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fune/xpcom/threads/nsThread.cpp

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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 "nsThread.h"
#include "base/message_loop.h"
#include "base/platform_thread.h"
// Chromium's logging can sometimes leak through...
#ifdef LOG
# undef LOG
#endif
#include "mozilla/ReentrantMonitor.h"
#include "nsMemoryPressure.h"
#include "nsThreadManager.h"
#include "nsIClassInfoImpl.h"
#include "nsCOMPtr.h"
#include "nsQueryObject.h"
#include "pratom.h"
#include "mozilla/BackgroundHangMonitor.h"
#include "mozilla/CycleCollectedJSContext.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/Logging.h"
#include "nsIObserverService.h"
#include "mozilla/IOInterposer.h"
#include "mozilla/ipc/MessageChannel.h"
#include "mozilla/ipc/BackgroundChild.h"
#include "mozilla/Preferences.h"
#include "mozilla/ProfilerRunnable.h"
#include "mozilla/SchedulerGroup.h"
#include "mozilla/Services.h"
#include "mozilla/SpinEventLoopUntil.h"
#include "mozilla/StaticLocalPtr.h"
#include "mozilla/StaticPrefs_threads.h"
#include "mozilla/TaskController.h"
#include "nsXPCOMPrivate.h"
#include "mozilla/ChaosMode.h"
#include "mozilla/Telemetry.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/Unused.h"
#include "mozilla/dom/DocGroup.h"
#include "mozilla/dom/ScriptSettings.h"
#include "nsThreadSyncDispatch.h"
#include "nsServiceManagerUtils.h"
#include "GeckoProfiler.h"
#include "ThreadEventQueue.h"
#include "ThreadEventTarget.h"
#include "ThreadDelay.h"
#include <limits>
#ifdef XP_LINUX
# ifdef __GLIBC__
# include <gnu/libc-version.h>
# endif
# include <sys/mman.h>
# include <sys/time.h>
# include <sys/resource.h>
# include <sched.h>
# include <stdio.h>
#endif
#ifdef XP_WIN
# include "mozilla/DynamicallyLinkedFunctionPtr.h"
# include <winbase.h>
using GetCurrentThreadStackLimitsFn = void(WINAPI*)(PULONG_PTR LowLimit,
PULONG_PTR HighLimit);
#endif
#define HAVE_UALARM \
_BSD_SOURCE || \
(_XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED) && \
!(_POSIX_C_SOURCE >= 200809L || _XOPEN_SOURCE >= 700)
#if defined(XP_LINUX) && !defined(ANDROID) && defined(_GNU_SOURCE)
# define HAVE_SCHED_SETAFFINITY
#endif
#ifdef XP_MACOSX
# include <mach/mach.h>
# include <mach/thread_policy.h>
# include <sys/qos.h>
#endif
#ifdef MOZ_CANARY
# include <unistd.h>
# include <execinfo.h>
# include <signal.h>
# include <fcntl.h>
# include "nsXULAppAPI.h"
#endif
using namespace mozilla;
extern void InitThreadLocalVariables();
static LazyLogModule sThreadLog("nsThread");
#ifdef LOG
# undef LOG
#endif
#define LOG(args) MOZ_LOG(sThreadLog, mozilla::LogLevel::Debug, args)
NS_DECL_CI_INTERFACE_GETTER(nsThread)
Array<char, nsThread::kRunnableNameBufSize> nsThread::sMainThreadRunnableName;
#ifdef EARLY_BETA_OR_EARLIER
const uint32_t kTelemetryWakeupCountLimit = 100;
#endif
//-----------------------------------------------------------------------------
// Because we do not have our own nsIFactory, we have to implement nsIClassInfo
// somewhat manually.
class nsThreadClassInfo : public nsIClassInfo {
public:
NS_DECL_ISUPPORTS_INHERITED // no mRefCnt
NS_DECL_NSICLASSINFO
nsThreadClassInfo() = default;
};
NS_IMETHODIMP_(MozExternalRefCountType)
nsThreadClassInfo::AddRef() { return 2; }
NS_IMETHODIMP_(MozExternalRefCountType)
nsThreadClassInfo::Release() { return 1; }
NS_IMPL_QUERY_INTERFACE(nsThreadClassInfo, nsIClassInfo)
NS_IMETHODIMP
nsThreadClassInfo::GetInterfaces(nsTArray<nsIID>& aArray) {
return NS_CI_INTERFACE_GETTER_NAME(nsThread)(aArray);
}
NS_IMETHODIMP
nsThreadClassInfo::GetScriptableHelper(nsIXPCScriptable** aResult) {
*aResult = nullptr;
return NS_OK;
}
NS_IMETHODIMP
nsThreadClassInfo::GetContractID(nsACString& aResult) {
aResult.SetIsVoid(true);
return NS_OK;
}
NS_IMETHODIMP
nsThreadClassInfo::GetClassDescription(nsACString& aResult) {
aResult.SetIsVoid(true);
return NS_OK;
}
NS_IMETHODIMP
nsThreadClassInfo::GetClassID(nsCID** aResult) {
*aResult = nullptr;
return NS_OK;
}
NS_IMETHODIMP
nsThreadClassInfo::GetFlags(uint32_t* aResult) {
*aResult = THREADSAFE;
return NS_OK;
}
NS_IMETHODIMP
nsThreadClassInfo::GetClassIDNoAlloc(nsCID* aResult) {
return NS_ERROR_NOT_AVAILABLE;
}
//-----------------------------------------------------------------------------
NS_IMPL_ADDREF(nsThread)
NS_IMPL_RELEASE(nsThread)
NS_INTERFACE_MAP_BEGIN(nsThread)
NS_INTERFACE_MAP_ENTRY(nsIThread)
NS_INTERFACE_MAP_ENTRY(nsIThreadInternal)
NS_INTERFACE_MAP_ENTRY(nsIEventTarget)
NS_INTERFACE_MAP_ENTRY(nsISerialEventTarget)
NS_INTERFACE_MAP_ENTRY(nsISupportsPriority)
NS_INTERFACE_MAP_ENTRY(nsIDirectTaskDispatcher)
NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIThread)
if (aIID.Equals(NS_GET_IID(nsIClassInfo))) {
static nsThreadClassInfo sThreadClassInfo;
foundInterface = static_cast<nsIClassInfo*>(&sThreadClassInfo);
} else
NS_INTERFACE_MAP_END
NS_IMPL_CI_INTERFACE_GETTER(nsThread, nsIThread, nsIThreadInternal,
nsIEventTarget, nsISerialEventTarget,
nsISupportsPriority)
//-----------------------------------------------------------------------------
// This event is responsible for notifying nsThread::Shutdown that it is time
// to call PR_JoinThread. It implements nsICancelableRunnable so that it can
// run on a DOM Worker thread (where all events must implement
// nsICancelableRunnable.)
class nsThreadShutdownAckEvent : public CancelableRunnable {
public:
explicit nsThreadShutdownAckEvent(NotNull<nsThreadShutdownContext*> aCtx)
: CancelableRunnable("nsThreadShutdownAckEvent"),
mShutdownContext(aCtx) {}
NS_IMETHOD Run() override {
mShutdownContext->mTerminatingThread->ShutdownComplete(mShutdownContext);
return NS_OK;
}
nsresult Cancel() override { return Run(); }
private:
virtual ~nsThreadShutdownAckEvent() = default;
NotNull<RefPtr<nsThreadShutdownContext>> mShutdownContext;
};
// This event is responsible for setting mShutdownContext
class nsThreadShutdownEvent : public Runnable {
public:
nsThreadShutdownEvent(NotNull<nsThread*> aThr,
NotNull<nsThreadShutdownContext*> aCtx)
: Runnable("nsThreadShutdownEvent"),
mThread(aThr),
mShutdownContext(aCtx) {}
NS_IMETHOD Run() override {
// Creates a cycle between `mThread` and the shutdown context which will be
// broken when the thread exits.
mThread->mShutdownContext = mShutdownContext;
MessageLoop::current()->Quit();
#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
// Let's leave a trace that we passed here in the thread's name.
nsAutoCString threadName(PR_GetThreadName(PR_GetCurrentThread()));
threadName.Append(",SHDRCV"_ns);
NS_SetCurrentThreadName(threadName.get());
#endif
return NS_OK;
}
private:
NotNull<RefPtr<nsThread>> mThread;
NotNull<RefPtr<nsThreadShutdownContext>> mShutdownContext;
};
//-----------------------------------------------------------------------------
static void SetThreadAffinity(unsigned int cpu) {
#ifdef HAVE_SCHED_SETAFFINITY
cpu_set_t cpus;
CPU_ZERO(&cpus);
CPU_SET(cpu, &cpus);
sched_setaffinity(0, sizeof(cpus), &cpus);
// Don't assert sched_setaffinity's return value because it intermittently (?)
// fails with EINVAL on Linux x64 try runs.
#elif defined(XP_MACOSX)
// OS X does not provide APIs to pin threads to specific processors, but you
// can tag threads as belonging to the same "affinity set" and the OS will try
// to run them on the same processor. To run threads on different processors,
// tag them as belonging to different affinity sets. Tag 0, the default, means
// "no affinity" so let's pretend each CPU has its own tag `cpu+1`.
thread_affinity_policy_data_t policy;
policy.affinity_tag = cpu + 1;
kern_return_t kr = thread_policy_set(
mach_thread_self(), THREAD_AFFINITY_POLICY, &policy.affinity_tag, 1);
// Setting the thread affinity is not supported on ARM.
MOZ_ALWAYS_TRUE(kr == KERN_SUCCESS || kr == KERN_NOT_SUPPORTED);
#elif defined(XP_WIN)
MOZ_ALWAYS_TRUE(SetThreadIdealProcessor(GetCurrentThread(), cpu) !=
(DWORD)-1);
#endif
}
static void SetupCurrentThreadForChaosMode() {
if (!ChaosMode::isActive(ChaosFeature::ThreadScheduling)) {
return;
}
#ifdef XP_LINUX
// PR_SetThreadPriority doesn't really work since priorities >
// PR_PRIORITY_NORMAL can't be set by non-root users. Instead we'll just use
// setpriority(2) to set random 'nice values'. In regular Linux this is only
// a dynamic adjustment so it still doesn't really do what we want, but tools
// like 'rr' can be more aggressive about honoring these values.
// Some of these calls may fail due to trying to lower the priority
// (e.g. something may have already called setpriority() for this thread).
// This makes it hard to have non-main threads with higher priority than the
// main thread, but that's hard to fix. Tools like rr can choose to honor the
// requested values anyway.
// Use just 4 priorities so there's a reasonable chance of any two threads
// having equal priority.
setpriority(PRIO_PROCESS, 0, ChaosMode::randomUint32LessThan(4));
#else
// We should set the affinity here but NSPR doesn't provide a way to expose
// it.
uint32_t priority = ChaosMode::randomUint32LessThan(PR_PRIORITY_LAST + 1);
PR_SetThreadPriority(PR_GetCurrentThread(), PRThreadPriority(priority));
#endif
// Force half the threads to CPU 0 so they compete for CPU
if (ChaosMode::randomUint32LessThan(2)) {
SetThreadAffinity(0);
}
}
namespace {
struct ThreadInitData {
RefPtr<nsThread> thread;
nsCString name;
};
} // namespace
void nsThread::MaybeRemoveFromThreadList() {
nsThreadManager& tm = nsThreadManager::get();
OffTheBooksMutexAutoLock mal(tm.ThreadListMutex());
if (isInList()) {
removeFrom(tm.ThreadList());
}
}
/*static*/
void nsThread::ThreadFunc(void* aArg) {
using mozilla::ipc::BackgroundChild;
UniquePtr<ThreadInitData> initData(static_cast<ThreadInitData*>(aArg));
RefPtr<nsThread>& self = initData->thread;
MOZ_ASSERT(self->mEventTarget);
MOZ_ASSERT(self->mEvents);
// Note: see the comment in nsThread::Init, where we set these same values.
DebugOnly<PRThread*> prev = self->mThread.exchange(PR_GetCurrentThread());
MOZ_ASSERT(!prev || prev == PR_GetCurrentThread());
self->mEventTarget->SetCurrentThread(self->mThread);
SetupCurrentThreadForChaosMode();
if (!initData->name.IsEmpty()) {
NS_SetCurrentThreadName(initData->name.BeginReading());
}
self->InitCommon();
// Inform the ThreadManager
nsThreadManager::get().RegisterCurrentThread(*self);
mozilla::IOInterposer::RegisterCurrentThread();
// This must come after the call to nsThreadManager::RegisterCurrentThread(),
// because that call is needed to properly set up this thread as an nsThread,
// which profiler_register_thread() requires. See bug 1347007.
const bool registerWithProfiler = !initData->name.IsEmpty();
if (registerWithProfiler) {
PROFILER_REGISTER_THREAD(initData->name.BeginReading());
}
{
// Scope for MessageLoop.
MessageLoop loop(
#if defined(XP_WIN) || defined(XP_MACOSX)
self->mIsUiThread ? MessageLoop::TYPE_MOZILLA_NONMAINUITHREAD
: MessageLoop::TYPE_MOZILLA_NONMAINTHREAD,
#else
MessageLoop::TYPE_MOZILLA_NONMAINTHREAD,
#endif
self);
// Now, process incoming events...
loop.Run();
self->mEvents->RunShutdownTasks();
BackgroundChild::CloseForCurrentThread();
// NB: The main thread does not shut down here! It shuts down via
// nsThreadManager::Shutdown.
// Do NS_ProcessPendingEvents but with special handling to set
// mEventsAreDoomed atomically with the removal of the last event. The key
// invariant here is that we will never permit PutEvent to succeed if the
// event would be left in the queue after our final call to
// NS_ProcessPendingEvents. We also have to keep processing events as long
// as we have outstanding mRequestedShutdownContexts.
while (true) {
// Check and see if we're waiting on any threads.
self->WaitForAllAsynchronousShutdowns();
if (self->mEvents->ShutdownIfNoPendingEvents()) {
break;
}
NS_ProcessPendingEvents(self);
}
}
mozilla::IOInterposer::UnregisterCurrentThread();
// Inform the threadmanager that this thread is going away
nsThreadManager::get().UnregisterCurrentThread(*self);
// The thread should only unregister itself if it was registered above.
if (registerWithProfiler) {
PROFILER_UNREGISTER_THREAD();
}
NotNull<RefPtr<nsThreadShutdownContext>> context =
WrapNotNull(self->mShutdownContext);
self->mShutdownContext = nullptr;
MOZ_ASSERT(context->mTerminatingThread == self);
// Take the joining thread from our shutdown context. This may have been
// cleared by the joining thread if it decided to cancel waiting on us, in
// which case we won't notify our caller, and leak.
RefPtr<nsThread> joiningThread;
{
MutexAutoLock lock(context->mJoiningThreadMutex);
joiningThread = context->mJoiningThread.forget();
MOZ_RELEASE_ASSERT(joiningThread || context->mThreadLeaked);
}
if (joiningThread) {
// Dispatch shutdown ACK
nsCOMPtr<nsIRunnable> event = new nsThreadShutdownAckEvent(context);
nsresult dispatch_ack_rv =
joiningThread->Dispatch(event, NS_DISPATCH_NORMAL);
// We do not expect this to ever happen, but If we cannot dispatch
// the ack event, someone probably blocks waiting on us and will
// crash with a hang later anyways. The best we can do is to tell
// the world what happened right here.
MOZ_RELEASE_ASSERT(NS_SUCCEEDED(dispatch_ack_rv));
#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
// Let's leave a trace that we passed here in the thread's name.
nsAutoCString threadName(PR_GetThreadName(PR_GetCurrentThread()));
threadName.Append(",SHDACK"_ns);
NS_SetCurrentThreadName(threadName.get());
#endif
} else {
NS_WARNING(
"nsThread exiting after StopWaitingAndLeakThread was called, thread "
"resources will be leaked!");
}
// Release any observer of the thread here.
self->SetObserver(nullptr);
// The PRThread will be deleted in PR_JoinThread(), so clear references.
self->mThread = nullptr;
self->mEventTarget->ClearCurrentThread();
}
void nsThread::InitCommon() {
mThreadId = uint32_t(PlatformThread::CurrentId());
{
#if defined(XP_LINUX)
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_getattr_np(pthread_self(), &attr);
size_t stackSize;
pthread_attr_getstack(&attr, &mStackBase, &stackSize);
// Glibc prior to 2.27 reports the stack size and base including the guard
// region, so we need to compensate for it to get accurate accounting.
// Also, this behavior difference isn't guarded by a versioned symbol, so we
// actually need to check the runtime glibc version, not the version we were
// compiled against.
static bool sAdjustForGuardSize = ({
# ifdef __GLIBC__
unsigned major, minor;
sscanf(gnu_get_libc_version(), "%u.%u", &major, &minor) < 2 ||
major < 2 || (major == 2 && minor < 27);
# else
false;
# endif
});
if (sAdjustForGuardSize) {
size_t guardSize;
pthread_attr_getguardsize(&attr, &guardSize);
// Note: This assumes that the stack grows down, as is the case on all of
// our tier 1 platforms. On platforms where the stack grows up, the
// mStackBase adjustment is unnecessary, but doesn't cause any harm other
// than under-counting stack memory usage by one page.
mStackBase = reinterpret_cast<char*>(mStackBase) + guardSize;
stackSize -= guardSize;
}
mStackSize = stackSize;
// This is a bit of a hack.
//
// We really do want the NOHUGEPAGE flag on our thread stacks, since we
// don't expect any of them to need anywhere near 2MB of space. But setting
// it here is too late to have an effect, since the first stack page has
// already been faulted in existence, and NSPR doesn't give us a way to set
// it beforehand.
//
// What this does get us, however, is a different set of VM flags on our
// thread stacks compared to normal heap memory. Which makes the Linux
// kernel report them as separate regions, even when they are adjacent to
// heap memory. This allows us to accurately track the actual memory
// consumption of our allocated stacks.
madvise(mStackBase, stackSize, MADV_NOHUGEPAGE);
pthread_attr_destroy(&attr);
#elif defined(XP_WIN)
static const StaticDynamicallyLinkedFunctionPtr<
GetCurrentThreadStackLimitsFn>
sGetStackLimits(L"kernel32.dll", "GetCurrentThreadStackLimits");
if (sGetStackLimits) {
ULONG_PTR stackBottom, stackTop;
sGetStackLimits(&stackBottom, &stackTop);
mStackBase = reinterpret_cast<void*>(stackBottom);
mStackSize = stackTop - stackBottom;
}
#endif
}
InitThreadLocalVariables();
}
//-----------------------------------------------------------------------------
#ifdef MOZ_CANARY
int sCanaryOutputFD = -1;
#endif
nsThread::nsThread(NotNull<SynchronizedEventQueue*> aQueue,
MainThreadFlag aMainThread,
nsIThreadManager::ThreadCreationOptions aOptions)
: mEvents(aQueue.get()),
mEventTarget(new ThreadEventTarget(
mEvents.get(), aMainThread == MAIN_THREAD, aOptions.blockDispatch)),
mOutstandingShutdownContexts(0),
mShutdownContext(nullptr),
mScriptObserver(nullptr),
mThreadName("<uninitialized>"),
mStackSize(aOptions.stackSize),
mNestedEventLoopDepth(0),
mShutdownRequired(false),
mPriority(PRIORITY_NORMAL),
mIsMainThread(aMainThread == MAIN_THREAD),
mUseHangMonitor(aMainThread == MAIN_THREAD),
mIsUiThread(aOptions.isUiThread),
mIsAPoolThreadFree(nullptr),
mCanInvokeJS(false),
#ifdef EARLY_BETA_OR_EARLIER
mLastWakeupCheckTime(TimeStamp::Now()),
#endif
mPerformanceCounterState(mNestedEventLoopDepth, mIsMainThread,
aOptions.longTaskLength) {
#if !(defined(XP_WIN) || defined(XP_MACOSX))
MOZ_ASSERT(!mIsUiThread,
"Non-main UI threads are only supported on Windows and macOS");
#endif
if (mIsMainThread) {
MOZ_ASSERT(!mIsUiThread,
"Setting isUIThread is not supported for main threads");
mozilla::TaskController::Get()->SetPerformanceCounterState(
&mPerformanceCounterState);
}
}
nsThread::nsThread()
: mEvents(nullptr),
mEventTarget(nullptr),
mOutstandingShutdownContexts(0),
mShutdownContext(nullptr),
mScriptObserver(nullptr),
mThreadName("<uninitialized>"),
mStackSize(0),
mNestedEventLoopDepth(0),
mShutdownRequired(false),
mPriority(PRIORITY_NORMAL),
mIsMainThread(false),
mUseHangMonitor(false),
mIsUiThread(false),
mCanInvokeJS(false),
#ifdef EARLY_BETA_OR_EARLIER
mLastWakeupCheckTime(TimeStamp::Now()),
#endif
mPerformanceCounterState(mNestedEventLoopDepth) {
MOZ_ASSERT(!NS_IsMainThread());
}
nsThread::~nsThread() {
NS_ASSERTION(mOutstandingShutdownContexts == 0,
"shouldn't be waiting on other threads to shutdown");
MaybeRemoveFromThreadList();
}
nsresult nsThread::Init(const nsACString& aName) {
MOZ_ASSERT(mEvents);
MOZ_ASSERT(mEventTarget);
MOZ_ASSERT(!mThread);
SetThreadNameInternal(aName);
PRThread* thread = nullptr;
nsThreadManager& tm = nsThreadManager::get();
{
OffTheBooksMutexAutoLock lock(tm.ThreadListMutex());
if (!tm.AllowNewXPCOMThreadsLocked()) {
return NS_ERROR_NOT_INITIALIZED;
}
// We need to fully start the thread while holding the thread list lock, as
// the next acquire of the lock could try to shut down this thread (e.g.
// during xpcom shutdown), which would hang if `PR_CreateThread` failed.
UniquePtr<ThreadInitData> initData(
new ThreadInitData{this, nsCString(aName)});
// ThreadFunc is responsible for setting mThread
if (!(thread = PR_CreateThread(PR_USER_THREAD, ThreadFunc, initData.get(),
PR_PRIORITY_NORMAL, PR_GLOBAL_THREAD,
PR_JOINABLE_THREAD, mStackSize))) {
return NS_ERROR_OUT_OF_MEMORY;
}
// The created thread now owns initData, so release our ownership of it.
Unused << initData.release();
// The thread has successfully started, so we can mark it as requiring
// shutdown & add it to the thread list.
mShutdownRequired = true;
tm.ThreadList().insertBack(this);
}
// Note: we set these both here and inside ThreadFunc, to what should be
// the same value. This is because calls within ThreadFunc need these values
// to be set, and our callers need these values to be set.
DebugOnly<PRThread*> prev = mThread.exchange(thread);
MOZ_ASSERT(!prev || prev == thread);
mEventTarget->SetCurrentThread(thread);
return NS_OK;
}
nsresult nsThread::InitCurrentThread() {
mThread = PR_GetCurrentThread();
nsThreadManager& tm = nsThreadManager::get();
{
OffTheBooksMutexAutoLock lock(tm.ThreadListMutex());
// NOTE: We don't check AllowNewXPCOMThreads here, as threads initialized
// this way do not need shutdown, so are OK to create after nsThreadManager
// shutdown. In addition, the main thread is initialized this way, which
// happens before AllowNewXPCOMThreads begins to return true.
tm.ThreadList().insertBack(this);
}
SetupCurrentThreadForChaosMode();
InitCommon();
tm.RegisterCurrentThread(*this);
return NS_OK;
}
void nsThread::GetThreadName(nsACString& aNameBuffer) {
auto lock = mThreadName.Lock();
aNameBuffer = lock.ref();
}
void nsThread::SetThreadNameInternal(const nsACString& aName) {
auto lock = mThreadName.Lock();
lock->Assign(aName);
}
//-----------------------------------------------------------------------------
// nsIEventTarget
NS_IMETHODIMP
nsThread::DispatchFromScript(nsIRunnable* aEvent, uint32_t aFlags) {
MOZ_ASSERT(mEventTarget);
NS_ENSURE_TRUE(mEventTarget, NS_ERROR_NOT_IMPLEMENTED);
nsCOMPtr<nsIRunnable> event(aEvent);
return mEventTarget->Dispatch(event.forget(), aFlags);
}
NS_IMETHODIMP
nsThread::Dispatch(already_AddRefed<nsIRunnable> aEvent, uint32_t aFlags) {
MOZ_ASSERT(mEventTarget);
NS_ENSURE_TRUE(mEventTarget, NS_ERROR_NOT_IMPLEMENTED);
LOG(("THRD(%p) Dispatch [%p %x]\n", this, /* XXX aEvent */ nullptr, aFlags));
return mEventTarget->Dispatch(std::move(aEvent), aFlags);
}
NS_IMETHODIMP
nsThread::DelayedDispatch(already_AddRefed<nsIRunnable> aEvent,
uint32_t aDelayMs) {
MOZ_ASSERT(mEventTarget);
NS_ENSURE_TRUE(mEventTarget, NS_ERROR_NOT_IMPLEMENTED);
return mEventTarget->DelayedDispatch(std::move(aEvent), aDelayMs);
}
NS_IMETHODIMP
nsThread::RegisterShutdownTask(nsITargetShutdownTask* aTask) {
MOZ_ASSERT(mEventTarget);
NS_ENSURE_TRUE(mEventTarget, NS_ERROR_NOT_IMPLEMENTED);
return mEventTarget->RegisterShutdownTask(aTask);
}
NS_IMETHODIMP
nsThread::UnregisterShutdownTask(nsITargetShutdownTask* aTask) {
MOZ_ASSERT(mEventTarget);
NS_ENSURE_TRUE(mEventTarget, NS_ERROR_NOT_IMPLEMENTED);
return mEventTarget->UnregisterShutdownTask(aTask);
}
NS_IMETHODIMP
nsThread::GetRunningEventDelay(TimeDuration* aDelay, TimeStamp* aStart) {
if (mIsAPoolThreadFree && *mIsAPoolThreadFree) {
// if there are unstarted threads in the pool, a new event to the
// pool would not be delayed at all (beyond thread start time)
*aDelay = TimeDuration();
*aStart = TimeStamp();
} else {
*aDelay = mLastEventDelay;
*aStart = mLastEventStart;
}
return NS_OK;
}
NS_IMETHODIMP
nsThread::SetRunningEventDelay(TimeDuration aDelay, TimeStamp aStart) {
mLastEventDelay = aDelay;
mLastEventStart = aStart;
return NS_OK;
}
NS_IMETHODIMP
nsThread::IsOnCurrentThread(bool* aResult) {
if (mEventTarget) {
return mEventTarget->IsOnCurrentThread(aResult);
}
*aResult = PR_GetCurrentThread() == mThread;
return NS_OK;
}
NS_IMETHODIMP_(bool)
nsThread::IsOnCurrentThreadInfallible() {
// This method is only going to be called if `mThread` is null, which
// only happens when the thread has exited the event loop. Therefore, when
// we are called, we can never be on this thread.
return false;
}
//-----------------------------------------------------------------------------
// nsIThread
NS_IMETHODIMP
nsThread::GetPRThread(PRThread** aResult) {
PRThread* thread = mThread; // atomic load
*aResult = thread;
return thread ? NS_OK : NS_ERROR_NOT_AVAILABLE;
}
NS_IMETHODIMP
nsThread::GetCanInvokeJS(bool* aResult) {
*aResult = mCanInvokeJS;
return NS_OK;
}
NS_IMETHODIMP
nsThread::SetCanInvokeJS(bool aCanInvokeJS) {
mCanInvokeJS = aCanInvokeJS;
return NS_OK;
}
NS_IMETHODIMP
nsThread::GetLastLongTaskEnd(TimeStamp* _retval) {
*_retval = mPerformanceCounterState.LastLongTaskEnd();
return NS_OK;
}
NS_IMETHODIMP
nsThread::GetLastLongNonIdleTaskEnd(TimeStamp* _retval) {
*_retval = mPerformanceCounterState.LastLongNonIdleTaskEnd();
return NS_OK;
}
NS_IMETHODIMP
nsThread::SetNameForWakeupTelemetry(const nsACString& aName) {
#ifdef EARLY_BETA_OR_EARLIER
mNameForWakeupTelemetry = aName;
#endif
return NS_OK;
}
NS_IMETHODIMP
nsThread::AsyncShutdown() {
LOG(("THRD(%p) async shutdown\n", this));
nsCOMPtr<nsIThreadShutdown> shutdown;
BeginShutdown(getter_AddRefs(shutdown));
return NS_OK;
}
NS_IMETHODIMP
nsThread::BeginShutdown(nsIThreadShutdown** aShutdown) {
LOG(("THRD(%p) begin shutdown\n", this));
MOZ_ASSERT(mEvents);
MOZ_ASSERT(mEventTarget);
MOZ_ASSERT(mThread != PR_GetCurrentThread());
if (NS_WARN_IF(mThread == PR_GetCurrentThread())) {
return NS_ERROR_UNEXPECTED;
}
// Prevent multiple calls to this method.
if (!mShutdownRequired.compareExchange(true, false)) {
return NS_ERROR_UNEXPECTED;
}
MOZ_ASSERT(mThread);
RefPtr<nsThread> currentThread = nsThreadManager::get().GetCurrentThread();
MOZ_DIAGNOSTIC_ASSERT(currentThread->EventQueue(),
"Shutdown() may only be called from an XPCOM thread");
// Allocate a shutdown context, and record that we're waiting for it.
RefPtr<nsThreadShutdownContext> context =
new nsThreadShutdownContext(WrapNotNull(this), currentThread);
++currentThread->mOutstandingShutdownContexts;
nsCOMPtr<nsIRunnable> clearOutstanding = NS_NewRunnableFunction(
"nsThread::ClearOutstandingShutdownContext",
[currentThread] { --currentThread->mOutstandingShutdownContexts; });
context->OnCompletion(clearOutstanding);
// Set mShutdownContext and wake up the thread in case it is waiting for
// events to process.
nsCOMPtr<nsIRunnable> event =
new nsThreadShutdownEvent(WrapNotNull(this), WrapNotNull(context));
if (!mEvents->PutEvent(event.forget(), EventQueuePriority::Normal)) {
// We do not expect this to happen. Let's collect some diagnostics.
nsAutoCString threadName;
GetThreadName(threadName);
MOZ_CRASH_UNSAFE_PRINTF("Attempt to shutdown an already dead thread: %s",
threadName.get());
}
// We could still end up with other events being added after the shutdown
// task, but that's okay because we process pending events in ThreadFunc
// after setting mShutdownContext just before exiting.
context.forget(aShutdown);
return NS_OK;
}
void nsThread::ShutdownComplete(NotNull<nsThreadShutdownContext*> aContext) {
MOZ_ASSERT(mEvents);
MOZ_ASSERT(mEventTarget);
MOZ_ASSERT(aContext->mTerminatingThread == this);
#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
{
MutexAutoLock lock(aContext->mJoiningThreadMutex);
// StopWaitingAndLeakThread is explicitely meant to not cause a
// nsThreadShutdownAckEvent on the joining thread, which is the only
// caller of ShutdownComplete.
MOZ_DIAGNOSTIC_ASSERT(!aContext->mThreadLeaked);
}
#endif
MaybeRemoveFromThreadList();
// Now, it should be safe to join without fear of dead-locking.
PR_JoinThread(aContext->mTerminatingPRThread);
MOZ_ASSERT(!mThread);
#ifdef DEBUG
nsCOMPtr<nsIThreadObserver> obs = mEvents->GetObserver();
MOZ_ASSERT(!obs, "Should have been cleared at shutdown!");
#endif
aContext->MarkCompleted();
}
void nsThread::WaitForAllAsynchronousShutdowns() {
// This is the motivating example for why SpinEventLoopUntil
// has the template parameter we are providing here.
SpinEventLoopUntil<ProcessFailureBehavior::IgnoreAndContinue>(
"nsThread::WaitForAllAsynchronousShutdowns"_ns,
[&]() { return mOutstandingShutdownContexts == 0; }, this);
}
NS_IMETHODIMP
nsThread::Shutdown() {
LOG(("THRD(%p) sync shutdown\n", this));
nsCOMPtr<nsIThreadShutdown> context;
nsresult rv = BeginShutdown(getter_AddRefs(context));
if (NS_FAILED(rv)) {
return NS_OK; // The thread has already shut down.
}
// If we are going to hang here we want to see the thread's name
nsAutoCString threadName;
GetThreadName(threadName);
// Process events on the current thread until we receive a shutdown ACK.
// Allows waiting; ensure no locks are held that would deadlock us!
SpinEventLoopUntil("nsThread::Shutdown: "_ns + threadName,
[&]() { return context->GetCompleted(); });
return NS_OK;
}
NS_IMETHODIMP
nsThread::HasPendingEvents(bool* aResult) {
if (NS_WARN_IF(PR_GetCurrentThread() != mThread)) {
return NS_ERROR_NOT_SAME_THREAD;
}
if (mIsMainThread) {
*aResult = TaskController::Get()->HasMainThreadPendingTasks();
} else {
*aResult = mEvents->HasPendingEvent();
}
return NS_OK;
}
NS_IMETHODIMP
nsThread::HasPendingHighPriorityEvents(bool* aResult) {
if (NS_WARN_IF(PR_GetCurrentThread() != mThread)) {
return NS_ERROR_NOT_SAME_THREAD;
}
// This function appears to never be called anymore.
*aResult = false;
return NS_OK;
}
NS_IMETHODIMP
nsThread::DispatchToQueue(already_AddRefed<nsIRunnable> aEvent,
EventQueuePriority aQueue) {
nsCOMPtr<nsIRunnable> event = aEvent;
if (NS_WARN_IF(!event)) {
return NS_ERROR_INVALID_ARG;
}
if (!mEvents->PutEvent(event.forget(), aQueue)) {
NS_WARNING(
"An idle event was posted to a thread that will never run it "
"(rejected)");
return NS_ERROR_UNEXPECTED;
}
return NS_OK;
}
NS_IMETHODIMP nsThread::SetThreadQoS(nsIThread::QoSPriority aPriority) {
if (!StaticPrefs::threads_use_low_power_enabled()) {
return NS_OK;
}
// The approach here is to have a thread set itself for its QoS level,
// so we assert if we aren't on the current thread.
MOZ_ASSERT(IsOnCurrentThread(), "Can only change the current thread's QoS");
#if defined(XP_MACOSX)
// Only arm64 macs may possess heterogeneous cores. On these, we can tell
// a thread to set its own QoS status. On intel macs things should behave
// normally, and the OS will ignore the QoS state of the thread.
if (aPriority == nsIThread::QOS_PRIORITY_LOW) {
pthread_set_qos_class_self_np(QOS_CLASS_BACKGROUND, 0);
} else if (NS_IsMainThread()) {
// MacOS documentation specifies that a main thread should be initialized at
// the USER_INTERACTIVE priority, so when we restore thread priorities the
// main thread should be setting itself to this.
pthread_set_qos_class_self_np(QOS_CLASS_USER_INTERACTIVE, 0);
} else {
pthread_set_qos_class_self_np(QOS_CLASS_DEFAULT, 0);
}
#endif
// Do nothing if an OS-specific implementation is unavailable.
return NS_OK;
}
#ifdef MOZ_CANARY
void canary_alarm_handler(int signum);
class Canary {
// XXX ToDo: support nested loops
public:
Canary() {
if (sCanaryOutputFD > 0 && EventLatencyIsImportant()) {
signal(SIGALRM, canary_alarm_handler);
ualarm(15000, 0);
}
}
~Canary() {
if (sCanaryOutputFD != 0 && EventLatencyIsImportant()) {
ualarm(0, 0);
}
}
static bool EventLatencyIsImportant() {
return NS_IsMainThread() && XRE_IsParentProcess();
}
};
void canary_alarm_handler(int signum) {
void* array[30];
const char msg[29] = "event took too long to run:\n";
// use write to be safe in the signal handler
write(sCanaryOutputFD, msg, sizeof(msg));
backtrace_symbols_fd(array, backtrace(array, 30), sCanaryOutputFD);
}
#endif
#define NOTIFY_EVENT_OBSERVERS(observers_, func_, params_) \
do { \
if (!observers_.IsEmpty()) { \
for (nsCOMPtr<nsIThreadObserver> obs_ : observers_.ForwardRange()) { \
obs_->func_ params_; \
} \
} \
} while (0)
size_t nsThread::ShallowSizeOfIncludingThis(
mozilla::MallocSizeOf aMallocSizeOf) const {
size_t n = 0;
if (mShutdownContext) {
n += aMallocSizeOf(mShutdownContext);
}
return aMallocSizeOf(this) + aMallocSizeOf(mThread) + n;
}
size_t nsThread::SizeOfEventQueues(mozilla::MallocSizeOf aMallocSizeOf) const {
size_t n = 0;
if (mEventTarget) {
// The size of mEvents is reported by mEventTarget.
n += mEventTarget->SizeOfIncludingThis(aMallocSizeOf);
}
return n;
}
size_t nsThread::SizeOfIncludingThis(
mozilla::MallocSizeOf aMallocSizeOf) const {
return ShallowSizeOfIncludingThis(aMallocSizeOf) +
SizeOfEventQueues(aMallocSizeOf);
}
NS_IMETHODIMP
nsThread::ProcessNextEvent(bool aMayWait, bool* aResult) {
MOZ_ASSERT(mEvents);
NS_ENSURE_TRUE(mEvents, NS_ERROR_NOT_IMPLEMENTED);
LOG(("THRD(%p) ProcessNextEvent [%u %u]\n", this, aMayWait,
mNestedEventLoopDepth));
if (NS_WARN_IF(PR_GetCurrentThread() != mThread)) {
return NS_ERROR_NOT_SAME_THREAD;
}
// The toplevel event loop normally blocks waiting for the next event, but
// if we're trying to shut this thread down, we must exit the event loop
// when the event queue is empty. This only applys to the toplevel event
// loop! Nested event loops (e.g. during sync dispatch) are waiting for
// some state change and must be able to block even if something has
// requested shutdown of the thread. Otherwise we'll just busywait as we
// endlessly look for an event, fail to find one, and repeat the nested
// event loop since its state change hasn't happened yet.
bool reallyWait = aMayWait && (mNestedEventLoopDepth > 0 || !ShuttingDown());
Maybe<dom::AutoNoJSAPI> noJSAPI;
if (mUseHangMonitor && reallyWait) {
BackgroundHangMonitor().NotifyWait();
}
if (mIsMainThread) {
DoMainThreadSpecificProcessing();
}
++mNestedEventLoopDepth;
// We only want to create an AutoNoJSAPI on threads that actually do DOM
// stuff (including workers). Those are exactly the threads that have an
// mScriptObserver.
bool callScriptObserver = !!mScriptObserver;
if (callScriptObserver) {
noJSAPI.emplace();
mScriptObserver->BeforeProcessTask(reallyWait);
}
DrainDirectTasks();
#ifdef EARLY_BETA_OR_EARLIER
// Need to capture mayWaitForWakeup state before OnProcessNextEvent,
// since on the main thread OnProcessNextEvent ends up waiting for the new
// events.
bool mayWaitForWakeup = reallyWait && !mEvents->HasPendingEvent();
#endif
nsCOMPtr<nsIThreadObserver> obs = mEvents->GetObserverOnThread();
if (obs) {
obs->OnProcessNextEvent(this, reallyWait);
}
NOTIFY_EVENT_OBSERVERS(EventQueue()->EventObservers(), OnProcessNextEvent,
(this, reallyWait));
DrainDirectTasks();
#ifdef MOZ_CANARY
Canary canary;
#endif
nsresult rv = NS_OK;
{
// Scope for |event| to make sure that its destructor fires while
// mNestedEventLoopDepth has been incremented, since that destructor can
// also do work.
nsCOMPtr<nsIRunnable> event;
bool usingTaskController = mIsMainThread;
if (usingTaskController) {
event = TaskController::Get()->GetRunnableForMTTask(reallyWait);
} else {
event = mEvents->GetEvent(reallyWait, &mLastEventDelay);
}
*aResult = (event.get() != nullptr);
if (event) {
#ifdef EARLY_BETA_OR_EARLIER
if (mayWaitForWakeup && mThread) {
++mWakeupCount;
if (mWakeupCount == kTelemetryWakeupCountLimit) {
TimeStamp now = TimeStamp::Now();
double ms = (now - mLastWakeupCheckTime).ToMilliseconds();
if (ms < 0) {
ms = 0;
}
const char* name = !mNameForWakeupTelemetry.IsEmpty()
? mNameForWakeupTelemetry.get()
: PR_GetThreadName(mThread);
if (!name) {
name = mIsMainThread ? "MainThread" : "(nameless thread)";
}
nsDependentCString key(name);
Telemetry::Accumulate(Telemetry::THREAD_WAKEUP, key,
static_cast<uint32_t>(ms));
mLastWakeupCheckTime = now;
mWakeupCount = 0;
}
}
#endif
LOG(("THRD(%p) running [%p]\n", this, event.get()));
Maybe<LogRunnable::Run> log;
if (!usingTaskController) {
log.emplace(event);
}
// Delay event processing to encourage whoever dispatched this event
// to run.
DelayForChaosMode(ChaosFeature::TaskRunning, 1000);
mozilla::TimeStamp now = mozilla::TimeStamp::Now();
if (mUseHangMonitor) {
BackgroundHangMonitor().NotifyActivity();
}
Maybe<PerformanceCounterState::Snapshot> snapshot;
if (!usingTaskController) {
snapshot.emplace(mPerformanceCounterState.RunnableWillRun(now, false));
}
mLastEventStart = now;
if (!usingTaskController) {
AUTO_PROFILE_FOLLOWING_RUNNABLE(event);
event->Run();
} else {
// Avoid generating "Runnable" profiler markers for the
// "TaskController::ExecutePendingMTTasks" runnables created
// by TaskController, which already adds "Runnable" markers
// when executing tasks.
event->Run();
}
if (usingTaskController) {
*aResult = TaskController::Get()->MTTaskRunnableProcessedTask();
} else {
mPerformanceCounterState.RunnableDidRun(EmptyCString(),
std::move(snapshot.ref()));
}
// To cover the event's destructor code inside the LogRunnable span.
event = nullptr;
} else {
mLastEventDelay = TimeDuration();
mLastEventStart = TimeStamp();
if (aMayWait) {
MOZ_ASSERT(ShuttingDown(),
"This should only happen when shutting down");
rv = NS_ERROR_UNEXPECTED;
}
}
}
DrainDirectTasks();
NOTIFY_EVENT_OBSERVERS(EventQueue()->EventObservers(), AfterProcessNextEvent,
(this, *aResult));
if (obs) {
obs->AfterProcessNextEvent(this, *aResult);
}
// In case some EventObserver dispatched some direct tasks; process them
// now.
DrainDirectTasks();
if (callScriptObserver) {
if (mScriptObserver) {
mScriptObserver->AfterProcessTask(mNestedEventLoopDepth);
}
noJSAPI.reset();
}
--mNestedEventLoopDepth;
return rv;
}
//-----------------------------------------------------------------------------
// nsISupportsPriority
NS_IMETHODIMP
nsThread::GetPriority(int32_t* aPriority) {
*aPriority = mPriority;
return NS_OK;
}
NS_IMETHODIMP
nsThread::SetPriority(int32_t aPriority) {
if (NS_WARN_IF(!mThread)) {
return NS_ERROR_NOT_INITIALIZED;
}
// NSPR defines the following four thread priorities:
// PR_PRIORITY_LOW
// PR_PRIORITY_NORMAL
// PR_PRIORITY_HIGH
// PR_PRIORITY_URGENT
// We map the priority values defined on nsISupportsPriority to these
// values.
mPriority = aPriority;
PRThreadPriority pri;
if (mPriority <= PRIORITY_HIGHEST) {
pri = PR_PRIORITY_URGENT;
} else if (mPriority < PRIORITY_NORMAL) {
pri = PR_PRIORITY_HIGH;
} else if (mPriority > PRIORITY_NORMAL) {
pri = PR_PRIORITY_LOW;
} else {
pri = PR_PRIORITY_NORMAL;
}
// If chaos mode is active, retain the randomly chosen priority
if (!ChaosMode::isActive(ChaosFeature::ThreadScheduling)) {
PR_SetThreadPriority(mThread, pri);
}
return NS_OK;
}
NS_IMETHODIMP
nsThread::AdjustPriority(int32_t aDelta) {
return SetPriority(mPriority + aDelta);
}
//-----------------------------------------------------------------------------
// nsIThreadInternal
NS_IMETHODIMP
nsThread::GetObserver(nsIThreadObserver** aObs) {
MOZ_ASSERT(mEvents);
NS_ENSURE_TRUE(mEvents, NS_ERROR_NOT_IMPLEMENTED);
nsCOMPtr<nsIThreadObserver> obs = mEvents->GetObserver();
obs.forget(aObs);
return NS_OK;
}
NS_IMETHODIMP
nsThread::SetObserver(nsIThreadObserver* aObs) {
MOZ_ASSERT(mEvents);
NS_ENSURE_TRUE(mEvents, NS_ERROR_NOT_IMPLEMENTED);
if (NS_WARN_IF(PR_GetCurrentThread() != mThread)) {
return NS_ERROR_NOT_SAME_THREAD;
}
mEvents->SetObserver(aObs);
return NS_OK;
}
uint32_t nsThread::RecursionDepth() const {
MOZ_ASSERT(PR_GetCurrentThread() == mThread);
return mNestedEventLoopDepth;
}
NS_IMETHODIMP
nsThread::AddObserver(nsIThreadObserver* aObserver) {
MOZ_ASSERT(mEvents);
NS_ENSURE_TRUE(mEvents, NS_ERROR_NOT_IMPLEMENTED);
if (NS_WARN_IF(!aObserver)) {
return NS_ERROR_INVALID_ARG;
}
if (NS_WARN_IF(PR_GetCurrentThread() != mThread)) {
return NS_ERROR_NOT_SAME_THREAD;
}
EventQueue()->AddObserver(aObserver);
return NS_OK;
}
NS_IMETHODIMP
nsThread::RemoveObserver(nsIThreadObserver* aObserver) {
MOZ_ASSERT(mEvents);
NS_ENSURE_TRUE(mEvents, NS_ERROR_NOT_IMPLEMENTED);
if (NS_WARN_IF(PR_GetCurrentThread() != mThread)) {
return NS_ERROR_NOT_SAME_THREAD;
}
EventQueue()->RemoveObserver(aObserver);
return NS_OK;
}
void nsThread::SetScriptObserver(
mozilla::CycleCollectedJSContext* aScriptObserver) {
if (!aScriptObserver) {
mScriptObserver = nullptr;
return;
}
MOZ_ASSERT(!mScriptObserver);
mScriptObserver = aScriptObserver;
}
void NS_DispatchMemoryPressure();
void nsThread::DoMainThreadSpecificProcessing() const {
MOZ_ASSERT(mIsMainThread);
ipc::CancelCPOWs();
// Fire a memory pressure notification, if one is pending.
if (!ShuttingDown()) {
NS_DispatchMemoryPressure();
}
}
//-----------------------------------------------------------------------------
// nsIDirectTaskDispatcher
NS_IMETHODIMP
nsThread::DispatchDirectTask(already_AddRefed<nsIRunnable> aEvent) {
if (!IsOnCurrentThread()) {
return NS_ERROR_FAILURE;
}
mDirectTasks.AddTask(std::move(aEvent));
return NS_OK;
}
NS_IMETHODIMP nsThread::DrainDirectTasks() {
if (!IsOnCurrentThread()) {
return NS_ERROR_FAILURE;
}
mDirectTasks.DrainTasks();
return NS_OK;
}
NS_IMETHODIMP nsThread::HaveDirectTasks(bool* aValue) {
if (!IsOnCurrentThread()) {
return NS_ERROR_FAILURE;
}
*aValue = mDirectTasks.HaveTasks();
return NS_OK;
}
NS_IMPL_ISUPPORTS(nsThreadShutdownContext, nsIThreadShutdown)
NS_IMETHODIMP
nsThreadShutdownContext::OnCompletion(nsIRunnable* aEvent) {
if (mCompleted) {
aEvent->Run();
} else {
mCompletionCallbacks.AppendElement(aEvent);
}
return NS_OK;
}
NS_IMETHODIMP
nsThreadShutdownContext::GetCompleted(bool* aCompleted) {
*aCompleted = mCompleted;
return NS_OK;
}
NS_IMETHODIMP
nsThreadShutdownContext::StopWaitingAndLeakThread() {
// Take the joining thread from `mJoiningThread` so that the terminating
// thread won't try to dispatch nsThreadShutdownAckEvent to us anymore.
RefPtr<nsThread> joiningThread;
{
MutexAutoLock lock(mJoiningThreadMutex);
if (!mJoiningThread) {
// Shutdown is already being resolved, so there's nothing for us to do.
return NS_ERROR_NOT_AVAILABLE;
}
joiningThread = mJoiningThread.forget();
mThreadLeaked = true;
}
MOZ_DIAGNOSTIC_ASSERT(joiningThread->IsOnCurrentThread());
MarkCompleted();
return NS_OK;
}
void nsThreadShutdownContext::MarkCompleted() {
MOZ_ASSERT(!mCompleted);
mCompleted = true;
nsTArray<nsCOMPtr<nsIRunnable>> callbacks(std::move(mCompletionCallbacks));
for (auto& callback : callbacks) {
callback->Run();
}
}
namespace mozilla {
PerformanceCounterState::Snapshot PerformanceCounterState::RunnableWillRun(
TimeStamp aNow, bool aIsIdleRunnable) {
if (mIsMainThread && IsNestedRunnable()) {
// Flush out any accumulated time that should be accounted to the
// current runnable before we start running a nested runnable. Don't
// do this for non-mainthread threads that may be running their own
// event loops, like SocketThread.
MaybeReportAccumulatedTime("nested runnable"_ns, aNow);
}
Snapshot snapshot(mCurrentEventLoopDepth, mCurrentRunnableIsIdleRunnable);
mCurrentEventLoopDepth = mNestedEventLoopDepth;
mCurrentRunnableIsIdleRunnable = aIsIdleRunnable;
mCurrentTimeSliceStart = aNow;
return snapshot;
}
void PerformanceCounterState::RunnableDidRun(const nsCString& aName,
Snapshot&& aSnapshot) {
// First thing: Restore our mCurrentEventLoopDepth so we can use
// IsNestedRunnable().
mCurrentEventLoopDepth = aSnapshot.mOldEventLoopDepth;
// We may not need the current timestamp; don't bother computing it if we
// don't.
TimeStamp now;
if (mLongTaskLength.isSome() || IsNestedRunnable()) {
now = TimeStamp::Now();
}
if (mLongTaskLength.isSome()) {
MaybeReportAccumulatedTime(aName, now);
}
// And now restore the rest of our state.
mCurrentRunnableIsIdleRunnable = aSnapshot.mOldIsIdleRunnable;
if (IsNestedRunnable()) {
// Reset mCurrentTimeSliceStart to right now, so our parent runnable's
// next slice can be properly accounted for.
mCurrentTimeSliceStart = now;
} else {
// We are done at the outermost level; we are no longer in a timeslice.
mCurrentTimeSliceStart = TimeStamp();
}
}
void PerformanceCounterState::MaybeReportAccumulatedTime(const nsCString& aName,
TimeStamp aNow) {
MOZ_ASSERT(mCurrentTimeSliceStart,
"How did we get here if we're not in a timeslice?");
if (!mLongTaskLength.isSome()) {
return;
}
TimeDuration duration = aNow - mCurrentTimeSliceStart;
#ifdef MOZ_COLLECTING_RUNNABLE_TELEMETRY
if (mIsMainThread && duration.ToMilliseconds() > LONGTASK_TELEMETRY_MS) {
Telemetry::Accumulate(Telemetry::EVENT_LONGTASK, aName,
duration.ToMilliseconds());
}
#endif
// Long tasks only matter on the main thread.
if (duration.ToMilliseconds() >= mLongTaskLength.value()) {
// Idle events (gc...) don't *really* count here
if (!mCurrentRunnableIsIdleRunnable) {
mLastLongNonIdleTaskEnd = aNow;
}
mLastLongTaskEnd = aNow;
if (profiler_thread_is_being_profiled_for_markers()) {
struct LongTaskMarker {
static constexpr Span<const char> MarkerTypeName() {
return MakeStringSpan("MainThreadLongTask");
}
static void StreamJSONMarkerData(
baseprofiler::SpliceableJSONWriter& aWriter) {
aWriter.StringProperty("category", "LongTask");
}
static MarkerSchema MarkerTypeDisplay() {
using MS = MarkerSchema;
MS schema{MS::Location::MarkerChart, MS::Location::MarkerTable};
schema.AddKeyLabelFormatSearchable("category", "Type",
MS::Format::String,
MS::Searchable::Searchable);
return schema;
}
};
profiler_add_marker(mCurrentRunnableIsIdleRunnable
? ProfilerString8View("LongIdleTask")
: ProfilerString8View("LongTask"),
geckoprofiler::category::OTHER,
MarkerTiming::Interval(mCurrentTimeSliceStart, aNow),
LongTaskMarker{});
}
}
}
} // namespace mozilla
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