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-rw-r--r--xpcom/threads/nsTimerImpl.cpp820
1 files changed, 820 insertions, 0 deletions
diff --git a/xpcom/threads/nsTimerImpl.cpp b/xpcom/threads/nsTimerImpl.cpp
new file mode 100644
index 0000000000..d143eebe86
--- /dev/null
+++ b/xpcom/threads/nsTimerImpl.cpp
@@ -0,0 +1,820 @@
+/* -*- 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 "nsTimerImpl.h"
+
+#include <utility>
+
+#include "TimerThread.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/IntegerPrintfMacros.h"
+#include "mozilla/Logging.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/ProfilerLabels.h"
+#include "mozilla/ResultExtensions.h"
+#include "mozilla/Sprintf.h"
+#include "mozilla/StaticMutex.h"
+#include "nsThreadManager.h"
+#include "nsThreadUtils.h"
+#include "pratom.h"
+
+#ifdef XP_WIN
+# include <process.h>
+# ifndef getpid
+# define getpid _getpid
+# endif
+#else
+# include <unistd.h>
+#endif
+
+using mozilla::Atomic;
+using mozilla::LogLevel;
+using mozilla::MakeRefPtr;
+using mozilla::MutexAutoLock;
+using mozilla::TimeDuration;
+using mozilla::TimeStamp;
+
+// Holds the timer thread and manages all interactions with it
+// under a locked mutex. This wrapper is not destroyed until after
+// nsThreadManager shutdown to ensure we don't UAF during an offthread access to
+// the timer thread.
+class TimerThreadWrapper {
+ public:
+ constexpr TimerThreadWrapper() : mThread(nullptr){};
+ ~TimerThreadWrapper() = default;
+
+ nsresult Init();
+ void Shutdown();
+
+ nsresult AddTimer(nsTimerImpl* aTimer, const MutexAutoLock& aProofOfLock)
+ MOZ_REQUIRES(aTimer->mMutex);
+ nsresult RemoveTimer(nsTimerImpl* aTimer, const MutexAutoLock& aProofOfLock)
+ MOZ_REQUIRES(aTimer->mMutex);
+ TimeStamp FindNextFireTimeForCurrentThread(TimeStamp aDefault,
+ uint32_t aSearchBound);
+ uint32_t AllowedEarlyFiringMicroseconds();
+ nsresult GetTimers(nsTArray<RefPtr<nsITimer>>& aRetVal);
+
+ private:
+ static mozilla::StaticMutex sMutex;
+ TimerThread* mThread MOZ_GUARDED_BY(sMutex);
+};
+
+mozilla::StaticMutex TimerThreadWrapper::sMutex;
+
+nsresult TimerThreadWrapper::Init() {
+ mozilla::StaticMutexAutoLock lock(sMutex);
+ mThread = new TimerThread();
+
+ NS_ADDREF(mThread);
+
+ return NS_OK;
+}
+
+void TimerThreadWrapper::Shutdown() {
+ RefPtr<TimerThread> thread;
+
+ {
+ mozilla::StaticMutexAutoLock lock(sMutex);
+ if (!mThread) {
+ return;
+ }
+ thread = mThread;
+ }
+ // Shutdown calls |nsTimerImpl::Cancel| which needs to make a call into
+ // |RemoveTimer|. This can't be done under the lock.
+ thread->Shutdown();
+
+ {
+ mozilla::StaticMutexAutoLock lock(sMutex);
+ NS_RELEASE(mThread);
+ }
+}
+
+nsresult TimerThreadWrapper::AddTimer(nsTimerImpl* aTimer,
+ const MutexAutoLock& aProofOfLock) {
+ mozilla::StaticMutexAutoLock lock(sMutex);
+ if (mThread) {
+ return mThread->AddTimer(aTimer, aProofOfLock);
+ }
+ return NS_ERROR_NOT_AVAILABLE;
+}
+
+nsresult TimerThreadWrapper::RemoveTimer(nsTimerImpl* aTimer,
+ const MutexAutoLock& aProofOfLock) {
+ mozilla::StaticMutexAutoLock lock(sMutex);
+ if (mThread) {
+ return mThread->RemoveTimer(aTimer, aProofOfLock);
+ }
+ return NS_ERROR_NOT_AVAILABLE;
+}
+
+TimeStamp TimerThreadWrapper::FindNextFireTimeForCurrentThread(
+ TimeStamp aDefault, uint32_t aSearchBound) {
+ mozilla::StaticMutexAutoLock lock(sMutex);
+ return mThread
+ ? mThread->FindNextFireTimeForCurrentThread(aDefault, aSearchBound)
+ : TimeStamp();
+}
+
+uint32_t TimerThreadWrapper::AllowedEarlyFiringMicroseconds() {
+ mozilla::StaticMutexAutoLock lock(sMutex);
+ return mThread ? mThread->AllowedEarlyFiringMicroseconds() : 0;
+}
+
+nsresult TimerThreadWrapper::GetTimers(nsTArray<RefPtr<nsITimer>>& aRetVal) {
+ RefPtr<TimerThread> thread;
+ {
+ mozilla::StaticMutexAutoLock lock(sMutex);
+ if (!mThread) {
+ return NS_ERROR_NOT_AVAILABLE;
+ }
+ thread = mThread;
+ }
+ return thread->GetTimers(aRetVal);
+}
+
+static TimerThreadWrapper gThreadWrapper;
+
+// This module prints info about the precision of timers.
+static mozilla::LazyLogModule sTimerLog("nsTimerImpl");
+
+mozilla::LogModule* GetTimerLog() { return sTimerLog; }
+
+TimeStamp NS_GetTimerDeadlineHintOnCurrentThread(TimeStamp aDefault,
+ uint32_t aSearchBound) {
+ return gThreadWrapper.FindNextFireTimeForCurrentThread(aDefault,
+ aSearchBound);
+}
+
+already_AddRefed<nsITimer> NS_NewTimer() { return NS_NewTimer(nullptr); }
+
+already_AddRefed<nsITimer> NS_NewTimer(nsIEventTarget* aTarget) {
+ return nsTimer::WithEventTarget(aTarget).forget();
+}
+
+mozilla::Result<nsCOMPtr<nsITimer>, nsresult> NS_NewTimerWithObserver(
+ nsIObserver* aObserver, uint32_t aDelay, uint32_t aType,
+ nsIEventTarget* aTarget) {
+ nsCOMPtr<nsITimer> timer;
+ MOZ_TRY(NS_NewTimerWithObserver(getter_AddRefs(timer), aObserver, aDelay,
+ aType, aTarget));
+ return std::move(timer);
+}
+nsresult NS_NewTimerWithObserver(nsITimer** aTimer, nsIObserver* aObserver,
+ uint32_t aDelay, uint32_t aType,
+ nsIEventTarget* aTarget) {
+ auto timer = nsTimer::WithEventTarget(aTarget);
+
+ MOZ_TRY(timer->Init(aObserver, aDelay, aType));
+ timer.forget(aTimer);
+ return NS_OK;
+}
+
+mozilla::Result<nsCOMPtr<nsITimer>, nsresult> NS_NewTimerWithCallback(
+ nsITimerCallback* aCallback, uint32_t aDelay, uint32_t aType,
+ nsIEventTarget* aTarget) {
+ nsCOMPtr<nsITimer> timer;
+ MOZ_TRY(NS_NewTimerWithCallback(getter_AddRefs(timer), aCallback, aDelay,
+ aType, aTarget));
+ return std::move(timer);
+}
+nsresult NS_NewTimerWithCallback(nsITimer** aTimer, nsITimerCallback* aCallback,
+ uint32_t aDelay, uint32_t aType,
+ nsIEventTarget* aTarget) {
+ auto timer = nsTimer::WithEventTarget(aTarget);
+
+ MOZ_TRY(timer->InitWithCallback(aCallback, aDelay, aType));
+ timer.forget(aTimer);
+ return NS_OK;
+}
+
+mozilla::Result<nsCOMPtr<nsITimer>, nsresult> NS_NewTimerWithCallback(
+ nsITimerCallback* aCallback, const TimeDuration& aDelay, uint32_t aType,
+ nsIEventTarget* aTarget) {
+ nsCOMPtr<nsITimer> timer;
+ MOZ_TRY(NS_NewTimerWithCallback(getter_AddRefs(timer), aCallback, aDelay,
+ aType, aTarget));
+ return std::move(timer);
+}
+nsresult NS_NewTimerWithCallback(nsITimer** aTimer, nsITimerCallback* aCallback,
+ const TimeDuration& aDelay, uint32_t aType,
+ nsIEventTarget* aTarget) {
+ auto timer = nsTimer::WithEventTarget(aTarget);
+
+ MOZ_TRY(timer->InitHighResolutionWithCallback(aCallback, aDelay, aType));
+ timer.forget(aTimer);
+ return NS_OK;
+}
+
+mozilla::Result<nsCOMPtr<nsITimer>, nsresult> NS_NewTimerWithCallback(
+ std::function<void(nsITimer*)>&& aCallback, uint32_t aDelay, uint32_t aType,
+ const char* aNameString, nsIEventTarget* aTarget) {
+ nsCOMPtr<nsITimer> timer;
+ MOZ_TRY(NS_NewTimerWithCallback(getter_AddRefs(timer), std::move(aCallback),
+ aDelay, aType, aNameString, aTarget));
+ return timer;
+}
+nsresult NS_NewTimerWithCallback(nsITimer** aTimer,
+ std::function<void(nsITimer*)>&& aCallback,
+ uint32_t aDelay, uint32_t aType,
+ const char* aNameString,
+ nsIEventTarget* aTarget) {
+ return NS_NewTimerWithCallback(aTimer, std::move(aCallback),
+ TimeDuration::FromMilliseconds(aDelay), aType,
+ aNameString, aTarget);
+}
+
+mozilla::Result<nsCOMPtr<nsITimer>, nsresult> NS_NewTimerWithCallback(
+ std::function<void(nsITimer*)>&& aCallback, const TimeDuration& aDelay,
+ uint32_t aType, const char* aNameString, nsIEventTarget* aTarget) {
+ nsCOMPtr<nsITimer> timer;
+ MOZ_TRY(NS_NewTimerWithCallback(getter_AddRefs(timer), std::move(aCallback),
+ aDelay, aType, aNameString, aTarget));
+ return timer;
+}
+nsresult NS_NewTimerWithCallback(nsITimer** aTimer,
+ std::function<void(nsITimer*)>&& aCallback,
+ const TimeDuration& aDelay, uint32_t aType,
+ const char* aNameString,
+ nsIEventTarget* aTarget) {
+ RefPtr<nsTimer> timer = nsTimer::WithEventTarget(aTarget);
+
+ MOZ_TRY(timer->InitWithClosureCallback(std::move(aCallback), aDelay, aType,
+ aNameString));
+ timer.forget(aTimer);
+ return NS_OK;
+}
+
+mozilla::Result<nsCOMPtr<nsITimer>, nsresult> NS_NewTimerWithFuncCallback(
+ nsTimerCallbackFunc aCallback, void* aClosure, uint32_t aDelay,
+ uint32_t aType, const char* aNameString, nsIEventTarget* aTarget) {
+ nsCOMPtr<nsITimer> timer;
+ MOZ_TRY(NS_NewTimerWithFuncCallback(getter_AddRefs(timer), aCallback,
+ aClosure, aDelay, aType, aNameString,
+ aTarget));
+ return std::move(timer);
+}
+nsresult NS_NewTimerWithFuncCallback(nsITimer** aTimer,
+ nsTimerCallbackFunc aCallback,
+ void* aClosure, uint32_t aDelay,
+ uint32_t aType, const char* aNameString,
+ nsIEventTarget* aTarget) {
+ auto timer = nsTimer::WithEventTarget(aTarget);
+
+ MOZ_TRY(timer->InitWithNamedFuncCallback(aCallback, aClosure, aDelay, aType,
+ aNameString));
+ timer.forget(aTimer);
+ return NS_OK;
+}
+
+mozilla::Result<nsCOMPtr<nsITimer>, nsresult> NS_NewTimerWithFuncCallback(
+ nsTimerCallbackFunc aCallback, void* aClosure, const TimeDuration& aDelay,
+ uint32_t aType, const char* aNameString, nsIEventTarget* aTarget) {
+ nsCOMPtr<nsITimer> timer;
+ MOZ_TRY(NS_NewTimerWithFuncCallback(getter_AddRefs(timer), aCallback,
+ aClosure, aDelay, aType, aNameString,
+ aTarget));
+ return std::move(timer);
+}
+nsresult NS_NewTimerWithFuncCallback(nsITimer** aTimer,
+ nsTimerCallbackFunc aCallback,
+ void* aClosure, const TimeDuration& aDelay,
+ uint32_t aType, const char* aNameString,
+ nsIEventTarget* aTarget) {
+ auto timer = nsTimer::WithEventTarget(aTarget);
+
+ MOZ_TRY(timer->InitHighResolutionWithNamedFuncCallback(
+ aCallback, aClosure, aDelay, aType, aNameString));
+ timer.forget(aTimer);
+ return NS_OK;
+}
+
+// This module prints info about which timers are firing, which is useful for
+// wakeups for the purposes of power profiling. Set the following environment
+// variable before starting the browser.
+//
+// MOZ_LOG=TimerFirings:4
+//
+// Then a line will be printed for every timer that fires.
+//
+// If you redirect this output to a file called "out", you can then
+// post-process it with a command something like the following.
+//
+// cat out | grep timer | sort | uniq -c | sort -r -n
+//
+// This will show how often each unique line appears, with the most common ones
+// first.
+//
+// More detailed docs are here:
+// https://developer.mozilla.org/en-US/docs/Mozilla/Performance/TimerFirings_logging
+//
+static mozilla::LazyLogModule sTimerFiringsLog("TimerFirings");
+
+static mozilla::LogModule* GetTimerFiringsLog() { return sTimerFiringsLog; }
+
+#include <math.h>
+
+/* static */
+mozilla::StaticMutex nsTimerImpl::sDeltaMutex;
+/* static */
+double nsTimerImpl::sDeltaSumSquared MOZ_GUARDED_BY(nsTimerImpl::sDeltaMutex) =
+ 0;
+/* static */
+double nsTimerImpl::sDeltaSum MOZ_GUARDED_BY(nsTimerImpl::sDeltaMutex) = 0;
+/* static */
+double nsTimerImpl::sDeltaNum MOZ_GUARDED_BY(nsTimerImpl::sDeltaMutex) = 0;
+
+static void myNS_MeanAndStdDev(double n, double sumOfValues,
+ double sumOfSquaredValues, double* meanResult,
+ double* stdDevResult) {
+ double mean = 0.0, var = 0.0, stdDev = 0.0;
+ if (n > 0.0 && sumOfValues >= 0) {
+ mean = sumOfValues / n;
+ double temp = (n * sumOfSquaredValues) - (sumOfValues * sumOfValues);
+ if (temp < 0.0 || n <= 1) {
+ var = 0.0;
+ } else {
+ var = temp / (n * (n - 1));
+ }
+ // for some reason, Windows says sqrt(0.0) is "-1.#J" (?!) so do this:
+ stdDev = var != 0.0 ? sqrt(var) : 0.0;
+ }
+ *meanResult = mean;
+ *stdDevResult = stdDev;
+}
+
+NS_IMPL_QUERY_INTERFACE(nsTimer, nsITimer)
+NS_IMPL_ADDREF(nsTimer)
+
+NS_IMPL_ISUPPORTS(nsTimerManager, nsITimerManager)
+
+NS_IMETHODIMP nsTimerManager::GetTimers(nsTArray<RefPtr<nsITimer>>& aRetVal) {
+ return gThreadWrapper.GetTimers(aRetVal);
+}
+
+NS_IMETHODIMP_(MozExternalRefCountType)
+nsTimer::Release(void) {
+ nsrefcnt count = --mRefCnt;
+ NS_LOG_RELEASE(this, count, "nsTimer");
+
+ if (count == 1) {
+ // Last ref, in nsTimerImpl::mITimer. Make sure the cycle is broken.
+ mImpl->CancelImpl(true);
+ } else if (count == 0) {
+ delete this;
+ }
+
+ return count;
+}
+
+nsTimerImpl::nsTimerImpl(nsITimer* aTimer, nsIEventTarget* aTarget)
+ : mEventTarget(aTarget),
+ mIsInTimerThread(false),
+ mType(0),
+ mGeneration(0),
+ mITimer(aTimer),
+ mMutex("nsTimerImpl::mMutex"),
+ mCallback(UnknownCallback{}),
+ mFiring(0) {
+ // XXX some code creates timers during xpcom shutdown, when threads are no
+ // longer available, so we cannot turn this on yet.
+ // MOZ_ASSERT(mEventTarget);
+}
+
+// static
+nsresult nsTimerImpl::Startup() { return gThreadWrapper.Init(); }
+
+void nsTimerImpl::Shutdown() {
+ if (MOZ_LOG_TEST(GetTimerLog(), LogLevel::Debug)) {
+ mozilla::StaticMutexAutoLock lock(sDeltaMutex);
+ double mean = 0, stddev = 0;
+ myNS_MeanAndStdDev(sDeltaNum, sDeltaSum, sDeltaSumSquared, &mean, &stddev);
+
+ MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+ ("sDeltaNum = %f, sDeltaSum = %f, sDeltaSumSquared = %f\n",
+ sDeltaNum, sDeltaSum, sDeltaSumSquared));
+ MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+ ("mean: %fms, stddev: %fms\n", mean, stddev));
+ }
+
+ gThreadWrapper.Shutdown();
+}
+
+nsresult nsTimerImpl::InitCommon(const TimeDuration& aDelay, uint32_t aType,
+ Callback&& newCallback,
+ const MutexAutoLock& aProofOfLock) {
+ if (!mEventTarget) {
+ return NS_ERROR_NOT_INITIALIZED;
+ }
+
+ gThreadWrapper.RemoveTimer(this, aProofOfLock);
+
+ // If we have an existing callback, using `swap` ensures it's destroyed after
+ // the mutex is unlocked in our caller.
+ std::swap(mCallback, newCallback);
+ ++mGeneration;
+
+ mType = (uint8_t)aType;
+ mDelay = aDelay;
+ mTimeout = TimeStamp::Now() + mDelay;
+
+ return gThreadWrapper.AddTimer(this, aProofOfLock);
+}
+
+nsresult nsTimerImpl::InitWithNamedFuncCallback(nsTimerCallbackFunc aFunc,
+ void* aClosure, uint32_t aDelay,
+ uint32_t aType,
+ const char* aName) {
+ return InitHighResolutionWithNamedFuncCallback(
+ aFunc, aClosure, TimeDuration::FromMilliseconds(aDelay), aType, aName);
+}
+
+nsresult nsTimerImpl::InitHighResolutionWithNamedFuncCallback(
+ nsTimerCallbackFunc aFunc, void* aClosure, const TimeDuration& aDelay,
+ uint32_t aType, const char* aName) {
+ if (NS_WARN_IF(!aFunc)) {
+ return NS_ERROR_INVALID_ARG;
+ }
+
+ Callback cb{FuncCallback{aFunc, aClosure, aName}};
+
+ MutexAutoLock lock(mMutex);
+ return InitCommon(aDelay, aType, std::move(cb), lock);
+}
+
+nsresult nsTimerImpl::InitWithCallback(nsITimerCallback* aCallback,
+ uint32_t aDelayInMs, uint32_t aType) {
+ return InitHighResolutionWithCallback(
+ aCallback, TimeDuration::FromMilliseconds(aDelayInMs), aType);
+}
+
+nsresult nsTimerImpl::InitHighResolutionWithCallback(
+ nsITimerCallback* aCallback, const TimeDuration& aDelay, uint32_t aType) {
+ if (NS_WARN_IF(!aCallback)) {
+ return NS_ERROR_INVALID_ARG;
+ }
+
+ // Goes out of scope after the unlock, prevents deadlock
+ Callback cb{nsCOMPtr{aCallback}};
+
+ MutexAutoLock lock(mMutex);
+ return InitCommon(aDelay, aType, std::move(cb), lock);
+}
+
+nsresult nsTimerImpl::Init(nsIObserver* aObserver, uint32_t aDelayInMs,
+ uint32_t aType) {
+ if (NS_WARN_IF(!aObserver)) {
+ return NS_ERROR_INVALID_ARG;
+ }
+
+ Callback cb{nsCOMPtr{aObserver}};
+
+ MutexAutoLock lock(mMutex);
+ return InitCommon(TimeDuration::FromMilliseconds(aDelayInMs), aType,
+ std::move(cb), lock);
+}
+
+nsresult nsTimerImpl::InitWithClosureCallback(
+ std::function<void(nsITimer*)>&& aCallback, const TimeDuration& aDelay,
+ uint32_t aType, const char* aNameString) {
+ if (NS_WARN_IF(!aCallback)) {
+ return NS_ERROR_INVALID_ARG;
+ }
+
+ Callback cb{ClosureCallback{std::move(aCallback), aNameString}};
+
+ MutexAutoLock lock(mMutex);
+ return InitCommon(aDelay, aType, std::move(cb), lock);
+}
+
+nsresult nsTimerImpl::Cancel() {
+ CancelImpl(false);
+ return NS_OK;
+}
+
+void nsTimerImpl::CancelImpl(bool aClearITimer) {
+ Callback cbTrash{UnknownCallback{}};
+ RefPtr<nsITimer> timerTrash;
+
+ {
+ MutexAutoLock lock(mMutex);
+ gThreadWrapper.RemoveTimer(this, lock);
+
+ // The swap ensures our callback isn't dropped until after the mutex is
+ // unlocked.
+ std::swap(cbTrash, mCallback);
+ ++mGeneration;
+
+ // Don't clear this if we're firing; once Fire returns, we'll get this call
+ // again.
+ if (aClearITimer && !mFiring) {
+ MOZ_RELEASE_ASSERT(
+ mITimer,
+ "mITimer was nulled already! "
+ "This indicates that someone has messed up the refcount on nsTimer!");
+ timerTrash.swap(mITimer);
+ }
+ }
+}
+
+nsresult nsTimerImpl::SetDelay(uint32_t aDelay) {
+ MutexAutoLock lock(mMutex);
+ if (GetCallback().is<UnknownCallback>() && !IsRepeating()) {
+ // This may happen if someone tries to re-use a one-shot timer
+ // by re-setting delay instead of reinitializing the timer.
+ NS_ERROR(
+ "nsITimer->SetDelay() called when the "
+ "one-shot timer is not set up.");
+ return NS_ERROR_NOT_INITIALIZED;
+ }
+
+ bool reAdd = false;
+ reAdd = NS_SUCCEEDED(gThreadWrapper.RemoveTimer(this, lock));
+
+ mDelay = TimeDuration::FromMilliseconds(aDelay);
+ mTimeout = TimeStamp::Now() + mDelay;
+
+ if (reAdd) {
+ gThreadWrapper.AddTimer(this, lock);
+ }
+
+ return NS_OK;
+}
+
+nsresult nsTimerImpl::GetDelay(uint32_t* aDelay) {
+ MutexAutoLock lock(mMutex);
+ *aDelay = mDelay.ToMilliseconds();
+ return NS_OK;
+}
+
+nsresult nsTimerImpl::SetType(uint32_t aType) {
+ MutexAutoLock lock(mMutex);
+ mType = (uint8_t)aType;
+ // XXX if this is called, we should change the actual type.. this could effect
+ // repeating timers. we need to ensure in Fire() that if mType has changed
+ // during the callback that we don't end up with the timer in the queue twice.
+ return NS_OK;
+}
+
+nsresult nsTimerImpl::GetType(uint32_t* aType) {
+ MutexAutoLock lock(mMutex);
+ *aType = mType;
+ return NS_OK;
+}
+
+nsresult nsTimerImpl::GetClosure(void** aClosure) {
+ MutexAutoLock lock(mMutex);
+ if (GetCallback().is<FuncCallback>()) {
+ *aClosure = GetCallback().as<FuncCallback>().mClosure;
+ } else {
+ *aClosure = nullptr;
+ }
+ return NS_OK;
+}
+
+nsresult nsTimerImpl::GetCallback(nsITimerCallback** aCallback) {
+ MutexAutoLock lock(mMutex);
+ if (GetCallback().is<InterfaceCallback>()) {
+ NS_IF_ADDREF(*aCallback = GetCallback().as<InterfaceCallback>());
+ } else {
+ *aCallback = nullptr;
+ }
+ return NS_OK;
+}
+
+nsresult nsTimerImpl::GetTarget(nsIEventTarget** aTarget) {
+ MutexAutoLock lock(mMutex);
+ NS_IF_ADDREF(*aTarget = mEventTarget);
+ return NS_OK;
+}
+
+nsresult nsTimerImpl::SetTarget(nsIEventTarget* aTarget) {
+ MutexAutoLock lock(mMutex);
+ if (NS_WARN_IF(!mCallback.is<UnknownCallback>())) {
+ return NS_ERROR_ALREADY_INITIALIZED;
+ }
+
+ if (aTarget) {
+ mEventTarget = aTarget;
+ } else {
+ mEventTarget = mozilla::GetCurrentSerialEventTarget();
+ }
+ return NS_OK;
+}
+
+nsresult nsTimerImpl::GetAllowedEarlyFiringMicroseconds(uint32_t* aValueOut) {
+ *aValueOut = gThreadWrapper.AllowedEarlyFiringMicroseconds();
+ return NS_OK;
+}
+
+void nsTimerImpl::Fire(int32_t aGeneration) {
+ uint8_t oldType;
+ uint32_t oldDelay;
+ TimeStamp oldTimeout;
+ Callback callbackDuringFire{UnknownCallback{}};
+ nsCOMPtr<nsITimer> timer;
+
+ {
+ // Don't fire callbacks or fiddle with refcounts when the mutex is locked.
+ // If some other thread Cancels/Inits after this, they're just too late.
+ MutexAutoLock lock(mMutex);
+ if (aGeneration != mGeneration) {
+ // This timer got rescheduled or cancelled before we fired, so ignore this
+ // firing
+ return;
+ }
+
+ // We modify mTimeout, so we must not be in the current TimerThread's
+ // mTimers list.
+ MOZ_ASSERT(!mIsInTimerThread);
+
+ ++mFiring;
+ callbackDuringFire = mCallback;
+ oldType = mType;
+ oldDelay = mDelay.ToMilliseconds();
+ oldTimeout = mTimeout;
+ // Ensure that the nsITimer does not unhook from the nsTimerImpl during
+ // Fire; this will cause null pointer crashes if the user of the timer drops
+ // its reference, and then uses the nsITimer* passed in the callback.
+ timer = mITimer;
+ }
+
+ AUTO_PROFILER_LABEL("nsTimerImpl::Fire", OTHER);
+
+ TimeStamp fireTime = TimeStamp::Now();
+ if (MOZ_LOG_TEST(GetTimerLog(), LogLevel::Debug)) {
+ TimeDuration delta = fireTime - oldTimeout;
+ int32_t d = delta.ToMilliseconds(); // delta in ms
+ {
+ mozilla::StaticMutexAutoLock lock(sDeltaMutex);
+ sDeltaSum += abs(d);
+ sDeltaSumSquared += double(d) * double(d);
+ sDeltaNum++;
+ }
+
+ MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+ ("[this=%p] expected delay time %4ums\n", this, oldDelay));
+ MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+ ("[this=%p] actual delay time %4dms\n", this, oldDelay + d));
+ MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+ ("[this=%p] (mType is %d) -------\n", this, oldType));
+ MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+ ("[this=%p] delta %4dms\n", this, d));
+ }
+
+ if (MOZ_LOG_TEST(GetTimerFiringsLog(), LogLevel::Debug)) {
+ LogFiring(callbackDuringFire, oldType, oldDelay);
+ }
+
+ callbackDuringFire.match(
+ [](const UnknownCallback&) {},
+ [&](const InterfaceCallback& i) { i->Notify(timer); },
+ [&](const ObserverCallback& o) {
+ o->Observe(timer, NS_TIMER_CALLBACK_TOPIC, nullptr);
+ },
+ [&](const FuncCallback& f) { f.mFunc(timer, f.mClosure); },
+ [&](const ClosureCallback& c) { c.mFunc(timer); });
+
+ TimeStamp now = TimeStamp::Now();
+
+ MutexAutoLock lock(mMutex);
+ if (aGeneration == mGeneration) {
+ if (IsRepeating()) {
+ // Repeating timer has not been re-init or canceled; reschedule
+ if (IsSlack()) {
+ mTimeout = now + mDelay;
+ } else {
+ if (mDelay) {
+ // If we are late enough finishing the callback that we have missed
+ // some firings, do not attempt to play catchup, just get back on the
+ // cadence we're supposed to maintain.
+ unsigned missedFirings =
+ static_cast<unsigned>((now - mTimeout) / mDelay);
+ mTimeout += mDelay * (missedFirings + 1);
+ } else {
+ // Can we stop allowing repeating timers with delay 0?
+ mTimeout = now;
+ }
+ }
+ gThreadWrapper.AddTimer(this, lock);
+ } else {
+ // Non-repeating timer that has not been re-scheduled. Clear.
+ // XXX(nika): Other callsites seem to go to some effort to avoid
+ // destroying mCallback when it's held. Why not this one?
+ mCallback = mozilla::AsVariant(UnknownCallback{});
+ }
+ }
+
+ --mFiring;
+
+ MOZ_LOG(GetTimerLog(), LogLevel::Debug,
+ ("[this=%p] Took %fms to fire timer callback\n", this,
+ (now - fireTime).ToMilliseconds()));
+}
+
+// See the big comment above GetTimerFiringsLog() to understand this code.
+void nsTimerImpl::LogFiring(const Callback& aCallback, uint8_t aType,
+ uint32_t aDelay) {
+ const char* typeStr;
+ switch (aType) {
+ case nsITimer::TYPE_ONE_SHOT:
+ typeStr = "ONE_SHOT ";
+ break;
+ case nsITimer::TYPE_ONE_SHOT_LOW_PRIORITY:
+ typeStr = "ONE_LOW ";
+ break;
+ case nsITimer::TYPE_REPEATING_SLACK:
+ typeStr = "SLACK ";
+ break;
+ case nsITimer::TYPE_REPEATING_SLACK_LOW_PRIORITY:
+ typeStr = "SLACK_LOW ";
+ break;
+ case nsITimer::TYPE_REPEATING_PRECISE: /* fall through */
+ case nsITimer::TYPE_REPEATING_PRECISE_CAN_SKIP:
+ typeStr = "PRECISE ";
+ break;
+ default:
+ MOZ_CRASH("bad type");
+ }
+
+ aCallback.match(
+ [&](const UnknownCallback&) {
+ MOZ_LOG(
+ GetTimerFiringsLog(), LogLevel::Debug,
+ ("[%d] ??? timer (%s, %5d ms)\n", getpid(), typeStr, aDelay));
+ },
+ [&](const InterfaceCallback& i) {
+ MOZ_LOG(GetTimerFiringsLog(), LogLevel::Debug,
+ ("[%d] iface timer (%s %5d ms): %p\n", getpid(), typeStr,
+ aDelay, i.get()));
+ },
+ [&](const ObserverCallback& o) {
+ MOZ_LOG(GetTimerFiringsLog(), LogLevel::Debug,
+ ("[%d] obs timer (%s %5d ms): %p\n", getpid(), typeStr,
+ aDelay, o.get()));
+ },
+ [&](const FuncCallback& f) {
+ MOZ_LOG(GetTimerFiringsLog(), LogLevel::Debug,
+ ("[%d] fn timer (%s %5d ms): %s\n", getpid(), typeStr,
+ aDelay, f.mName));
+ },
+ [&](const ClosureCallback& c) {
+ MOZ_LOG(GetTimerFiringsLog(), LogLevel::Debug,
+ ("[%d] closure timer (%s %5d ms): %s\n", getpid(), typeStr,
+ aDelay, c.mName));
+ });
+}
+
+void nsTimerImpl::GetName(nsACString& aName,
+ const MutexAutoLock& aProofOfLock) {
+ GetCallback().match(
+ [&](const UnknownCallback&) { aName.AssignLiteral("Canceled_timer"); },
+ [&](const InterfaceCallback& i) {
+ if (nsCOMPtr<nsINamed> named = do_QueryInterface(i)) {
+ named->GetName(aName);
+ } else {
+ aName.AssignLiteral("Anonymous_interface_timer");
+ }
+ },
+ [&](const ObserverCallback& o) {
+ if (nsCOMPtr<nsINamed> named = do_QueryInterface(o)) {
+ named->GetName(aName);
+ } else {
+ aName.AssignLiteral("Anonymous_observer_timer");
+ }
+ },
+ [&](const FuncCallback& f) { aName.Assign(f.mName); },
+ [&](const ClosureCallback& c) { aName.Assign(c.mName); });
+}
+
+nsresult nsTimerImpl::GetName(nsACString& aName) {
+ MutexAutoLock lock(mMutex);
+ GetName(aName, lock);
+ return NS_OK;
+}
+
+nsTimer::~nsTimer() = default;
+
+size_t nsTimer::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) {
+ return aMallocSizeOf(this);
+}
+
+/* static */
+RefPtr<nsTimer> nsTimer::WithEventTarget(nsIEventTarget* aTarget) {
+ if (!aTarget) {
+ aTarget = mozilla::GetCurrentSerialEventTarget();
+ }
+ return do_AddRef(new nsTimer(aTarget));
+}
+
+/* static */
+nsresult nsTimer::XPCOMConstructor(REFNSIID aIID, void** aResult) {
+ *aResult = nullptr;
+ auto timer = WithEventTarget(nullptr);
+
+ return timer->QueryInterface(aIID, aResult);
+}