diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /gfx/layers/CanvasDrawEventRecorder.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | gfx/layers/CanvasDrawEventRecorder.h | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/gfx/layers/CanvasDrawEventRecorder.h b/gfx/layers/CanvasDrawEventRecorder.h new file mode 100644 index 0000000000..30bb028f4d --- /dev/null +++ b/gfx/layers/CanvasDrawEventRecorder.h @@ -0,0 +1,285 @@ +/* -*- 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_layers_CanvasDrawEventRecorder_h +#define mozilla_layers_CanvasDrawEventRecorder_h + +#include "mozilla/gfx/DrawEventRecorder.h" +#include "mozilla/ipc/CrossProcessSemaphore.h" +#include "mozilla/ipc/SharedMemoryBasic.h" + +namespace mozilla { +namespace layers { + +class CanvasEventRingBuffer final : public gfx::EventRingBuffer { + public: + /** + * WriterServices allows consumers of CanvasEventRingBuffer to provide + * functions required by the write side of a CanvasEventRingBuffer without + * introducing unnecessary dependencies on IPC code. + */ + class WriterServices { + public: + virtual ~WriterServices() = default; + + /** + * @returns true if the reader of the CanvasEventRingBuffer has permanently + * stopped processing, otherwise returns false. + */ + virtual bool ReaderClosed() = 0; + + /** + * Causes the reader to resume processing when it is in a stopped state. + */ + virtual void ResumeReader() = 0; + }; + + /** + * ReaderServices allows consumers of CanvasEventRingBuffer to provide + * functions required by the read side of a CanvasEventRingBuffer without + * introducing unnecessary dependencies on IPC code. + */ + class ReaderServices { + public: + virtual ~ReaderServices() = default; + + /** + * @returns true if the writer of the CanvasEventRingBuffer has permanently + * stopped processing, otherwise returns false. + */ + virtual bool WriterClosed() = 0; + }; + + CanvasEventRingBuffer() {} + + /** + * Initialize the write side of a CanvasEventRingBuffer returning handles to + * the shared memory for the buffer and the two semaphores for waiting in the + * reader and the writer. + * + * @param aOtherPid process ID to share the handles to + * @param aReadHandle handle to the shared memory for the buffer + * @param aReaderSem reading blocked semaphore + * @param aWriterSem writing blocked semaphore + * @param aWriterServices provides functions required by the writer + * @returns true if initialization succeeds + */ + bool InitWriter(base::ProcessId aOtherPid, + ipc::SharedMemoryBasic::Handle* aReadHandle, + CrossProcessSemaphoreHandle* aReaderSem, + CrossProcessSemaphoreHandle* aWriterSem, + UniquePtr<WriterServices> aWriterServices); + + /** + * Initialize the read side of a CanvasEventRingBuffer. + * + * @param aReadHandle handle to the shared memory for the buffer + * @param aReaderSem reading blocked semaphore + * @param aWriterSem writing blocked semaphore + * @param aReaderServices provides functions required by the reader + * @returns true if initialization succeeds + */ + bool InitReader(ipc::SharedMemoryBasic::Handle aReadHandle, + CrossProcessSemaphoreHandle aReaderSem, + CrossProcessSemaphoreHandle aWriterSem, + UniquePtr<ReaderServices> aReaderServices); + + bool good() const final { return mGood; } + + bool WriterFailed() const { return mWrite->state == State::Failed; } + + void SetIsBad() final { + mGood = false; + mRead->state = State::Failed; + } + + void write(const char* const aData, const size_t aSize) final; + + bool HasDataToRead(); + + /* + * This will put the reader into a stopped state if there is no more data to + * read. If this returns false the caller is responsible for continuing + * translation at a later point. If it returns false the writer will start the + * translation again when more data is written. + * + * @returns true if stopped + */ + bool StopIfEmpty(); + + /* + * Waits for data to become available. This will wait for aTimeout duration + * aRetryCount number of times, checking to see if the other side is closed in + * between each one. + * + * @param aTimeout duration to wait + * @param aRetryCount number of times to retry + * @returns true if data is available to read. + */ + bool WaitForDataToRead(TimeDuration aTimeout, int32_t aRetryCount); + + int32_t ReadNextEvent(); + + void read(char* const aOut, const size_t aSize) final; + + /** + * Writes a checkpoint event to the buffer. + * + * @returns the write count after the checkpoint has been written + */ + uint32_t CreateCheckpoint(); + + /** + * Waits until the given checkpoint has been read from the buffer. + * + * @params aCheckpoint the checkpoint to wait for + * @params aTimeout duration to wait while reader is not active + * @returns true if the checkpoint was reached, false if the reader is closed + * or we timeout. + */ + bool WaitForCheckpoint(uint32_t aCheckpoint); + + /** + * Used to send data back to the writer. This is done through the same shared + * memory so the writer must wait and read the response after it has submitted + * the event that uses this. + * + * @param aData the data to be written back to the writer + * @param aSize the number of chars to write + */ + void ReturnWrite(const char* aData, size_t aSize); + + /** + * Used to read data sent back from the reader via ReturnWrite. This is done + * through the same shared memory so the writer must wait until all expected + * data is read before writing new events to the buffer. + * + * @param aOut the pointer to read into + * @param aSize the number of chars to read + */ + void ReturnRead(char* aOut, size_t aSize); + + protected: + bool WaitForAndRecalculateAvailableSpace() final; + void UpdateWriteTotalsBy(uint32_t aCount) final; + + private: + enum class State : uint32_t { + Processing, + + /** + * This is the important state to make sure the other side signals or starts + * us as soon as data or space is available. We set AboutToWait first and + * then re-check the condition. If we went straight to Waiting or Stopped + * then in between the last check and setting the state, the other side + * could have used all available data or space and never have signaled us + * because it didn't know we were about to wait, causing a deadlock. + * While we are in this state, the other side must wait until we resolve the + * AboutToWait state to one of the other states and then signal or start us + * if it needs to. + */ + AboutToWait, + Waiting, + Stopped, + Failed, + }; + + struct ReadFooter { + Atomic<uint32_t> count; + Atomic<uint32_t> returnCount; + Atomic<State> state; + }; + + struct WriteFooter { + Atomic<uint32_t> count; + Atomic<uint32_t> returnCount; + Atomic<uint32_t> requiredDifference; + Atomic<State> state; + }; + + CanvasEventRingBuffer(const CanvasEventRingBuffer&) = delete; + void operator=(const CanvasEventRingBuffer&) = delete; + + void IncrementWriteCountBy(uint32_t aCount); + + bool WaitForReadCount(uint32_t aReadCount, TimeDuration aTimeout); + + bool WaitForAndRecalculateAvailableData(); + + void UpdateReadTotalsBy(uint32_t aCount); + void IncrementReadCountBy(uint32_t aCount); + + void CheckAndSignalReader(); + + void CheckAndSignalWriter(); + + uint32_t WaitForBytesToWrite(); + + uint32_t WaitForBytesToRead(); + + RefPtr<ipc::SharedMemoryBasic> mSharedMemory; + UniquePtr<CrossProcessSemaphore> mReaderSemaphore; + UniquePtr<CrossProcessSemaphore> mWriterSemaphore; + UniquePtr<WriterServices> mWriterServices; + UniquePtr<ReaderServices> mReaderServices; + char* mBuf = nullptr; + uint32_t mOurCount = 0; + WriteFooter* mWrite = nullptr; + ReadFooter* mRead = nullptr; + bool mGood = false; +}; + +class CanvasDrawEventRecorder final : public gfx::DrawEventRecorderPrivate { + public: + MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(CanvasDrawEventRecorder, final) + explicit CanvasDrawEventRecorder(){}; + + bool Init(base::ProcessId aOtherPid, ipc::SharedMemoryBasic::Handle* aHandle, + CrossProcessSemaphoreHandle* aReaderSem, + CrossProcessSemaphoreHandle* aWriterSem, + UniquePtr<CanvasEventRingBuffer::WriterServices> aWriterServices) { + return mOutputStream.InitWriter(aOtherPid, aHandle, aReaderSem, aWriterSem, + std::move(aWriterServices)); + } + + void RecordEvent(const gfx::RecordedEvent& aEvent) final { + if (!mOutputStream.good()) { + return; + } + + aEvent.RecordToStream(mOutputStream); + } + + void StoreSourceSurfaceRecording(gfx::SourceSurface* aSurface, + const char* aReason) final; + + void Flush() final {} + + void ReturnRead(char* aOut, size_t aSize) { + mOutputStream.ReturnRead(aOut, aSize); + } + + uint32_t CreateCheckpoint() { return mOutputStream.CreateCheckpoint(); } + + /** + * Waits until the given checkpoint has been read by the translator. + * + * @params aCheckpoint the checkpoint to wait for + * @returns true if the checkpoint was reached, false if the reader is closed + * or we timeout. + */ + bool WaitForCheckpoint(uint32_t aCheckpoint) { + return mOutputStream.WaitForCheckpoint(aCheckpoint); + } + + private: + CanvasEventRingBuffer mOutputStream; +}; + +} // namespace layers +} // namespace mozilla + +#endif // mozilla_layers_CanvasDrawEventRecorder_h |