Introduces rtc_base/synchronization/mutex.h.
This change introduces a new non-reentrant mutex to WebRTC. It
enables eventual migration to Abseil's mutex.
The mutex types supportable by webrtc::Mutex are
- absl::Mutex
- CriticalSection (Windows only)
- pthread_mutex (POSIX only)
In addition to introducing the mutexes, the CL also changes
PacketBuffer to use the new mutex instead of rtc::CriticalSection.
The method of yielding from critical_section.cc was given a
mini-cleanup and YieldCurrentThread() was added to
rtc_base/synchronization/yield.h/cc.
Additionally, google_benchmark benchmarks for the mutexes were added
(test courtesy of danilchap@), and some results from a pthread/Abseil
shootout were added showing Abseil has the advantage in higher
contention.
Bug: webrtc:11567, webrtc:11634
Change-Id: Iaec324ccb32ec3851bf6db3fd290f5ea5dee4c81
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/176230
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31443}
diff --git a/modules/video_coding/packet_buffer.cc b/modules/video_coding/packet_buffer.cc
index d62dc84..ad82211 100644
--- a/modules/video_coding/packet_buffer.cc
+++ b/modules/video_coding/packet_buffer.cc
@@ -78,7 +78,7 @@
PacketBuffer::InsertResult PacketBuffer::InsertPacket(
std::unique_ptr<PacketBuffer::Packet> packet) {
PacketBuffer::InsertResult result;
- rtc::CritScope lock(&crit_);
+ MutexLock lock(&mutex_);
uint16_t seq_num = packet->seq_num;
size_t index = seq_num % buffer_.size();
@@ -136,7 +136,7 @@
}
void PacketBuffer::ClearTo(uint16_t seq_num) {
- rtc::CritScope lock(&crit_);
+ MutexLock lock(&mutex_);
// We have already cleared past this sequence number, no need to do anything.
if (is_cleared_to_first_seq_num_ &&
AheadOf<uint16_t>(first_seq_num_, seq_num)) {
@@ -173,25 +173,25 @@
}
void PacketBuffer::Clear() {
- rtc::CritScope lock(&crit_);
+ MutexLock lock(&mutex_);
ClearInternal();
}
PacketBuffer::InsertResult PacketBuffer::InsertPadding(uint16_t seq_num) {
PacketBuffer::InsertResult result;
- rtc::CritScope lock(&crit_);
+ MutexLock lock(&mutex_);
UpdateMissingPackets(seq_num);
result.packets = FindFrames(static_cast<uint16_t>(seq_num + 1));
return result;
}
absl::optional<int64_t> PacketBuffer::LastReceivedPacketMs() const {
- rtc::CritScope lock(&crit_);
+ MutexLock lock(&mutex_);
return last_received_packet_ms_;
}
absl::optional<int64_t> PacketBuffer::LastReceivedKeyframePacketMs() const {
- rtc::CritScope lock(&crit_);
+ MutexLock lock(&mutex_);
return last_received_keyframe_packet_ms_;
}