zqz/platform-external-webrtc
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Speculative revert of 8631 "Remove lock from Bitrate() and FrameRate() in Video..."

Browse Source 
We ran into the alignment problem on Mac 10.9 debug again.  This is the only CL I see in the range that adds an rtc::CriticalSection, so I'm trying out reverting it before attempting another roll.

> Remove lock from Bitrate() and FrameRate() in VideoSender.
> These methods are called on the VideoSender's construction thread, which is the same thread as modifies the value of _encoder.  It's therefore safe to not require a lock to access _encoder on this thread.
> 
> I'm making access to the rate variables from VCMGenericEncoder, thread safe, by using a lock that's not associated with the encoder.  There should be little to no contention there.  While modifying VCMGenericEncoder, I noticed that a couple of member variables weren't needed, so I removed them.
> 
> The reason for this change is that getStats is currently contending with the encoder when Bitrate() is called. On my machine, this means that getStats can take about 25-30ms instead of ~1ms.
> 
> Also adding some documentation for other methods and a suggestion for how we could avoid contention between the encoder and the network thread.
> 
> BUG=2822
> R=mflodman@webrtc.org
> 
> Review URL: https://webrtc-codereview.appspot.com/43479004

TBR=tommi@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/45529004

Cr-Commit-Position: refs/heads/master@{#8640}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8640 4adac7df-926f-26a2-2b94-8c16560cd09d
This commit is contained in:
tommi@webrtc.org
2015-03-07 09:26:16 +00:00
parent dc08a230da
commit 92696cd0c6
3 changed files with 52 additions and 80 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
webrtc/modules/video_coding/main/source/generic_encoder.h
View File

@ -16,7 +16,6 @@
#include <stdio.h>
#include "webrtc/base/criticalsection.h"
#include "webrtc/base/scoped_ptr.h"
namespace webrtc {
@ -75,9 +74,9 @@ class VCMGenericEncoder
{
friend class VCMCodecDataBase;
public:
VCMGenericEncoder(VideoEncoder* encoder,
VideoEncoderRateObserver* rate_observer,
bool internalSource);
VCMGenericEncoder(VideoEncoder* encoder,
VideoEncoderRateObserver* rate_observer,
bool internalSource);
~VCMGenericEncoder();
/**
* Free encoder memory
@ -103,9 +102,6 @@ public:
* Set new target bitrate (bits/s) and framerate.
* Return Value: new bit rate if OK, otherwise <0s.
*/
// TODO(tommi): We could replace BitRate and FrameRate below with a GetRates
// method that matches SetRates. For fetching current rates, we'd then only
// grab the lock once instead of twice.
int32_t SetRates(uint32_t target_bitrate, uint32_t frameRate);
/**
* Set a new packet loss rate and a new round-trip time in milliseconds.
@ -136,10 +132,11 @@ public:
private:
VideoEncoder* const encoder_;
VideoEncoderRateObserver* const rate_observer_;
uint32_t bit_rate_;
uint32_t frame_rate_;
const bool internal_source_;
mutable rtc::CriticalSection rates_lock_;
VideoCodecType _codecType;
VCMEncodedFrameCallback* _VCMencodedFrameCallback;
uint32_t _bitRate;
uint32_t _frameRate;
bool _internalSource;
}; // end of VCMGenericEncoder class
} // namespace webrtc