiated, so we release-assert
// its non-nullness in all such operations.
//
// Accesses to CorePS are guarded by gPSMutex. Getters and setters take a
// PSAutoLock reference as an argument as proof that the gPSMutex is currently
// locked. This makes it clear when gPSMutex is locked and helps avoid
// accidental unlocked accesses to global state. There are ways to circumvent
// this mechanism, but please don't do so without *very* good reason and a
// detailed explanation.
//
// The exceptions to this rule:
//
// - mProcessStartTime, because it's immutable;
//
// - each thread's RacyRegisteredThread object is accessible without locking via
// TLSRegisteredThread::RacyRegisteredThread().
class CorePS {
private:
CorePS()
: mProcessStartTime(TimeStamp::ProcessCreation())
#ifdef USE_LUL_STACKWALK
,
mLul(nullptr)
#endif
{
}
~CorePS() {}
public:
static void Create(PSLockRef aLock) {
MOZ_ASSERT(!sInstance);
sInstance = new CorePS();
}
static void Destroy(PSLockRef aLock) {
MOZ_ASSERT(sInstance);
delete sInstance;
sInstance = nullptr;
}
// Unlike ActivePS::Exists(), CorePS::Exists() can be called without gPSMutex
// being locked. This is because CorePS is instantiated so early on the main
// thread that we don't have to worry about it being racy.
static bool Exists() { return !!sInstance; }
static void AddSizeOf(PSLockRef, MallocSizeOf aMallocSizeOf,
size_t& aProfSize, size_t& aLulSize) {
MOZ_ASSERT(sInstance);
aProfSize += aMallocSizeOf(sInstance);
for (auto& registeredThread : sInstance->mRegisteredThreads) {
aProfSize += registeredThread->SizeOfIncludingThis(aMallocSizeOf);
}
for (auto& registeredPage : sInstance->mRegisteredPages) {
aProfSize += registeredPage->SizeOfIncludingThis(aMallocSizeOf);
}
// Measurement of the following things may be added later if DMD finds it
// is worthwhile:
// - CorePS::mRegisteredThreads itself (its elements' children are
// measured above)
// - CorePS::mRegisteredPages itself (its elements' children are
// measured above)
// - CorePS::mInterposeObserver
#if defined(USE_LUL_STACKWALK)
if (sInstance->mLul) {
aLulSize += sInstance->mLul->SizeOfIncludingThis(aMallocSizeOf);
}
#endif
}
// No PSLockRef is needed for this field because it's immutable.
PS_GET_LOCKLESS(const TimeStamp&, ProcessStartTime)
PS_GET(const Vector<UniquePtr<RegisteredThread>>&, RegisteredThreads)
static void AppendRegisteredThread(
PSLockRef, UniquePtr<RegisteredThread>&& aRegisteredThread) {
MOZ_ASSERT(sInstance);
MOZ_RELEASE_ASSERT(
sInstance->mRegisteredThreads.append(std::move(aRegisteredThread)));
}
static void RemoveRegisteredThread(PSLockRef,
RegisteredThread* aRegisteredThread) {
MOZ_ASSERT(sInstance);
// Remove aRegisteredThread from mRegisteredThreads.
for (UniquePtr<RegisteredThread>& rt : sInstance->mRegisteredThreads) {
if (rt.get() == aRegisteredThread) {
sInstance->mRegisteredThreads.erase(&rt);
return;
}
}
}
PS_GET(Vector<RefPtr<PageInformation>>&, RegisteredPages)
static void AppendRegisteredPage(PSLockRef,
RefPtr<PageInformation>&& aRegisteredPage) {
MOZ_ASSERT(sInstance);
struct RegisteredPageComparator {
PageInformation* aA;
bool operator()(PageInformation* aB) const { return aA->Equals(aB); }
};
auto foundPageIter = std::find_if(
sInstance->mRegisteredPages.begin(), sInstance->mRegisteredPages.end(),
RegisteredPageComparator{aRegisteredPage.get()});
if (foundPageIter != sInstance->mRegisteredPages.end()) {
if ((*foundPageIter)->Url() == "about:blank") {
// When a BrowsingContext is loaded, the first url loaded in it will be
// about:blank, and if the principal matches, the first document loaded
// in it will share an inner window. That's why we should delete the
// intermittent about:blank if they share the inner window.
sInstance->mRegisteredPages.erase(foundPageIter);
} else {
// Do not register the same page again.
return;
}
}
MOZ_RELEASE_ASSERT(
sInstance->mRegisteredPages.append(std::move(aRegisteredPage)));
}
static void RemoveRegisteredPage(PSLockRef,
uint64_t aRegisteredInnerWindowID) {
MOZ_ASSERT(sInstance);
// Remove RegisteredPage from mRegisteredPages by given inner window ID.
sInstance->mRegisteredPages.eraseIf([&](const RefPtr<PageInformation>& rd) {
return rd->InnerWindowID() == aRegisteredInnerWindowID;
});
}
static void ClearRegisteredPages(PSLockRef) {
MOZ_ASSERT(sInstance);
sInstance->mRegisteredPages.clear();
}
PS_GET(const Vector<BaseProfilerCount*>&, Counters)
static void AppendCounter(PSLockRef, BaseProfilerCount* aCounter) {
MOZ_ASSERT(sInstance);
// we don't own the counter; they may be stored in static objects
MOZ_RELEASE_ASSERT(sInstance->mCounters.append(aCounter));
}
static void RemoveCounter(PSLockRef, BaseProfilerCount* aCounter) {
// we may be called to remove a counter after the profiler is stopped or
// late in shutdown.
if (sInstance) {
auto* counter = std::find(sInstance->mCounters.begin(),
sInstance->mCounters.end(), aCounter);
MOZ_RELEASE_ASSERT(counter != sInstance->mCounters.end());
sInstance->mCounters.erase(counter);
}
}
#ifdef USE_LUL_STACKWALK
static lul::LUL* Lul(PSLockRef) {
MOZ_ASSERT(sInstance);
return sInstance->mLul.get();
}
static void SetLul(PSLockRef, UniquePtr<lul::LUL> aLul) {
MOZ_ASSERT(sInstance);
sInstance->mLul = std::move(aLul);
}
#endif
PS_GET_AND_SET(const std::string&, ProcessName)
PS_GET_AND_SET(const std::string&, ETLDplus1)
private:
// The singleton instance
static CorePS* sInstance;
// The time that the process started.
const TimeStamp mProcessStartTime;
// Info on all the registered threads.
// ThreadIds in mRegisteredThreads are unique.
Vector<UniquePtr<RegisteredThread>> mRegisteredThreads;
// Info on all the registered pages.
// InnerWindowIDs in mRegisteredPages are unique.
Vector<RefPtr<PageInformation>> mRegisteredPages;
// Non-owning pointers to all active counters
Vector<BaseProfilerCount*> mCounters;
#ifdef USE_LUL_STACKWALK
// LUL's state. Null prior to the first activation, non-null thereafter.
UniquePtr<lul::LUL> mLul;
#endif
// Process name, provided by child process initialization code.
std::string mProcessName;
// Private name, provided by child process initialization code (eTLD+1 in
// fission)
std::string mETLDplus1;
};
CorePS* CorePS::sInstance = nullptr;
class SamplerThread;
static SamplerThread* NewSamplerThread(PSLockRef aLock, uint32_t aGeneration,
double aInterval, uint32_t aFeatures);
struct LiveProfiledThreadData {
RegisteredThread* mRegisteredThread;
UniquePtr<ProfiledThreadData> mProfiledThreadData;
};
// The buffer size is provided as a number of "entries", this is their size in
// bytes.
constexpr static uint32_t scBytesPerEntry = 8;
// This class contains the profiler's global state that is valid only when the
// profiler is active. When not instantiated, the profiler is inactive.
//
// Accesses to ActivePS are guarded by gPSMutex, in much the same fashion as
// CorePS.
//
class ActivePS {
private:
constexpr static uint32_t ChunkSizeForEntries(uint32_t aEntries) {
return uint32_t(std::min(size_t(ClampToAllowedEntries(aEntries)) *
scBytesPerEntry / scMinimumNumberOfChunks,
size_t(scMaximumChunkSize)));
}
static uint32_t AdjustFeatures(uint32_t aFeatures, uint32_t aFilterCount) {
// Filter out any features unavailable in this platform/configuration.
aFeatures &= AvailableFeatures();
// Some features imply others.
if (aFeatures & ProfilerFeature::FileIOAll) {
aFeatures |= ProfilerFeature::MainThreadIO | ProfilerFeature::FileIO;
} else if (aFeatures & ProfilerFeature::FileIO) {
aFeatures |= ProfilerFeature::MainThreadIO;
}
return aFeatures;
}
ActivePS(PSLockRef aLock, const TimeStamp& aProfilingStartTime,
PowerOfTwo32 aCapacity, double aInterval, uint32_t aFeatures,
const char** aFilters, uint32_t aFilterCount,
const Maybe<double>& aDuration)
: mProfilingStartTime(aProfilingStartTime),
mGeneration(sNextGeneration++),
mCapacity(aCapacity),
mDuration(aDuration),
mInterval(aInterval),
mFeatures(AdjustFeatures(aFeatures, aFilterCount)),
mProfileBufferChunkManager(
MakeUnique<ProfileBufferChunkManagerWithLocalLimit>(
size_t(ClampToAllowedEntries(aCapacity.Value())) *
scBytesPerEntry,
ChunkSizeForEntries(aCapacity.Value()))),
mProfileBuffer([this]() -> ProfileChunkedBuffer& {
ProfileChunkedBuffer& buffer = profiler_get_core_buffer();
buffer.SetChunkManager(*mProfileBufferChunkManager);
return buffer;
}()),
// The new sampler thread doesn't start sampling immediately because the
// main loop within Run() is blocked until this function's caller
// unlocks gPSMutex.
mSamplerThread(
NewSamplerThread(aLock, mGeneration, aInterval, aFeatures)),
mIsPaused(false),
mIsSamplingPaused(false) {
// Deep copy and lower-case aFilters.
MOZ_ALWAYS_TRUE(mFilters.resize(aFilterCount));
MOZ_ALWAYS_TRUE(mFiltersLowered.resize(aFilterCount));
for (uint32_t i = 0; i < aFilterCount; ++i) {
mFilters[i] = aFilters[i];
mFiltersLowered[i].reserve(mFilters[i].size());
std::transform(mFilters[i].cbegin(), mFilters[i].cend(),
std::back_inserter(mFiltersLowered[i]), ::tolower);
}
}
~ActivePS() {
if (mProfileBufferChunkManager) {
// We still control the chunk manager, remove it from the core buffer.
profiler_get_core_buffer().ResetChunkManager();
}
}
bool ThreadSelected(const char* aThreadName) {
if (mFiltersLowered.empty()) {
return true;
}
std::string name = aThreadName;
std::transform(name.begin(), name.end(), name.begin(), ::tolower);
for (const auto& filter : mFiltersLowered) {
if (filter == "*") {
return true;
}
// Crude, non UTF-8 compatible, case insensitive substring search
if (name.find(filter) != std::string::npos) {
return true;
}
// If the filter is "pid:<my pid>", profile all threads.
if (mozilla::profiler::detail::FilterHasPid(filter.c_str())) {
return true;
}
}
return false;
}
public:
static void Create(PSLockRef aLock, const TimeStamp& aProfilingStartTime,
PowerOfTwo32 aCapacity, double aInterval,
uint32_t aFeatures, const char** aFilters,
uint32_t aFilterCount, const Maybe<double>& aDuration) {
MOZ_ASSERT(!sInstance);
sInstance = new ActivePS(aLock, aProfilingStartTime, aCapacity, aInterval,
aFeatures, aFilters, aFilterCount, aDuration);
}
[[nodiscard]] static SamplerThread* Destroy(PSLockRef aLock) {
MOZ_ASSERT(sInstance);
auto samplerThread = sInstance->mSamplerThread;
delete sInstance;
sInstance = nullptr;
return samplerThread;
}
static bool Exists(PSLockRef) { return !!sInstance; }
static bool Equals(PSLockRef, PowerOfTwo32 aCapacity,
const Maybe<double>& aDuration, double aInterval,
uint32_t aFeatures, const char** aFilters,
uint32_t aFilterCount) {
MOZ_ASSERT(sInstance);
if (sInstance->mCapacity != aCapacity ||
sInstance->mDuration != aDuration ||
sInstance->mInterval != aInterval ||
sInstance->mFeatures != aFeatures ||
sInstance->mFilters.length() != aFilterCount) {
return false;
}
for (uint32_t i = 0; i < sInstance->mFilters.length(); ++i) {
if (strcmp(sInstance->mFilters[i].c_str(), aFilters[i]) != 0) {
return false;
}
}
return true;
}
static size_t SizeOf(PSLockRef, MallocSizeOf aMallocSizeOf) {
MOZ_ASSERT(sInstance);
size_t n = aMallocSizeOf(sInstance);
n += sInstance->mProfileBuffer.SizeOfExcludingThis(aMallocSizeOf);
// Measurement of the following members may be added later if DMD finds it
// is worthwhile:
// - mLiveProfiledThreads (both the array itself, and the contents)
// - mDeadProfiledThreads (both the array itself, and the contents)
//
return n;
}
static UniquePtr<ProfileBufferChunkManagerWithLocalLimit>
ExtractBaseProfilerChunkManager(PSLockRef) {
MOZ_ASSERT(sInstance);
return std::move(sInstance->mProfileBufferChunkManager);
}
static bool ShouldProfileThread(PSLockRef aLock, ThreadInfo* aInfo) {
MOZ_ASSERT(sInstance);
return sInstance->ThreadSelected(aInfo->Name());
}
PS_GET_LOCKLESS(TimeStamp, ProfilingStartTime)
PS_GET(uint32_t, Generation)
PS_GET(PowerOfTwo32, Capacity)
PS_GET(Maybe<double>, Duration)
PS_GET(double, Interval)
PS_GET(uint32_t, Features)
#define PS_GET_FEATURE(n_, str_, Name_, desc_) \
static bool Feature##Name_(PSLockRef) { \
MOZ_ASSERT(sInstance); \
return ProfilerFeature::Has##Name_(sInstance->mFeatures); \
}
BASE_PROFILER_FOR_EACH_FEATURE(PS_GET_FEATURE)
#undef PS_GET_FEATURE
PS_GET(const Vector<std::string>&, Filters)
PS_GET(const Vector<std::string>&, FiltersLowered)
static void FulfillChunkRequests(PSLockRef) {
MOZ_ASSERT(sInstance);
if (sInstance->mProfileBufferChunkManager) {
sInstance->mProfileBufferChunkManager->FulfillChunkRequests();
}
}
static ProfileBuffer& Buffer(PSLockRef) {
MOZ_ASSERT(sInstance);
return sInstance->mProfileBuffer;
}
static const Vector<LiveProfiledThreadData>& LiveProfiledThreads(PSLockRef) {
MOZ_ASSERT(sInstance);
return sInstance->mLiveProfiledThreads;
}
// Returns an array containing (RegisteredThread*, ProfiledThreadData*) pairs
// for all threads that should be included in a profile, both for threads
// that are still registered, and for threads that have been unregistered but
// still have data in the buffer.
// For threads that have already been unregistered, the RegisteredThread
// pointer will be null.
// The returned array is sorted by thread register time.
// Do not hold on to the return value across thread registration or profiler
// restarts.
static Vector<std::pair<RegisteredThread*, ProfiledThreadData*>>
ProfiledThreads(PSLockRef) {
MOZ_ASSERT(sInstance);
Vector<std::pair<RegisteredThread*, ProfiledThreadData*>> array;
MOZ_RELEASE_ASSERT(
array.initCapacity(sInstance->mLiveProfiledThreads.length() +
sInstance->mDeadProfiledThreads.length()));
for (auto& t : sInstance->mLiveProfiledThreads) {
MOZ_RELEASE_ASSERT(array.append(
std::make_pair(t.mRegisteredThread, t.mProfiledThreadData.get())));
}
for (auto& t : sInstance->mDeadProfiledThreads) {
MOZ_RELEASE_ASSERT(
array.append(std::make_pair((RegisteredThread*)nullptr, t.get())));
}
std::sort(array.begin(), array.end(),
[](const std::pair<RegisteredThread*, ProfiledThreadData*>& a,
const std::pair<RegisteredThread*, ProfiledThreadData*>& b) {
return a.second->Info()->RegisterTime() <
b.second->Info()->RegisterTime();
});
return array;
}
static Vector<RefPtr<PageInformation>> ProfiledPages(PSLockRef aLock) {
MOZ_ASSERT(sInstance);
Vector<RefPtr<PageInformation>> array;
for (auto& d : CorePS::RegisteredPages(aLock)) {
MOZ_RELEASE_ASSERT(array.append(d));
}
for (auto& d : sInstance->mDeadProfiledPages) {
MOZ_RELEASE_ASSERT(array.append(d));
}
// We don't need to sort the pages like threads since we won't show them
// as a list.
return array;
}
// Do a linear search through mLiveProfiledThreads to find the
// ProfiledThreadData object for a RegisteredThread.
static ProfiledThreadData* GetProfiledThreadData(
PSLockRef, RegisteredThread* aRegisteredThread) {
MOZ_ASSERT(sInstance);
for (const LiveProfiledThreadData& thread :
sInstance->mLiveProfiledThreads) {
if (thread.mRegisteredThread == aRegisteredThread) {
return thread.mProfiledThreadData.get();
}
}
return nullptr;
}
static ProfiledThreadData* AddLiveProfiledThread(
PSLockRef, RegisteredThread* aRegisteredThread,
UniquePtr<ProfiledThreadData>&& aProfiledThreadData) {
MOZ_ASSERT(sInstance);
MOZ_RELEASE_ASSERT(
sInstance->mLiveProfiledThreads.append(LiveProfiledThreadData{
aRegisteredThread, std::move(aProfiledThreadData)}));
// Return a weak pointer to the ProfiledThreadData object.
return sInstance->mLiveProfiledThreads.back().mProfiledThreadData.get();
}
static void UnregisterThread(PSLockRef aLockRef,
RegisteredThread* aRegisteredThread) {
MOZ_ASSERT(sInstance);
DiscardExpiredDeadProfiledThreads(aLockRef);
// Find the right entry in the mLiveProfiledThreads array and remove the
// element, moving the ProfiledThreadData object for the thread into the
// mDeadProfiledThreads array.
// The thread's RegisteredThread object gets destroyed here.
for (size_t i = 0; i < sInstance->mLiveProfiledThreads.length(); i++) {
LiveProfiledThreadData& thread = sInstance->mLiveProfiledThreads[i];
if (thread.mRegisteredThread == aRegisteredThread) {
thread.mProfiledThreadData->NotifyUnregistered(
sInstance->mProfileBuffer.BufferRangeEnd());
MOZ_RELEASE_ASSERT(sInstance->mDeadProfiledThreads.append(
std::move(thread.mProfiledThreadData)));
sInstance->mLiveProfiledThreads.erase(
&sInstance->mLiveProfiledThreads[i]);
return;
}
}
}
PS_GET_AND_SET(bool, IsPaused)
// True if sampling is paused (though generic `SetIsPaused()` or specific
// `SetIsSamplingPaused()`).
static bool IsSamplingPaused(PSLockRef lock) {
MOZ_ASSERT(sInstance);
return IsPaused(lock) || sInstance->mIsSamplingPaused;
}
static void SetIsSamplingPaused(PSLockRef, bool aIsSamplingPaused) {
MOZ_ASSERT(sInstance);
sInstance->mIsSamplingPaused = aIsSamplingPaused;
}
static void DiscardExpiredDeadProfiledThreads(PSLockRef) {
MOZ_ASSERT(sInstance);
uint64_t bufferRangeStart = sInstance->mProfileBuffer.BufferRangeStart();
// Discard any dead threads that were unregistered before bufferRangeStart.
sInstance->mDeadProfiledThreads.eraseIf(
[bufferRangeStart](
const UniquePtr<ProfiledThreadData>& aProfiledThreadData) {
Maybe<uint64_t> bufferPosition =
aProfiledThreadData->BufferPositionWhenUnregistered();
MOZ_RELEASE_ASSERT(bufferPosition,
"should have unregistered this thread");
return *bufferPosition < bufferRangeStart;
});
}
static void UnregisterPage(PSLockRef aLock,
uint64_t aRegisteredInnerWindowID) {
MOZ_ASSERT(sInstance);
auto& registeredPages = CorePS::RegisteredPages(aLock);
for (size_t i = 0; i < registeredPages.length(); i++) {
RefPtr<PageInformation>& page = registeredPages[i];
if (page->InnerWindowID() == aRegisteredInnerWindowID) {
page->NotifyUnregistered(sInstance->mProfileBuffer.BufferRangeEnd());
MOZ_RELEASE_ASSERT(
sInstance->mDeadProfiledPages.append(std::move(page)));
registeredPages.erase(®isteredPages[i--]);
}
}
}
static void DiscardExpiredPages(PSLockRef) {
MOZ_ASSERT(sInstance);
uint64_t bufferRangeStart = sInstance->mProfileBuffer.BufferRangeStart();
// Discard any dead pages that were unregistered before
// bufferRangeStart.
sInstance->mDeadProfiledPages.eraseIf(
[bufferRangeStart](const RefPtr<PageInformation>& aProfiledPage) {
Maybe<uint64_t> bufferPosition =
aProfiledPage->BufferPositionWhenUnregistered();
MOZ_RELEASE_ASSERT(bufferPosition,
"should have unregistered this page");
return *bufferPosition < bufferRangeStart;
});
}
static void ClearUnregisteredPages(PSLockRef) {
MOZ_ASSERT(sInstance);
sInstance->mDeadProfiledPages.clear();
}
static void ClearExpiredExitProfiles(PSLockRef) {
MOZ_ASSERT(sInstance);
uint64_t bufferRangeStart = sInstance->mProfileBuffer.BufferRangeStart();
// Discard exit profiles that were gathered before our buffer RangeStart.
sInstance->mExitProfiles.eraseIf(
[bufferRangeStart](const ExitProfile& aExitProfile) {
return aExitProfile.mBufferPositionAtGatherTime < bufferRangeStart;
});
}
static void AddExitProfile(PSLockRef aLock, const std::string& aExitProfile) {
MOZ_ASSERT(sInstance);
ClearExpiredExitProfiles(aLock);
MOZ_RELEASE_ASSERT(sInstance->mExitProfiles.append(
ExitProfile{aExitProfile, sInstance->mProfileBuffer.BufferRangeEnd()}));
}
static Vector<std::string> MoveExitProfiles(PSLockRef aLock) {
MOZ_ASSERT(sInstance);
ClearExpiredExitProfiles(aLock);
Vector<std::string> profiles;
MOZ_RELEASE_ASSERT(
profiles.initCapacity(sInstance->mExitProfiles.length()));
for (auto& profile : sInstance->mExitProfiles) {
MOZ_RELEASE_ASSERT(profiles.append(std::move(profile.mJSON)));
}
sInstance->mExitProfiles.clear();
return profiles;
}
private:
// The singleton instance.
static ActivePS* sInstance;
const TimeStamp mProfilingStartTime;
// We need to track activity generations. If we didn't we could have the
// following scenario.
//
// - profiler_stop() locks gPSMutex, de-instantiates ActivePS, unlocks
// gPSMutex, deletes the SamplerThread (which does a join).
//
// - profiler_start() runs on a different thread, locks gPSMutex,
// re-instantiates ActivePS, unlocks gPSMutex -- all before the join
// completes.
//
// - SamplerThread::Run() locks gPSMutex, sees that ActivePS is instantiated,
// and continues as if the start/stop pair didn't occur. Also
// profiler_stop() is stuck, unable to finish.
//
// By checking ActivePS *and* the generation, we can avoid this scenario.
// sNextGeneration is used to track the next generation number; it is static
// because it must persist across different ActivePS instantiations.
const uint32_t mGeneration;
static uint32_t sNextGeneration;
// The maximum number of 8-byte entries in mProfileBuffer.
const PowerOfTwo32 mCapacity;
// The maximum duration of entries in mProfileBuffer, in seconds.
const Maybe<double> mDuration;
// The interval between samples, measured in milliseconds.
const double mInterval;
// The profile features that are enabled.
const uint32_t mFeatures;
// Substrings of names of threads we want to profile.
Vector<std::string> mFilters;
Vector<std::string> mFiltersLowered;
// The chunk manager used by `mProfileBuffer` below.
// May become null if it gets transferred to the Gecko Profiler.
UniquePtr<ProfileBufferChunkManagerWithLocalLimit> mProfileBufferChunkManager;
// The buffer into which all samples are recorded.
ProfileBuffer mProfileBuffer;
// ProfiledThreadData objects for any threads that were profiled at any point
// during this run of the profiler:
// - mLiveProfiledThreads contains all threads that are still registered, and
// - mDeadProfiledThreads contains all threads that have already been
// unregistered but for which there is still data in the profile buffer.
Vector<LiveProfiledThreadData> mLiveProfiledThreads;
Vector<UniquePtr<ProfiledThreadData>> mDeadProfiledThreads;
// Info on all the dead pages.
// Registered pages are being moved to this array after unregistration.
// We are keeping them in case we need them in the profile data.
// We are removing them when we ensure that we won't need them anymore.
Vector<RefPtr<PageInformation>> mDeadProfiledPages;
// The current sampler thread. This class is not responsible for destroying
// the SamplerThread object; the Destroy() method returns it so the caller
// can destroy it.
SamplerThread* const mSamplerThread;
// Is the profiler fully paused?
bool mIsPaused;
// Is the profiler periodic sampling paused?
bool mIsSamplingPaused;
struct ExitProfile {
std::string mJSON;
uint64_t mBufferPositionAtGatherTime;
};
Vector<ExitProfile> mExitProfiles;
};
ActivePS* ActivePS::sInstance = nullptr;
uint32_t ActivePS::sNextGeneration = 0;
#undef PS_GET
#undef PS_GET_LOCKLESS
#undef PS_GET_AND_SET
namespace detail {
TimeStamp GetProfilingStartTime() {
if (!CorePS::Exists()) {
return {};
}
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
return {};
}
return ActivePS::ProfilingStartTime();
}
[[nodiscard]] MFBT_API UniquePtr<ProfileBufferChunkManagerWithLocalLimit>
ExtractBaseProfilerChunkManager() {
PSAutoLock lock;
if (MOZ_UNLIKELY(!ActivePS::Exists(lock))) {
return nullptr;
}
return ActivePS::ExtractBaseProfilerChunkManager(lock);
}
} // namespace detail
Atomic<uint32_t, MemoryOrdering::Relaxed> RacyFeatures::sActiveAndFeatures(0);
/* static */
void RacyFeatures::SetActive(uint32_t aFeatures) {
sActiveAndFeatures = Active | aFeatures;
}
/* static */
void RacyFeatures::SetInactive() { sActiveAndFeatures = 0; }
/* static */
bool RacyFeatures::IsActive() { return uint32_t(sActiveAndFeatures) & Active; }
/* static */
void RacyFeatures::SetPaused() { sActiveAndFeatures |= Paused; }
/* static */
void RacyFeatures::SetUnpaused() { sActiveAndFeatures &= ~Paused; }
/* static */
void RacyFeatures::SetSamplingPaused() { sActiveAndFeatures |= SamplingPaused; }
/* static */
void RacyFeatures::SetSamplingUnpaused() {
sActiveAndFeatures &= ~SamplingPaused;
}
/* static */
bool RacyFeatures::IsActiveWithFeature(uint32_t aFeature) {
uint32_t af = sActiveAndFeatures; // copy it first
return (af & Active) && (af & aFeature);
}
/* static */
bool RacyFeatures::IsActiveWithoutFeature(uint32_t aFeature) {
uint32_t af = sActiveAndFeatures; // copy it first
return (af & Active) && !(af & aFeature);
}
/* static */
bool RacyFeatures::IsActiveAndUnpaused() {
uint32_t af = sActiveAndFeatures; // copy it first
return (af & Active) && !(af & Paused);
}
/* static */
bool RacyFeatures::IsActiveAndSamplingUnpaused() {
uint32_t af = sActiveAndFeatures; // copy it first
return (af & Active) && !(af & (Paused | SamplingPaused));
}
// Each live thread has a RegisteredThread, and we store a reference to it in
// TLS. This class encapsulates that TLS.
class TLSRegisteredThread {
public:
static bool Init(PSLockRef) {
bool ok1 = sRegisteredThread.init();
bool ok2 = AutoProfilerLabel::sProfilingStack.init();
return ok1 && ok2;
}
// Get the entire RegisteredThread. Accesses are guarded by gPSMutex.
static class RegisteredThread* RegisteredThread(PSLockRef) {
return sRegisteredThread.get();
}
// Get only the RacyRegisteredThread. Accesses are not guarded by gPSMutex.
static class RacyRegisteredThread* RacyRegisteredThread() {
class RegisteredThread* registeredThread = sRegisteredThread.get();
return registeredThread ? ®isteredThread->RacyRegisteredThread()
: nullptr;
}
// Get only the ProfilingStack. Accesses are not guarded by gPSMutex.
// RacyRegisteredThread() can also be used to get the ProfilingStack, but that
// is marginally slower because it requires an extra pointer indirection.
static ProfilingStack* Stack() {
return AutoProfilerLabel::sProfilingStack.get();
}
static void SetRegisteredThread(PSLockRef,
class RegisteredThread* aRegisteredThread) {
sRegisteredThread.set(aRegisteredThread);
AutoProfilerLabel::sProfilingStack.set(
aRegisteredThread
? &aRegisteredThread->RacyRegisteredThread().ProfilingStack()
: nullptr);
}
private:
// This is a non-owning reference to the RegisteredThread;
// CorePS::mRegisteredThreads is the owning reference. On thread
// deregistration, this reference is cleared and the RegisteredThread is
// destroyed.
static MOZ_THREAD_LOCAL(class RegisteredThread*) sRegisteredThread;
};
MOZ_THREAD_LOCAL(RegisteredThread*) TLSRegisteredThread::sRegisteredThread;
/* static */
ProfilingStack* AutoProfilerLabel::GetProfilingStack() {
return sProfilingStack.get();
}
// Although you can access a thread's ProfilingStack via
// TLSRegisteredThread::sRegisteredThread, we also have a second TLS pointer
// directly to the ProfilingStack. Here's why.
//
// - We need to be able to push to and pop from the ProfilingStack in
// AutoProfilerLabel.
//
// - The class functions are hot and must be defined in BaseProfiler.h so they
// can be inlined.
//
// - We don't want to expose TLSRegisteredThread (and RegisteredThread) in
// BaseProfiler.h.
//
// This second pointer isn't ideal, but does provide a way to satisfy those
// constraints. TLSRegisteredThread is responsible for updating it.
MOZ_THREAD_LOCAL(ProfilingStack*) AutoProfilerLabel::sProfilingStack;
namespace detail {
[[nodiscard]] MFBT_API TimeStamp GetThreadRegistrationTime() {
if (!CorePS::Exists()) {
return {};
}
PSAutoLock lock;
RegisteredThread* registeredThread =
TLSRegisteredThread::RegisteredThread(lock);
if (!registeredThread) {
return {};
}
return registeredThread->Info()->RegisterTime();
}
} // namespace detail
// The name of the main thread.
static const char* const kMainThreadName = "GeckoMain";
////////////////////////////////////////////////////////////////////////
// BEGIN sampling/unwinding code
// Additional registers that have to be saved when thread is paused.
#if defined(GP_PLAT_x86_linux) || defined(GP_PLAT_x86_android) || \
defined(GP_ARCH_x86)
# define UNWINDING_REGS_HAVE_ECX_EDX
#elif defined(GP_PLAT_amd64_linux) || defined(GP_PLAT_amd64_android) || \
defined(GP_PLAT_amd64_freebsd) || defined(GP_ARCH_amd64) || \
defined(__x86_64__)
# define UNWINDING_REGS_HAVE_R10_R12
#elif defined(GP_PLAT_arm_linux) || defined(GP_PLAT_arm_android)
# define UNWINDING_REGS_HAVE_LR_R7
#elif defined(GP_PLAT_arm64_linux) || defined(GP_PLAT_arm64_android) || \
defined(GP_PLAT_arm64_freebsd) || defined(GP_ARCH_arm64) || \
defined(__aarch64__)
# define UNWINDING_REGS_HAVE_LR_R11
#endif
// The registers used for stack unwinding and a few other sampling purposes.
// The ctor does nothing; users are responsible for filling in the fields.
class Registers {
public:
Registers()
: mPC{nullptr},
mSP{nullptr},
mFP{nullptr}
#if defined(UNWINDING_REGS_HAVE_ECX_EDX)
,
mEcx{nullptr},
mEdx{nullptr}
#elif defined(UNWINDING_REGS_HAVE_R10_R12)
,
mR10{nullptr},
mR12{nullptr}
#elif defined(UNWINDING_REGS_HAVE_LR_R7)
,
mLR{nullptr},
mR7{nullptr}
#elif defined(UNWINDING_REGS_HAVE_LR_R11)
,
mLR{nullptr},
mR11{nullptr}
#endif
{
}
void Clear() { memset(this, 0, sizeof(*this)); }
// These fields are filled in by
// Sampler::SuspendAndSampleAndResumeThread() for periodic and backtrace
// samples, and by REGISTERS_SYNC_POPULATE for synchronous samples.
Address mPC; // Instruction pointer.
Address mSP; // Stack pointer.
Address mFP; // Frame pointer.
#if defined(UNWINDING_REGS_HAVE_ECX_EDX)
Address mEcx; // Temp for return address.
Address mEdx; // Temp for frame pointer.
#elif defined(UNWINDING_REGS_HAVE_R10_R12)
Address mR10; // Temp for return address.
Address mR12; // Temp for frame pointer.
#elif defined(UNWINDING_REGS_HAVE_LR_R7)
Address mLR; // ARM link register, or temp for return address.
Address mR7; // Temp for frame pointer.
#elif defined(UNWINDING_REGS_HAVE_LR_R11)
Address mLR; // ARM link register, or temp for return address.
Address mR11; // Temp for frame pointer.
#endif
#if defined(GP_OS_linux) || defined(GP_OS_android) || defined(GP_OS_freebsd)
// This contains all the registers, which means it duplicates the four fields
// above. This is ok.
ucontext_t* mContext; // The context from the signal handler.
#endif
};
// Setting MAX_NATIVE_FRAMES too high risks the unwinder wasting a lot of time
// looping on corrupted stacks.
static const size_t MAX_NATIVE_FRAMES = 1024;
struct NativeStack {
void* mPCs[MAX_NATIVE_FRAMES];
void* mSPs[MAX_NATIVE_FRAMES];
size_t mCount; // Number of frames filled.
NativeStack() : mPCs(), mSPs(), mCount(0) {}
};
// Merges the profiling stack and native stack, outputting the details to
// aCollector.
static void MergeStacks(bool aIsSynchronous,
const RegisteredThread& aRegisteredThread,
const NativeStack& aNativeStack,
ProfilerStackCollector& aCollector) {
// WARNING: this function runs within the profiler's "critical section".
// WARNING: this function might be called while the profiler is inactive, and
// cannot rely on ActivePS.
const ProfilingStack& profilingStack =
aRegisteredThread.RacyRegisteredThread().ProfilingStack();
const ProfilingStackFrame* profilingStackFrames = profilingStack.frames;
uint32_t profilingStackFrameCount = profilingStack.stackSize();
Maybe<uint64_t> samplePosInBuffer;
if (!aIsSynchronous) {
// aCollector.SamplePositionInBuffer() will return Nothing() when
// profiler_suspend_and_sample_thread is called from the background hang
// reporter.
samplePosInBuffer = aCollector.SamplePositionInBuffer();
}
// While the profiling stack array is ordered oldest-to-youngest, the JS and
// native arrays are ordered youngest-to-oldest. We must add frames to aInfo
// oldest-to-youngest. Thus, iterate over the profiling stack forwards and JS
// and native arrays backwards. Note: this means the terminating condition
// jsIndex and nativeIndex is being < 0.
uint32_t profilingStackIndex = 0;
int32_t nativeIndex = aNativeStack.mCount - 1;
uint8_t* lastLabelFrameStackAddr = nullptr;
// Iterate as long as there is at least one frame remaining.
while (profilingStackIndex != profilingStackFrameCount || nativeIndex >= 0) {
// There are 1 to 3 frames available. Find and add the oldest.
uint8_t* profilingStackAddr = nullptr;
uint8_t* nativeStackAddr = nullptr;
if (profilingStackIndex != profilingStackFrameCount) {
const ProfilingStackFrame& profilingStackFrame =
profilingStackFrames[profilingStackIndex];
if (profilingStackFrame.isLabelFrame() ||
profilingStackFrame.isSpMarkerFrame()) {
lastLabelFrameStackAddr = (uint8_t*)profilingStackFrame.stackAddress();
}
// Skip any JS_OSR frames. Such frames are used when the JS interpreter
// enters a jit frame on a loop edge (via on-stack-replacement, or OSR).
// To avoid both the profiling stack frame and jit frame being recorded
// (and showing up twice), the interpreter marks the interpreter
// profiling stack frame as JS_OSR to ensure that it doesn't get counted.
if (profilingStackFrame.isOSRFrame()) {
profilingStackIndex++;
continue;
}
MOZ_ASSERT(lastLabelFrameStackAddr);
profilingStackAddr = lastLabelFrameStackAddr;
}
if (nativeIndex >= 0) {
nativeStackAddr = (uint8_t*)aNativeStack.mSPs[nativeIndex];
}
// If there's a native stack frame which has the same SP as a profiling
// stack frame, pretend we didn't see the native stack frame. Ditto for a
// native stack frame which has the same SP as a JS stack frame. In effect
// this means profiling stack frames or JS frames trump conflicting native
// frames.
if (nativeStackAddr && (profilingStackAddr == nativeStackAddr)) {
nativeStackAddr = nullptr;
nativeIndex--;
MOZ_ASSERT(profilingStackAddr);
}
// Sanity checks.
MOZ_ASSERT_IF(profilingStackAddr, profilingStackAddr != nativeStackAddr);
MOZ_ASSERT_IF(nativeStackAddr, nativeStackAddr != profilingStackAddr);
// Check to see if profiling stack frame is top-most.
if (profilingStackAddr > nativeStackAddr) {
MOZ_ASSERT(profilingStackIndex < profilingStackFrameCount);
const ProfilingStackFrame& profilingStackFrame =
profilingStackFrames[profilingStackIndex];
// Sp marker frames are just annotations and should not be recorded in
// the profile.
if (!profilingStackFrame.isSpMarkerFrame()) {
if (aIsSynchronous && profilingStackFrame.categoryPair() ==
ProfilingCategoryPair::PROFILER) {
// For stacks captured synchronously (ie. marker stacks), stop
// walking the stack as soon as we enter the profiler category,
// to avoid showing profiler internal code in marker stacks.
return;
}
aCollector.CollectProfilingStackFrame(profilingStackFrame);
}
profilingStackIndex++;
continue;
}
// If we reach here, there must be a native stack frame and it must be the
// greatest frame.
if (nativeStackAddr) {
MOZ_ASSERT(nativeIndex >= 0);
void* addr = (void*)aNativeStack.mPCs[nativeIndex];
aCollector.CollectNativeLeafAddr(addr);
}
if (nativeIndex >= 0) {
nativeIndex--;
}
}
}
#if defined(GP_OS_windows) && defined(USE_MOZ_STACK_WALK)
static HANDLE GetThreadHandle(PlatformData* aData);
#endif
#if defined(USE_FRAME_POINTER_STACK_WALK) || defined(USE_MOZ_STACK_WALK)
static void StackWalkCallback(uint32_t aFrameNumber, void* aPC, void* aSP,
void* aClosure) {
NativeStack* nativeStack = static_cast<NativeStack*>(aClosure);
MOZ_ASSERT(nativeStack->mCount < MAX_NATIVE_FRAMES);
nativeStack->mSPs[nativeStack->mCount] = aSP;
nativeStack->mPCs[nativeStack->mCount] = aPC;
nativeStack->mCount++;
}
#endif
#if defined(USE_FRAME_POINTER_STACK_WALK)
static void DoFramePointerBacktrace(PSLockRef aLock,
const RegisteredThread& aRegisteredThread,
const Registers& aRegs,
NativeStack& aNativeStack) {
// WARNING: this function runs within the profiler's "critical section".
// WARNING: this function might be called while the profiler is inactive, and
// cannot rely on ActivePS.
// Start with the current function. We use 0 as the frame number here because
// the FramePointerStackWalk() call below will use 1..N. This is a bit weird
// but it doesn't matter because StackWalkCallback() doesn't use the frame
// number argument.
StackWalkCallback(/* frameNum */ 0, aRegs.mPC, aRegs.mSP, &aNativeStack);
uint32_t maxFrames = uint32_t(MAX_NATIVE_FRAMES - aNativeStack.mCount);
const void* stackEnd = aRegisteredThread.StackTop();
if (aRegs.mFP >= aRegs.mSP && aRegs.mFP <= stackEnd) {
FramePointerStackWalk(StackWalkCallback, maxFrames, &aNativeStack,
reinterpret_cast<void**>(aRegs.mFP),
const_cast<void*>(stackEnd));
}
}
#endif
#if defined(USE_MOZ_STACK_WALK)
static void DoMozStackWalkBacktrace(PSLockRef aLock,
const RegisteredThread& aRegisteredThread,
const Registers& aRegs,
NativeStack& aNativeStack) {
// WARNING: this function runs within the profiler's "critical section".
// WARNING: this function might be called while the profiler is inactive, and
// cannot rely on ActivePS.
// Start with the current function. We use 0 as the frame number here because
// the MozStackWalkThread() call below will use 1..N. This is a bit weird but
// it doesn't matter because StackWalkCallback() doesn't use the frame number
// argument.
StackWalkCallback(/* frameNum */ 0, aRegs.mPC, aRegs.mSP, &aNativeStack);
uint32_t maxFrames = uint32_t(MAX_NATIVE_FRAMES - aNativeStack.mCount);
HANDLE thread = GetThreadHandle(aRegisteredThread.GetPlatformData());
MOZ_ASSERT(thread);
MozStackWalkThread(StackWalkCallback, maxFrames, &aNativeStack, thread,
/* context */ nullptr);
}
#endif
#ifdef USE_EHABI_STACKWALK
static void DoEHABIBacktrace(PSLockRef aLock,
const RegisteredThread& aRegisteredThread,
const Registers& aRegs,
NativeStack& aNativeStack) {
// WARNING: this function runs within the profiler's "critical section".
// WARNING: this function might be called while the profiler is inactive, and
// cannot rely on ActivePS.
aNativeStack.mCount =
EHABIStackWalk(aRegs.mContext->uc_mcontext,
const_cast<void*>(aRegisteredThread.StackTop()),
aNativeStack.mSPs, aNativeStack.mPCs, MAX_NATIVE_FRAMES);
}
#endif
#ifdef USE_LUL_STACKWALK
// See the comment at the callsite for why this function is necessary.
# if defined(MOZ_HAVE_ASAN_IGNORE)
MOZ_ASAN_IGNORE static void ASAN_memcpy(void* aDst, const void* aSrc,
size_t aLen) {
// The obvious thing to do here is call memcpy(). However, although
// ASAN_memcpy() is not instrumented by ASAN, memcpy() still is, and the
// false positive still manifests! So we must implement memcpy() ourselves
// within this function.
char* dst = static_cast<char*>(aDst);
const char* src = static_cast<const char*>(aSrc);
for (size_t i = 0; i < aLen; i++) {
dst[i] = src[i];
}
}
# endif
static void DoLULBacktrace(PSLockRef aLock,
const RegisteredThread& aRegisteredThread,
const Registers& aRegs, NativeStack& aNativeStack) {
// WARNING: this function runs within the profiler's "critical section".
// WARNING: this function might be called while the profiler is inactive, and
// cannot rely on ActivePS.
const mcontext_t* mc = &aRegs.mContext->uc_mcontext;
lul::UnwindRegs startRegs;
memset(&startRegs, 0, sizeof(startRegs));
# if defined(GP_PLAT_amd64_linux) || defined(GP_PLAT_amd64_android)
startRegs.xip = lul::TaggedUWord(mc->gregs[REG_RIP]);
startRegs.xsp = lul::TaggedUWord(mc->gregs[REG_RSP]);
startRegs.xbp = lul::TaggedUWord(mc->gregs[REG_RBP]);
# elif defined(GP_PLAT_amd64_freebsd)
startRegs.xip = lul::TaggedUWord(mc->mc_rip);
startRegs.xsp = lul::TaggedUWord(mc->mc_rsp);
startRegs.xbp = lul::TaggedUWord(mc->mc_rbp);
# elif defined(GP_PLAT_arm_linux) || defined(GP_PLAT_arm_android)
startRegs.r15 = lul::TaggedUWord(mc->arm_pc);
startRegs.r14 = lul::TaggedUWord(mc->arm_lr);
startRegs.r13 = lul::TaggedUWord(mc->arm_sp);
startRegs.r12 = lul::TaggedUWord(mc->arm_ip);
startRegs.r11 = lul::TaggedUWord(mc->arm_fp);
startRegs.r7 = lul::TaggedUWord(mc->arm_r7);
# elif defined(GP_PLAT_arm64_linux) || defined(GP_PLAT_arm64_android)
startRegs.pc = lul::TaggedUWord(mc->pc);
startRegs.x29 = lul::TaggedUWord(mc->regs[29]);
startRegs.x30 = lul::TaggedUWord(mc->regs[30]);
startRegs.sp = lul::TaggedUWord(mc->sp);
# elif defined(GP_PLAT_arm64_freebsd)
startRegs.pc = lul::TaggedUWord(mc->mc_gpregs.gp_elr);
startRegs.x29 = lul::TaggedUWord(mc->mc_gpregs.gp_x[29]);
startRegs.x30 = lul::TaggedUWord(mc->mc_gpregs.gp_lr);
startRegs.sp = lul::TaggedUWord(mc->mc_gpregs.gp_sp);
# elif defined(GP_PLAT_x86_linux) || defined(GP_PLAT_x86_android)
startRegs.xip = lul::TaggedUWord(mc->gregs[REG_EIP]);
startRegs.xsp = lul::TaggedUWord(mc->gregs[REG_ESP]);
startRegs.xbp = lul::TaggedUWord(mc->gregs[REG_EBP]);
# elif defined(GP_PLAT_mips64_linux)
startRegs.pc = lul::TaggedUWord(mc->pc);
startRegs.sp = lul::TaggedUWord(mc->gregs[29]);
startRegs.fp = lul::TaggedUWord(mc->gregs[30]);
# else
# error "Unknown plat"
# endif
// Copy up to N_STACK_BYTES from rsp-REDZONE upwards, but not going past the
// stack's registered top point. Do some basic sanity checks too. This
// assumes that the TaggedUWord holding the stack pointer value is valid, but
// it should be, since it was constructed that way in the code just above.
// We could construct |stackImg| so that LUL reads directly from the stack in
// question, rather than from a copy of it. That would reduce overhead and
// space use a bit. However, it gives a problem with dynamic analysis tools
// (ASan, TSan, Valgrind) which is that such tools will report invalid or
// racing memory accesses, and such accesses will be reported deep inside LUL.
// By taking a copy here, we can either sanitise the copy (for Valgrind) or
// copy it using an unchecked memcpy (for ASan, TSan). That way we don't have
// to try and suppress errors inside LUL.
//
// N_STACK_BYTES is set to 160KB. This is big enough to hold all stacks
// observed in some minutes of testing, whilst keeping the size of this
// function (DoNativeBacktrace)'s frame reasonable. Most stacks observed in
// practice are small, 4KB or less, and so the copy costs are insignificant
// compared to other profiler overhead.
//
// |stackImg| is allocated on this (the sampling thread's) stack. That
// implies that the frame for this function is at least N_STACK_BYTES large.
// In general it would be considered unacceptable to have such a large frame
// on a stack, but it only exists for the unwinder thread, and so is not
// expected to be a problem. Allocating it on the heap is troublesome because
// this function runs whilst the sampled thread is suspended, so any heap
// allocation risks deadlock. Allocating it as a global variable is not
// thread safe, which would be a problem if we ever allow multiple sampler
// threads. Hence allocating it on the stack seems to be the least-worst
// option.
lul::StackImage stackImg;
{
# if defined(GP_PLAT_amd64_linux) || defined(GP_PLAT_amd64_android) || \
defined(GP_PLAT_amd64_freebsd)
uintptr_t rEDZONE_SIZE = 128;
uintptr_t start = startRegs.xsp.Value() - rEDZONE_SIZE;
# elif defined(GP_PLAT_arm_linux) || defined(GP_PLAT_arm_android)
uintptr_t rEDZONE_SIZE = 0;
uintptr_t start = startRegs.r13.Value() - rEDZONE_SIZE;
# elif defined(GP_PLAT_arm64_linux) || defined(GP_PLAT_arm64_android) || \
defined(GP_PLAT_arm64_freebsd)
uintptr_t rEDZONE_SIZE = 0;
uintptr_t start = startRegs.sp.Value() - rEDZONE_SIZE;
# elif defined(GP_PLAT_x86_linux) || defined(GP_PLAT_x86_android)
uintptr_t rEDZONE_SIZE = 0;
uintptr_t start = startRegs.xsp.Value() - rEDZONE_SIZE;
# elif defined(GP_PLAT_mips64_linux)
uintptr_t rEDZONE_SIZE = 0;
uintptr_t start = startRegs.sp.Value() - rEDZONE_SIZE;
# else
# error "Unknown plat"
# endif
uintptr_t end = reinterpret_cast<uintptr_t>(aRegisteredThread.StackTop());
uintptr_t ws = sizeof(void*);
start &= ~(ws - 1);
end &= ~(ws - 1);
uintptr_t nToCopy = 0;
if (start < end) {
nToCopy = end - start;
if (nToCopy > lul::N_STACK_BYTES) nToCopy = lul::N_STACK_BYTES;
}
MOZ_ASSERT(nToCopy <= lul::N_STACK_BYTES);
stackImg.mLen = nToCopy;
stackImg.mStartAvma = start;
if (nToCopy > 0) {
// If this is a vanilla memcpy(), ASAN makes the following complaint:
//
// ERROR: AddressSanitizer: stack-buffer-underflow ...
// ...
// HINT: this may be a false positive if your program uses some custom
// stack unwind mechanism or swapcontext
//
// This code is very much a custom stack unwind mechanism! So we use an
// alternative memcpy() implementation that is ignored by ASAN.
# if defined(MOZ_HAVE_ASAN_IGNORE)
ASAN_memcpy(&stackImg.mContents[0], (void*)start, nToCopy);
# else
memcpy(&stackImg.mContents[0], (void*)start, nToCopy);
# endif
(void)VALGRIND_MAKE_MEM_DEFINED(&stackImg.mContents[0], nToCopy);
}
}
size_t framePointerFramesAcquired = 0;
lul::LUL* lul = CorePS::Lul(aLock);
lul->Unwind(reinterpret_cast<uintptr_t*>(aNativeStack.mPCs),
reinterpret_cast<uintptr_t*>(aNativeStack.mSPs),
&aNativeStack.mCount, &framePointerFramesAcquired,
MAX_NATIVE_FRAMES, &startRegs, &stackImg);
// Update stats in the LUL stats object. Unfortunately this requires
// three global memory operations.
lul->mStats.mContext += 1;
lul->mStats.mCFI += aNativeStack.mCount - 1 - framePointerFramesAcquired;
lul->mStats.mFP += framePointerFramesAcquired;
}
#endif
#ifdef HAVE_NATIVE_UNWIND
static void DoNativeBacktrace(PSLockRef aLock,
const RegisteredThread& aRegisteredThread,
const Registers& aRegs,
NativeStack& aNativeStack) {
// This method determines which stackwalker is used for periodic and
// synchronous samples. (Backtrace samples are treated differently, see
// profiler_suspend_and_sample_thread() for details). The only part of the
// ordering that matters is that LUL must precede FRAME_POINTER, because on
// Linux they can both be present.
# if defined(USE_LUL_STACKWALK)
DoLULBacktrace(aLock, aRegisteredThread, aRegs, aNativeStack);
# elif defined(USE_EHABI_STACKWALK)
DoEHABIBacktrace(aLock, aRegisteredThread, aRegs, aNativeStack);
# elif defined(USE_FRAME_POINTER_STACK_WALK)
DoFramePointerBacktrace(aLock, aRegisteredThread, aRegs, aNativeStack);
# elif defined(USE_MOZ_STACK_WALK)
DoMozStackWalkBacktrace(aLock, aRegisteredThread, aRegs, aNativeStack);
# else
# error "Invalid configuration"
# endif
}
#endif
// Writes some components shared by periodic and synchronous profiles to
// ActivePS's ProfileBuffer. (This should only be called from DoSyncSample()
// and DoPeriodicSample().)
//
// The grammar for entry sequences is in a comment above
// ProfileBuffer::StreamSamplesToJSON.
static inline void DoSharedSample(
PSLockRef aLock, bool aIsSynchronous, RegisteredThread& aRegisteredThread,
const Registers& aRegs, uint64_t aSamplePos, uint64_t aBufferRangeStart,
ProfileBuffer& aBuffer,
StackCaptureOptions aCaptureOptions = StackCaptureOptions::Full) {
// WARNING: this function runs within the profiler's "critical section".
MOZ_ASSERT(!aBuffer.IsThreadSafe(),
"Mutexes cannot be used inside this critical section");
MOZ_RELEASE_ASSERT(ActivePS::Exists(aLock));
ProfileBufferCollector collector(aBuffer, aSamplePos, aBufferRangeStart);
NativeStack nativeStack;
#if defined(HAVE_NATIVE_UNWIND)
if (ActivePS::FeatureStackWalk(aLock) &&
aCaptureOptions == StackCaptureOptions::Full) {
DoNativeBacktrace(aLock, aRegisteredThread, aRegs, nativeStack);
MergeStacks(aIsSynchronous, aRegisteredThread, nativeStack, collector);
} else
#endif
{
MergeStacks(aIsSynchronous, aRegisteredThread, nativeStack, collector);
// We can't walk the whole native stack, but we can record the top frame.
if (aCaptureOptions == StackCaptureOptions::Full) {
aBuffer.AddEntry(ProfileBufferEntry::NativeLeafAddr((void*)aRegs.mPC));
}
}
}
// Writes the components of a synchronous sample to the given ProfileBuffer.
static void DoSyncSample(PSLockRef aLock, RegisteredThread& aRegisteredThread,
const TimeStamp& aNow, const Registers& aRegs,
ProfileBuffer& aBuffer,
StackCaptureOptions aCaptureOptions) {
// WARNING: this function runs within the profiler's "critical section".
MOZ_ASSERT(aCaptureOptions != StackCaptureOptions::NoStack,
"DoSyncSample should not be called when no capture is needed");
const uint64_t bufferRangeStart = aBuffer.BufferRangeStart();
const uint64_t samplePos =
aBuffer.AddThreadIdEntry(aRegisteredThread.Info()->ThreadId());
TimeDuration delta = aNow - CorePS::ProcessStartTime();
aBuffer.AddEntry(ProfileBufferEntry::Time(delta.ToMilliseconds()));
DoSharedSample(aLock, /* aIsSynchronous = */ true, aRegisteredThread, aRegs,
samplePos, bufferRangeStart, aBuffer, aCaptureOptions);
}
// Writes the components of a periodic sample to ActivePS's ProfileBuffer.
// The ThreadId entry is already written in the main ProfileBuffer, its location
// is `aSamplePos`, we can write the rest to `aBuffer` (which may be different).
static void DoPeriodicSample(PSLockRef aLock,
RegisteredThread& aRegisteredThread,
ProfiledThreadData& aProfiledThreadData,
const Registers& aRegs, uint64_t aSamplePos,
uint64_t aBufferRangeStart,
ProfileBuffer& aBuffer) {
// WARNING: this function runs within the profiler's "critical section".
DoSharedSample(aLock, /* aIsSynchronous = */ false, aRegisteredThread, aRegs,
aSamplePos, aBufferRangeStart, aBuffer);
}
#undef UNWINDING_REGS_HAVE_ECX_EDX
#undef UNWINDING_REGS_HAVE_R10_R12
#undef UNWINDING_REGS_HAVE_LR_R7
#undef UNWINDING_REGS_HAVE_LR_R11
// END sampling/unwinding code
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
// BEGIN saving/streaming code
const static uint64_t kJS_MAX_SAFE_UINTEGER = +9007199254740991ULL;
static int64_t SafeJSInteger(uint64_t aValue) {
return aValue <= kJS_MAX_SAFE_UINTEGER ? int64_t(aValue) : -1;
}
static void AddSharedLibraryInfoToStream(JSONWriter& aWriter,
const SharedLibrary& aLib) {
aWriter.StartObjectElement();
aWriter.IntProperty("start", SafeJSInteger(aLib.GetStart()));
aWriter.IntProperty("end", SafeJSInteger(aLib.GetEnd()));
aWriter.IntProperty("offset", SafeJSInteger(aLib.GetOffset()));
aWriter.StringProperty("name", aLib.GetModuleName());
aWriter.StringProperty("path", aLib.GetModulePath());
aWriter.StringProperty("debugName", aLib.GetDebugName());
aWriter.StringProperty("debugPath", aLib.GetDebugPath());
aWriter.StringProperty("breakpadId", aLib.GetBreakpadId());
aWriter.StringProperty("codeId", aLib.GetCodeId());
aWriter.StringProperty("arch", aLib.GetArch());
aWriter.EndObject();
}
void AppendSharedLibraries(JSONWriter& aWriter) {
SharedLibraryInfo info = SharedLibraryInfo::GetInfoForSelf();
info.SortByAddress();
for (size_t i = 0; i < info.GetSize(); i++) {
AddSharedLibraryInfoToStream(aWriter, info.GetEntry(i));
}
}
static void StreamCategories(SpliceableJSONWriter& aWriter) {
// Same order as ProfilingCategory. Format:
// [
// {
// name: "Idle",
// color: "transparent",
// subcategories: ["Other"],
// },
// {
// name: "Other",
// color: "grey",
// subcategories: [
// "JSM loading",
// "Subprocess launching",
// "DLL loading"
// ]
// },
// ...
// ]
#define CATEGORY_JSON_BEGIN_CATEGORY(name, labelAsString, color) \
aWriter.Start(); \
aWriter.StringProperty("name", labelAsString); \
aWriter.StringProperty("color", color); \
aWriter.StartArrayProperty("subcategories");
#define CATEGORY_JSON_SUBCATEGORY(supercategory, name, labelAsString) \
aWriter.StringElement(labelAsString);
#define CATEGORY_JSON_END_CATEGORY \
aWriter.EndArray(); \
aWriter.EndObject();
MOZ_PROFILING_CATEGORY_LIST(CATEGORY_JSON_BEGIN_CATEGORY,
CATEGORY_JSON_SUBCATEGORY,
CATEGORY_JSON_END_CATEGORY)
#undef CATEGORY_JSON_BEGIN_CATEGORY
#undef CATEGORY_JSON_SUBCATEGORY
#undef CATEGORY_JSON_END_CATEGORY
}
static void StreamMarkerSchema(SpliceableJSONWriter& aWriter) {
// Get an array view with all registered marker-type-specific functions.
base_profiler_markers_detail::Streaming::LockedMarkerTypeFunctionsList
markerTypeFunctionsArray;
// List of streamed marker names, this is used to spot duplicates.
std::set<std::string> names;
// Stream the display schema for each different one. (Duplications may come
// from the same code potentially living in different libraries.)
for (const auto& markerTypeFunctions : markerTypeFunctionsArray) {
auto name = markerTypeFunctions.mMarkerTypeNameFunction();
// std::set.insert(T&&) returns a pair, its `second` is true if the element
// was actually inserted (i.e., it was not there yet.)
const bool didInsert =
names.insert(std::string(name.data(), name.size())).second;
if (didInsert) {
markerTypeFunctions.mMarkerSchemaFunction().Stream(aWriter, name);
}
}
}
static int64_t MicrosecondsSince1970();
static void StreamMetaJSCustomObject(PSLockRef aLock,
SpliceableJSONWriter& aWriter,
bool aIsShuttingDown) {
MOZ_RELEASE_ASSERT(CorePS::Exists() && ActivePS::Exists(aLock));
aWriter.IntProperty("version", GECKO_PROFILER_FORMAT_VERSION);
// The "startTime" field holds the number of milliseconds since midnight
// January 1, 1970 GMT. This grotty code computes (Now - (Now -
// ProcessStartTime)) to convert CorePS::ProcessStartTime() into that form.
// Note: This is the only absolute time in the profile! All other timestamps
// are relative to this startTime.
TimeDuration delta = TimeStamp::Now() - CorePS::ProcessStartTime();
aWriter.DoubleProperty(
"startTime", MicrosecondsSince1970() / 1000.0 - delta.ToMilliseconds());
aWriter.DoubleProperty("profilingStartTime", (ActivePS::ProfilingStartTime() -
CorePS::ProcessStartTime())
.ToMilliseconds());
if (const TimeStamp contentEarliestTime =
ActivePS::Buffer(aLock)
.UnderlyingChunkedBuffer()
.GetEarliestChunkStartTimeStamp();
!contentEarliestTime.IsNull()) {
aWriter.DoubleProperty(
"contentEarliestTime",
(contentEarliestTime - CorePS::ProcessStartTime()).ToMilliseconds());
} else {
aWriter.NullProperty("contentEarliestTime");
}
const double profilingEndTime = profiler_time();
aWriter.DoubleProperty("profilingEndTime", profilingEndTime);
if (aIsShuttingDown) {
aWriter.DoubleProperty("shutdownTime", profilingEndTime);
} else {
aWriter.NullProperty("shutdownTime");
}
aWriter.StartArrayProperty("categories");
StreamCategories(aWriter);
aWriter.EndArray();
aWriter.StartArrayProperty("markerSchema");
StreamMarkerSchema(aWriter);
aWriter.EndArray();
if (!profiler_is_main_thread()) {
// Leave the rest of the properties out if we're not on the main thread.
// At the moment, the only case in which this function is called on a
// background thread is if we're in a content process and are going to
// send this profile to the parent process. In that case, the parent
// process profile's "meta" object already has the rest of the properties,
// and the parent process profile is dumped on that process's main thread.
return;
}
aWriter.DoubleProperty("interval", ActivePS::Interval(aLock));
aWriter.IntProperty("stackwalk", ActivePS::FeatureStackWalk(aLock));
#ifdef DEBUG
aWriter.IntProperty("debug", 1);
#else
aWriter.IntProperty("debug", 0);
#endif
aWriter.IntProperty("gcpoison", 0);
aWriter.IntProperty("asyncstack", 0);
aWriter.IntProperty("processType", 0);
}
static void StreamPages(PSLockRef aLock, SpliceableJSONWriter& aWriter) {
MOZ_RELEASE_ASSERT(CorePS::Exists());
ActivePS::DiscardExpiredPages(aLock);
for (const auto& page : ActivePS::ProfiledPages(aLock)) {
page->StreamJSON(aWriter);
}
}
static void locked_profiler_stream_json_for_this_process(
PSLockRef aLock, SpliceableJSONWriter& aWriter, double aSinceTime,
bool aIsShuttingDown, bool aOnlyThreads = false) {
LOG("locked_profiler_stream_json_for_this_process");
MOZ_RELEASE_ASSERT(CorePS::Exists() && ActivePS::Exists(aLock));
AUTO_PROFILER_STATS(base_locked_profiler_stream_json_for_this_process);
const double collectionStartMs = profiler_time();
ProfileBuffer& buffer = ActivePS::Buffer(aLock);
// If there is a set "Window length", discard older data.
Maybe<double> durationS = ActivePS::Duration(aLock);
if (durationS.isSome()) {
const double durationStartMs = collectionStartMs - *durationS * 1000;
buffer.DiscardSamplesBeforeTime(durationStartMs);
}
if (!aOnlyThreads) {
// Put shared library info
aWriter.StartArrayProperty("libs");
AppendSharedLibraries(aWriter);
aWriter.EndArray();
// Put meta data
aWriter.StartObjectProperty("meta");
{ StreamMetaJSCustomObject(aLock, aWriter, aIsShuttingDown); }
aWriter.EndObject();
// Put page data
aWriter.StartArrayProperty("pages");
{ StreamPages(aLock, aWriter); }
aWriter.EndArray();
buffer.StreamProfilerOverheadToJSON(aWriter, CorePS::ProcessStartTime(),
aSinceTime);
buffer.StreamCountersToJSON(aWriter, CorePS::ProcessStartTime(),
aSinceTime);
// Lists the samples for each thread profile
aWriter.StartArrayProperty("threads");
}
// if aOnlyThreads is true, the only output will be the threads array items.
{
ActivePS::DiscardExpiredDeadProfiledThreads(aLock);
Vector<std::pair<RegisteredThread*, ProfiledThreadData*>> threads =
ActivePS::ProfiledThreads(aLock);
for (auto& thread : threads) {
ProfiledThreadData* profiledThreadData = thread.second;
profiledThreadData->StreamJSON(
buffer, aWriter, CorePS::ProcessName(aLock), CorePS::ETLDplus1(aLock),
CorePS::ProcessStartTime(), aSinceTime);
}
}
if (!aOnlyThreads) {
aWriter.EndArray();
aWriter.StartArrayProperty("pausedRanges");
{ buffer.StreamPausedRangesToJSON(aWriter, aSinceTime); }
aWriter.EndArray();
}
const double collectionEndMs = profiler_time();
// Record timestamps for the collection into the buffer, so that consumers
// know why we didn't collect any samples for its duration.
// We put these entries into the buffer after we've collected the profile,
// so they'll be visible for the *next* profile collection (if they haven't
// been overwritten due to buffer wraparound by then).
buffer.AddEntry(ProfileBufferEntry::CollectionStart(collectionStartMs));
buffer.AddEntry(ProfileBufferEntry::CollectionEnd(collectionEndMs));
}
bool profiler_stream_json_for_this_process(SpliceableJSONWriter& aWriter,
double aSinceTime,
bool aIsShuttingDown,
bool aOnlyThreads) {
LOG("profiler_stream_json_for_this_process");
MOZ_RELEASE_ASSERT(CorePS::Exists());
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
return false;
}
locked_profiler_stream_json_for_this_process(lock, aWriter, aSinceTime,
aIsShuttingDown, aOnlyThreads);
return true;
}
// END saving/streaming code
////////////////////////////////////////////////////////////////////////
static char FeatureCategory(uint32_t aFeature) {
if (aFeature & DefaultFeatures()) {
if (aFeature & AvailableFeatures()) {
return 'D';
}
return 'd';
}
if (aFeature & StartupExtraDefaultFeatures()) {
if (aFeature & AvailableFeatures()) {
return 'S';
}
return 's';
}
if (aFeature & AvailableFeatures()) {
return '-';
}
return 'x';
}
static void PrintUsage() {
PrintToConsole(
"\n"
"Profiler environment variable usage:\n"
"\n"
" MOZ_BASE_PROFILER_HELP\n"
" If set to any value, prints this message.\n"
" (Only BaseProfiler features are known here; Use MOZ_PROFILER_HELP\n"
" for Gecko Profiler help, with more features).\n"
"\n"
" MOZ_BASE_PROFILER_{,DEBUG_,VERBOSE}LOGGING\n"
" Enables BaseProfiler logging to stdout. The levels of logging\n"
" available are MOZ_BASE_PROFILER_LOGGING' (least verbose),\n"
" '..._DEBUG_LOGGING', '..._VERBOSE_LOGGING' (most verbose)\n"
"\n"
" MOZ_PROFILER_STARTUP\n"
" If set to any value other than '' or '0'/'N'/'n', starts the\n"
" profiler immediately on start-up.\n"
" Useful if you want profile code that runs very early.\n"
"\n"
" MOZ_PROFILER_STARTUP_ENTRIES=<%u..%u>\n"
" If MOZ_PROFILER_STARTUP is set, specifies the number of entries\n"
" per process in the profiler's circular buffer when the profiler is\n"
" first started.\n"
" If unset, the platform default is used:\n"
" %u entries per process, or %u when MOZ_PROFILER_STARTUP is set.\n"
" (%u bytes per entry -> %u or %u total bytes per process)\n"
" Optional units in bytes: KB, KiB, MB, MiB, GB, GiB\n"
"\n"
" MOZ_PROFILER_STARTUP_DURATION=<1..>\n"
" If MOZ_PROFILER_STARTUP is set, specifies the maximum life time\n"
" of entries in the the profiler's circular buffer when the profiler\n"
" is first started, in seconds.\n"
" If unset, the life time of the entries will only be restricted by\n"
" MOZ_PROFILER_STARTUP_ENTRIES (or its default value), and no\n"
" additional time duration restriction will be applied.\n"
"\n"
" MOZ_PROFILER_STARTUP_INTERVAL=<1..1000>\n"
" If MOZ_PROFILER_STARTUP is set, specifies the sample interval,\n"
" measured in milliseconds, when the profiler is first started.\n"
" If unset, the platform default is used.\n"
"\n"
" MOZ_PROFILER_STARTUP_FEATURES_BITFIELD=<Number>\n"
" If MOZ_PROFILER_STARTUP is set, specifies the profiling\n"
" features, as the integer value of the features bitfield.\n"
" If unset, the value from MOZ_PROFILER_STARTUP_FEATURES is used.\n"
"\n"
" MOZ_PROFILER_STARTUP_FEATURES=<Features>\n"
" If MOZ_PROFILER_STARTUP is set, specifies the profiling\n"
" features, as a comma-separated list of strings.\n"
" Ignored if MOZ_PROFILER_STARTUP_FEATURES_BITFIELD is set.\n"
" If unset, the platform default is used.\n"
"\n"
" Features: (x=unavailable, D/d=default/unavailable,\n"
" S/s=MOZ_PROFILER_STARTUP extra "
"default/unavailable)\n",
unsigned(scMinimumBufferEntries), unsigned(scMaximumBufferEntries),
unsigned(BASE_PROFILER_DEFAULT_ENTRIES.Value()),
unsigned(BASE_PROFILER_DEFAULT_STARTUP_ENTRIES.Value()),
unsigned(scBytesPerEntry),
unsigned(BASE_PROFILER_DEFAULT_ENTRIES.Value() * scBytesPerEntry),
unsigned(BASE_PROFILER_DEFAULT_STARTUP_ENTRIES.Value() *
scBytesPerEntry));
#define PRINT_FEATURE(n_, str_, Name_, desc_) \
PrintToConsole(" %c %7u: \"%s\" (%s)\n", \
FeatureCategory(ProfilerFeature::Name_), \
ProfilerFeature::Name_, str_, desc_);
BASE_PROFILER_FOR_EACH_FEATURE(PRINT_FEATURE)
#undef PRINT_FEATURE
PrintToConsole(
" - \"default\" (All above D+S defaults)\n"
"\n"
" MOZ_PROFILER_STARTUP_FILTERS=<Filters>\n"
" If MOZ_PROFILER_STARTUP is set, specifies the thread filters, as "
"a\n"
" comma-separated list of strings. A given thread will be sampled if\n"
" any of the filters is a case-insensitive substring of the thread\n"
" name. If unset, a default is used.\n"
"\n"
" MOZ_PROFILER_SHUTDOWN\n"
" If set, the profiler saves a profile to the named file on shutdown.\n"
"\n"
" MOZ_PROFILER_SYMBOLICATE\n"
" If set, the profiler will pre-symbolicate profiles.\n"
" *Note* This will add a significant pause when gathering data, and\n"
" is intended mainly for local development.\n"
"\n"
" MOZ_PROFILER_LUL_TEST\n"
" If set to any value, runs LUL unit tests at startup.\n"
"\n"
" This platform %s native unwinding.\n"
"\n",
#if defined(HAVE_NATIVE_UNWIND)
"supports"
#else
"does not support"
#endif
);
}
////////////////////////////////////////////////////////////////////////
// BEGIN Sampler
#if defined(GP_OS_linux) || defined(GP_OS_android)
struct SigHandlerCoordinator;
#endif
// Sampler performs setup and teardown of the state required to sample with the
// profiler. Sampler may exist when ActivePS is not present.
//
// SuspendAndSampleAndResumeThread must only be called from a single thread,
// and must not sample the thread it is being called from. A separate Sampler
// instance must be used for each thread which wants to capture samples.
// WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
//
// With the exception of SamplerThread, all Sampler objects must be Disable-d
// before releasing the lock which was used to create them. This avoids races
// on linux with the SIGPROF signal handler.
class Sampler {
public:
// Sets up the profiler such that it can begin sampling.
explicit Sampler(PSLockRef aLock);
// Disable the sampler, restoring it to its previous state. This must be
// called once, and only once, before the Sampler is destroyed.
void Disable(PSLockRef aLock);
// This method suspends and resumes the samplee thread. It calls the passed-in
// function-like object aProcessRegs (passing it a populated |const
// Registers&| arg) while the samplee thread is suspended.
//
// Func must be a function-like object of type `void()`.
template <typename Func>
void SuspendAndSampleAndResumeThread(
PSLockRef aLock, const RegisteredThread& aRegisteredThread,
const TimeStamp& aNow, const Func& aProcessRegs);
private:
#if defined(GP_OS_linux) || defined(GP_OS_android) || defined(GP_OS_freebsd)
// Used to restore the SIGPROF handler when ours is removed.
struct sigaction mOldSigprofHandler;
// This process' ID. Needed as an argument for tgkill in
// SuspendAndSampleAndResumeThread.
BaseProfilerProcessId mMyPid;
// The sampler thread's ID. Used to assert that it is not sampling itself,
// which would lead to deadlock.
BaseProfilerThreadId mSamplerTid;
public:
// This is the one-and-only variable used to communicate between the sampler
// thread and the samplee thread's signal handler. It's static because the
// samplee thread's signal handler is static.
static struct SigHandlerCoordinator* sSigHandlerCoordinator;
#endif
};
// END Sampler
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
// BEGIN SamplerThread
// The sampler thread controls sampling and runs whenever the profiler is
// active. It periodically runs through all registered threads, finds those
// that should be sampled, then pauses and samples them.
class SamplerThread {
public:
// Creates a sampler thread, but doesn't start it.
SamplerThread(PSLockRef aLock, uint32_t aActivityGeneration,
double aIntervalMilliseconds, uint32_t aFeatures);
~SamplerThread();
// This runs on (is!) the sampler thread.
void Run();
// This runs on the main thread.
void Stop(PSLockRef aLock);
private:
// This suspends the calling thread for the given number of microseconds.
// Best effort timing.
void SleepMicro(uint32_t aMicroseconds);
// The sampler used to suspend and sample threads.
Sampler mSampler;
// The activity generation, for detecting when the sampler thread must stop.
const uint32_t mActivityGeneration;
// The interval between samples, measured in microseconds.
const int mIntervalMicroseconds;
// The OS-specific handle for the sampler thread.
#if defined(GP_OS_windows)
HANDLE mThread;
#elif defined(GP_OS_darwin) || defined(GP_OS_linux) || \
defined(GP_OS_android) || defined(GP_OS_freebsd)
pthread_t mThread;
#endif
#if defined(GP_OS_windows)
bool mNoTimerResolutionChange = true;
#endif
SamplerThread(const SamplerThread&) = delete;
void operator=(const SamplerThread&) = delete;
};
// This function is required because we need to create a SamplerThread within
// ActivePS's constructor, but SamplerThread is defined after ActivePS. It
// could probably be removed by moving some code around.
static SamplerThread* NewSamplerThread(PSLockRef aLock, uint32_t aGeneration,
double aInterval, uint32_t aFeatures) {
return new SamplerThread(aLock, aGeneration, aInterval, aFeatures);
}
// This function is the sampler thread. This implementation is used for all
// targets.
void SamplerThread::Run() {
// TODO: If possible, name this thread later on, after NSPR becomes available.
// PR_SetCurrentThreadName("SamplerThread");
// Features won't change during this SamplerThread's lifetime, so we can read
// them once and store them locally.
const uint32_t features = []() -> uint32_t {
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
// If there is no active profiler, it doesn't matter what we return,
// because this thread will exit before any feature is used.
return 0;
}
return ActivePS::Features(lock);
}();
// Not *no*-stack-sampling means we do want stack sampling.
const bool stackSampling = !ProfilerFeature::HasNoStackSampling(features);
// Use local ProfileBuffer to capture the stack.
// (This is to avoid touching the CorePS::CoreBuffer lock while
// a thread is suspended, because that thread could be working with
// the CorePS::CoreBuffer as well.)
ProfileBufferChunkManagerSingle localChunkManager(
ProfileBufferChunkManager::scExpectedMaximumStackSize);
ProfileChunkedBuffer localBuffer(
ProfileChunkedBuffer::ThreadSafety::WithoutMutex, localChunkManager);
ProfileBuffer localProfileBuffer(localBuffer);
// Will be kept between collections, to know what each collection does.
auto previousState = localBuffer.GetState();
// This will be positive if we are running behind schedule (sampling less
// frequently than desired) and negative if we are ahead of schedule.
TimeDuration lastSleepOvershoot = 0;
TimeStamp sampleStart = TimeStamp::Now();
while (true) {
// This scope is for |lock|. It ends before we sleep below.
{
PSAutoLock lock;
TimeStamp lockAcquired = TimeStamp::Now();
if (!ActivePS::Exists(lock)) {
return;
}
// At this point profiler_stop() might have been called, and
// profiler_start() might have been called on another thread. If this
// happens the generation won't match.
if (ActivePS::Generation(lock) != mActivityGeneration) {
return;
}
ActivePS::ClearExpiredExitProfiles(lock);
TimeStamp expiredMarkersCleaned = TimeStamp::Now();
if (int(gSkipSampling) <= 0 && !ActivePS::IsSamplingPaused(lock)) {
TimeDuration delta = sampleStart - CorePS::ProcessStartTime();
ProfileBuffer& buffer = ActivePS::Buffer(lock);
// handle per-process generic counters
const Vector<BaseProfilerCount*>& counters = CorePS::Counters(lock);
for (auto& counter : counters) {
// create Buffer entries for each counter
buffer.AddEntry(ProfileBufferEntry::CounterId(counter));
buffer.AddEntry(ProfileBufferEntry::Time(delta.ToMilliseconds()));
int64_t count;
uint64_t number;
counter->Sample(count, number);
buffer.AddEntry(ProfileBufferEntry::Count(count));
if (number) {
buffer.AddEntry(ProfileBufferEntry::Number(number));
}
}
TimeStamp countersSampled = TimeStamp::Now();
if (stackSampling) {
const Vector<LiveProfiledThreadData>& liveThreads =
ActivePS::LiveProfiledThreads(lock);
for (auto& thread : liveThreads) {
RegisteredThread* registeredThread = thread.mRegisteredThread;
ProfiledThreadData* profiledThreadData =
thread.mProfiledThreadData.get();
RefPtr<ThreadInfo> info = registeredThread->Info();
// If the thread is asleep and has been sampled before in the same
// sleep episode, find and copy the previous sample, as that's
// cheaper than taking a new sample.
if (registeredThread->RacyRegisteredThread()
.CanDuplicateLastSampleDueToSleep()) {
bool dup_ok = ActivePS::Buffer(lock).DuplicateLastSample(
info->ThreadId(), CorePS::ProcessStartTime(),
profiledThreadData->LastSample());
if (dup_ok) {
continue;
}
}
AUTO_PROFILER_STATS(base_SamplerThread_Run_DoPeriodicSample);
TimeStamp now = TimeStamp::Now();
// Record the global profiler buffer's range start now, before
// adding the first entry for this thread's sample.
const uint64_t bufferRangeStart = buffer.BufferRangeStart();
// Add the thread ID now, so we know its position in the main
// buffer, which is used by some JS data. (DoPeriodicSample only
// knows about the temporary local buffer.)
const uint64_t samplePos =
buffer.AddThreadIdEntry(registeredThread->Info()->ThreadId());
profiledThreadData->LastSample() = Some(samplePos);
// Also add the time, so it's always there after the thread ID, as
// expected by the parser. (Other stack data is optional.)
TimeDuration delta = now - CorePS::ProcessStartTime();
buffer.AddEntry(ProfileBufferEntry::Time(delta.ToMilliseconds()));
mSampler.SuspendAndSampleAndResumeThread(
lock, *registeredThread, now,
[&](const Registers& aRegs, const TimeStamp& aNow) {
DoPeriodicSample(lock, *registeredThread, *profiledThreadData,
aRegs, samplePos, bufferRangeStart,
localProfileBuffer);
});
// If data is complete, copy it into the global buffer.
auto state = localBuffer.GetState();
if (state.mClearedBlockCount != previousState.mClearedBlockCount) {
LOG("Stack sample too big for local storage, needed %u bytes",
unsigned(state.mRangeEnd - previousState.mRangeEnd));
} else if (state.mRangeEnd - previousState.mRangeEnd >=
*profiler_get_core_buffer().BufferLength()) {
LOG("Stack sample too big for profiler storage, needed %u bytes",
unsigned(state.mRangeEnd - previousState.mRangeEnd));
} else {
profiler_get_core_buffer().AppendContents(localBuffer);
}
// Clean up for the next run.
localBuffer.Clear();
previousState = localBuffer.GetState();
}
}
#if defined(USE_LUL_STACKWALK)
// The LUL unwind object accumulates frame statistics. Periodically we
// should poke it to give it a chance to print those statistics. This
// involves doing I/O (fprintf, __android_log_print, etc.) and so
// can't safely be done from the critical section inside
// SuspendAndSampleAndResumeThread, which is why it is done here.
lul::LUL* lul = CorePS::Lul(lock);
if (lul) {
lul->MaybeShowStats();
}
#endif
TimeStamp threadsSampled = TimeStamp::Now();
{
AUTO_PROFILER_STATS(Sampler_FulfillChunkRequests);
ActivePS::FulfillChunkRequests(lock);
}
buffer.CollectOverheadStats(delta, lockAcquired - sampleStart,
expiredMarkersCleaned - lockAcquired,
countersSampled - expiredMarkersCleaned,
threadsSampled - countersSampled);
}
}
// gPSMutex is not held after this point.
// Calculate how long a sleep to request. After the sleep, measure how
// long we actually slept and take the difference into account when
// calculating the sleep interval for the next iteration. This is an
// attempt to keep "to schedule" in the presence of inaccuracy of the
// actual sleep intervals.
TimeStamp targetSleepEndTime =
sampleStart + TimeDuration::FromMicroseconds(mIntervalMicroseconds);
TimeStamp beforeSleep = TimeStamp::Now();
TimeDuration targetSleepDuration = targetSleepEndTime - beforeSleep;
double sleepTime = std::max(
0.0, (targetSleepDuration - lastSleepOvershoot).ToMicroseconds());
SleepMicro(static_cast<uint32_t>(sleepTime));
sampleStart = TimeStamp::Now();
lastSleepOvershoot =
sampleStart - (beforeSleep + TimeDuration::FromMicroseconds(sleepTime));
}
}
// Temporary closing namespaces from enclosing platform.cpp.
} // namespace baseprofiler
} // namespace mozilla
// We #include these files directly because it means those files can use
// declarations from this file trivially. These provide target-specific
// implementations of all SamplerThread methods except Run().
#if defined(GP_OS_windows)
# include "platform-win32.cpp"
#elif defined(GP_OS_darwin)
# include "platform-macos.cpp"
#elif defined(GP_OS_linux) || defined(GP_OS_android) || defined(GP_OS_freebsd)
# include "platform-linux-android.cpp"
#else
# error "bad platform"
#endif
namespace mozilla {
namespace baseprofiler {
UniquePlatformData AllocPlatformData(BaseProfilerThreadId aThreadId) {
return UniquePlatformData(new PlatformData(aThreadId));
}
void PlatformDataDestructor::operator()(PlatformData* aData) { delete aData; }
// END SamplerThread
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
// BEGIN externally visible functions
static uint32_t ParseFeature(const char* aFeature, bool aIsStartup) {
if (strcmp(aFeature, "default") == 0) {
return (aIsStartup ? (DefaultFeatures() | StartupExtraDefaultFeatures())
: DefaultFeatures()) &
AvailableFeatures();
}
#define PARSE_FEATURE_BIT(n_, str_, Name_, desc_) \
if (strcmp(aFeature, str_) == 0) { \
return ProfilerFeature::Name_; \
}
BASE_PROFILER_FOR_EACH_FEATURE(PARSE_FEATURE_BIT)
#undef PARSE_FEATURE_BIT
PrintToConsole("\nUnrecognized feature \"%s\".\n\n", aFeature);
// Since we may have an old feature we don't implement anymore, don't exit.
PrintUsage();
return 0;
}
uint32_t ParseFeaturesFromStringArray(const char** aFeatures,
uint32_t aFeatureCount,
bool aIsStartup /* = false */) {
uint32_t features = 0;
for (size_t i = 0; i < aFeatureCount; i++) {
features |= ParseFeature(aFeatures[i], aIsStartup);
}
return features;
}
// Find the RegisteredThread for the current thread. This should only be called
// in places where TLSRegisteredThread can't be used.
static RegisteredThread* FindCurrentThreadRegisteredThread(PSLockRef aLock) {
BaseProfilerThreadId id = profiler_current_thread_id();
const Vector<UniquePtr<RegisteredThread>>& registeredThreads =
CorePS::RegisteredThreads(aLock);
for (auto& registeredThread : registeredThreads) {
if (registeredThread->Info()->ThreadId() == id) {
return registeredThread.get();
}
}
return nullptr;
}
static ProfilingStack* locked_register_thread(PSLockRef aLock,
const char* aName,
void* aStackTop) {
MOZ_RELEASE_ASSERT(CorePS::Exists());
MOZ_ASSERT(!FindCurrentThreadRegisteredThread(aLock));
VTUNE_REGISTER_THREAD(aName);
if (!TLSRegisteredThread::Init(aLock)) {
return nullptr;
}
RefPtr<ThreadInfo> info = new ThreadInfo(aName, profiler_current_thread_id(),
profiler_is_main_thread());
UniquePtr<RegisteredThread> registeredThread =
MakeUnique<RegisteredThread>(info, aStackTop);
TLSRegisteredThread::SetRegisteredThread(aLock, registeredThread.get());
if (ActivePS::Exists(aLock) && ActivePS::ShouldProfileThread(aLock, info)) {
registeredThread->RacyRegisteredThread().SetIsBeingProfiled(true);
ActivePS::AddLiveProfiledThread(aLock, registeredThread.get(),
MakeUnique<ProfiledThreadData>(info));
}
ProfilingStack* profilingStack =
®isteredThread->RacyRegisteredThread().ProfilingStack();
CorePS::AppendRegisteredThread(aLock, std::move(registeredThread));
return profilingStack;
}
static void locked_profiler_start(PSLockRef aLock, PowerOfTwo32 aCapacity,
double aInterval, uint32_t aFeatures,
const char** aFilters, uint32_t aFilterCount,
const Maybe<double>& aDuration);
static Vector<const char*> SplitAtCommas(const char* aString,
UniquePtr<char[]>& aStorage) {
size_t len = strlen(aString);
aStorage = MakeUnique<char[]>(len + 1);
PodCopy(aStorage.get(), aString, len + 1);
// Iterate over all characters in aStorage and split at commas, by
// overwriting commas with the null char.
Vector<const char*> array;
size_t currentElementStart = 0;
for (size_t i = 0; i <= len; i++) {
if (aStorage[i] == ',') {
aStorage[i] = '\0';
}
if (aStorage[i] == '\0') {
// Only add non-empty elements, otherwise ParseFeatures would later
// complain about unrecognized features.
if (currentElementStart != i) {
MOZ_RELEASE_ASSERT(array.append(&aStorage[currentElementStart]));
}
currentElementStart = i + 1;
}
}
return array;
}
static const char* get_size_suffix(const char* str) {
const char* ptr = str;
while (isdigit(*ptr)) {
ptr++;
}
return ptr;
}
void profiler_init(void* aStackTop) {
LOG("profiler_init");
profiler_init_main_thread_id();
VTUNE_INIT();
MOZ_RELEASE_ASSERT(!CorePS::Exists());
if (getenv("MOZ_BASE_PROFILER_HELP")) {
PrintUsage();
exit(0);
}
SharedLibraryInfo::Initialize();
uint32_t features = DefaultFeatures() & AvailableFeatures();
UniquePtr<char[]> filterStorage;
Vector<const char*> filters;
MOZ_RELEASE_ASSERT(filters.append(kMainThreadName));
PowerOfTwo32 capacity = BASE_PROFILER_DEFAULT_ENTRIES;
Maybe<double> duration = Nothing();
double interval = BASE_PROFILER_DEFAULT_INTERVAL;
{
PSAutoLock lock;
// We've passed the possible failure point. Instantiate CorePS, which
// indicates that the profiler has initialized successfully.
CorePS::Create(lock);
Unused << locked_register_thread(lock, kMainThreadName, aStackTop);
// Platform-specific initialization.
PlatformInit(lock);
// (Linux-only) We could create CorePS::mLul and read unwind info into it
// at this point. That would match the lifetime implied by destruction of
// it in profiler_shutdown() just below. However, that gives a big delay on
// startup, even if no profiling is actually to be done. So, instead, it is
// created on demand at the first call to PlatformStart().
const char* startupEnv = getenv("MOZ_PROFILER_STARTUP");
if (!startupEnv || startupEnv[0] == '\0' ||
((startupEnv[0] == '0' || startupEnv[0] == 'N' ||
startupEnv[0] == 'n') &&
startupEnv[1] == '\0')) {
return;
}
// Hidden option to stop Base Profiler, mostly due to Talos intermittents,
// TODO: Investigate root cause and remove this in bugs 1648324 and 1648325.
if (getenv("MOZ_PROFILER_STARTUP_NO_BASE")) {
return;
}
LOG("- MOZ_PROFILER_STARTUP is set");
// Startup default capacity may be different.
capacity = BASE_PROFILER_DEFAULT_STARTUP_ENTRIES;
const char* startupCapacity = getenv("MOZ_PROFILER_STARTUP_ENTRIES");
if (startupCapacity && startupCapacity[0] != '\0') {
errno = 0;
long capacityLong = strtol(startupCapacity, nullptr, 10);
std::string_view sizeSuffix = get_size_suffix(startupCapacity);
if (sizeSuffix == "KB") {
capacityLong *= 1000 / scBytesPerEntry;
} else if (sizeSuffix == "KiB") {
capacityLong *= 1024 / scBytesPerEntry;
} else if (sizeSuffix == "MB") {
capacityLong *= (1000 * 1000) / scBytesPerEntry;
} else if (sizeSuffix == "MiB") {
capacityLong *= (1024 * 1024) / scBytesPerEntry;
} else if (sizeSuffix == "GB") {
capacityLong *= (1000 * 1000 * 1000) / scBytesPerEntry;
} else if (sizeSuffix == "GiB") {
capacityLong *= (1024 * 1024 * 1024) / scBytesPerEntry;
} else if (!sizeSuffix.empty()) {
PrintToConsole(
"- MOZ_PROFILER_STARTUP_ENTRIES unit must be one of the "
"following: KB, KiB, MB, MiB, GB, GiB");
PrintUsage();
exit(1);
}
// `long` could be 32 or 64 bits, so we force a 64-bit comparison with
// the maximum 32-bit signed number (as more than that is clamped down to
// 2^31 anyway).
if (errno == 0 && capacityLong > 0 &&
static_cast<uint64_t>(capacityLong) <=
static_cast<uint64_t>(INT32_MAX)) {
capacity = PowerOfTwo32(
ClampToAllowedEntries(static_cast<uint32_t>(capacityLong)));
LOG("- MOZ_PROFILER_STARTUP_ENTRIES = %u", unsigned(capacity.Value()));
} else {
PrintToConsole("- MOZ_PROFILER_STARTUP_ENTRIES not a valid integer: %s",
startupCapacity);
PrintUsage();
exit(1);
}
}
const char* startupDuration = getenv("MOZ_PROFILER_STARTUP_DURATION");
if (startupDuration && startupDuration[0] != '\0') {
// The duration is a floating point number. Use StringToDouble rather than
// strtod, so that "." is used as the decimal separator regardless of OS
// locale.
auto durationVal = StringToDouble(std::string(startupDuration));
if (durationVal && *durationVal >= 0.0) {
if (*durationVal > 0.0) {
duration = Some(*durationVal);
}
LOG("- MOZ_PROFILER_STARTUP_DURATION = %f", *durationVal);
} else {
PrintToConsole("- MOZ_PROFILER_STARTUP_DURATION not a valid float: %s",
startupDuration);
PrintUsage();
exit(1);
}
}
const char* startupInterval = getenv("MOZ_PROFILER_STARTUP_INTERVAL");
if (startupInterval && startupInterval[0] != '\0') {
// The interval is a floating point number. Use StringToDouble rather than
// strtod, so that "." is used as the decimal separator regardless of OS
// locale.
auto intervalValue = StringToDouble(MakeStringSpan(startupInterval));
if (intervalValue && *intervalValue > 0.0 && *intervalValue <= 1000.0) {
interval = *intervalValue;
LOG("- MOZ_PROFILER_STARTUP_INTERVAL = %f", interval);
} else {
PrintToConsole("- MOZ_PROFILER_STARTUP_INTERVAL not a valid float: %s",
startupInterval);
PrintUsage();
exit(1);
}
}
features |= StartupExtraDefaultFeatures() & AvailableFeatures();
const char* startupFeaturesBitfield =
getenv("MOZ_PROFILER_STARTUP_FEATURES_BITFIELD");
if (startupFeaturesBitfield && startupFeaturesBitfield[0] != '\0') {
errno = 0;
features = strtol(startupFeaturesBitfield, nullptr, 10);
if (errno == 0) {
LOG("- MOZ_PROFILER_STARTUP_FEATURES_BITFIELD = %d", features);
} else {
PrintToConsole(
"- MOZ_PROFILER_STARTUP_FEATURES_BITFIELD not a valid integer: %s",
startupFeaturesBitfield);
PrintUsage();
exit(1);
}
} else {
const char* startupFeatures = getenv("MOZ_PROFILER_STARTUP_FEATURES");
if (startupFeatures) {
// Interpret startupFeatures as a list of feature strings, separated by
// commas.
UniquePtr<char[]> featureStringStorage;
Vector<const char*> featureStringArray =
SplitAtCommas(startupFeatures, featureStringStorage);
features = ParseFeaturesFromStringArray(featureStringArray.begin(),
featureStringArray.length(),
/* aIsStartup */ true);
LOG("- MOZ_PROFILER_STARTUP_FEATURES = %d", features);
}
}
const char* startupFilters = getenv("MOZ_PROFILER_STARTUP_FILTERS");
if (startupFilters && startupFilters[0] != '\0') {
filters = SplitAtCommas(startupFilters, filterStorage);
LOG("- MOZ_PROFILER_STARTUP_FILTERS = %s", startupFilters);
if (mozilla::profiler::detail::FiltersExcludePid(filters)) {
LOG(" -> This process is excluded and won't be profiled");
return;
}
}
locked_profiler_start(lock, capacity, interval, features, filters.begin(),
filters.length(), duration);
}
// TODO: Install memory counter if it is possible from mozglue.
// #if defined(MOZ_REPLACE_MALLOC) && defined(MOZ_PROFILER_MEMORY)
// // start counting memory allocations (outside of lock because this may
// call
// // profiler_add_sampled_counter which would attempt to take the lock.)
// mozilla::profiler::install_memory_counter(true);
// #endif
}
static void locked_profiler_save_profile_to_file(PSLockRef aLock,
const char* aFilename,
bool aIsShuttingDown);
static SamplerThread* locked_profiler_stop(PSLockRef aLock);
void profiler_shutdown() {
LOG("profiler_shutdown");
VTUNE_SHUTDOWN();
MOZ_RELEASE_ASSERT(profiler_is_main_thread());
MOZ_RELEASE_ASSERT(CorePS::Exists());
// If the profiler is active we must get a handle to the SamplerThread before
// ActivePS is destroyed, in order to delete it.
SamplerThread* samplerThread = nullptr;
{
PSAutoLock lock;
// Save the profile on shutdown if requested.
if (ActivePS::Exists(lock)) {
const char* filename = getenv("MOZ_PROFILER_SHUTDOWN");
if (filename && filename[0] != '\0') {
locked_profiler_save_profile_to_file(lock, filename,
/* aIsShuttingDown */ true);
}
samplerThread = locked_profiler_stop(lock);
}
CorePS::Destroy(lock);
// We just destroyed CorePS and the ThreadInfos it contains, so we can
// clear this thread's TLSRegisteredThread.
TLSRegisteredThread::SetRegisteredThread(lock, nullptr);
}
// We do these operations with gPSMutex unlocked. The comments in
// profiler_stop() explain why.
if (samplerThread) {
delete samplerThread;
}
}
static bool WriteProfileToJSONWriter(SpliceableChunkedJSONWriter& aWriter,
double aSinceTime, bool aIsShuttingDown,
bool aOnlyThreads = false) {
LOG("WriteProfileToJSONWriter");
MOZ_RELEASE_ASSERT(CorePS::Exists());
if (!aOnlyThreads) {
aWriter.Start();
{
if (!profiler_stream_json_for_this_process(
aWriter, aSinceTime, aIsShuttingDown, aOnlyThreads)) {
return false;
}
// Don't include profiles from other processes because this is a
// synchronous function.
aWriter.StartArrayProperty("processes");
aWriter.EndArray();
}
aWriter.End();
} else {
aWriter.StartBareList();
if (!profiler_stream_json_for_this_process(aWriter, aSinceTime,
aIsShuttingDown, aOnlyThreads)) {
return false;
}
aWriter.EndBareList();
}
return true;
}
void profiler_set_process_name(const std::string& aProcessName,
const std::string* aETLDplus1) {
LOG("profiler_set_process_name(\"%s\", \"%s\")", aProcessName.c_str(),
aETLDplus1 ? aETLDplus1->c_str() : "<none>");
PSAutoLock lock;
CorePS::SetProcessName(lock, aProcessName);
if (aETLDplus1) {
CorePS::SetETLDplus1(lock, *aETLDplus1);
}
}
UniquePtr<char[]> profiler_get_profile(double aSinceTime, bool aIsShuttingDown,
bool aOnlyThreads) {
LOG("profiler_get_profile");
SpliceableChunkedJSONWriter b{FailureLatchInfallibleSource::Singleton()};
if (!WriteProfileToJSONWriter(b, aSinceTime, aIsShuttingDown, aOnlyThreads)) {
return nullptr;
}
return b.ChunkedWriteFunc().CopyData();
}
void profiler_get_start_params(int* aCapacity, Maybe<double>* aDuration,
double* aInterval, uint32_t* aFeatures,
Vector<const char*>* aFilters) {
MOZ_RELEASE_ASSERT(CorePS::Exists());
if (!aCapacity || !aDuration || !aInterval || !aFeatures || !aFilters) {
return;
}
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
*aCapacity = 0;
*aDuration = Nothing();
*aInterval = 0;
*aFeatures = 0;
aFilters->clear();
return;
}
*aCapacity = ActivePS::Capacity(lock).Value();
*aDuration = ActivePS::Duration(lock);
*aInterval = ActivePS::Interval(lock);
*aFeatures = ActivePS::Features(lock);
const Vector<std::string>& filters = ActivePS::Filters(lock);
MOZ_ALWAYS_TRUE(aFilters->resize(filters.length()));
for (uint32_t i = 0; i < filters.length(); ++i) {
(*aFilters)[i] = filters[i].c_str();
}
}
void GetProfilerEnvVarsForChildProcess(
std::function<void(const char* key, const char* value)>&& aSetEnv) {
MOZ_RELEASE_ASSERT(CorePS::Exists());
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
aSetEnv("MOZ_PROFILER_STARTUP", "");
return;
}
aSetEnv("MOZ_PROFILER_STARTUP", "1");
auto capacityString =
Smprintf("%u", unsigned(ActivePS::Capacity(lock).Value()));
aSetEnv("MOZ_PROFILER_STARTUP_ENTRIES", capacityString.get());
// Use AppendFloat instead of Smprintf with %f because the decimal
// separator used by %f is locale-dependent. But the string we produce needs
// to be parseable by strtod, which only accepts the period character as a
// decimal separator. AppendFloat always uses the period character.
std::string intervalString = std::to_string(ActivePS::Interval(lock));
aSetEnv("MOZ_PROFILER_STARTUP_INTERVAL", intervalString.c_str());
auto featuresString = Smprintf("%d", ActivePS::Features(lock));
aSetEnv("MOZ_PROFILER_STARTUP_FEATURES_BITFIELD", featuresString.get());
std::string filtersString;
const Vector<std::string>& filters = ActivePS::Filters(lock);
for (uint32_t i = 0; i < filters.length(); ++i) {
filtersString += filters[i];
if (i != filters.length() - 1) {
filtersString += ",";
}
}
aSetEnv("MOZ_PROFILER_STARTUP_FILTERS", filtersString.c_str());
}
void profiler_received_exit_profile(const std::string& aExitProfile) {
MOZ_RELEASE_ASSERT(CorePS::Exists());
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
return;
}
ActivePS::AddExitProfile(lock, aExitProfile);
}
Vector<std::string> profiler_move_exit_profiles() {
MOZ_RELEASE_ASSERT(CorePS::Exists());
PSAutoLock lock;
Vector<std::string> profiles;
if (ActivePS::Exists(lock)) {
profiles = ActivePS::MoveExitProfiles(lock);
}
return profiles;
}
static void locked_profiler_save_profile_to_file(PSLockRef aLock,
const char* aFilename,
bool aIsShuttingDown = false) {
LOG("locked_profiler_save_profile_to_file(%s)", aFilename);
MOZ_RELEASE_ASSERT(CorePS::Exists() && ActivePS::Exists(aLock));
std::ofstream stream;
stream.open(aFilename);
if (stream.is_open()) {
OStreamJSONWriteFunc jw(stream);
SpliceableJSONWriter w(jw, FailureLatchInfallibleSource::Singleton());
w.Start();
{
locked_profiler_stream_json_for_this_process(aLock, w, /* sinceTime */ 0,
aIsShuttingDown);
w.StartArrayProperty("processes");
Vector<std::string> exitProfiles = ActivePS::MoveExitProfiles(aLock);
for (auto& exitProfile : exitProfiles) {
if (!exitProfile.empty()) {
w.Splice(exitProfile);
}
}
w.EndArray();
}
w.End();
stream.close();
}
}
void baseprofiler_save_profile_to_file(const char* aFilename) {
LOG("baseprofiler_save_profile_to_file(%s)", aFilename);
MOZ_RELEASE_ASSERT(CorePS::Exists());
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
return;
}
locked_profiler_save_profile_to_file(lock, aFilename);
}
uint32_t profiler_get_available_features() {
MOZ_RELEASE_ASSERT(CorePS::Exists());
return AvailableFeatures();
}
Maybe<ProfilerBufferInfo> profiler_get_buffer_info() {
MOZ_RELEASE_ASSERT(CorePS::Exists());
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
return Nothing();
}
return Some(ActivePS::Buffer(lock).GetProfilerBufferInfo());
}
// This basically duplicates AutoProfilerLabel's constructor.
static void* MozGlueBaseLabelEnter(const char* aLabel,
const char* aDynamicString, void* aSp) {
ProfilingStack* profilingStack = AutoProfilerLabel::sProfilingStack.get();
if (profilingStack) {
profilingStack->pushLabelFrame(aLabel, aDynamicString, aSp,
ProfilingCategoryPair::OTHER);
}
return profilingStack;
}
// This basically duplicates AutoProfilerLabel's destructor.
static void MozGlueBaseLabelExit(void* sProfilingStack) {
if (sProfilingStack) {
reinterpret_cast<ProfilingStack*>(sProfilingStack)->pop();
}
}
static void locked_profiler_start(PSLockRef aLock, PowerOfTwo32 aCapacity,
double aInterval, uint32_t aFeatures,
const char** aFilters, uint32_t aFilterCount,
const Maybe<double>& aDuration) {
const TimeStamp profilingStartTime = TimeStamp::Now();
if (LOG_TEST) {
LOG("locked_profiler_start");
LOG("- capacity = %d", int(aCapacity.Value()));
LOG("- duration = %.2f", aDuration ? *aDuration : -1);
LOG("- interval = %.2f", aInterval);
#define LOG_FEATURE(n_, str_, Name_, desc_) \
if (ProfilerFeature::Has##Name_(aFeatures)) { \
LOG("- feature = %s", str_); \
}
BASE_PROFILER_FOR_EACH_FEATURE(LOG_FEATURE)
#undef LOG_FEATURE
for (uint32_t i = 0; i < aFilterCount; i++) {
LOG("- threads = %s", aFilters[i]);
}
}
MOZ_RELEASE_ASSERT(CorePS::Exists() && !ActivePS::Exists(aLock));
mozilla::base_profiler_markers_detail::EnsureBufferForMainThreadAddMarker();
#if defined(GP_PLAT_amd64_windows) || defined(GP_PLAT_arm64_windows)
mozilla::WindowsStackWalkInitialization();
#endif
// Fall back to the default values if the passed-in values are unreasonable.
// We want to be able to store at least one full stack.
// TODO: Review magic numbers.
PowerOfTwo32 capacity =
(aCapacity.Value() >=
ProfileBufferChunkManager::scExpectedMaximumStackSize / scBytesPerEntry)
? aCapacity
: BASE_PROFILER_DEFAULT_ENTRIES;
Maybe<double> duration = aDuration;
if (aDuration && *aDuration <= 0) {
duration = Nothing();
}
double interval = aInterval > 0 ? aInterval : BASE_PROFILER_DEFAULT_INTERVAL;
ActivePS::Create(aLock, profilingStartTime, capacity, interval, aFeatures,
aFilters, aFilterCount, duration);
// Set up profiling for each registered thread, if appropriate.
const Vector<UniquePtr<RegisteredThread>>& registeredThreads =
CorePS::RegisteredThreads(aLock);
for (auto& registeredThread : registeredThreads) {
RefPtr<ThreadInfo> info = registeredThread->Info();
if (ActivePS::ShouldProfileThread(aLock, info)) {
registeredThread->RacyRegisteredThread().SetIsBeingProfiled(true);
ActivePS::AddLiveProfiledThread(aLock, registeredThread.get(),
MakeUnique<ProfiledThreadData>(info));
registeredThread->RacyRegisteredThread().ReinitializeOnResume();
}
}
// Setup support for pushing/popping labels in mozglue.
RegisterProfilerLabelEnterExit(MozGlueBaseLabelEnter, MozGlueBaseLabelExit);
// At the very end, set up RacyFeatures.
RacyFeatures::SetActive(ActivePS::Features(aLock));
}
void profiler_start(PowerOfTwo32 aCapacity, double aInterval,
uint32_t aFeatures, const char** aFilters,
uint32_t aFilterCount, const Maybe<double>& aDuration) {
LOG("profiler_start");
SamplerThread* samplerThread = nullptr;
{
PSAutoLock lock;
// Initialize if necessary.
if (!CorePS::Exists()) {
profiler_init(nullptr);
}
// Reset the current state if the profiler is running.
if (ActivePS::Exists(lock)) {
samplerThread = locked_profiler_stop(lock);
}
locked_profiler_start(lock, aCapacity, aInterval, aFeatures, aFilters,
aFilterCount, aDuration);
}
// TODO: Install memory counter if it is possible from mozglue.
// #if defined(MOZ_REPLACE_MALLOC) && defined(MOZ_PROFILER_MEMORY)
// // start counting memory allocations (outside of lock because this may
// call
// // profiler_add_sampled_counter which would attempt to take the lock.)
// mozilla::profiler::install_memory_counter(true);
// #endif
// We do these operations with gPSMutex unlocked. The comments in
// profiler_stop() explain why.
if (samplerThread) {
delete samplerThread;
}
}
void profiler_ensure_started(PowerOfTwo32 aCapacity, double aInterval,
uint32_t aFeatures, const char** aFilters,
uint32_t aFilterCount,
const Maybe<double>& aDuration) {
LOG("profiler_ensure_started");
// bool startedProfiler = false; (See TODO below)
SamplerThread* samplerThread = nullptr;
{
PSAutoLock lock;
// Initialize if necessary.
if (!CorePS::Exists()) {
profiler_init(nullptr);
}
if (ActivePS::Exists(lock)) {
// The profiler is active.
if (!ActivePS::Equals(lock, aCapacity, aDuration, aInterval, aFeatures,
aFilters, aFilterCount)) {
// Stop and restart with different settings.
samplerThread = locked_profiler_stop(lock);
locked_profiler_start(lock, aCapacity, aInterval, aFeatures, aFilters,
aFilterCount, aDuration);
// startedProfiler = true; (See TODO below)
}
} else {
// The profiler is stopped.
locked_profiler_start(lock, aCapacity, aInterval, aFeatures, aFilters,
aFilterCount, aDuration);
// startedProfiler = true; (See TODO below)
}
}
// TODO: Install memory counter if it is possible from mozglue.
// #if defined(MOZ_REPLACE_MALLOC) && defined(MOZ_PROFILER_MEMORY)
// // start counting memory allocations (outside of lock because this may
// // call profiler_add_sampled_counter which would attempt to take the
// // lock.)
// mozilla::profiler::install_memory_counter(true);
// #endif
// We do these operations with gPSMutex unlocked. The comments in
// profiler_stop() explain why.
if (samplerThread) {
delete samplerThread;
}
}
[[nodiscard]] static SamplerThread* locked_profiler_stop(PSLockRef aLock) {
LOG("locked_profiler_stop");
MOZ_RELEASE_ASSERT(CorePS::Exists() && ActivePS::Exists(aLock));
// At the very start, clear RacyFeatures.
RacyFeatures::SetInactive();
// TODO: Uninstall memory counter if it is possible from mozglue.
// #if defined(MOZ_REPLACE_MALLOC) && defined(MOZ_PROFILER_MEMORY)
// mozilla::profiler::install_memory_counter(false);
// #endif
// Remove support for pushing/popping labels in mozglue.
RegisterProfilerLabelEnterExit(nullptr, nullptr);
// Stop sampling live threads.
const Vector<LiveProfiledThreadData>& liveProfiledThreads =
ActivePS::LiveProfiledThreads(aLock);
for (auto& thread : liveProfiledThreads) {
RegisteredThread* registeredThread = thread.mRegisteredThread;
registeredThread->RacyRegisteredThread().SetIsBeingProfiled(false);
}
// The Stop() call doesn't actually stop Run(); that happens in this
// function's caller when the sampler thread is destroyed. Stop() just gives
// the SamplerThread a chance to do some cleanup with gPSMutex locked.
SamplerThread* samplerThread = ActivePS::Destroy(aLock);
samplerThread->Stop(aLock);
mozilla::base_profiler_markers_detail::ReleaseBufferForMainThreadAddMarker();
return samplerThread;
}
void profiler_stop() {
LOG("profiler_stop");
MOZ_RELEASE_ASSERT(CorePS::Exists());
SamplerThread* samplerThread;
{
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
return;
}
samplerThread = locked_profiler_stop(lock);
}
// We delete with gPSMutex unlocked. Otherwise we would get a deadlock: we
// would be waiting here with gPSMutex locked for SamplerThread::Run() to
// return so the join operation within the destructor can complete, but Run()
// needs to lock gPSMutex to return.
//
// Because this call occurs with gPSMutex unlocked, it -- including the final
// iteration of Run()'s loop -- must be able detect deactivation and return
// in a way that's safe with respect to other gPSMutex-locking operations
// that may have occurred in the meantime.
delete samplerThread;
}
bool profiler_is_paused() {
MOZ_RELEASE_ASSERT(CorePS::Exists());
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
return false;
}
return ActivePS::IsPaused(lock);
}
void profiler_pause() {
LOG("profiler_pause");
MOZ_RELEASE_ASSERT(CorePS::Exists());
{
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
return;
}
RacyFeatures::SetPaused();
ActivePS::SetIsPaused(lock, true);
ActivePS::Buffer(lock).AddEntry(ProfileBufferEntry::Pause(profiler_time()));
}
}
void profiler_resume() {
LOG("profiler_resume");
MOZ_RELEASE_ASSERT(CorePS::Exists());
{
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
return;
}
ActivePS::Buffer(lock).AddEntry(
ProfileBufferEntry::Resume(profiler_time()));
ActivePS::SetIsPaused(lock, false);
RacyFeatures::SetUnpaused();
}
}
bool profiler_is_sampling_paused() {
MOZ_RELEASE_ASSERT(CorePS::Exists());
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
return false;
}
return ActivePS::IsSamplingPaused(lock);
}
void profiler_pause_sampling() {
LOG("profiler_pause_sampling");
MOZ_RELEASE_ASSERT(CorePS::Exists());
{
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
return;
}
RacyFeatures::SetSamplingPaused();
ActivePS::SetIsSamplingPaused(lock, true);
ActivePS::Buffer(lock).AddEntry(
ProfileBufferEntry::PauseSampling(profiler_time()));
}
}
void profiler_resume_sampling() {
LOG("profiler_resume_sampling");
MOZ_RELEASE_ASSERT(CorePS::Exists());
{
PSAutoLock lock;
if (!ActivePS::Exists(lock)) {
return;
}
ActivePS::Buffer(lock).AddEntry(
ProfileBufferEntry::ResumeSampling(profiler_time()));
ActivePS::SetIsSamplingPaused(lock, false);
RacyFeatures::SetSamplingUnpaused();
}
}
bool profiler_feature_active(uint32_t aFeature) {
// This function runs both on and off the main thread.
MOZ_RELEASE_ASSERT(CorePS::Exists());
// This function is hot enough that we use RacyFeatures, not ActivePS.
return RacyFeatures::IsActiveWithFeature(aFeature);
}
bool profiler_active_without_feature(uint32_t aFeature) {
// This function runs both on and off the main thread.
// This function is hot enough that we use RacyFeatures, not ActivePS.
return RacyFeatures::IsActiveWithoutFeature(aFeature);
}
void profiler_add_sampled_counter(BaseProfilerCount* aCounter) {
DEBUG_LOG("profiler_add_sampled_counter(%s)", aCounter->mLabel);
PSAutoLock lock;
CorePS::AppendCounter(lock, aCounter);
}
void profiler_remove_sampled_counter(BaseProfilerCount* aCounter) {
DEBUG_LOG("profiler_remove_sampled_counter(%s)", aCounter->mLabel);
PSAutoLock lock;
// Note: we don't enforce a final sample, though we could do so if the
// profiler was active
CorePS::RemoveCounter(lock, aCounter);
}
ProfilingStack* profiler_register_thread(const char* aName,
void* aGuessStackTop) {
DEBUG_LOG("profiler_register_thread(%s)", aName);
MOZ_RELEASE_ASSERT(CorePS::Exists());
PSAutoLock lock;
if (RegisteredThread* thread = FindCurrentThreadRegisteredThread(lock);
thread) {
LOG("profiler_register_thread(%s) - thread %" PRIu64
" already registered as %s",
aName, uint64_t(profiler_current_thread_id().ToNumber()),
thread->Info()->Name());
// TODO: Use new name. This is currently not possible because the
// RegisteredThread's ThreadInfo cannot be changed.
// In the meantime, we record a marker that could be used in the frontend.
std::string text("Thread ");
text += std::to_string(profiler_current_thread_id().ToNumber());
text += " \"";
text += thread->Info()->Name();
text += "\" attempted to re-register as \"";
text += aName;
text += "\"";
BASE_PROFILER_MARKER_TEXT("profiler_register_thread again", OTHER_Profiling,
MarkerThreadId::MainThread(), text);
return &thread->RacyRegisteredThread().ProfilingStack();
}
void* stackTop = GetStackTop(aGuessStackTop);
return locked_register_thread(lock, aName, stackTop);
}
void profiler_unregister_thread() {
if (!CorePS::Exists()) {
// This function can be called after the main thread has already shut down.
return;
}
PSAutoLock lock;
RegisteredThread* registeredThread = FindCurrentThreadRegisteredThread(lock);
MOZ_RELEASE_ASSERT(registeredThread ==
TLSRegisteredThread::RegisteredThread(lock));
if (registeredThread) {
RefPtr<ThreadInfo> info = registeredThread->Info();
DEBUG_LOG("profiler_unregister_thread: %s", info->Name());
if (ActivePS::Exists(lock)) {
ActivePS::UnregisterThread(lock, registeredThread);
}
// Clear the pointer to the RegisteredThread object that we're about to
// destroy.
TLSRegisteredThread::SetRegisteredThread(lock, nullptr);
// Remove the thread from the list of registered threads. This deletes the
// registeredThread object.
CorePS::RemoveRegisteredThread(lock, registeredThread);
} else {
LOG("profiler_unregister_thread() - thread %" PRIu64
" already unregistered",
uint64_t(profiler_current_thread_id().ToNumber()));
// We cannot record a marker on this thread because it was already
// unregistered. Send it to the main thread (unless this *is* already the
// main thread, which has been unregistered); this may be useful to catch
// mismatched register/unregister pairs in Firefox.
if (BaseProfilerThreadId tid = profiler_current_thread_id();
tid != profiler_main_thread_id()) {
BASE_PROFILER_MARKER_TEXT(
"profiler_unregister_thread again", OTHER_Profiling,
MarkerThreadId::MainThread(),
std::to_string(profiler_current_thread_id().ToNumber()));
}
// There are two ways FindCurrentThreadRegisteredThread() might have failed.
//
// - TLSRegisteredThread::Init() failed in locked_register_thread().
//
// - We've already called profiler_unregister_thread() for this thread.
// (Whether or not it should, this does happen in practice.)
//
// Either way, TLSRegisteredThread should be empty.
MOZ_RELEASE_ASSERT(!TLSRegisteredThread::RegisteredThread(lock));
}
}
void profiler_register_page(uint64_t aTabID, uint64_t aInnerWindowID,
const std::string& aUrl,
uint64_t aEmbedderInnerWindowID) {
DEBUG_LOG("profiler_register_page(%" PRIu64 ", %" PRIu64 ", %s, %" PRIu64 ")",
aTabID, aInnerWindowID, aUrl.c_str(), aEmbedderInnerWindowID);
MOZ_RELEASE_ASSERT(CorePS::Exists());
PSAutoLock lock;
// When a Browsing context is first loaded, the first url loaded in it will be
// about:blank. Because of that, this call keeps the first non-about:blank
// registration of window and discards the previous one.
RefPtr<PageInformation> pageInfo =
new PageInformation(aTabID, aInnerWindowID, aUrl, aEmbedderInnerWindowID);
CorePS::AppendRegisteredPage(lock, std::move(pageInfo));
// After appending the given page to CorePS, look for the expired
// pages and remove them if there are any.
if (ActivePS::Exists(lock)) {
ActivePS::DiscardExpiredPages(lock);
}
}
void profiler_unregister_page(uint64_t aRegisteredInnerWindowID) {
if (!CorePS::Exists()) {
// This function can be called after the main thread has already shut down.
return;
}
PSAutoLock lock;
// During unregistration, if the profiler is active, we have to keep the
// page information since there may be some markers associated with the given
// page. But if profiler is not active. we have no reason to keep the
// page information here because there can't be any marker associated with it.
if (ActivePS::Exists(lock)) {
ActivePS::UnregisterPage(lock, aRegisteredInnerWindowID);
} else {
CorePS::RemoveRegisteredPage(lock, aRegisteredInnerWindowID);
}
}
void profiler_clear_all_pages() {
if (!CorePS::Exists()) {
// This function can be called after the main thread has already shut down.
return;
}
{
PSAutoLock lock;
CorePS::ClearRegisteredPages(lock);
if (ActivePS::Exists(lock)) {
ActivePS::ClearUnregisteredPages(lock);
}
}
}
void profiler_thread_sleep() {
// This function runs both on and off the main thread.
MOZ_RELEASE_ASSERT(CorePS::Exists());
RacyRegisteredThread* racyRegisteredThread =
TLSRegisteredThread::RacyRegisteredThread();
if (!racyRegisteredThread) {
return;
}
racyRegisteredThread->SetSleeping();
}
void profiler_thread_wake() {
// This function runs both on and off the main thread.
MOZ_RELEASE_ASSERT(CorePS::Exists());
RacyRegisteredThread* racyRegisteredThread =
TLSRegisteredThread::RacyRegisteredThread();
if (!racyRegisteredThread) {
return;
}
racyRegisteredThread->SetAwake();
}
bool detail::IsThreadBeingProfiled() {
MOZ_RELEASE_ASSERT(CorePS::Exists());
const RacyRegisteredThread* racyRegisteredThread =
TLSRegisteredThread::RacyRegisteredThread();
return racyRegisteredThread && racyRegisteredThread->IsBeingProfiled();
}
bool profiler_thread_is_sleeping() {
MOZ_RELEASE_ASSERT(profiler_is_main_thread());
MOZ_RELEASE_ASSERT(CorePS::Exists());
RacyRegisteredThread* racyRegisteredThread =
TLSRegisteredThread::RacyRegisteredThread();
if (!racyRegisteredThread) {
return false;
}
return racyRegisteredThread->IsSleeping();
}
double profiler_time() {
MOZ_RELEASE_ASSERT(CorePS::Exists());
TimeDuration delta = TimeStamp::Now() - CorePS::ProcessStartTime();
return delta.ToMilliseconds();
}
bool profiler_capture_backtrace_into(ProfileChunkedBuffer& aChunkedBuffer,
StackCaptureOptions aCaptureOptions) {
MOZ_RELEASE_ASSERT(CorePS::Exists());
PSAutoLock lock;
if (!ActivePS::Exists(lock) ||
aCaptureOptions == StackCaptureOptions::NoStack) {
return false;
}
RegisteredThread* registeredThread =
TLSRegisteredThread::RegisteredThread(lock);
if (!registeredThread) {
MOZ_ASSERT(registeredThread);
return false;
}
ProfileBuffer profileBuffer(aChunkedBuffer);
Registers regs;
#if defined(HAVE_NATIVE_UNWIND)
REGISTERS_SYNC_POPULATE(regs);
#else
regs.Clear();
#endif
DoSyncSample(lock, *registeredThread, TimeStamp::Now(), regs, profileBuffer,
aCaptureOptions);
return true;
}
UniquePtr<ProfileChunkedBuffer> profiler_capture_backtrace() {
MOZ_RELEASE_ASSERT(CorePS::Exists());
AUTO_BASE_PROFILER_LABEL("baseprofiler::profiler_capture_backtrace",
PROFILER);
// Quick is-active check before allocating a buffer.
// If NoMarkerStacks is set, we don't want to capture a backtrace.
if (!profiler_active_without_feature(ProfilerFeature::NoMarkerStacks)) {
return nullptr;
}
auto buffer = MakeUnique<ProfileChunkedBuffer>(
ProfileChunkedBuffer::ThreadSafety::WithoutMutex,
MakeUnique<ProfileBufferChunkManagerSingle>(
ProfileBufferChunkManager::scExpectedMaximumStackSize));
if (!profiler_capture_backtrace_into(*buffer, StackCaptureOptions::Full)) {
return nullptr;
}
return buffer;
}
UniqueProfilerBacktrace profiler_get_backtrace() {
UniquePtr<ProfileChunkedBuffer> buffer = profiler_capture_backtrace();
if (!buffer) {
return nullptr;
}
return UniqueProfilerBacktrace(
new ProfilerBacktrace("SyncProfile", std::move(buffer)));
}
void ProfilerBacktraceDestructor::operator()(ProfilerBacktrace* aBacktrace) {
delete aBacktrace;
}
bool profiler_is_locked_on_current_thread() {
// This function is used to help users avoid calling `profiler_...` functions
// when the profiler may already have a lock in place, which would prevent a
// 2nd recursive lock (resulting in a crash or a never-ending wait).
// So we must return `true` for any of:
// - The main profiler mutex, used by most functions, and/or
// - The buffer mutex, used directly in some functions without locking the
// main mutex, e.g., marker-related functions.
return PSAutoLock::IsLockedOnCurrentThread() ||
profiler_get_core_buffer().IsThreadSafeAndLockedOnCurrentThread();
}
// This is a simplified version of profiler_add_marker that can be easily passed
// into the JS engine.
void profiler_add_js_marker(const char* aMarkerName, const char* aMarkerText) {
BASE_PROFILER_MARKER_TEXT(
ProfilerString8View::WrapNullTerminatedString(aMarkerName), JS, {},
ProfilerString8View::WrapNullTerminatedString(aMarkerText));
}
// NOTE: aCollector's methods will be called while the target thread is paused.
// Doing things in those methods like allocating -- which may try to claim
// locks -- is a surefire way to deadlock.
void profiler_suspend_and_sample_thread(BaseProfilerThreadId aThreadId,
uint32_t aFeatures,
ProfilerStackCollector& aCollector,
bool aSampleNative /* = true */) {
const bool isSynchronous = [&aThreadId]() {
const BaseProfilerThreadId currentThreadId = profiler_current_thread_id();
if (!aThreadId.IsSpecified()) {
aThreadId = currentThreadId;
return true;
}
return aThreadId == currentThreadId;
}();
// Lock the profiler mutex
PSAutoLock lock;
const Vector<UniquePtr<RegisteredThread>>& registeredThreads =
CorePS::RegisteredThreads(lock);
for (auto& thread : registeredThreads) {
RefPtr<ThreadInfo> info = thread->Info();
RegisteredThread& registeredThread = *thread.get();
if (info->ThreadId() == aThreadId) {
if (info->IsMainThread()) {
aCollector.SetIsMainThread();
}
// Allocate the space for the native stack
NativeStack nativeStack;
auto collectStack = [&](const Registers& aRegs, const TimeStamp& aNow) {
// The target thread is now suspended. Collect a native
// backtrace, and call the callback.
#if defined(HAVE_FASTINIT_NATIVE_UNWIND)
if (aSampleNative) {
// We can only use FramePointerStackWalk or MozStackWalk from
// suspend_and_sample_thread as other stackwalking methods may not be
// initialized.
# if defined(USE_FRAME_POINTER_STACK_WALK)
DoFramePointerBacktrace(lock, registeredThread, aRegs, nativeStack);
# elif defined(USE_MOZ_STACK_WALK)
DoMozStackWalkBacktrace(lock, registeredThread, aRegs, nativeStack);
# else
# error "Invalid configuration"
# endif
MergeStacks(isSynchronous, registeredThread, nativeStack, aCollector);
} else
#endif
{
MergeStacks(isSynchronous, registeredThread, nativeStack, aCollector);
aCollector.CollectNativeLeafAddr((void*)aRegs.mPC);
}
};
if (isSynchronous) {
// Sampling the current thread, do NOT suspend it!
Registers regs;
#if defined(HAVE_NATIVE_UNWIND)
REGISTERS_SYNC_POPULATE(regs);
#else
regs.Clear();
#endif
collectStack(regs, TimeStamp::Now());
} else {
// Suspend, sample, and then resume the target thread.
Sampler sampler(lock);
TimeStamp now = TimeStamp::Now();
sampler.SuspendAndSampleAndResumeThread(lock, registeredThread, now,
collectStack);
// NOTE: Make sure to disable the sampler before it is destroyed, in
// case the profiler is running at the same time.
sampler.Disable(lock);
}
break;
}
}
}
// END externally visible functions
////////////////////////////////////////////////////////////////////////
} // namespace baseprofiler
} // namespace mozilla