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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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "vm/HelperThreads.h"
#include "mozilla/ReverseIterator.h" // mozilla::Reversed(...)
#include "mozilla/ScopeExit.h"
#include "mozilla/Span.h" // mozilla::Span<TaggedScriptThingIndex>
#include "mozilla/Utf8.h" // mozilla::Utf8Unit
#include <algorithm>
#include "frontend/CompilationStencil.h" // frontend::CompilationStencil
#include "gc/GC.h"
#include "jit/Ion.h"
#include "jit/IonCompileTask.h"
#include "jit/JitRuntime.h"
#include "jit/JitScript.h"
#include "js/CompileOptions.h" // JS::PrefableCompileOptions, JS::ReadOnlyCompileOptions
#include "js/experimental/CompileScript.h" // JS::ThreadStackQuotaForSize
#include "js/friend/StackLimits.h" // js::ReportOverRecursed
#include "js/HelperThreadAPI.h"
#include "js/Stack.h"
#include "js/UniquePtr.h"
#include "js/Utility.h"
#include "threading/CpuCount.h"
#include "vm/ErrorReporting.h"
#include "vm/HelperThreadState.h"
#include "vm/InternalThreadPool.h"
#include "vm/MutexIDs.h"
#include "wasm/WasmGenerator.h"
using namespace js;
using mozilla::TimeDuration;
using mozilla::TimeStamp;
using mozilla::Utf8Unit;
using JS::DispatchReason;
namespace js {
Mutex gHelperThreadLock(mutexid::GlobalHelperThreadState);
GlobalHelperThreadState* gHelperThreadState = nullptr;
} // namespace js
bool js::CreateHelperThreadsState() {
MOZ_ASSERT(!gHelperThreadState);
gHelperThreadState = js_new<GlobalHelperThreadState>();
return gHelperThreadState;
}
void js::DestroyHelperThreadsState() {
AutoLockHelperThreadState lock;
if (!gHelperThreadState) {
return;
}
gHelperThreadState->finish(lock);
js_delete(gHelperThreadState);
gHelperThreadState = nullptr;
}
bool js::EnsureHelperThreadsInitialized() {
MOZ_ASSERT(gHelperThreadState);
return gHelperThreadState->ensureInitialized();
}
static size_t ClampDefaultCPUCount(size_t cpuCount) {
// It's extremely rare for SpiderMonkey to have more than a few cores worth
// of work. At higher core counts, performance can even decrease due to NUMA
// (and SpiderMonkey's lack of NUMA-awareness), contention, and general lack
// of optimization for high core counts. So to avoid wasting thread stack
// resources (and cluttering gdb and core dumps), clamp to 8 cores for now.
return std::min<size_t>(cpuCount, 8);
}
static size_t ThreadCountForCPUCount(size_t cpuCount) {
// We need at least two threads for tier-2 wasm compilations, because
// there's a master task that holds a thread while other threads do the
// compilation.
return std::max<size_t>(cpuCount, 2);
}
bool js::SetFakeCPUCount(size_t count) {
HelperThreadState().setCpuCount(count);
return true;
}
void GlobalHelperThreadState::setCpuCount(size_t count) {
// This must be called before any threads have been initialized.
AutoLockHelperThreadState lock;
MOZ_ASSERT(!isInitialized(lock));
// We can't do this if an external thread pool is in use.
MOZ_ASSERT(!dispatchTaskCallback);
cpuCount = count;
threadCount = ThreadCountForCPUCount(count);
}
size_t js::GetHelperThreadCount() { return HelperThreadState().threadCount; }
size_t js::GetHelperThreadCPUCount() { return HelperThreadState().cpuCount; }
size_t js::GetMaxWasmCompilationThreads() {
return HelperThreadState().maxWasmCompilationThreads();
}
void JS::SetProfilingThreadCallbacks(
JS::RegisterThreadCallback registerThread,
JS::UnregisterThreadCallback unregisterThread) {
HelperThreadState().registerThread = registerThread;
HelperThreadState().unregisterThread = unregisterThread;
}
// Bug 1630189: Without MOZ_NEVER_INLINE, Windows PGO builds have a linking
// error for HelperThreadTaskCallback.
JS_PUBLIC_API MOZ_NEVER_INLINE void JS::SetHelperThreadTaskCallback(
HelperThreadTaskCallback callback, size_t threadCount, size_t stackSize) {
AutoLockHelperThreadState lock;
HelperThreadState().setDispatchTaskCallback(callback, threadCount, stackSize,
lock);
}
void GlobalHelperThreadState::setDispatchTaskCallback(
JS::HelperThreadTaskCallback callback, size_t threadCount, size_t stackSize,
const AutoLockHelperThreadState& lock) {
MOZ_ASSERT(!isInitialized(lock));
MOZ_ASSERT(!dispatchTaskCallback);
MOZ_ASSERT(threadCount != 0);
MOZ_ASSERT(stackSize >= 16 * 1024);
dispatchTaskCallback = callback;
this->threadCount = threadCount;
this->stackQuota = JS::ThreadStackQuotaForSize(stackSize);
}
bool js::StartOffThreadWasmCompile(wasm::CompileTask* task,
wasm::CompileMode mode) {
return HelperThreadState().submitTask(task, mode);
}
bool GlobalHelperThreadState::submitTask(wasm::CompileTask* task,
wasm::CompileMode mode) {
AutoLockHelperThreadState lock;
if (!wasmWorklist(lock, mode).pushBack(task)) {
return false;
}
dispatch(DispatchReason::NewTask, lock);
return true;
}
size_t js::RemovePendingWasmCompileTasks(
const wasm::CompileTaskState& taskState, wasm::CompileMode mode,
const AutoLockHelperThreadState& lock) {
wasm::CompileTaskPtrFifo& worklist =
HelperThreadState().wasmWorklist(lock, mode);
return worklist.eraseIf([&taskState](wasm::CompileTask* task) {
return &task->state == &taskState;
});
}
void js::StartOffThreadWasmTier2Generator(wasm::UniqueTier2GeneratorTask task) {
(void)HelperThreadState().submitTask(std::move(task));
}
bool GlobalHelperThreadState::submitTask(wasm::UniqueTier2GeneratorTask task) {
AutoLockHelperThreadState lock;
MOZ_ASSERT(isInitialized(lock));
if (!wasmTier2GeneratorWorklist(lock).append(task.get())) {
return false;
}
(void)task.release();
dispatch(DispatchReason::NewTask, lock);
return true;
}
static void CancelOffThreadWasmTier2GeneratorLocked(
AutoLockHelperThreadState& lock) {
if (!HelperThreadState().isInitialized(lock)) {
return;
}
// Remove pending tasks from the tier2 generator worklist and cancel and
// delete them.
{
wasm::Tier2GeneratorTaskPtrVector& worklist =
HelperThreadState().wasmTier2GeneratorWorklist(lock);
for (size_t i = 0; i < worklist.length(); i++) {
wasm::Tier2GeneratorTask* task = worklist[i];
HelperThreadState().remove(worklist, &i);
js_delete(task);
}
}
// There is at most one running Tier2Generator task and we assume that
// below.
static_assert(GlobalHelperThreadState::MaxTier2GeneratorTasks == 1,
"code must be generalized");
// If there is a running Tier2 generator task, shut it down in a predictable
// way. The task will be deleted by the normal deletion logic.
for (auto* helper : HelperThreadState().helperTasks(lock)) {
if (helper->is<wasm::Tier2GeneratorTask>()) {
// Set a flag that causes compilation to shortcut itself.
helper->as<wasm::Tier2GeneratorTask>()->cancel();
// Wait for the generator task to finish. This avoids a shutdown race
// where the shutdown code is trying to shut down helper threads and the
// ongoing tier2 compilation is trying to finish, which requires it to
// have access to helper threads.
uint32_t oldFinishedCount =
HelperThreadState().wasmTier2GeneratorsFinished(lock);
while (HelperThreadState().wasmTier2GeneratorsFinished(lock) ==
oldFinishedCount) {
HelperThreadState().wait(lock);
}
// At most one of these tasks.
break;
}
}
}
void js::CancelOffThreadWasmTier2Generator() {
AutoLockHelperThreadState lock;
CancelOffThreadWasmTier2GeneratorLocked(lock);
}
bool js::StartOffThreadIonCompile(jit::IonCompileTask* task,
const AutoLockHelperThreadState& lock) {
return HelperThreadState().submitTask(task, lock);
}
bool GlobalHelperThreadState::submitTask(
jit::IonCompileTask* task, const AutoLockHelperThreadState& locked) {
MOZ_ASSERT(isInitialized(locked));
if (!ionWorklist(locked).append(task)) {
return false;
}
// The build is moving off-thread. Freeze the LifoAlloc to prevent any
// unwanted mutations.
task->alloc().lifoAlloc()->setReadOnly();
dispatch(DispatchReason::NewTask, locked);
return true;
}
bool js::AutoStartIonFreeTask::addIonCompileToFreeTaskBatch(
jit::IonCompileTask* task) {
return jitRuntime_->addIonCompileToFreeTaskBatch(task);
}
js::AutoStartIonFreeTask::~AutoStartIonFreeTask() {
jitRuntime_->maybeStartIonFreeTask(force_);
}
void jit::JitRuntime::maybeStartIonFreeTask(bool force) {
IonFreeCompileTasks& tasks = ionFreeTaskBatch_.ref();
if (tasks.empty()) {
return;
}
// Start an IonFreeTask if we have at least eight tasks. If |force| is true we
// always start an IonFreeTask.
if (!force) {
constexpr size_t MinBatchSize = 8;
static_assert(IonFreeCompileTasks::InlineLength >= MinBatchSize,
"Minimum batch size shouldn't require malloc");
if (tasks.length() < MinBatchSize) {
return;
}
}
auto freeTask = js::MakeUnique<jit::IonFreeTask>(std::move(tasks));
if (!freeTask) {
// Free compilation data on the main thread instead.
MOZ_ASSERT(!tasks.empty(), "shouldn't have moved tasks on OOM");
jit::FreeIonCompileTasks(tasks);
tasks.clearAndFree();
return;
}
AutoLockHelperThreadState lock;
if (!HelperThreadState().submitTask(std::move(freeTask), lock)) {
// If submitTask OOMs, then freeTask hasn't been moved so we can still use
// its task list.
jit::FreeIonCompileTasks(freeTask->compileTasks());
}
tasks.clearAndFree();
}
bool GlobalHelperThreadState::submitTask(
UniquePtr<jit::IonFreeTask>&& task,
const AutoLockHelperThreadState& locked) {
MOZ_ASSERT(isInitialized(locked));
if (!ionFreeList(locked).append(std::move(task))) {
return false;
}
dispatch(DispatchReason::NewTask, locked);
return true;
}
/*
* Move an IonCompilationTask for which compilation has either finished, failed,
* or been cancelled into the global finished compilation list. All off thread
* compilations which are started must eventually be finished.
*/
void js::FinishOffThreadIonCompile(jit::IonCompileTask* task,
const AutoLockHelperThreadState& lock) {
AutoEnterOOMUnsafeRegion oomUnsafe;
if (!HelperThreadState().ionFinishedList(lock).append(task)) {
oomUnsafe.crash("FinishOffThreadIonCompile");
}
task->script()
->runtimeFromAnyThread()
->jitRuntime()
->numFinishedOffThreadTasksRef(lock)++;
}
static JSRuntime* GetSelectorRuntime(const CompilationSelector& selector) {
struct Matcher {
JSRuntime* operator()(JSScript* script) {
return script->runtimeFromMainThread();
}
JSRuntime* operator()(Zone* zone) { return zone->runtimeFromMainThread(); }
JSRuntime* operator()(ZonesInState zbs) { return zbs.runtime; }
JSRuntime* operator()(JSRuntime* runtime) { return runtime; }
};
return selector.match(Matcher());
}
static bool JitDataStructuresExist(const CompilationSelector& selector) {
struct Matcher {
bool operator()(JSScript* script) { return !!script->zone()->jitZone(); }
bool operator()(Zone* zone) { return !!zone->jitZone(); }
bool operator()(ZonesInState zbs) { return zbs.runtime->hasJitRuntime(); }
bool operator()(JSRuntime* runtime) { return runtime->hasJitRuntime(); }
};
return selector.match(Matcher());
}
static bool IonCompileTaskMatches(const CompilationSelector& selector,
jit::IonCompileTask* task) {
struct TaskMatches {
jit::IonCompileTask* task_;
bool operator()(JSScript* script) { return script == task_->script(); }
bool operator()(Zone* zone) {
return zone == task_->script()->zoneFromAnyThread();
}
bool operator()(JSRuntime* runtime) {
return runtime == task_->script()->runtimeFromAnyThread();
}
bool operator()(ZonesInState zbs) {
return zbs.runtime == task_->script()->runtimeFromAnyThread() &&
zbs.state == task_->script()->zoneFromAnyThread()->gcState();
}
};
return selector.match(TaskMatches{task});
}
// If we're canceling Ion compilations for a zone/runtime, force a new
// IonFreeTask even if there are just a few tasks. This lets us free as much
// memory as possible.
static bool ShouldForceIonFreeTask(const CompilationSelector& selector) {
struct Matcher {
bool operator()(JSScript* script) { return false; }
bool operator()(Zone* zone) { return true; }
bool operator()(ZonesInState zbs) { return true; }
bool operator()(JSRuntime* runtime) { return true; }
};
return selector.match(Matcher());
}
void js::CancelOffThreadIonCompile(const CompilationSelector& selector) {
if (!JitDataStructuresExist(selector)) {
return;
}
if (jit::IsPortableBaselineInterpreterEnabled()) {
return;
}
jit::JitRuntime* jitRuntime = GetSelectorRuntime(selector)->jitRuntime();
MOZ_ASSERT(jitRuntime);
AutoStartIonFreeTask freeTask(jitRuntime, ShouldForceIonFreeTask(selector));
{
AutoLockHelperThreadState lock;
if (!HelperThreadState().isInitialized(lock)) {
return;
}
/* Cancel any pending entries for which processing hasn't started. */
GlobalHelperThreadState::IonCompileTaskVector& worklist =
HelperThreadState().ionWorklist(lock);
for (size_t i = 0; i < worklist.length(); i++) {
jit::IonCompileTask* task = worklist[i];
if (IonCompileTaskMatches(selector, task)) {
// Once finished, tasks are added to a Linked list which is
// allocated with the IonCompileTask class. The IonCompileTask is
// allocated in the LifoAlloc so we need the LifoAlloc to be mutable.
worklist[i]->alloc().lifoAlloc()->setReadWrite();
FinishOffThreadIonCompile(task, lock);
HelperThreadState().remove(worklist, &i);
}
}
/* Wait for in progress entries to finish up. */
bool cancelled;
do {
cancelled = false;
for (auto* helper : HelperThreadState().helperTasks(lock)) {
if (!helper->is<jit::IonCompileTask>()) {
continue;
}
jit::IonCompileTask* ionCompileTask = helper->as<jit::IonCompileTask>();
if (IonCompileTaskMatches(selector, ionCompileTask)) {
ionCompileTask->mirGen().cancel();
cancelled = true;
}
}
if (cancelled) {
HelperThreadState().wait(lock);
}
} while (cancelled);
/* Cancel code generation for any completed entries. */
GlobalHelperThreadState::IonCompileTaskVector& finished =
HelperThreadState().ionFinishedList(lock);
for (size_t i = 0; i < finished.length(); i++) {
jit::IonCompileTask* task = finished[i];
if (IonCompileTaskMatches(selector, task)) {
JSRuntime* rt = task->script()->runtimeFromAnyThread();
rt->jitRuntime()->numFinishedOffThreadTasksRef(lock)--;
jit::FinishOffThreadTask(rt, freeTask, task);
HelperThreadState().remove(finished, &i);
}
}
}
/* Cancel lazy linking for pending tasks (attached to the ionScript). */
JSRuntime* runtime = GetSelectorRuntime(selector);
jit::IonCompileTask* task =
runtime->jitRuntime()->ionLazyLinkList(runtime).getFirst();
while (task) {
jit::IonCompileTask* next = task->getNext();
if (IonCompileTaskMatches(selector, task)) {
jit::FinishOffThreadTask(runtime, freeTask, task);
}
task = next;
}
}
#ifdef DEBUG
bool js::HasOffThreadIonCompile(Zone* zone) {
if (jit::IsPortableBaselineInterpreterEnabled()) {
return false;
}
AutoLockHelperThreadState lock;
if (!HelperThreadState().isInitialized(lock)) {
return false;
}
GlobalHelperThreadState::IonCompileTaskVector& worklist =
HelperThreadState().ionWorklist(lock);
for (size_t i = 0; i < worklist.length(); i++) {
jit::IonCompileTask* task = worklist[i];
if (task->script()->zoneFromAnyThread() == zone) {
return true;
}
}
for (auto* helper : HelperThreadState().helperTasks(lock)) {
if (!helper->is<jit::IonCompileTask>()) {
continue;
}
JSScript* script = helper->as<jit::IonCompileTask>()->script();
if (script->zoneFromAnyThread() == zone) {
return true;
}
}
GlobalHelperThreadState::IonCompileTaskVector& finished =
HelperThreadState().ionFinishedList(lock);
for (size_t i = 0; i < finished.length(); i++) {
jit::IonCompileTask* task = finished[i];
if (task->script()->zoneFromAnyThread() == zone) {
return true;
}
}
JSRuntime* rt = zone->runtimeFromMainThread();
if (rt->hasJitRuntime()) {
jit::IonCompileTask* task =
rt->jitRuntime()->ionLazyLinkList(rt).getFirst();
while (task) {
if (task->script()->zone() == zone) {
return true;
}
task = task->getNext();
}
}
return false;
}
#endif
void js::StartOffThreadDelazification(
JSContext* maybeCx, const JS::ReadOnlyCompileOptions& options,
const frontend::CompilationStencil& stencil) {
// Skip delazify tasks if we parse everything on-demand or ahead.
auto strategy = options.eagerDelazificationStrategy();
if (strategy == JS::DelazificationOption::OnDemandOnly ||
strategy == JS::DelazificationOption::ParseEverythingEagerly) {
return;
}
// Skip delazify task if code coverage is enabled.
if (maybeCx && maybeCx->realm()->collectCoverageForDebug()) {
return;
}
if (!CanUseExtraThreads()) {
return;
}
JSRuntime* maybeRuntime = maybeCx ? maybeCx->runtime() : nullptr;
UniquePtr<DelazifyTask> task;
task = DelazifyTask::Create(maybeRuntime, options, stencil);
if (!task) {
return;
}
// Schedule delazification task if there is any function to delazify.
if (!task->done()) {
AutoLockHelperThreadState lock;
HelperThreadState().submitTask(task.release(), lock);
}
}
UniquePtr<DelazifyTask> DelazifyTask::Create(
JSRuntime* maybeRuntime, const JS::ReadOnlyCompileOptions& options,
const frontend::CompilationStencil& stencil) {
UniquePtr<DelazifyTask> task;
task.reset(js_new<DelazifyTask>(maybeRuntime, options.prefableOptions()));
if (!task) {
return nullptr;
}
if (!task->init(options, stencil)) {
// In case of errors, skip this and delazify on-demand.
return nullptr;
}
return task;
}
DelazifyTask::DelazifyTask(
JSRuntime* maybeRuntime,
const JS::PrefableCompileOptions& initialPrefableOptions)
: maybeRuntime(maybeRuntime),
delazificationCx(initialPrefableOptions, HelperThreadState().stackQuota) {
}
DelazifyTask::~DelazifyTask() {
// The LinkedListElement destructor will remove us from any list we are part
// of without synchronization, so ensure that doesn't happen.
MOZ_DIAGNOSTIC_ASSERT(!isInList());
}
bool DelazifyTask::init(const JS::ReadOnlyCompileOptions& options,
const frontend::CompilationStencil& stencil) {
return delazificationCx.init(options, stencil);
}
size_t DelazifyTask::sizeOfExcludingThis(
mozilla::MallocSizeOf mallocSizeOf) const {
return delazificationCx.sizeOfExcludingThis(mallocSizeOf);
}
void DelazifyTask::runHelperThreadTask(AutoLockHelperThreadState& lock) {
{
AutoUnlockHelperThreadState unlock(lock);
// NOTE: We do not report errors beyond this scope, as there is no where
// to report these errors to. In the mean time, prevent the eager
// delazification from running after any kind of errors.
(void)runTask();
}
// If we should continue to delazify even more functions, then re-add this
// task to the vector of delazification tasks. This might happen when the
// DelazifyTask is interrupted by a higher priority task. (see
// mozilla::TaskController & mozilla::Task)
if (!delazificationCx.done()) {
HelperThreadState().submitTask(this, lock);
} else {
UniquePtr<FreeDelazifyTask> freeTask(js_new<FreeDelazifyTask>(this));
if (freeTask) {
HelperThreadState().submitTask(std::move(freeTask), lock);
}
}
}
bool DelazifyTask::runTask() { return delazificationCx.delazify(); }
bool DelazifyTask::done() const { return delazificationCx.done(); }
void FreeDelazifyTask::runHelperThreadTask(AutoLockHelperThreadState& locked) {
{
AutoUnlockHelperThreadState unlock(locked);
js_delete(task);
task = nullptr;
}
js_delete(this);
}
static void CancelPendingDelazifyTask(JSRuntime* rt,
AutoLockHelperThreadState& lock) {
auto& delazifyList = HelperThreadState().delazifyWorklist(lock);
auto end = delazifyList.end();
for (auto iter = delazifyList.begin(); iter != end;) {
DelazifyTask* task = *iter;
++iter;
if (task->runtimeMatchesOrNoRuntime(rt)) {
task->removeFrom(delazifyList);
js_delete(task);
}
}
}
static void WaitUntilCancelledDelazifyTasks(JSRuntime* rt,
AutoLockHelperThreadState& lock) {
if (!HelperThreadState().isInitialized(lock)) {
return;
}
while (true) {
CancelPendingDelazifyTask(rt, lock);
// If running tasks are delazifying any functions, then we have to wait
// until they complete to remove them from the pending list. DelazifyTask
// are inserting themself back to be processed once more after delazifying a
// function.
bool inProgress = false;
for (auto* helper : HelperThreadState().helperTasks(lock)) {
if (helper->is<DelazifyTask>() &&
helper->as<DelazifyTask>()->runtimeMatchesOrNoRuntime(rt)) {
inProgress = true;
break;
}
}
if (!inProgress) {
break;
}
HelperThreadState().wait(lock);
}
#ifdef DEBUG
for (DelazifyTask* task : HelperThreadState().delazifyWorklist(lock)) {
MOZ_ASSERT(!task->runtimeMatchesOrNoRuntime(rt));
}
for (auto* helper : HelperThreadState().helperTasks(lock)) {
MOZ_ASSERT_IF(helper->is<DelazifyTask>(),
!helper->as<DelazifyTask>()->runtimeMatchesOrNoRuntime(rt));
}
#endif
}
static void WaitUntilEmptyFreeDelazifyTaskVector(
AutoLockHelperThreadState& lock) {
if (!HelperThreadState().isInitialized(lock)) {
return;
}
while (true) {
bool inProgress = false;
auto& freeList = HelperThreadState().freeDelazifyTaskVector(lock);
if (!freeList.empty()) {
inProgress = true;
}
// If running tasks are delazifying any functions, then we have to wait
// until they complete to remove them from the pending list. DelazifyTask
// are inserting themself back to be processed once more after delazifying a
// function.
for (auto* helper : HelperThreadState().helperTasks(lock)) {
if (helper->is<FreeDelazifyTask>()) {
inProgress = true;
break;
}
}
if (!inProgress) {
break;
}
HelperThreadState().wait(lock);
}
}
void js::CancelOffThreadDelazify(JSRuntime* runtime) {
AutoLockHelperThreadState lock;
// Cancel all Delazify tasks from the given runtime, and wait if tasks are
// from the given runtime are being executed.
WaitUntilCancelledDelazifyTasks(runtime, lock);
// Empty the free list of delazify task, in case one of the delazify task
// ended and therefore did not returned to the pending list of delazify tasks.
WaitUntilEmptyFreeDelazifyTaskVector(lock);
}
static bool HasAnyDelazifyTask(JSRuntime* rt, AutoLockHelperThreadState& lock) {
auto& delazifyList = HelperThreadState().delazifyWorklist(lock);
for (auto task : delazifyList) {
if (task->runtimeMatchesOrNoRuntime(rt)) {
return true;
}
}
for (auto* helper : HelperThreadState().helperTasks(lock)) {
if (helper->is<DelazifyTask>() &&
helper->as<DelazifyTask>()->runtimeMatchesOrNoRuntime(rt)) {
return true;
}
}
return false;
}
void js::WaitForAllDelazifyTasks(JSRuntime* rt) {
AutoLockHelperThreadState lock;
if (!HelperThreadState().isInitialized(lock)) {
return;
}
while (true) {
if (!HasAnyDelazifyTask(rt, lock)) {
break;
}
HelperThreadState().wait(lock);
}
}
void GlobalHelperThreadState::submitTask(
DelazifyTask* task, const AutoLockHelperThreadState& locked) {
delazifyWorklist(locked).insertBack(task);
dispatch(DispatchReason::NewTask, locked);
}
bool GlobalHelperThreadState::submitTask(
UniquePtr<FreeDelazifyTask> task, const AutoLockHelperThreadState& locked) {
if (!freeDelazifyTaskVector(locked).append(std::move(task))) {
return false;
}
dispatch(DispatchReason::NewTask, locked);
return true;
}
bool GlobalHelperThreadState::ensureInitialized() {
MOZ_ASSERT(CanUseExtraThreads());
MOZ_ASSERT(this == &HelperThreadState());
AutoLockHelperThreadState lock;
if (isInitialized(lock)) {
return true;
}
for (size_t& i : runningTaskCount) {
i = 0;
}
useInternalThreadPool_ = !dispatchTaskCallback;
if (useInternalThreadPool(lock)) {
if (!InternalThreadPool::Initialize(threadCount, lock)) {
return false;
}
}
MOZ_ASSERT(dispatchTaskCallback);
if (!ensureThreadCount(threadCount, lock)) {
finishThreads(lock);
return false;
}
MOZ_ASSERT(threadCount != 0);
isInitialized_ = true;
return true;
}
bool GlobalHelperThreadState::ensureThreadCount(
size_t count, AutoLockHelperThreadState& lock) {
if (!helperTasks_.reserve(count)) {
return false;
}
if (useInternalThreadPool(lock)) {
InternalThreadPool& pool = InternalThreadPool::Get();
if (pool.threadCount(lock) < count) {
if (!pool.ensureThreadCount(count, lock)) {
return false;
}
threadCount = pool.threadCount(lock);
}
}
return true;
}
GlobalHelperThreadState::GlobalHelperThreadState()
: cpuCount(0),
threadCount(0),
totalCountRunningTasks(0),
registerThread(nullptr),
unregisterThread(nullptr),
wasmTier2GeneratorsFinished_(0) {
MOZ_ASSERT(!gHelperThreadState);
cpuCount = ClampDefaultCPUCount(GetCPUCount());
threadCount = ThreadCountForCPUCount(cpuCount);
MOZ_ASSERT(cpuCount > 0, "GetCPUCount() seems broken");
}
void GlobalHelperThreadState::finish(AutoLockHelperThreadState& lock) {
if (!isInitialized(lock)) {
return;
}
MOZ_ASSERT_IF(!JSRuntime::hasLiveRuntimes(), gcParallelMarkingThreads == 0);
finishThreads(lock);
// Make sure there are no Ion free tasks left. We check this here because,
// unlike the other tasks, we don't explicitly block on this when
// destroying a runtime.
auto& freeList = ionFreeList(lock);
while (!freeList.empty()) {
UniquePtr<jit::IonFreeTask> task = std::move(freeList.back());
freeList.popBack();
jit::FreeIonCompileTasks(task->compileTasks());
}
}
void GlobalHelperThreadState::finishThreads(AutoLockHelperThreadState& lock) {
waitForAllTasksLocked(lock);
terminating_ = true;
if (InternalThreadPool::IsInitialized()) {
InternalThreadPool::ShutDown(lock);
}
}
#ifdef DEBUG
void GlobalHelperThreadState::assertIsLockedByCurrentThread() const {
gHelperThreadLock.assertOwnedByCurrentThread();
}
#endif // DEBUG
void GlobalHelperThreadState::dispatch(
DispatchReason reason, const AutoLockHelperThreadState& locked) {
if (canStartTasks(locked) && tasksPending_ < threadCount) {
// This doesn't guarantee that we don't dispatch more tasks to the external
// pool than necessary if tasks are taking a long time to start, but it does
// limit the number.
tasksPending_++;
// The hazard analysis can't tell that the callback doesn't GC.
JS::AutoSuppressGCAnalysis nogc;
dispatchTaskCallback(reason);
}
}
void GlobalHelperThreadState::wait(
AutoLockHelperThreadState& locked,
TimeDuration timeout /* = TimeDuration::Forever() */) {
consumerWakeup.wait_for(locked, timeout);
}
void GlobalHelperThreadState::notifyAll(const AutoLockHelperThreadState&) {
consumerWakeup.notify_all();
}
void GlobalHelperThreadState::notifyOne(const AutoLockHelperThreadState&) {
consumerWakeup.notify_one();
}
bool GlobalHelperThreadState::hasActiveThreads(
const AutoLockHelperThreadState& lock) {
return !helperTasks(lock).empty();
}
void js::WaitForAllHelperThreads() { HelperThreadState().waitForAllTasks(); }
void js::WaitForAllHelperThreads(AutoLockHelperThreadState& lock) {
HelperThreadState().waitForAllTasksLocked(lock);
}
void GlobalHelperThreadState::waitForAllTasks() {
AutoLockHelperThreadState lock;
waitForAllTasksLocked(lock);
}
void GlobalHelperThreadState::waitForAllTasksLocked(
AutoLockHelperThreadState& lock) {
CancelOffThreadWasmTier2GeneratorLocked(lock);
while (canStartTasks(lock) || tasksPending_ || hasActiveThreads(lock)) {
wait(lock);
}
MOZ_ASSERT(gcParallelWorklist().isEmpty(lock));
MOZ_ASSERT(ionWorklist(lock).empty());
MOZ_ASSERT(wasmWorklist(lock, wasm::CompileMode::Tier1).empty());
MOZ_ASSERT(promiseHelperTasks(lock).empty());
MOZ_ASSERT(compressionWorklist(lock).empty());
MOZ_ASSERT(ionFreeList(lock).empty());
MOZ_ASSERT(wasmWorklist(lock, wasm::CompileMode::Tier2).empty());
MOZ_ASSERT(wasmTier2GeneratorWorklist(lock).empty());
MOZ_ASSERT(!tasksPending_);
MOZ_ASSERT(!hasActiveThreads(lock));
}
// A task can be a "master" task, ie, it will block waiting for other worker
// threads that perform work on its behalf. If so it must not take the last
// available thread; there must always be at least one worker thread able to do
// the actual work. (Or the system may deadlock.)
//
// If a task is a master task it *must* pass isMaster=true here, or perform a
// similar calculation to avoid deadlock from starvation.
//
// isMaster should only be true if the thread calling checkTaskThreadLimit() is
// a helper thread.
//
// NOTE: Calling checkTaskThreadLimit() from a helper thread in the dynamic
// region after currentTask.emplace() and before currentTask.reset() may cause
// it to return a different result than if it is called outside that dynamic
// region, as the predicate inspects the values of the threads' currentTask
// members.
bool GlobalHelperThreadState::checkTaskThreadLimit(
ThreadType threadType, size_t maxThreads, bool isMaster,
const AutoLockHelperThreadState& lock) const {
MOZ_ASSERT(maxThreads > 0);
if (!isMaster && maxThreads >= threadCount) {
return true;
}
size_t count = runningTaskCount[threadType];
if (count >= maxThreads) {
return false;
}
MOZ_ASSERT(threadCount >= totalCountRunningTasks);
size_t idle = threadCount - totalCountRunningTasks;
// It is possible for the number of idle threads to be zero here, because
// checkTaskThreadLimit() can be called from non-helper threads. Notably,
// the compression task scheduler invokes it, and runs off a helper thread.
if (idle == 0) {
return false;
}
// A master thread that's the last available thread must not be allowed to
// run.
if (isMaster && idle == 1) {
return false;
}
return true;
}
static inline bool IsHelperThreadSimulatingOOM(js::ThreadType threadType) {
#if defined(DEBUG) || defined(JS_OOM_BREAKPOINT)
return js::oom::simulator.targetThread() == threadType;
#else
return false;
#endif
}
void GlobalHelperThreadState::addSizeOfIncludingThis(
JS::GlobalStats* stats, const AutoLockHelperThreadState& lock) const {
#ifdef DEBUG
assertIsLockedByCurrentThread();
#endif
mozilla::MallocSizeOf mallocSizeOf = stats->mallocSizeOf_;
JS::HelperThreadStats& htStats = stats->helperThread;
htStats.stateData += mallocSizeOf(this);
if (InternalThreadPool::IsInitialized()) {
htStats.stateData +=
InternalThreadPool::Get().sizeOfIncludingThis(mallocSizeOf, lock);
}
// Report memory used by various containers
htStats.stateData +=
ionWorklist_.sizeOfExcludingThis(mallocSizeOf) +
ionFinishedList_.sizeOfExcludingThis(mallocSizeOf) +
ionFreeList_.sizeOfExcludingThis(mallocSizeOf) +
wasmWorklist_tier1_.sizeOfExcludingThis(mallocSizeOf) +
wasmWorklist_tier2_.sizeOfExcludingThis(mallocSizeOf) +
wasmTier2GeneratorWorklist_.sizeOfExcludingThis(mallocSizeOf) +
promiseHelperTasks_.sizeOfExcludingThis(mallocSizeOf) +
compressionPendingList_.sizeOfExcludingThis(mallocSizeOf) +
compressionWorklist_.sizeOfExcludingThis(mallocSizeOf) +
compressionFinishedList_.sizeOfExcludingThis(mallocSizeOf) +
gcParallelWorklist_.sizeOfExcludingThis(mallocSizeOf, lock) +
helperTasks_.sizeOfExcludingThis(mallocSizeOf);
// Report IonCompileTasks on wait lists
for (auto task : ionWorklist_) {
htStats.ionCompileTask += task->sizeOfExcludingThis(mallocSizeOf);
}
for (auto task : ionFinishedList_) {
htStats.ionCompileTask += task->sizeOfExcludingThis(mallocSizeOf);
}
for (const auto& task : ionFreeList_) {
for (auto* compileTask : task->compileTasks()) {
htStats.ionCompileTask += compileTask->sizeOfExcludingThis(mallocSizeOf);
}
}
// Report wasm::CompileTasks on wait lists
for (auto task : wasmWorklist_tier1_) {
htStats.wasmCompile += task->sizeOfExcludingThis(mallocSizeOf);
}
for (auto task : wasmWorklist_tier2_) {
htStats.wasmCompile += task->sizeOfExcludingThis(mallocSizeOf);
}
// Report number of helper threads.
MOZ_ASSERT(htStats.idleThreadCount == 0);
MOZ_ASSERT(threadCount >= totalCountRunningTasks);
htStats.activeThreadCount = totalCountRunningTasks;
htStats.idleThreadCount = threadCount - totalCountRunningTasks;
}
size_t GlobalHelperThreadState::maxIonCompilationThreads() const {
if (IsHelperThreadSimulatingOOM(js::THREAD_TYPE_ION)) {
return 1;
}
return threadCount;
}
size_t GlobalHelperThreadState::maxIonFreeThreads() const {
// IonFree tasks are low priority. Limit to one thread to help avoid jemalloc
// lock contention.
return 1;
}
size_t GlobalHelperThreadState::maxWasmCompilationThreads() const {
if (IsHelperThreadSimulatingOOM(js::THREAD_TYPE_WASM_COMPILE_TIER1) ||
IsHelperThreadSimulatingOOM(js::THREAD_TYPE_WASM_COMPILE_TIER2)) {
return 1;
}
return std::min(cpuCount, threadCount);
}
size_t GlobalHelperThreadState::maxWasmTier2GeneratorThreads() const {
return MaxTier2GeneratorTasks;
}
size_t GlobalHelperThreadState::maxPromiseHelperThreads() const {
if (IsHelperThreadSimulatingOOM(js::THREAD_TYPE_PROMISE_TASK)) {
return 1;
}
return std::min(cpuCount, threadCount);
}
size_t GlobalHelperThreadState::maxDelazifyThreads() const {
if (IsHelperThreadSimulatingOOM(js::THREAD_TYPE_DELAZIFY)) {
return 1;
}
return std::min(cpuCount, threadCount);
}
size_t GlobalHelperThreadState::maxCompressionThreads() const {
if (IsHelperThreadSimulatingOOM(js::THREAD_TYPE_COMPRESS)) {
return 1;
}
// Compression is triggered on major GCs to compress ScriptSources. It is
// considered low priority work.
return 1;
}
size_t GlobalHelperThreadState::maxGCParallelThreads() const {
if (IsHelperThreadSimulatingOOM(js::THREAD_TYPE_GCPARALLEL)) {
return 1;
}
return threadCount;
}
HelperThreadTask* GlobalHelperThreadState::maybeGetWasmTier1CompileTask(
const AutoLockHelperThreadState& lock) {
return maybeGetWasmCompile(lock, wasm::CompileMode::Tier1);
}
HelperThreadTask* GlobalHelperThreadState::maybeGetWasmTier2CompileTask(
const AutoLockHelperThreadState& lock) {
return maybeGetWasmCompile(lock, wasm::CompileMode::Tier2);
}
HelperThreadTask* GlobalHelperThreadState::maybeGetWasmCompile(
const AutoLockHelperThreadState& lock, wasm::CompileMode mode) {
if (!canStartWasmCompile(lock, mode)) {
return nullptr;
}
return wasmWorklist(lock, mode).popCopyFront();
}
bool GlobalHelperThreadState::canStartWasmTier1CompileTask(
const AutoLockHelperThreadState& lock) {
return canStartWasmCompile(lock, wasm::CompileMode::Tier1);
}
bool GlobalHelperThreadState::canStartWasmTier2CompileTask(
const AutoLockHelperThreadState& lock) {
return canStartWasmCompile(lock, wasm::CompileMode::Tier2);
}
bool GlobalHelperThreadState::canStartWasmCompile(
const AutoLockHelperThreadState& lock, wasm::CompileMode mode) {
if (wasmWorklist(lock, mode).empty()) {
return false;
}
// Parallel compilation and background compilation should be disabled on
// unicore systems.
MOZ_RELEASE_ASSERT(cpuCount > 1);
// If Tier2 is very backlogged we must give priority to it, since the Tier2
// queue holds onto Tier1 tasks. Indeed if Tier2 is backlogged we will
// devote more resources to Tier2 and not start any Tier1 work at all.
bool tier2oversubscribed = wasmTier2GeneratorWorklist(lock).length() > 20;
// For Tier1 and Once compilation, honor the maximum allowed threads to
// compile wasm jobs at once, to avoid oversaturating the machine.
//
// For Tier2 compilation we need to allow other things to happen too, so we
// do not allow all logical cores to be used for background work; instead we
// wish to use a fraction of the physical cores. We can't directly compute
// the physical cores from the logical cores, but 1/3 of the logical cores
// is a safe estimate for the number of physical cores available for
// background work.
size_t physCoresAvailable = size_t(ceil(cpuCount / 3.0));
size_t threads;
ThreadType threadType;
if (mode == wasm::CompileMode::Tier2) {
if (tier2oversubscribed) {
threads = maxWasmCompilationThreads();
} else {
threads = physCoresAvailable;
}
threadType = THREAD_TYPE_WASM_COMPILE_TIER2;
} else {
if (tier2oversubscribed) {
threads = 0;
} else {
threads = maxWasmCompilationThreads();
}
threadType = THREAD_TYPE_WASM_COMPILE_TIER1;
}
return threads != 0 && checkTaskThreadLimit(threadType, threads, lock);
}
HelperThreadTask* GlobalHelperThreadState::maybeGetWasmTier2GeneratorTask(
const AutoLockHelperThreadState& lock) {
if (!canStartWasmTier2GeneratorTask(lock)) {
return nullptr;
}
return wasmTier2GeneratorWorklist(lock).popCopy();
}
bool GlobalHelperThreadState::canStartWasmTier2GeneratorTask(
const AutoLockHelperThreadState& lock) {
return !wasmTier2GeneratorWorklist(lock).empty() &&
checkTaskThreadLimit(THREAD_TYPE_WASM_GENERATOR_TIER2,
maxWasmTier2GeneratorThreads(),
/*isMaster=*/true, lock);
}
HelperThreadTask* GlobalHelperThreadState::maybeGetPromiseHelperTask(
const AutoLockHelperThreadState& lock) {
if (!canStartPromiseHelperTask(lock)) {
return nullptr;
}
return promiseHelperTasks(lock).popCopy();
}
bool GlobalHelperThreadState::canStartPromiseHelperTask(
const AutoLockHelperThreadState& lock) {
// PromiseHelperTasks can be wasm compilation tasks that in turn block on
// wasm compilation so set isMaster = true.
return !promiseHelperTasks(lock).empty() &&
checkTaskThreadLimit(THREAD_TYPE_PROMISE_TASK,
maxPromiseHelperThreads(),
/*isMaster=*/true, lock);
}
static bool IonCompileTaskHasHigherPriority(jit::IonCompileTask* first,
jit::IonCompileTask* second) {
// Return true if priority(first) > priority(second).
//
// This method can return whatever it wants, though it really ought to be a
// total order. The ordering is allowed to race (change on the fly), however.
// A higher warm-up counter indicates a higher priority.
jit::JitScript* firstJitScript = first->script()->jitScript();
jit::JitScript* secondJitScript = second->script()->jitScript();
return firstJitScript->warmUpCount() / first->script()->length() >
secondJitScript->warmUpCount() / second->script()->length();
}
HelperThreadTask* GlobalHelperThreadState::maybeGetIonCompileTask(
const AutoLockHelperThreadState& lock) {
if (!canStartIonCompileTask(lock)) {
return nullptr;
}
return highestPriorityPendingIonCompile(lock,
/* checkExecutionStatus */ true);
}
HelperThreadTask* GlobalHelperThreadState::maybeGetLowPrioIonCompileTask(
const AutoLockHelperThreadState& lock) {
if (!canStartIonCompileTask(lock)) {
return nullptr;
}
return highestPriorityPendingIonCompile(lock,
/* checkExecutionStatus */ false);
}
bool GlobalHelperThreadState::canStartIonCompileTask(
const AutoLockHelperThreadState& lock) {
return !ionWorklist(lock).empty() &&
checkTaskThreadLimit(THREAD_TYPE_ION, maxIonCompilationThreads(),
lock);
}
HelperThreadTask* GlobalHelperThreadState::maybeGetIonFreeTask(
const AutoLockHelperThreadState& lock) {
if (!canStartIonFreeTask(lock)) {
return nullptr;
}
UniquePtr<jit::IonFreeTask> task = std::move(ionFreeList(lock).back());
ionFreeList(lock).popBack();
return task.release();
}
bool GlobalHelperThreadState::canStartIonFreeTask(
const AutoLockHelperThreadState& lock) {
return !ionFreeList(lock).empty() &&
checkTaskThreadLimit(THREAD_TYPE_ION_FREE, maxIonFreeThreads(), lock);
}
jit::IonCompileTask* GlobalHelperThreadState::highestPriorityPendingIonCompile(
const AutoLockHelperThreadState& lock, bool checkExecutionStatus) {
auto& worklist = ionWorklist(lock);
MOZ_ASSERT(!worklist.empty());
// Get the highest priority IonCompileTask which has not started compilation
// yet.
size_t index = worklist.length();
for (size_t i = 0; i < worklist.length(); i++) {
if (checkExecutionStatus && !worklist[i]->isMainThreadRunningJS()) {
continue;
}
if (i < index ||
IonCompileTaskHasHigherPriority(worklist[i], worklist[index])) {
index = i;
}
}
if (index == worklist.length()) {
return nullptr;
}
jit::IonCompileTask* task = worklist[index];
worklist.erase(&worklist[index]);
return task;
}
HelperThreadTask* GlobalHelperThreadState::maybeGetFreeDelazifyTask(
const AutoLockHelperThreadState& lock) {
auto& freeList = freeDelazifyTaskVector(lock);
if (!freeList.empty()) {
UniquePtr<FreeDelazifyTask> task = std::move(freeList.back());
freeList.popBack();
return task.release();
}
return nullptr;
}
bool GlobalHelperThreadState::canStartFreeDelazifyTask(
const AutoLockHelperThreadState& lock) {
return !freeDelazifyTaskVector(lock).empty() &&
checkTaskThreadLimit(THREAD_TYPE_DELAZIFY_FREE, maxDelazifyThreads(),
/*isMaster=*/true, lock);
}
HelperThreadTask* GlobalHelperThreadState::maybeGetDelazifyTask(
const AutoLockHelperThreadState& lock) {
// NOTE: We want to span all cores availables with delazification tasks, in
// order to parse a maximum number of functions ahead of their executions.
// Thus, as opposed to parse task which have a higher priority, we are not
// exclusively executing these task on parse threads.
auto& worklist = delazifyWorklist(lock);
if (worklist.isEmpty()) {
return nullptr;
}
return worklist.popFirst();
}
bool GlobalHelperThreadState::canStartDelazifyTask(
const AutoLockHelperThreadState& lock) {
return !delazifyWorklist(lock).isEmpty() &&
checkTaskThreadLimit(THREAD_TYPE_DELAZIFY, maxDelazifyThreads(),
/*isMaster=*/true, lock);
}
HelperThreadTask* GlobalHelperThreadState::maybeGetCompressionTask(
const AutoLockHelperThreadState& lock) {
if (!canStartCompressionTask(lock)) {
return nullptr;
}
auto& worklist = compressionWorklist(lock);
UniquePtr<SourceCompressionTask> task = std::move(worklist.back());
worklist.popBack();
return task.release();
}
bool GlobalHelperThreadState::canStartCompressionTask(
const AutoLockHelperThreadState& lock) {
return !compressionWorklist(lock).empty() &&
checkTaskThreadLimit(THREAD_TYPE_COMPRESS, maxCompressionThreads(),
lock);
}
void GlobalHelperThreadState::startHandlingCompressionTasks(
ScheduleCompressionTask schedule, JSRuntime* maybeRuntime,
const AutoLockHelperThreadState& lock) {
MOZ_ASSERT((schedule == ScheduleCompressionTask::GC) ==
(maybeRuntime != nullptr));
auto& pending = compressionPendingList(lock);
for (size_t i = 0; i < pending.length(); i++) {
UniquePtr<SourceCompressionTask>& task = pending[i];
if (schedule == ScheduleCompressionTask::API ||
(task->runtimeMatches(maybeRuntime) && task->shouldStart())) {
// OOMing during appending results in the task not being scheduled
// and deleted.
(void)submitTask(std::move(task), lock);
remove(pending, &i);
}
}
}
bool GlobalHelperThreadState::submitTask(
UniquePtr<SourceCompressionTask> task,
const AutoLockHelperThreadState& locked) {
if (!compressionWorklist(locked).append(std::move(task))) {
return false;
}
dispatch(DispatchReason::NewTask, locked);
return true;
}
bool GlobalHelperThreadState::submitTask(
GCParallelTask* task, const AutoLockHelperThreadState& locked) {
gcParallelWorklist().insertBack(task, locked);
dispatch(DispatchReason::NewTask, locked);
return true;
}
HelperThreadTask* GlobalHelperThreadState::maybeGetGCParallelTask(
const AutoLockHelperThreadState& lock) {
if (!canStartGCParallelTask(lock)) {
return nullptr;
}
return gcParallelWorklist().popFirst(lock);
}
bool GlobalHelperThreadState::canStartGCParallelTask(
const AutoLockHelperThreadState& lock) {
return !gcParallelWorklist().isEmpty(lock) &&
checkTaskThreadLimit(THREAD_TYPE_GCPARALLEL, maxGCParallelThreads(),
lock);
}
bool js::EnqueueOffThreadCompression(JSContext* cx,
UniquePtr<SourceCompressionTask> task) {
AutoLockHelperThreadState lock;
auto& pending = HelperThreadState().compressionPendingList(lock);
if (!pending.append(std::move(task))) {
ReportOutOfMemory(cx);
return false;
}
return true;
}
void js::StartHandlingCompressionsOnGC(JSRuntime* runtime) {
AutoLockHelperThreadState lock;
HelperThreadState().startHandlingCompressionTasks(
GlobalHelperThreadState::ScheduleCompressionTask::GC, runtime, lock);
}
template <typename T>
static void ClearCompressionTaskList(T& list, JSRuntime* runtime) {
for (size_t i = 0; i < list.length(); i++) {
if (list[i]->runtimeMatches(runtime)) {
HelperThreadState().remove(list, &i);
}
}
}
void js::CancelOffThreadCompressions(JSRuntime* runtime) {
if (!CanUseExtraThreads()) {
return;
}
AutoLockHelperThreadState lock;
// Cancel all pending compression tasks.
ClearCompressionTaskList(HelperThreadState().compressionPendingList(lock),
runtime);
ClearCompressionTaskList(HelperThreadState().compressionWorklist(lock),
runtime);
// Cancel all in-process compression tasks and wait for them to join so we
// clean up the finished tasks.
while (true) {
bool inProgress = false;
for (auto* helper : HelperThreadState().helperTasks(lock)) {
if (!helper->is<SourceCompressionTask>()) {
continue;
}
if (helper->as<SourceCompressionTask>()->runtimeMatches(runtime)) {
inProgress = true;
}
}
if (!inProgress) {
break;
}
HelperThreadState().wait(lock);
}
// Clean up finished tasks.
ClearCompressionTaskList(HelperThreadState().compressionFinishedList(lock),
runtime);
}
void js::AttachFinishedCompressions(JSRuntime* runtime,
AutoLockHelperThreadState& lock) {
auto& finished = HelperThreadState().compressionFinishedList(lock);
for (size_t i = 0; i < finished.length(); i++) {
if (finished[i]->runtimeMatches(runtime)) {
UniquePtr<SourceCompressionTask> compressionTask(std::move(finished[i]));
HelperThreadState().remove(finished, &i);
compressionTask->complete();
}
}
}
void js::SweepPendingCompressions(AutoLockHelperThreadState& lock) {
auto& pending = HelperThreadState().compressionPendingList(lock);
for (size_t i = 0; i < pending.length(); i++) {
if (pending[i]->shouldCancel()) {
HelperThreadState().remove(pending, &i);
}
}
}
void js::RunPendingSourceCompressions(JSRuntime* runtime) {
if (!CanUseExtraThreads()) {
return;
}
AutoLockHelperThreadState lock;
HelperThreadState().startHandlingCompressionTasks(
GlobalHelperThreadState::ScheduleCompressionTask::API, nullptr, lock);
// Wait until all tasks have started compression.
while (!HelperThreadState().compressionWorklist(lock).empty()) {
HelperThreadState().wait(lock);
}
// Wait for all in-process compression tasks to complete.
HelperThreadState().waitForAllTasksLocked(lock);
AttachFinishedCompressions(runtime, lock);
}
void PromiseHelperTask::executeAndResolveAndDestroy(JSContext* cx) {
execute();
run(cx, JS::Dispatchable::NotShuttingDown);
}
void PromiseHelperTask::runHelperThreadTask(AutoLockHelperThreadState& lock) {
{
AutoUnlockHelperThreadState unlock(lock);
execute();
}
// Don't release the lock between dispatching the resolve and destroy
// operation (which may start immediately on another thread) and returning
// from this method.
dispatchResolveAndDestroy(lock);
}
bool js::StartOffThreadPromiseHelperTask(JSContext* cx,
UniquePtr<PromiseHelperTask> task) {
// Execute synchronously if there are no helper threads.
if (!CanUseExtraThreads()) {
task.release()->executeAndResolveAndDestroy(cx);
return true;
}
if (!HelperThreadState().submitTask(task.get())) {
ReportOutOfMemory(cx);
return false;
}
(void)task.release();
return true;
}
bool js::StartOffThreadPromiseHelperTask(PromiseHelperTask* task) {
MOZ_ASSERT(CanUseExtraThreads());
return HelperThreadState().submitTask(task);
}
bool GlobalHelperThreadState::submitTask(PromiseHelperTask* task) {
AutoLockHelperThreadState lock;
if (!promiseHelperTasks(lock).append(task)) {
return false;
}
dispatch(DispatchReason::NewTask, lock);
return true;
}
void GlobalHelperThreadState::trace(JSTracer* trc) {
{
AutoLockHelperThreadState lock;
#ifdef DEBUG
// Since we hold the helper thread lock here we must disable GCMarker's
// checking of the atom marking bitmap since that also relies on taking the
// lock.
GCMarker* marker = nullptr;
if (trc->isMarkingTracer()) {
marker = GCMarker::fromTracer(trc);
marker->setCheckAtomMarking(false);
}
auto reenableAtomMarkingCheck = mozilla::MakeScopeExit([marker] {
if (marker) {
marker->setCheckAtomMarking(true);
}
});
#endif
for (auto task : ionWorklist(lock)) {
task->alloc().lifoAlloc()->setReadWrite();
task->trace(trc);
task->alloc().lifoAlloc()->setReadOnly();
}
for (auto task : ionFinishedList(lock)) {
task->trace(trc);
}
for (auto* helper : HelperThreadState().helperTasks(lock)) {
if (helper->is<jit::IonCompileTask>()) {
helper->as<jit::IonCompileTask>()->trace(trc);
}
}
}
// The lazy link list is only accessed on the main thread, so trace it after
// releasing the lock.
JSRuntime* rt = trc->runtime();
if (auto* jitRuntime = rt->jitRuntime()) {
jit::IonCompileTask* task = jitRuntime->ionLazyLinkList(rt).getFirst();
while (task) {
task->trace(trc);
task = task->getNext();
}
}
}
// Definition of helper thread tasks.
//
// Priority is determined by the order they're listed here.
const GlobalHelperThreadState::Selector GlobalHelperThreadState::selectors[] = {
&GlobalHelperThreadState::maybeGetGCParallelTask,
&GlobalHelperThreadState::maybeGetIonCompileTask,
&GlobalHelperThreadState::maybeGetWasmTier1CompileTask,
&GlobalHelperThreadState::maybeGetPromiseHelperTask,
&GlobalHelperThreadState::maybeGetFreeDelazifyTask,
&GlobalHelperThreadState::maybeGetDelazifyTask,
&GlobalHelperThreadState::maybeGetCompressionTask,
&GlobalHelperThreadState::maybeGetLowPrioIonCompileTask,
&GlobalHelperThreadState::maybeGetIonFreeTask,
&GlobalHelperThreadState::maybeGetWasmTier2CompileTask,
&GlobalHelperThreadState::maybeGetWasmTier2GeneratorTask};
bool GlobalHelperThreadState::canStartTasks(
const AutoLockHelperThreadState& lock) {
return canStartGCParallelTask(lock) || canStartIonCompileTask(lock) ||
canStartWasmTier1CompileTask(lock) ||
canStartPromiseHelperTask(lock) || canStartFreeDelazifyTask(lock) ||
canStartDelazifyTask(lock) || canStartCompressionTask(lock) ||
canStartIonFreeTask(lock) || canStartWasmTier2CompileTask(lock) ||
canStartWasmTier2GeneratorTask(lock);
}
void JS::RunHelperThreadTask() {
MOZ_ASSERT(CanUseExtraThreads());
AutoLockHelperThreadState lock;
if (!gHelperThreadState || HelperThreadState().isTerminating(lock)) {
return;
}
HelperThreadState().runOneTask(lock);
}
void GlobalHelperThreadState::runOneTask(AutoLockHelperThreadState& lock) {
MOZ_ASSERT(tasksPending_ > 0);
tasksPending_--;
// The selectors may depend on the HelperThreadState not changing between task
// selection and task execution, in particular, on new tasks not being added
// (because of the lifo structure of the work lists). Unlocking the
// HelperThreadState between task selection and execution is not well-defined.
HelperThreadTask* task = findHighestPriorityTask(lock);
if (task) {
runTaskLocked(task, lock);
dispatch(DispatchReason::FinishedTask, lock);
}
notifyAll(lock);
}
HelperThreadTask* GlobalHelperThreadState::findHighestPriorityTask(
const AutoLockHelperThreadState& locked) {
// Return the highest priority task that is ready to start, or nullptr.
for (const auto& selector : selectors) {
if (auto* task = (this->*(selector))(locked)) {
return task;
}
}
return nullptr;
}