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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
#include "ProfileBufferEntry.h"
#include <ostream>
#include <type_traits>
#include "mozilla/Logging.h"
#include "mozilla/ScopeExit.h"
#include "mozilla/Sprintf.h"
#include "mozilla/StackWalk.h"
#include "BaseProfiler.h"
#include "mozilla/BaseProfilerMarkers.h"
#include "platform.h"
#include "ProfileBuffer.h"
#include "ProfilerBacktrace.h"
namespace mozilla {
namespace baseprofiler {
////////////////////////////////////////////////////////////////////////
// BEGIN ProfileBufferEntry
ProfileBufferEntry::ProfileBufferEntry()
: mKind(Kind::INVALID), mStorage{0, 0, 0, 0, 0, 0, 0, 0} {}
// aString must be a static string.
ProfileBufferEntry::ProfileBufferEntry(Kind aKind, const char* aString)
: mKind(aKind) {
memcpy(mStorage, &aString, sizeof(aString));
}
ProfileBufferEntry::ProfileBufferEntry(Kind aKind, char aChars[kNumChars])
: mKind(aKind) {
memcpy(mStorage, aChars, kNumChars);
}
ProfileBufferEntry::ProfileBufferEntry(Kind aKind, void* aPtr) : mKind(aKind) {
memcpy(mStorage, &aPtr, sizeof(aPtr));
}
ProfileBufferEntry::ProfileBufferEntry(Kind aKind, double aDouble)
: mKind(aKind) {
memcpy(mStorage, &aDouble, sizeof(aDouble));
}
ProfileBufferEntry::ProfileBufferEntry(Kind aKind, int aInt) : mKind(aKind) {
memcpy(mStorage, &aInt, sizeof(aInt));
}
ProfileBufferEntry::ProfileBufferEntry(Kind aKind, int64_t aInt64)
: mKind(aKind) {
memcpy(mStorage, &aInt64, sizeof(aInt64));
}
ProfileBufferEntry::ProfileBufferEntry(Kind aKind, uint64_t aUint64)
: mKind(aKind) {
memcpy(mStorage, &aUint64, sizeof(aUint64));
}
ProfileBufferEntry::ProfileBufferEntry(Kind aKind,
BaseProfilerThreadId aThreadId)
: mKind(aKind) {
static_assert(std::is_trivially_copyable_v<BaseProfilerThreadId>);
static_assert(sizeof(aThreadId) <= sizeof(mStorage));
memcpy(mStorage, &aThreadId, sizeof(aThreadId));
}
const char* ProfileBufferEntry::GetString() const {
const char* result;
memcpy(&result, mStorage, sizeof(result));
return result;
}
void* ProfileBufferEntry::GetPtr() const {
void* result;
memcpy(&result, mStorage, sizeof(result));
return result;
}
double ProfileBufferEntry::GetDouble() const {
double result;
memcpy(&result, mStorage, sizeof(result));
return result;
}
int ProfileBufferEntry::GetInt() const {
int result;
memcpy(&result, mStorage, sizeof(result));
return result;
}
int64_t ProfileBufferEntry::GetInt64() const {
int64_t result;
memcpy(&result, mStorage, sizeof(result));
return result;
}
uint64_t ProfileBufferEntry::GetUint64() const {
uint64_t result;
memcpy(&result, mStorage, sizeof(result));
return result;
}
BaseProfilerThreadId ProfileBufferEntry::GetThreadId() const {
BaseProfilerThreadId result;
static_assert(std::is_trivially_copyable_v<BaseProfilerThreadId>);
memcpy(&result, mStorage, sizeof(result));
return result;
}
void ProfileBufferEntry::CopyCharsInto(char (&aOutArray)[kNumChars]) const {
memcpy(aOutArray, mStorage, kNumChars);
}
// END ProfileBufferEntry
////////////////////////////////////////////////////////////////////////
// As mentioned in ProfileBufferEntry.h, the JSON format contains many
// arrays whose elements are laid out according to various schemas to help
// de-duplication. This RAII class helps write these arrays by keeping track of
// the last non-null element written and adding the appropriate number of null
// elements when writing new non-null elements. It also automatically opens and
// closes an array element on the given JSON writer.
//
// You grant the AutoArraySchemaWriter exclusive access to the JSONWriter and
// the UniqueJSONStrings objects for the lifetime of AutoArraySchemaWriter. Do
// not access them independently while the AutoArraySchemaWriter is alive.
// If you need to add complex objects, call FreeFormElement(), which will give
// you temporary access to the writer.
//
// Example usage:
//
// // Define the schema of elements in this type of array: [FOO, BAR, BAZ]
// enum Schema : uint32_t {
// FOO = 0,
// BAR = 1,
// BAZ = 2
// };
//
// AutoArraySchemaWriter writer(someJsonWriter, someUniqueStrings);
// if (shouldWriteFoo) {
// writer.IntElement(FOO, getFoo());
// }
// ... etc ...
//
// The elements need to be added in-order.
class MOZ_RAII AutoArraySchemaWriter {
public:
explicit AutoArraySchemaWriter(SpliceableJSONWriter& aWriter)
: mJSONWriter(aWriter), mNextFreeIndex(0) {
mJSONWriter.StartArrayElement();
}
~AutoArraySchemaWriter() { mJSONWriter.EndArray(); }
template <typename T>
void IntElement(uint32_t aIndex, T aValue) {
static_assert(!std::is_same_v<T, uint64_t>,
"Narrowing uint64 -> int64 conversion not allowed");
FillUpTo(aIndex);
mJSONWriter.IntElement(static_cast<int64_t>(aValue));
}
void DoubleElement(uint32_t aIndex, double aValue) {
FillUpTo(aIndex);
mJSONWriter.DoubleElement(aValue);
}
void TimeMsElement(uint32_t aIndex, double aTime_ms) {
FillUpTo(aIndex);
mJSONWriter.TimeDoubleMsElement(aTime_ms);
}
void BoolElement(uint32_t aIndex, bool aValue) {
FillUpTo(aIndex);
mJSONWriter.BoolElement(aValue);
}
protected:
SpliceableJSONWriter& Writer() { return mJSONWriter; }
void FillUpTo(uint32_t aIndex) {
MOZ_ASSERT(aIndex >= mNextFreeIndex);
mJSONWriter.NullElements(aIndex - mNextFreeIndex);
mNextFreeIndex = aIndex + 1;
}
private:
SpliceableJSONWriter& mJSONWriter;
uint32_t mNextFreeIndex;
};
// Same as AutoArraySchemaWriter, but this can also write strings (output as
// indexes into the table of unique strings).
class MOZ_RAII AutoArraySchemaWithStringsWriter : public AutoArraySchemaWriter {
public:
AutoArraySchemaWithStringsWriter(SpliceableJSONWriter& aWriter,
UniqueJSONStrings& aStrings)
: AutoArraySchemaWriter(aWriter), mStrings(aStrings) {}
void StringElement(uint32_t aIndex, const Span<const char>& aValue) {
FillUpTo(aIndex);
mStrings.WriteElement(Writer(), aValue);
}
private:
UniqueJSONStrings& mStrings;
};
UniqueStacks::StackKey UniqueStacks::BeginStack(const FrameKey& aFrame) {
return StackKey(GetOrAddFrameIndex(aFrame));
}
UniqueStacks::StackKey UniqueStacks::AppendFrame(const StackKey& aStack,
const FrameKey& aFrame) {
return StackKey(aStack, GetOrAddStackIndex(aStack),
GetOrAddFrameIndex(aFrame));
}
bool UniqueStacks::FrameKey::NormalFrameData::operator==(
const NormalFrameData& aOther) const {
return mLocation == aOther.mLocation &&
mRelevantForJS == aOther.mRelevantForJS &&
mInnerWindowID == aOther.mInnerWindowID && mLine == aOther.mLine &&
mColumn == aOther.mColumn && mCategoryPair == aOther.mCategoryPair;
}
UniqueStacks::UniqueStacks()
: mUniqueStrings(MakeUnique<UniqueJSONStrings>(
FailureLatchInfallibleSource::Singleton())),
mFrameTableWriter(FailureLatchInfallibleSource::Singleton()),
mStackTableWriter(FailureLatchInfallibleSource::Singleton()) {
mFrameTableWriter.StartBareList();
mStackTableWriter.StartBareList();
}
uint32_t UniqueStacks::GetOrAddStackIndex(const StackKey& aStack) {
uint32_t count = mStackToIndexMap.count();
auto entry = mStackToIndexMap.lookupForAdd(aStack);
if (entry) {
MOZ_ASSERT(entry->value() < count);
return entry->value();
}
MOZ_RELEASE_ASSERT(mStackToIndexMap.add(entry, aStack, count));
StreamStack(aStack);
return count;
}
uint32_t UniqueStacks::GetOrAddFrameIndex(const FrameKey& aFrame) {
uint32_t count = mFrameToIndexMap.count();
auto entry = mFrameToIndexMap.lookupForAdd(aFrame);
if (entry) {
MOZ_ASSERT(entry->value() < count);
return entry->value();
}
MOZ_RELEASE_ASSERT(mFrameToIndexMap.add(entry, aFrame, count));
StreamNonJITFrame(aFrame);
return count;
}
void UniqueStacks::SpliceFrameTableElements(SpliceableJSONWriter& aWriter) {
mFrameTableWriter.EndBareList();
aWriter.TakeAndSplice(mFrameTableWriter.TakeChunkedWriteFunc());
}
void UniqueStacks::SpliceStackTableElements(SpliceableJSONWriter& aWriter) {
mStackTableWriter.EndBareList();
aWriter.TakeAndSplice(mStackTableWriter.TakeChunkedWriteFunc());
}
void UniqueStacks::StreamStack(const StackKey& aStack) {
enum Schema : uint32_t { PREFIX = 0, FRAME = 1 };
AutoArraySchemaWriter writer(mStackTableWriter);
if (aStack.mPrefixStackIndex.isSome()) {
writer.IntElement(PREFIX, *aStack.mPrefixStackIndex);
}
writer.IntElement(FRAME, aStack.mFrameIndex);
}
void UniqueStacks::StreamNonJITFrame(const FrameKey& aFrame) {
using NormalFrameData = FrameKey::NormalFrameData;
enum Schema : uint32_t {
LOCATION = 0,
RELEVANT_FOR_JS = 1,
INNER_WINDOW_ID = 2,
IMPLEMENTATION = 3,
LINE = 4,
COLUMN = 5,
CATEGORY = 6,
SUBCATEGORY = 7
};
AutoArraySchemaWithStringsWriter writer(mFrameTableWriter, *mUniqueStrings);
const NormalFrameData& data = aFrame.mData.as<NormalFrameData>();
writer.StringElement(LOCATION, data.mLocation);
writer.BoolElement(RELEVANT_FOR_JS, data.mRelevantForJS);
// It's okay to convert uint64_t to double here because DOM always creates IDs
// that are convertible to double.
writer.DoubleElement(INNER_WINDOW_ID, data.mInnerWindowID);
if (data.mLine.isSome()) {
writer.IntElement(LINE, *data.mLine);
}
if (data.mColumn.isSome()) {
writer.IntElement(COLUMN, *data.mColumn);
}
if (data.mCategoryPair.isSome()) {
const ProfilingCategoryPairInfo& info =
GetProfilingCategoryPairInfo(*data.mCategoryPair);
writer.IntElement(CATEGORY, uint32_t(info.mCategory));
writer.IntElement(SUBCATEGORY, info.mSubcategoryIndex);
}
}
struct ProfileSample {
uint32_t mStack;
double mTime;
Maybe<double> mResponsiveness;
};
static void WriteSample(SpliceableJSONWriter& aWriter,
const ProfileSample& aSample) {
enum Schema : uint32_t {
STACK = 0,
TIME = 1,
EVENT_DELAY = 2,
};
AutoArraySchemaWriter writer(aWriter);
writer.IntElement(STACK, aSample.mStack);
writer.TimeMsElement(TIME, aSample.mTime);
if (aSample.mResponsiveness.isSome()) {
writer.DoubleElement(EVENT_DELAY, *aSample.mResponsiveness);
}
}
class EntryGetter {
public:
explicit EntryGetter(ProfileChunkedBuffer::Reader& aReader,
uint64_t aInitialReadPos = 0)
: mBlockIt(
aReader.At(ProfileBufferBlockIndex::CreateFromProfileBufferIndex(
aInitialReadPos))),
mBlockItEnd(aReader.end()) {
if (!ReadLegacyOrEnd()) {
// Find and read the next non-legacy entry.
Next();
}
}
bool Has() const { return mBlockIt != mBlockItEnd; }
const ProfileBufferEntry& Get() const {
MOZ_ASSERT(Has(), "Caller should have checked `Has()` before `Get()`");
return mEntry;
}
void Next() {
MOZ_ASSERT(Has(), "Caller should have checked `Has()` before `Next()`");
for (;;) {
++mBlockIt;
if (ReadLegacyOrEnd()) {
// Either we're at the end, or we could read a legacy entry -> Done.
break;
}
// Otherwise loop around until we hit the end or a legacy entry.
}
}
ProfileBufferBlockIndex CurBlockIndex() const {
return mBlockIt.CurrentBlockIndex();
}
uint64_t CurPos() const {
return CurBlockIndex().ConvertToProfileBufferIndex();
}
private:
// Try to read the entry at the current `mBlockIt` position.
// * If we're at the end of the buffer, just return `true`.
// * If there is a "legacy" entry (containing a real `ProfileBufferEntry`),
// read it into `mEntry`, and return `true` as well.
// * Otherwise the entry contains a "modern" type that cannot be read into
// `mEntry`, return `false` (so `EntryGetter` can skip to another entry).
bool ReadLegacyOrEnd() {
if (!Has()) {
return true;
}
// Read the entry "kind", which is always at the start of all entries.
ProfileBufferEntryReader aER = *mBlockIt;
auto type = static_cast<ProfileBufferEntry::Kind>(
aER.ReadObject<ProfileBufferEntry::KindUnderlyingType>());
MOZ_ASSERT(static_cast<ProfileBufferEntry::KindUnderlyingType>(type) <
static_cast<ProfileBufferEntry::KindUnderlyingType>(
ProfileBufferEntry::Kind::MODERN_LIMIT));
if (type >= ProfileBufferEntry::Kind::LEGACY_LIMIT) {
aER.SetRemainingBytes(0);
return false;
}
// Here, we have a legacy item, we need to read it from the start.
// Because the above `ReadObject` moved the reader, we ned to reset it to
// the start of the entry before reading the whole entry.
aER = *mBlockIt;
aER.ReadBytes(&mEntry, aER.RemainingBytes());
return true;
}
ProfileBufferEntry mEntry;
ProfileChunkedBuffer::BlockIterator mBlockIt;
const ProfileChunkedBuffer::BlockIterator mBlockItEnd;
};
// The following grammar shows legal sequences of profile buffer entries.
// The sequences beginning with a ThreadId entry are known as "samples".
//
// (
// ( /* Samples */
// ThreadId
// Time
// ( NativeLeafAddr
// | Label FrameFlags? DynamicStringFragment* LineNumber? CategoryPair?
// | JitReturnAddr
// )+
// Responsiveness?
// )
// | MarkerData
// | ( /* Counters */
// CounterId
// Time
// (
// CounterKey
// Count
// Number?
// )*
// )
// | CollectionStart
// | CollectionEnd
// | Pause
// | Resume
// | ( ProfilerOverheadTime /* Sampling start timestamp */
// ProfilerOverheadDuration /* Lock acquisition */
// ProfilerOverheadDuration /* Expired data cleaning */
// ProfilerOverheadDuration /* Counters */
// ProfilerOverheadDuration /* Threads */
// )
// )*
//
// The most complicated part is the stack entry sequence that begins with
// Label. Here are some examples.
//
// - ProfilingStack frames without a dynamic string:
//
// Label("js::RunScript")
// CategoryPair(ProfilingCategoryPair::JS)
//
// Label("XREMain::XRE_main")
// LineNumber(4660)
// CategoryPair(ProfilingCategoryPair::OTHER)
//
// Label("ElementRestyler::ComputeStyleChangeFor")
// LineNumber(3003)
// CategoryPair(ProfilingCategoryPair::CSS)
//
// - ProfilingStack frames with a dynamic string:
//
// Label("nsObserverService::NotifyObservers")
// FrameFlags(uint64_t(ProfilingStackFrame::Flags::IS_LABEL_FRAME))
// DynamicStringFragment("domwindo")
// DynamicStringFragment("wopened")
// LineNumber(291)
// CategoryPair(ProfilingCategoryPair::OTHER)
//
// Label("")
// FrameFlags(uint64_t(ProfilingStackFrame::Flags::IS_JS_FRAME))
// DynamicStringFragment("closeWin")
// DynamicStringFragment("dow (chr")
// DynamicStringFragment("obal/con")
// DynamicStringFragment("tent/glo")
// DynamicStringFragment("balOverl")
// DynamicStringFragment("ay.js:5)")
// DynamicStringFragment("") # this string holds the closing '\0'
// LineNumber(25)
// CategoryPair(ProfilingCategoryPair::JS)
//
// Label("")
// FrameFlags(uint64_t(ProfilingStackFrame::Flags::IS_JS_FRAME))
// DynamicStringFragment("bound (s")
// DynamicStringFragment("elf-host")
// DynamicStringFragment("ed:914)")
// LineNumber(945)
// CategoryPair(ProfilingCategoryPair::JS)
//
// - A profiling stack frame with an overly long dynamic string:
//
// Label("")
// FrameFlags(uint64_t(ProfilingStackFrame::Flags::IS_LABEL_FRAME))
// DynamicStringFragment("(too lon")
// DynamicStringFragment("g)")
// LineNumber(100)
// CategoryPair(ProfilingCategoryPair::NETWORK)
//
// - A wasm JIT frame:
//
// Label("")
// FrameFlags(uint64_t(0))
// DynamicStringFragment("wasm-fun")
// DynamicStringFragment("ction[87")
// DynamicStringFragment("36] (blo")
// DynamicStringFragment("b:http:/")
// DynamicStringFragment("/webasse")
// DynamicStringFragment("mbly.org")
// DynamicStringFragment("/3dc5759")
// DynamicStringFragment("4-ce58-4")
// DynamicStringFragment("626-975b")
// DynamicStringFragment("-08ad116")
// DynamicStringFragment("30bc1:38")
// DynamicStringFragment("29856)")
//
// - A JS frame in a synchronous sample:
//
// Label("")
// FrameFlags(uint64_t(ProfilingStackFrame::Flags::IS_LABEL_FRAME))
// DynamicStringFragment("u (https")
// DynamicStringFragment("://perf-")
// DynamicStringFragment("html.io/")
// DynamicStringFragment("ac0da204")
// DynamicStringFragment("aaa44d75")
// DynamicStringFragment("a800.bun")
// DynamicStringFragment("dle.js:2")
// DynamicStringFragment("5)")
// Because this is a format entirely internal to the Profiler, any parsing
// error indicates a bug in the ProfileBuffer writing or the parser itself,
// or possibly flaky hardware.
#define ERROR_AND_CONTINUE(msg) \
{ \
fprintf(stderr, "ProfileBuffer parse error: %s", msg); \
MOZ_ASSERT(false, msg); \
continue; \
}
BaseProfilerThreadId ProfileBuffer::StreamSamplesToJSON(
SpliceableJSONWriter& aWriter, BaseProfilerThreadId aThreadId,
double aSinceTime, UniqueStacks& aUniqueStacks) const {
UniquePtr<char[]> dynStrBuf = MakeUnique<char[]>(kMaxFrameKeyLength);
return mEntries.Read([&](ProfileChunkedBuffer::Reader* aReader) {
MOZ_ASSERT(aReader,
"ProfileChunkedBuffer cannot be out-of-session when sampler is "
"running");
BaseProfilerThreadId processedThreadId;
EntryGetter e(*aReader);
for (;;) {
// This block skips entries until we find the start of the next sample.
// This is useful in three situations.
//
// - The circular buffer overwrites old entries, so when we start parsing
// we might be in the middle of a sample, and we must skip forward to
// the start of the next sample.
//
// - We skip samples that don't have an appropriate ThreadId or Time.
//
// - We skip range Pause, Resume, CollectionStart, Counter and
// CollectionEnd entries between samples.
while (e.Has()) {
if (e.Get().IsThreadId()) {
break;
}
e.Next();
}
if (!e.Has()) {
break;
}
// Due to the skip_to_next_sample block above, if we have an entry here it
// must be a ThreadId entry.
MOZ_ASSERT(e.Get().IsThreadId());
BaseProfilerThreadId threadId = e.Get().GetThreadId();
e.Next();
// Ignore samples that are for the wrong thread.
if (threadId != aThreadId && aThreadId.IsSpecified()) {
continue;
}
MOZ_ASSERT(
aThreadId.IsSpecified() || !processedThreadId.IsSpecified(),
"Unspecified aThreadId should only be used with 1-sample buffer");
ProfileSample sample;
if (e.Has() && e.Get().IsTime()) {
sample.mTime = e.Get().GetDouble();
e.Next();
// Ignore samples that are too old.
if (sample.mTime < aSinceTime) {
continue;
}
} else {
ERROR_AND_CONTINUE("expected a Time entry");
}
UniqueStacks::StackKey stack =
aUniqueStacks.BeginStack(UniqueStacks::FrameKey("(root)"));
int numFrames = 0;
while (e.Has()) {
if (e.Get().IsNativeLeafAddr()) {
numFrames++;
void* pc = e.Get().GetPtr();
e.Next();
static const uint32_t BUF_SIZE = 256;
char buf[BUF_SIZE];
// want to sign extend 32-bit addresses starting with 0xFXXXXXX.
unsigned long long pcULL = (unsigned long long)(uintptr_t)pc;
SprintfLiteral(buf, "0x%llx", pcULL);
// If the "MOZ_PROFILER_SYMBOLICATE" env-var is set, we add a local
// symbolication description to the PC address. This is off by
// default, and mainly intended for local development.
static const bool preSymbolicate = []() {
const char* symbolicate = getenv("MOZ_PROFILER_SYMBOLICATE");
return symbolicate && symbolicate[0] != '\0';
}();
if (preSymbolicate) {
MozCodeAddressDetails details;
if (MozDescribeCodeAddress(pc, &details)) {
// Replace \0 terminator with space.
const uint32_t pcLen = strlen(buf);
buf[pcLen] = ' ';
// Add description after space. Note: Using a frame number of 0,
// as using `numFrames` wouldn't help here, and would prevent
// combining same function calls that happen at different depths.
// TODO: Remove unsightly "#00: " if too annoying. :-)
MozFormatCodeAddressDetails(
buf + pcLen + 1, BUF_SIZE - (pcLen + 1), 0, pc, &details);
}
}
stack = aUniqueStacks.AppendFrame(stack, UniqueStacks::FrameKey(buf));
} else if (e.Get().IsLabel()) {
numFrames++;
const char* label = e.Get().GetString();
e.Next();
using FrameFlags = ProfilingStackFrame::Flags;
uint32_t frameFlags = 0;
if (e.Has() && e.Get().IsFrameFlags()) {
frameFlags = uint32_t(e.Get().GetUint64());
e.Next();
}
bool relevantForJS =
frameFlags & uint32_t(FrameFlags::RELEVANT_FOR_JS);
// Copy potential dynamic string fragments into dynStrBuf, so that
// dynStrBuf will then contain the entire dynamic string.
size_t i = 0;
dynStrBuf[0] = '\0';
while (e.Has()) {
if (e.Get().IsDynamicStringFragment()) {
char chars[ProfileBufferEntry::kNumChars];
e.Get().CopyCharsInto(chars);
for (char c : chars) {
if (i < kMaxFrameKeyLength) {
dynStrBuf[i] = c;
i++;
}
}
e.Next();
} else {
break;
}
}
dynStrBuf[kMaxFrameKeyLength - 1] = '\0';
bool hasDynamicString = (i != 0);
std::string frameLabel;
if (label[0] != '\0' && hasDynamicString) {
if (frameFlags & uint32_t(FrameFlags::STRING_TEMPLATE_METHOD)) {
frameLabel += label;
frameLabel += '.';
frameLabel += dynStrBuf.get();
} else if (frameFlags &
uint32_t(FrameFlags::STRING_TEMPLATE_GETTER)) {
frameLabel += "get ";
frameLabel += label;
frameLabel += '.';
frameLabel += dynStrBuf.get();
} else if (frameFlags &
uint32_t(FrameFlags::STRING_TEMPLATE_SETTER)) {
frameLabel += "set ";
frameLabel += label;
frameLabel += '.';
frameLabel += dynStrBuf.get();
} else {
frameLabel += label;
frameLabel += ' ';
frameLabel += dynStrBuf.get();
}
} else if (hasDynamicString) {
frameLabel += dynStrBuf.get();
} else {
frameLabel += label;
}
uint64_t innerWindowID = 0;
if (e.Has() && e.Get().IsInnerWindowID()) {
innerWindowID = uint64_t(e.Get().GetUint64());
e.Next();
}
Maybe<unsigned> line;
if (e.Has() && e.Get().IsLineNumber()) {
line = Some(unsigned(e.Get().GetInt()));
e.Next();
}
Maybe<unsigned> column;
if (e.Has() && e.Get().IsColumnNumber()) {
column = Some(unsigned(e.Get().GetInt()));
e.Next();
}
Maybe<ProfilingCategoryPair> categoryPair;
if (e.Has() && e.Get().IsCategoryPair()) {
categoryPair =
Some(ProfilingCategoryPair(uint32_t(e.Get().GetInt())));
e.Next();
}
stack = aUniqueStacks.AppendFrame(
stack, UniqueStacks::FrameKey(std::move(frameLabel),
relevantForJS, innerWindowID, line,
column, categoryPair));
} else {
break;
}
}
if (numFrames == 0) {
// It is possible to have empty stacks if native stackwalking is
// Thus, don't use ERROR_AND_CONTINUE, but just continue.
continue;
}
sample.mStack = aUniqueStacks.GetOrAddStackIndex(stack);
if (e.Has() && e.Get().IsResponsiveness()) {
sample.mResponsiveness = Some(e.Get().GetDouble());
e.Next();
}
WriteSample(aWriter, sample);
processedThreadId = threadId;
}
return processedThreadId;
});
}
void ProfileBuffer::StreamMarkersToJSON(SpliceableJSONWriter& aWriter,
BaseProfilerThreadId aThreadId,
const TimeStamp& aProcessStartTime,
double aSinceTime,
UniqueStacks& aUniqueStacks) const {
mEntries.ReadEach([&](ProfileBufferEntryReader& aER) {
auto type = static_cast<ProfileBufferEntry::Kind>(
aER.ReadObject<ProfileBufferEntry::KindUnderlyingType>());
MOZ_ASSERT(static_cast<ProfileBufferEntry::KindUnderlyingType>(type) <
static_cast<ProfileBufferEntry::KindUnderlyingType>(
ProfileBufferEntry::Kind::MODERN_LIMIT));
if (type == ProfileBufferEntry::Kind::Marker) {
::mozilla::base_profiler_markers_detail::DeserializeAfterKindAndStream(
aER,
[&](const BaseProfilerThreadId& aMarkerThreadId) {
return (aMarkerThreadId == aThreadId) ? &aWriter : nullptr;
},
[&](ProfileChunkedBuffer& aChunkedBuffer) {
ProfilerBacktrace backtrace("", &aChunkedBuffer);
backtrace.StreamJSON(aWriter, TimeStamp::ProcessCreation(),
aUniqueStacks);
},
// We don't have Rust markers in the mozglue.
[&](mozilla::base_profiler_markers_detail::Streaming::
DeserializerTag) {
MOZ_ASSERT_UNREACHABLE("No Rust markers in mozglue.");
});
} else {
// The entry was not a marker, we need to skip to the end.
aER.SetRemainingBytes(0);
}
});
}
void ProfileBuffer::StreamProfilerOverheadToJSON(
SpliceableJSONWriter& aWriter, const TimeStamp& aProcessStartTime,
double aSinceTime) const {
mEntries.Read([&](ProfileChunkedBuffer::Reader* aReader) {
MOZ_ASSERT(aReader,
"ProfileChunkedBuffer cannot be out-of-session when sampler is "
"running");
EntryGetter e(*aReader);
enum Schema : uint32_t {
TIME = 0,
LOCKING = 1,
MARKER_CLEANING = 2,
COUNTERS = 3,
THREADS = 4
};
aWriter.StartObjectProperty("profilerOverhead");
aWriter.StartObjectProperty("samples");
// Stream all sampling overhead data. We skip other entries, because we
// process them in StreamSamplesToJSON()/etc.
{
JSONSchemaWriter schema(aWriter);
schema.WriteField("time");
schema.WriteField("locking");
schema.WriteField("expiredMarkerCleaning");
schema.WriteField("counters");
schema.WriteField("threads");
}
aWriter.StartArrayProperty("data");
double firstTime = 0.0;
double lastTime = 0.0;
ProfilerStats intervals, overheads, lockings, cleanings, counters, threads;
while (e.Has()) {
// valid sequence: ProfilerOverheadTime, ProfilerOverheadDuration * 4
if (e.Get().IsProfilerOverheadTime()) {
double time = e.Get().GetDouble();
if (time >= aSinceTime) {
e.Next();
if (!e.Has() || !e.Get().IsProfilerOverheadDuration()) {
ERROR_AND_CONTINUE(
"expected a ProfilerOverheadDuration entry after "
"ProfilerOverheadTime");
}
double locking = e.Get().GetDouble();
e.Next();
if (!e.Has() || !e.Get().IsProfilerOverheadDuration()) {
ERROR_AND_CONTINUE(
"expected a ProfilerOverheadDuration entry after "
"ProfilerOverheadTime,ProfilerOverheadDuration");
}
double cleaning = e.Get().GetDouble();
e.Next();
if (!e.Has() || !e.Get().IsProfilerOverheadDuration()) {
ERROR_AND_CONTINUE(
"expected a ProfilerOverheadDuration entry after "
"ProfilerOverheadTime,ProfilerOverheadDuration*2");
}
double counter = e.Get().GetDouble();
e.Next();
if (!e.Has() || !e.Get().IsProfilerOverheadDuration()) {
ERROR_AND_CONTINUE(
"expected a ProfilerOverheadDuration entry after "
"ProfilerOverheadTime,ProfilerOverheadDuration*3");
}
double thread = e.Get().GetDouble();
if (firstTime == 0.0) {
firstTime = time;
} else {
// Note that we'll have 1 fewer interval than other numbers (because
// we need both ends of an interval to know its duration). The final
// difference should be insignificant over the expected many
// thousands of iterations.
intervals.Count(time - lastTime);
}
lastTime = time;
overheads.Count(locking + cleaning + counter + thread);
lockings.Count(locking);
cleanings.Count(cleaning);
counters.Count(counter);
threads.Count(thread);
AutoArraySchemaWriter writer(aWriter);
writer.TimeMsElement(TIME, time);
writer.DoubleElement(LOCKING, locking);
writer.DoubleElement(MARKER_CLEANING, cleaning);
writer.DoubleElement(COUNTERS, counter);
writer.DoubleElement(THREADS, thread);
}
}
e.Next();
}
aWriter.EndArray(); // data
aWriter.EndObject(); // samples
// Only output statistics if there is at least one full interval (and
// therefore at least two samplings.)
if (intervals.n > 0) {
aWriter.StartObjectProperty("statistics");
aWriter.DoubleProperty("profiledDuration", lastTime - firstTime);
aWriter.IntProperty("samplingCount", overheads.n);
aWriter.DoubleProperty("overheadDurations", overheads.sum);
aWriter.DoubleProperty("overheadPercentage",
overheads.sum / (lastTime - firstTime));
#define PROFILER_STATS(name, var) \
aWriter.DoubleProperty("mean" name, (var).sum / (var).n); \
aWriter.DoubleProperty("min" name, (var).min); \
aWriter.DoubleProperty("max" name, (var).max);
PROFILER_STATS("Interval", intervals);
PROFILER_STATS("Overhead", overheads);
PROFILER_STATS("Lockings", lockings);
PROFILER_STATS("Cleaning", cleanings);
PROFILER_STATS("Counter", counters);
PROFILER_STATS("Thread", threads);
#undef PROFILER_STATS
aWriter.EndObject(); // statistics
}
aWriter.EndObject(); // profilerOverhead
});
}
struct CounterSample {
double mTime;
uint64_t mNumber;
int64_t mCount;
};
using CounterSamples = Vector<CounterSample>;
// HashMap lookup, if not found, a default value is inserted.
// Returns reference to (existing or new) value inside the HashMap.
template <typename HashM, typename Key>
static auto& LookupOrAdd(HashM& aMap, Key&& aKey) {
auto addPtr = aMap.lookupForAdd(aKey);
if (!addPtr) {
MOZ_RELEASE_ASSERT(aMap.add(addPtr, std::forward<Key>(aKey),
typename HashM::Entry::ValueType{}));
MOZ_ASSERT(!!addPtr);
}
return addPtr->value();
}
void ProfileBuffer::StreamCountersToJSON(SpliceableJSONWriter& aWriter,
const TimeStamp& aProcessStartTime,
double aSinceTime) const {
// Because this is a format entirely internal to the Profiler, any parsing
// error indicates a bug in the ProfileBuffer writing or the parser itself,
// or possibly flaky hardware.
mEntries.Read([&](ProfileChunkedBuffer::Reader* aReader) {
MOZ_ASSERT(aReader,
"ProfileChunkedBuffer cannot be out-of-session when sampler is "
"running");
EntryGetter e(*aReader);
enum Schema : uint32_t { TIME = 0, COUNT = 1, NUMBER = 2 };
// Stream all counters. We skip other entries, because we process them in
// StreamSamplesToJSON()/etc.
//
// Valid sequence in the buffer:
// CounterID
// Time
// ( Count Number? )*
//
// And the JSON (example):
// "counters": {
// "name": "malloc",
// "category": "Memory",
// "description": "Amount of allocated memory",
// "samples": {
// "schema": {"time": 0, "count": 1, "number": 2},
// "data": [
// [
// 16117.033968000002,
// 2446216,
// 6801320
// ],
// [
// 16118.037638,
// 2446216,
// 6801320
// ],
// ],
// },
// }
// Build the map of counters and populate it
HashMap<void*, CounterSamples> counters;
while (e.Has()) {
// skip all non-Counters, including if we start in the middle of a counter
if (e.Get().IsCounterId()) {
void* id = e.Get().GetPtr();
CounterSamples& data = LookupOrAdd(counters, id);
e.Next();
if (!e.Has() || !e.Get().IsTime()) {
ERROR_AND_CONTINUE("expected a Time entry");
}
double time = e.Get().GetDouble();
e.Next();
if (time >= aSinceTime) {
if (!e.Has() || !e.Get().IsCount()) {
ERROR_AND_CONTINUE("expected a Count entry");
}
int64_t count = e.Get().GetUint64();
e.Next();
uint64_t number;
if (!e.Has() || !e.Get().IsNumber()) {
number = 0;
} else {
number = e.Get().GetInt64();
e.Next();
}
CounterSample sample = {time, number, count};
MOZ_RELEASE_ASSERT(data.append(sample));
} else {
// skip counter sample - only need to skip the initial counter
// id, then let the loop at the top skip the rest
}
} else {
e.Next();
}
}
// we have a map of counter entries; dump them to JSON
if (counters.count() == 0) {
return;
}
aWriter.StartArrayProperty("counters");
for (auto iter = counters.iter(); !iter.done(); iter.next()) {
CounterSamples& samples = iter.get().value();
size_t size = samples.length();
if (size == 0) {
continue;
}
const BaseProfilerCount* base_counter =
static_cast<const BaseProfilerCount*>(iter.get().key());
aWriter.Start();
aWriter.StringProperty("name", MakeStringSpan(base_counter->mLabel));
aWriter.StringProperty("category",
MakeStringSpan(base_counter->mCategory));
aWriter.StringProperty("description",
MakeStringSpan(base_counter->mDescription));
bool hasNumber = false;
for (size_t i = 0; i < size; i++) {
if (samples[i].mNumber != 0) {
hasNumber = true;
break;
}
}
aWriter.StartObjectProperty("samples");
{
JSONSchemaWriter schema(aWriter);
schema.WriteField("time");
schema.WriteField("count");
if (hasNumber) {
schema.WriteField("number");
}
}
aWriter.StartArrayProperty("data");
uint64_t previousNumber = 0;
int64_t previousCount = 0;
for (size_t i = 0; i < size; i++) {
// Encode as deltas, and only encode if different than the last
// sample
if (i == 0 || samples[i].mNumber != previousNumber ||
samples[i].mCount != previousCount) {
MOZ_ASSERT(i == 0 || samples[i].mTime >= samples[i - 1].mTime);
MOZ_ASSERT(samples[i].mNumber >= previousNumber);
MOZ_ASSERT(samples[i].mNumber - previousNumber <=
uint64_t(std::numeric_limits<int64_t>::max()));
AutoArraySchemaWriter writer(aWriter);
writer.TimeMsElement(TIME, samples[i].mTime);
writer.IntElement(COUNT, samples[i].mCount - previousCount);
if (hasNumber) {
writer.IntElement(NUMBER, static_cast<int64_t>(samples[i].mNumber -
previousNumber));
}
previousNumber = samples[i].mNumber;
previousCount = samples[i].mCount;
}
}
aWriter.EndArray(); // data
aWriter.EndObject(); // samples
aWriter.End(); // for each counter
}
aWriter.EndArray(); // counters
});
}
#undef ERROR_AND_CONTINUE
static void AddPausedRange(SpliceableJSONWriter& aWriter, const char* aReason,
const Maybe<double>& aStartTime,
const Maybe<double>& aEndTime) {
aWriter.Start();
if (aStartTime) {
aWriter.TimeDoubleMsProperty("startTime", *aStartTime);
} else {
aWriter.NullProperty("startTime");
}
if (aEndTime) {
aWriter.TimeDoubleMsProperty("endTime", *aEndTime);
} else {
aWriter.NullProperty("endTime");
}
aWriter.StringProperty("reason", MakeStringSpan(aReason));
aWriter.End();
}
void ProfileBuffer::StreamPausedRangesToJSON(SpliceableJSONWriter& aWriter,
double aSinceTime) const {
mEntries.Read([&](ProfileChunkedBuffer::Reader* aReader) {
MOZ_ASSERT(aReader,
"ProfileChunkedBuffer cannot be out-of-session when sampler is "
"running");
EntryGetter e(*aReader);
Maybe<double> currentPauseStartTime;
Maybe<double> currentCollectionStartTime;
while (e.Has()) {
if (e.Get().IsPause()) {
currentPauseStartTime = Some(e.Get().GetDouble());
} else if (e.Get().IsResume()) {
AddPausedRange(aWriter, "profiler-paused", currentPauseStartTime,
Some(e.Get().GetDouble()));
currentPauseStartTime = Nothing();
} else if (e.Get().IsCollectionStart()) {
currentCollectionStartTime = Some(e.Get().GetDouble());
} else if (e.Get().IsCollectionEnd()) {
AddPausedRange(aWriter, "collecting", currentCollectionStartTime,
Some(e.Get().GetDouble()));
currentCollectionStartTime = Nothing();
}
e.Next();
}
if (currentPauseStartTime) {
AddPausedRange(aWriter, "profiler-paused", currentPauseStartTime,
Nothing());
}
if (currentCollectionStartTime) {
AddPausedRange(aWriter, "collecting", currentCollectionStartTime,
Nothing());
}
});
}
bool ProfileBuffer::DuplicateLastSample(BaseProfilerThreadId aThreadId,
const TimeStamp& aProcessStartTime,
Maybe<uint64_t>& aLastSample) {
if (!aLastSample) {
return false;
}
ProfileChunkedBuffer tempBuffer(
ProfileChunkedBuffer::ThreadSafety::WithoutMutex, WorkerChunkManager());
auto retrieveWorkerChunk = MakeScopeExit(
[&]() { WorkerChunkManager().Reset(tempBuffer.GetAllChunks()); });
const bool ok = mEntries.Read([&](ProfileChunkedBuffer::Reader* aReader) {
MOZ_ASSERT(aReader,
"ProfileChunkedBuffer cannot be out-of-session when sampler is "
"running");
EntryGetter e(*aReader, *aLastSample);
if (e.CurPos() != *aLastSample) {
// The last sample is no longer within the buffer range, so we cannot
// use it. Reset the stored buffer position to Nothing().
aLastSample.reset();
return false;
}
MOZ_RELEASE_ASSERT(e.Has() && e.Get().IsThreadId() &&
e.Get().GetThreadId() == aThreadId);
e.Next();
// Go through the whole entry and duplicate it, until we find the next
// one.
while (e.Has()) {
switch (e.Get().GetKind()) {
case ProfileBufferEntry::Kind::Pause:
case ProfileBufferEntry::Kind::Resume:
case ProfileBufferEntry::Kind::PauseSampling:
case ProfileBufferEntry::Kind::ResumeSampling:
case ProfileBufferEntry::Kind::CollectionStart:
case ProfileBufferEntry::Kind::CollectionEnd:
case ProfileBufferEntry::Kind::ThreadId:
// We're done.
return true;
case ProfileBufferEntry::Kind::Time:
// Copy with new time
AddEntry(
tempBuffer,
ProfileBufferEntry::Time(
(TimeStamp::Now() - aProcessStartTime).ToMilliseconds()));
break;
case ProfileBufferEntry::Kind::Number:
case ProfileBufferEntry::Kind::Count:
case ProfileBufferEntry::Kind::Responsiveness:
// Don't copy anything not part of a thread's stack sample
break;
case ProfileBufferEntry::Kind::CounterId:
// CounterId is normally followed by Time - if so, we'd like
// to skip it. If we duplicate Time, it won't hurt anything, just
// waste buffer space (and this can happen if the CounterId has
// fallen off the end of the buffer, but Time (and Number/Count)
// are still in the buffer).
e.Next();
if (e.Has() && e.Get().GetKind() != ProfileBufferEntry::Kind::Time) {
// this would only happen if there was an invalid sequence
// in the buffer. Don't skip it.
continue;
}
// we've skipped Time
break;
case ProfileBufferEntry::Kind::ProfilerOverheadTime:
// ProfilerOverheadTime is normally followed by
// ProfilerOverheadDuration*4 - if so, we'd like to skip it. Don't
// duplicate, as we are in the middle of a sampling and will soon
// capture its own overhead.
e.Next();
// A missing Time would only happen if there was an invalid
// sequence in the buffer. Don't skip unexpected entry.
if (e.Has() &&
e.Get().GetKind() !=
ProfileBufferEntry::Kind::ProfilerOverheadDuration) {
continue;
}
e.Next();
if (e.Has() &&
e.Get().GetKind() !=
ProfileBufferEntry::Kind::ProfilerOverheadDuration) {
continue;
}
e.Next();
if (e.Has() &&
e.Get().GetKind() !=
ProfileBufferEntry::Kind::ProfilerOverheadDuration) {
continue;
}
e.Next();
if (e.Has() &&
e.Get().GetKind() !=
ProfileBufferEntry::Kind::ProfilerOverheadDuration) {
continue;
}
// we've skipped ProfilerOverheadTime and
// ProfilerOverheadDuration*4.
break;
default: {
// Copy anything else we don't know about.
AddEntry(tempBuffer, e.Get());
break;
}
}
e.Next();
}
return true;
});
if (!ok) {
return false;
}
// If the buffer was big enough, there won't be any cleared blocks.
if (tempBuffer.GetState().mClearedBlockCount != 0) {
// No need to try to read stack again as it won't fit. Reset the stored
// buffer position to Nothing().
aLastSample.reset();
return false;
}
aLastSample = Some(AddThreadIdEntry(aThreadId));
tempBuffer.Read([&](ProfileChunkedBuffer::Reader* aReader) {
MOZ_ASSERT(aReader, "tempBuffer cannot be out-of-session");
EntryGetter e(*aReader);
while (e.Has()) {
AddEntry(e.Get());
e.Next();
}
});
return true;
}
void ProfileBuffer::DiscardSamplesBeforeTime(double aTime) {
// This function does nothing!
Unused << aTime;
}
// END ProfileBuffer
////////////////////////////////////////////////////////////////////////
} // namespace baseprofiler
} // namespace mozilla