Fix race in Voice Engine's Channel where it accesses RemoteNtpTimeEstimator from both the audio playback thread and the network thread without locking.

BUG=3681
R=pbos@webrtc.org, xians@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/24379004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7030 4adac7df-926f-26a2-2b94-8c16560cd09d
This commit is contained in:
stefan@webrtc.org 2014-09-02 18:58:24 +00:00
parent 9f341283f6
commit 8e24d87778
2 changed files with 20 additions and 14 deletions

View File

@ -16,7 +16,6 @@
#include "webrtc/modules/audio_processing/include/audio_processing.h"
#include "webrtc/modules/interface/module_common_types.h"
#include "webrtc/modules/rtp_rtcp/interface/receive_statistics.h"
#include "webrtc/modules/rtp_rtcp/interface/remote_ntp_time_estimator.h"
#include "webrtc/modules/rtp_rtcp/interface/rtp_payload_registry.h"
#include "webrtc/modules/rtp_rtcp/interface/rtp_receiver.h"
#include "webrtc/modules/rtp_rtcp/source/rtp_receiver_strategy.h"
@ -699,15 +698,18 @@ int32_t Channel::GetAudioFrame(int32_t id, AudioFrame& audioFrame)
(unwrap_timestamp - capture_start_rtp_time_stamp_) /
(GetPlayoutFrequency() / 1000);
// Compute ntp time.
audioFrame.ntp_time_ms_ = ntp_estimator_->Estimate(audioFrame.timestamp_);
// |ntp_time_ms_| won't be valid until at least 2 RTCP SRs are received.
if (audioFrame.ntp_time_ms_ > 0) {
// Compute |capture_start_ntp_time_ms_| so that
// |capture_start_ntp_time_ms_| + |elapsed_time_ms_| == |ntp_time_ms_|
{
CriticalSectionScoped lock(ts_stats_lock_.get());
capture_start_ntp_time_ms_ =
audioFrame.ntp_time_ms_ - audioFrame.elapsed_time_ms_;
// Compute ntp time.
audioFrame.ntp_time_ms_ = ntp_estimator_.Estimate(
audioFrame.timestamp_);
// |ntp_time_ms_| won't be valid until at least 2 RTCP SRs are received.
if (audioFrame.ntp_time_ms_ > 0) {
// Compute |capture_start_ntp_time_ms_| so that
// |capture_start_ntp_time_ms_| + |elapsed_time_ms_| == |ntp_time_ms_|
capture_start_ntp_time_ms_ =
audioFrame.ntp_time_ms_ - audioFrame.elapsed_time_ms_;
}
}
}
@ -877,7 +879,7 @@ Channel::Channel(int32_t channelId,
_outputExternalMediaCallbackPtr(NULL),
_timeStamp(0), // This is just an offset, RTP module will add it's own random offset
_sendTelephoneEventPayloadType(106),
ntp_estimator_(new RemoteNtpTimeEstimator(Clock::GetRealTimeClock())),
ntp_estimator_(Clock::GetRealTimeClock()),
jitter_buffer_playout_timestamp_(0),
playout_timestamp_rtp_(0),
playout_timestamp_rtcp_(0),
@ -1949,8 +1951,11 @@ int32_t Channel::ReceivedRTCPPacket(const int8_t* data, int32_t length) {
"Channel::IncomingRTPPacket() RTCP packet is invalid");
}
ntp_estimator_->UpdateRtcpTimestamp(rtp_receiver_->SSRC(),
_rtpRtcpModule.get());
{
CriticalSectionScoped lock(ts_stats_lock_.get());
ntp_estimator_.UpdateRtcpTimestamp(rtp_receiver_->SSRC(),
_rtpRtcpModule.get());
}
return 0;
}

View File

@ -17,6 +17,7 @@
#include "webrtc/modules/audio_conference_mixer/interface/audio_conference_mixer_defines.h"
#include "webrtc/modules/audio_processing/rms_level.h"
#include "webrtc/modules/bitrate_controller/include/bitrate_controller.h"
#include "webrtc/modules/rtp_rtcp/interface/remote_ntp_time_estimator.h"
#include "webrtc/modules/rtp_rtcp/interface/rtp_header_parser.h"
#include "webrtc/modules/rtp_rtcp/interface/rtp_rtcp.h"
#include "webrtc/modules/utility/interface/file_player.h"
@ -548,7 +549,7 @@ private:
uint32_t _timeStamp;
uint8_t _sendTelephoneEventPayloadType;
scoped_ptr<RemoteNtpTimeEstimator> ntp_estimator_;
RemoteNtpTimeEstimator ntp_estimator_ GUARDED_BY(ts_stats_lock_);
// Timestamp of the audio pulled from NetEq.
uint32_t jitter_buffer_playout_timestamp_;
@ -566,7 +567,7 @@ private:
int64_t capture_start_rtp_time_stamp_;
// The capture ntp time (in local timebase) of the first played out audio
// frame.
int64_t capture_start_ntp_time_ms_;
int64_t capture_start_ntp_time_ms_ GUARDED_BY(ts_stats_lock_);
// uses
Statistics* _engineStatisticsPtr;