summaryrefslogtreecommitdiffstats
path: root/xpcom/threads/EventQueue.h
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--xpcom/threads/EventQueue.h136
1 files changed, 136 insertions, 0 deletions
diff --git a/xpcom/threads/EventQueue.h b/xpcom/threads/EventQueue.h
new file mode 100644
index 0000000000..a604d03367
--- /dev/null
+++ b/xpcom/threads/EventQueue.h
@@ -0,0 +1,136 @@
+/* -*- 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/. */
+
+#ifndef mozilla_EventQueue_h
+#define mozilla_EventQueue_h
+
+#include "mozilla/Mutex.h"
+#include "mozilla/Queue.h"
+#include "mozilla/TimeStamp.h"
+#include "nsCOMPtr.h"
+
+class nsIRunnable;
+
+namespace mozilla {
+
+#define EVENT_QUEUE_PRIORITY_LIST(EVENT_PRIORITY) \
+ EVENT_PRIORITY(Idle, 0) \
+ EVENT_PRIORITY(DeferredTimers, 1) \
+ EVENT_PRIORITY(Low, 2) \
+ EVENT_PRIORITY(InputLow, 3) \
+ EVENT_PRIORITY(Normal, 4) \
+ EVENT_PRIORITY(MediumHigh, 5) \
+ EVENT_PRIORITY(InputHigh, 6) \
+ EVENT_PRIORITY(Vsync, 7) \
+ EVENT_PRIORITY(InputHighest, 8) \
+ EVENT_PRIORITY(RenderBlocking, 9) \
+ EVENT_PRIORITY(Control, 10)
+
+enum class EventQueuePriority {
+#define EVENT_PRIORITY(NAME, VALUE) NAME = VALUE,
+ EVENT_QUEUE_PRIORITY_LIST(EVENT_PRIORITY)
+#undef EVENT_PRIORITY
+ Invalid
+};
+
+class IdlePeriodState;
+
+namespace detail {
+
+// EventQueue is our unsynchronized event queue implementation. It is a queue
+// of runnables used for non-main thread, as well as optionally providing
+// forwarding to TaskController.
+//
+// Since EventQueue is unsynchronized, it should be wrapped in an outer
+// SynchronizedEventQueue implementation (like ThreadEventQueue).
+template <size_t ItemsPerPage>
+class EventQueueInternal {
+ public:
+ explicit EventQueueInternal(bool aForwardToTC) : mForwardToTC(aForwardToTC) {}
+
+ // Add an event to the end of the queue. Implementors are free to use
+ // aPriority however they wish. If the runnable supports
+ // nsIRunnablePriority and the implementing class supports
+ // prioritization, aPriority represents the result of calling
+ // nsIRunnablePriority::GetPriority(). *aDelay is time the event has
+ // already been delayed (used when moving an event from one queue to
+ // another)
+ void PutEvent(already_AddRefed<nsIRunnable>&& aEvent,
+ EventQueuePriority aPriority, const MutexAutoLock& aProofOfLock,
+ mozilla::TimeDuration* aDelay = nullptr);
+
+ // Get an event from the front of the queue. This should return null if the
+ // queue is non-empty but the event in front is not ready to run.
+ // *aLastEventDelay is the time the event spent in queues before being
+ // retrieved.
+ already_AddRefed<nsIRunnable> GetEvent(
+ const MutexAutoLock& aProofOfLock,
+ mozilla::TimeDuration* aLastEventDelay = nullptr);
+
+ // Returns true if the queue is empty. Implies !HasReadyEvent().
+ bool IsEmpty(const MutexAutoLock& aProofOfLock);
+
+ // Returns true if the queue is non-empty and if the event in front is ready
+ // to run. Implies !IsEmpty(). This should return true iff GetEvent returns a
+ // non-null value.
+ bool HasReadyEvent(const MutexAutoLock& aProofOfLock);
+
+ // Returns the number of events in the queue.
+ size_t Count(const MutexAutoLock& aProofOfLock) const;
+ // For some reason, if we put this in the .cpp file the linker can't find it
+ already_AddRefed<nsIRunnable> PeekEvent(const MutexAutoLock& aProofOfLock) {
+ if (mQueue.IsEmpty()) {
+ return nullptr;
+ }
+
+ nsCOMPtr<nsIRunnable> result = mQueue.FirstElement();
+ return result.forget();
+ }
+
+ void EnableInputEventPrioritization(const MutexAutoLock& aProofOfLock) {}
+ void FlushInputEventPrioritization(const MutexAutoLock& aProofOfLock) {}
+ void SuspendInputEventPrioritization(const MutexAutoLock& aProofOfLock) {}
+ void ResumeInputEventPrioritization(const MutexAutoLock& aProofOfLock) {}
+
+ size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
+ return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+ }
+
+ size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
+ size_t size = mQueue.ShallowSizeOfExcludingThis(aMallocSizeOf);
+ size += mDispatchTimes.ShallowSizeOfExcludingThis(aMallocSizeOf);
+ return size;
+ }
+
+ private:
+ mozilla::Queue<nsCOMPtr<nsIRunnable>, ItemsPerPage> mQueue;
+ // This queue is only populated when the profiler is turned on.
+ mozilla::Queue<mozilla::TimeStamp, ItemsPerPage> mDispatchTimes;
+ TimeDuration mLastEventDelay;
+ // This indicates PutEvent forwards runnables to the TaskController. This
+ // should be true for the top level event queue on the main thread.
+ bool mForwardToTC;
+};
+
+} // namespace detail
+
+class EventQueue final : public mozilla::detail::EventQueueInternal<16> {
+ public:
+ explicit EventQueue(bool aForwardToTC = false)
+ : mozilla::detail::EventQueueInternal<16>(aForwardToTC) {}
+};
+
+template <size_t ItemsPerPage = 16>
+class EventQueueSized final
+ : public mozilla::detail::EventQueueInternal<ItemsPerPage> {
+ public:
+ explicit EventQueueSized(bool aForwardToTC = false)
+ : mozilla::detail::EventQueueInternal<ItemsPerPage>(aForwardToTC) {}
+};
+
+} // namespace mozilla
+
+#endif // mozilla_EventQueue_h