Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 192 insertions, 0 deletions

diff --git a/dom/media/MediaTimer.cpp b/dom/media/MediaTimer.cpp
new file mode 100644
index 0000000000..c34eb816fa
--- /dev/null
+++ b/dom/media/MediaTimer.cpp
@@ -0,0 +1,192 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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 "MediaTimer.h"
+
+#include "mozilla/DebugOnly.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/SharedThreadPool.h"
+#include "mozilla/Unused.h"
+#include "nsComponentManagerUtils.h"
+#include "nsThreadUtils.h"
+#include <math.h>
+
+namespace mozilla {
+
+MediaTimer::MediaTimer(bool aFuzzy)
+    : mMonitor("MediaTimer Monitor"),
+      mCreationTimeStamp(TimeStamp::Now()),
+      mUpdateScheduled(false),
+      mFuzzy(aFuzzy) {
+  TIMER_LOG("MediaTimer::MediaTimer");
+
+  // Use the SharedThreadPool to create an nsIThreadPool with a maximum of one
+  // thread, which is equivalent to an nsIThread for our purposes.
+  RefPtr<SharedThreadPool> threadPool(
+      SharedThreadPool::Get("MediaTimer"_ns, 1));
+  mThread = threadPool.get();
+  mTimer = NS_NewTimer(mThread);
+}
+
+void MediaTimer::DispatchDestroy() {
+  // Hold a strong reference to the thread so that it doesn't get deleted in
+  // Destroy(), which may run completely before the stack if Dispatch() begins
+  // to unwind.
+  nsCOMPtr<nsIEventTarget> thread = mThread;
+  nsresult rv =
+      thread->Dispatch(NewNonOwningRunnableMethod("MediaTimer::Destroy", this,
+                                                  &MediaTimer::Destroy),
+                       NS_DISPATCH_NORMAL);
+  MOZ_DIAGNOSTIC_ASSERT(NS_SUCCEEDED(rv));
+  Unused << rv;
+  (void)rv;
+}
+
+void MediaTimer::Destroy() {
+  MOZ_ASSERT(OnMediaTimerThread());
+  TIMER_LOG("MediaTimer::Destroy");
+
+  // Reject any outstanding entries.
+  {
+    MonitorAutoLock lock(mMonitor);
+    Reject();
+
+    // Cancel the timer if necessary.
+    CancelTimerIfArmed();
+  }
+
+  delete this;
+}
+
+bool MediaTimer::OnMediaTimerThread() {
+  bool rv = false;
+  mThread->IsOnCurrentThread(&rv);
+  return rv;
+}
+
+RefPtr<MediaTimerPromise> MediaTimer::WaitFor(const TimeDuration& aDuration,
+                                              const char* aCallSite) {
+  return WaitUntil(TimeStamp::Now() + aDuration, aCallSite);
+}
+
+RefPtr<MediaTimerPromise> MediaTimer::WaitUntil(const TimeStamp& aTimeStamp,
+                                                const char* aCallSite) {
+  MonitorAutoLock mon(mMonitor);
+  TIMER_LOG("MediaTimer::WaitUntil %" PRId64, RelativeMicroseconds(aTimeStamp));
+  Entry e(aTimeStamp, aCallSite);
+  RefPtr<MediaTimerPromise> p = e.mPromise.get();
+  mEntries.push(e);
+  ScheduleUpdate();
+  return p;
+}
+
+void MediaTimer::Cancel() {
+  MonitorAutoLock mon(mMonitor);
+  TIMER_LOG("MediaTimer::Cancel");
+  Reject();
+}
+
+void MediaTimer::ScheduleUpdate() {
+  mMonitor.AssertCurrentThreadOwns();
+  if (mUpdateScheduled) {
+    return;
+  }
+  mUpdateScheduled = true;
+
+  nsresult rv = mThread->Dispatch(
+      NewRunnableMethod("MediaTimer::Update", this, &MediaTimer::Update),
+      NS_DISPATCH_NORMAL);
+  MOZ_DIAGNOSTIC_ASSERT(NS_SUCCEEDED(rv));
+  Unused << rv;
+  (void)rv;
+}
+
+void MediaTimer::Update() {
+  MonitorAutoLock mon(mMonitor);
+  UpdateLocked();
+}
+
+bool MediaTimer::IsExpired(const TimeStamp& aTarget, const TimeStamp& aNow) {
+  MOZ_ASSERT(OnMediaTimerThread());
+  mMonitor.AssertCurrentThreadOwns();
+  // Treat this timer as expired in fuzzy mode even if it is fired
+  // slightly (< 1ms) before the schedule target. So we don't need to schedule a
+  // timer with very small timeout again when the client doesn't need a high-res
+  // timer.
+  TimeStamp t = mFuzzy ? aTarget - TimeDuration::FromMilliseconds(1) : aTarget;
+  return t <= aNow;
+}
+
+void MediaTimer::UpdateLocked() {
+  MOZ_ASSERT(OnMediaTimerThread());
+  mMonitor.AssertCurrentThreadOwns();
+  mUpdateScheduled = false;
+
+  TIMER_LOG("MediaTimer::UpdateLocked");
+
+  // Resolve all the promises whose time is up.
+  TimeStamp now = TimeStamp::Now();
+  while (!mEntries.empty() && IsExpired(mEntries.top().mTimeStamp, now)) {
+    mEntries.top().mPromise->Resolve(true, __func__);
+    DebugOnly<TimeStamp> poppedTimeStamp = mEntries.top().mTimeStamp;
+    mEntries.pop();
+    MOZ_ASSERT_IF(!mEntries.empty(),
+                  *&poppedTimeStamp <= mEntries.top().mTimeStamp);
+  }
+
+  // If we've got no more entries, cancel any pending timer and bail out.
+  if (mEntries.empty()) {
+    CancelTimerIfArmed();
+    return;
+  }
+
+  // We've got more entries - (re)arm the timer for the soonest one.
+  if (!TimerIsArmed() || mEntries.top().mTimeStamp < mCurrentTimerTarget) {
+    CancelTimerIfArmed();
+    ArmTimer(mEntries.top().mTimeStamp, now);
+  }
+}
+
+void MediaTimer::Reject() {
+  mMonitor.AssertCurrentThreadOwns();
+  while (!mEntries.empty()) {
+    mEntries.top().mPromise->Reject(false, __func__);
+    mEntries.pop();
+  }
+}
+
+/*
+ * We use a callback function, rather than a callback method, to ensure that
+ * the nsITimer does not artifically keep the refcount of the MediaTimer above
+ * zero. When the MediaTimer is destroyed, it safely cancels the nsITimer so
+ * that we never fire against a dangling closure.
+ */
+
+/* static */
+void MediaTimer::TimerCallback(nsITimer* aTimer, void* aClosure) {
+  static_cast<MediaTimer*>(aClosure)->TimerFired();
+}
+
+void MediaTimer::TimerFired() {
+  MonitorAutoLock mon(mMonitor);
+  MOZ_ASSERT(OnMediaTimerThread());
+  mCurrentTimerTarget = TimeStamp();
+  UpdateLocked();
+}
+
+void MediaTimer::ArmTimer(const TimeStamp& aTarget, const TimeStamp& aNow) {
+  MOZ_DIAGNOSTIC_ASSERT(!TimerIsArmed());
+  MOZ_DIAGNOSTIC_ASSERT(aTarget > aNow);
+
+  const TimeDuration delay = aTarget - aNow;
+  TIMER_LOG("MediaTimer::ArmTimer delay=%.3fms", delay.ToMilliseconds());
+  mCurrentTimerTarget = aTarget;
+  MOZ_ALWAYS_SUCCEEDS(mTimer->InitHighResolutionWithNamedFuncCallback(
+      &TimerCallback, this, delay, nsITimer::TYPE_ONE_SHOT,
+      "MediaTimer::TimerCallback"));
+}
+
+}  // namespace mozilla