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Removes a global non POD instance from the RTP_RTCP module that was introduced in https://code.google.com/p/webrtc/source/detail?r=1076.

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Review URL: https://webrtc-codereview.appspot.com/314001

git-svn-id: http://webrtc.googlecode.com/svn/trunk@1698 4adac7df-926f-26a2-2b94-8c16560cd09d
This commit is contained in:
henrike@webrtc.org 2012-02-15 23:54:59 +00:00
parent 0a272eb44b
commit f5da4da409
5 changed files with 149 additions and 104 deletions
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5
src/modules/rtp_rtcp/interface/rtp_rtcp_defines.h
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@ -251,15 +251,14 @@ protected:
// timestamps in an RTP/RTCP module.
class RtpRtcpClock {
public:
virtual ~RtpRtcpClock() {}
// Return a timestamp in milliseconds relative to some arbitrary
// source; the source is fixed for this clock.
virtual WebRtc_UWord32 GetTimeInMS() = 0;
// Retrieve an NTP absolute timestamp.
virtual void CurrentNTP(WebRtc_UWord32& secs, WebRtc_UWord32& frac) = 0;
protected:
virtual ~RtpRtcpClock() {}
};
// RtpReceiveBitrateUpdate is used to signal changes in bitrate estimates for

20
src/modules/rtp_rtcp/source/rtp_rtcp_impl.cc
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@ -37,8 +37,19 @@ namespace webrtc {
const WebRtc_UWord16 kDefaultRtt = 200;
RtpRtcp* RtpRtcp::CreateRtpRtcp(const WebRtc_Word32 id,
const bool audio) {
return CreateRtpRtcp(id, audio, ModuleRTPUtility::GetSystemClock());
bool audio) {
if(audio) {
WEBRTC_TRACE(kTraceModuleCall, kTraceRtpRtcp, id, "CreateRtpRtcp(audio)");
} else {
WEBRTC_TRACE(kTraceModuleCall, kTraceRtpRtcp, id, "CreateRtpRtcp(video)");
}
// ModuleRTPUtility::GetSystemClock() creates a new instance of a system
// clock implementation. The OwnsClock() function informs the module that
// it is responsible for deleting the instance.
ModuleRtpRtcpImpl* rtp_rtcp_instance = new ModuleRtpRtcpImpl(id,
audio, ModuleRTPUtility::GetSystemClock());
rtp_rtcp_instance->OwnsClock();
return rtp_rtcp_instance;
}
RtpRtcp* RtpRtcp::CreateRtpRtcp(const WebRtc_Word32 id,
@ -76,6 +87,7 @@ ModuleRtpRtcpImpl::ModuleRtpRtcpImpl(const WebRtc_Word32 id,
_rtpReceiver(id, audio, clock, this),
_rtcpSender(id, audio, clock, this),
_rtcpReceiver(id, clock, this),
_owns_clock(false),
_clock(*clock),
_id(id),
_audio(audio),
@ -83,7 +95,6 @@ ModuleRtpRtcpImpl::ModuleRtpRtcpImpl(const WebRtc_Word32 id,
_lastProcessTime(clock->GetTimeInMS()),
_lastBitrateProcessTime(clock->GetTimeInMS()),
_lastPacketTimeoutProcessTime(clock->GetTimeInMS()),
_packetOverHead(28), // IPV4 UDP
_criticalSectionModulePtrs(CriticalSectionWrapper::CreateCriticalSection()),
_criticalSectionModulePtrsFeedback(
@ -156,6 +167,9 @@ ModuleRtpRtcpImpl::~ModuleRtpRtcpImpl() {
delete _criticalSectionModulePtrs;
delete _criticalSectionModulePtrsFeedback;
if (_owns_clock) {
delete &_clock;
}
}
WebRtc_Word32 ModuleRtpRtcpImpl::ChangeUniqueId(const WebRtc_Word32 id) {

5
src/modules/rtp_rtcp/source/rtp_rtcp_impl.h
View File

@ -535,6 +535,10 @@ public:
void OnRequestSendReport();
// Following function is only called when constructing the object so no
// need to worry about data race.
void OwnsClock() { _owns_clock = true; }
protected:
void RegisterChildModule(RtpRtcp* module);
@ -560,6 +564,7 @@ protected:
RTCPSender _rtcpSender;
RTCPReceiver _rtcpReceiver;
bool _owns_clock;
RtpRtcpClock& _clock;
private:
void SendKeyFrame();

181
src/modules/rtp_rtcp/source/rtp_utility.cc
View File

@ -50,65 +50,45 @@ namespace ModuleRTPUtility {
#if defined(_WIN32)
class WindowsHelpTimer {
public:
struct reference_point {
struct reference_point {
FILETIME file_time;
LARGE_INTEGER counterMS;
};
};
struct WindowsHelpTimer {
volatile LONG _timeInMs;
volatile LONG _numWrapTimeInMs;
reference_point _ref_point;
volatile LONG _sync_flag;
};
void Synchronize(WindowsHelpTimer* help_timer) {
const LONG start_value = 0;
const LONG new_value = 1;
const LONG synchronized_value = 2;
LONG compare_flag = new_value;
while (help_timer->_sync_flag == start_value) {
const LONG new_value = 1;
compare_flag = InterlockedCompareExchange(
&help_timer->_sync_flag, new_value, start_value);
}
if (compare_flag != start_value) {
// This thread was not the one that incremented the sync flag.
// Block until synchronization finishes.
while (compare_flag != synchronized_value) {
::Sleep(0);
}
return;
}
// Only the synchronizing thread gets here so this part can be
// considered single threaded.
WindowsHelpTimer() {
// set timer accuracy to 1 ms
timeBeginPeriod(1);
_timeInMs = 0;
_numWrapTimeInMs = 0;
synchronize();
};
virtual ~WindowsHelpTimer() {
timeEndPeriod(1);
};
void get_time(FILETIME& current_time) {
// we can't use query performance counter due to speed stepping
DWORD t = timeGetTime();
// NOTE: we have a miss match in sign between _timeInMs(LONG) and t(DWORD)
// however we only use it here without +- etc
volatile LONG* timeInMsPtr = &_timeInMs;
DWORD old = InterlockedExchange(timeInMsPtr, t); // make sure that we only
// inc wrapper once
if (old > t) {
// wrap
_numWrapTimeInMs++;
}
LARGE_INTEGER elapsedMS;
elapsedMS.HighPart = _numWrapTimeInMs;
elapsedMS.LowPart = t;
elapsedMS.QuadPart = elapsedMS.QuadPart - _ref_point.counterMS.QuadPart;
//
// Translate to 100-nanoseconds intervals (FILETIME resolution) and add to
// reference FILETIME to get current FILETIME.
//
ULARGE_INTEGER filetime_ref_as_ul;
filetime_ref_as_ul.HighPart = _ref_point.file_time.dwHighDateTime;
filetime_ref_as_ul.LowPart = _ref_point.file_time.dwLowDateTime;
filetime_ref_as_ul.QuadPart +=
(ULONGLONG)((elapsedMS.QuadPart) * 1000 * 10);
//
// Copy to result
//
current_time.dwHighDateTime = filetime_ref_as_ul.HighPart;
current_time.dwLowDateTime = filetime_ref_as_ul.LowPart;
};
private:
void synchronize() {
FILETIME ft0 = { 0, 0 }, ft1 = { 0, 0 };
FILETIME ft0 = { 0, 0 },
ft1 = { 0, 0 };
//
// Spin waiting for a change in system time. Get the matching
// performance counter value for that time.
@ -116,24 +96,54 @@ private:
::GetSystemTimeAsFileTime(&ft0);
do {
::GetSystemTimeAsFileTime(&ft1);
_ref_point.counterMS.QuadPart = ::timeGetTime();
help_timer->_ref_point.counterMS.QuadPart = ::timeGetTime();
::Sleep(0);
} while ((ft0.dwHighDateTime == ft1.dwHighDateTime) &&
(ft0.dwLowDateTime == ft1.dwLowDateTime));
help_timer->_ref_point.file_time = ft1;
}
_ref_point.file_time = ft1;
void get_time(WindowsHelpTimer* help_timer, FILETIME& current_time) {
// we can't use query performance counter due to speed stepping
DWORD t = timeGetTime();
// NOTE: we have a missmatch in sign between _timeInMs(LONG) and
// (DWORD) however we only use it here without +- etc
volatile LONG* timeInMsPtr = &help_timer->_timeInMs;
// Make sure that we only inc wrapper once.
DWORD old = InterlockedExchange(timeInMsPtr, t);
if(old > t) {
// wrap
help_timer->_numWrapTimeInMs++;
}
// this needs to be long due to Windows, not an issue due to its usage
volatile LONG _timeInMs;
volatile WebRtc_UWord32 _numWrapTimeInMs;
reference_point _ref_point;
};
LARGE_INTEGER elapsedMS;
elapsedMS.HighPart = help_timer->_numWrapTimeInMs;
elapsedMS.LowPart = t;
// A clock reading times from the Windows API.
class WindowsSystemClock : public RtpRtcpClock {
public:
WindowsSystemClock()
: _helpTimer() {}
elapsedMS.QuadPart = elapsedMS.QuadPart -
help_timer->_ref_point.counterMS.QuadPart;
// Translate to 100-nanoseconds intervals (FILETIME resolution)
// and add to reference FILETIME to get current FILETIME.
ULARGE_INTEGER filetime_ref_as_ul;
filetime_ref_as_ul.HighPart =
help_timer->_ref_point.file_time.dwHighDateTime;
filetime_ref_as_ul.LowPart =
help_timer->_ref_point.file_time.dwLowDateTime;
filetime_ref_as_ul.QuadPart +=
(ULONGLONG)((elapsedMS.QuadPart)*1000*10);
// Copy to result
current_time.dwHighDateTime = filetime_ref_as_ul.HighPart;
current_time.dwLowDateTime = filetime_ref_as_ul.LowPart;
}
// A clock reading times from the Windows API.
class WindowsSystemClock : public RtpRtcpClock {
public:
WindowsSystemClock(WindowsHelpTimer* helpTimer)
: _helpTimer(helpTimer) {}
virtual ~WindowsSystemClock() {}
@ -141,8 +151,8 @@ public:
virtual void CurrentNTP(WebRtc_UWord32& secs, WebRtc_UWord32& frac);
private:
WindowsHelpTimer _helpTimer;
private:
WindowsHelpTimer* _helpTimer;
};
#elif defined(WEBRTC_LINUX) || defined(WEBRTC_MAC)
@ -174,9 +184,9 @@ void WindowsSystemClock::CurrentNTP(WebRtc_UWord32& secs,
WebRtc_UWord64 Time;
struct timeval tv;
// we can't use query performance counter since they can change depending on
// We can't use query performance counter since they can change depending on
// speed steping
_helpTimer.get_time(StartTime);
get_time(_helpTimer, StartTime);
Time = (((WebRtc_UWord64) StartTime.dwHighDateTime) << 32) +
(WebRtc_UWord64) StartTime.dwLowDateTime;
@ -238,21 +248,34 @@ void UnixSystemClock::CurrentNTP(WebRtc_UWord32& secs, WebRtc_UWord32& frac) {
}
#endif
RtpRtcpClock* GetSystemClock() {
// TODO(hellner): violates the style guide (non-POD static instance).
#if defined(_WIN32)
static WindowsSystemClock system_clock;
#elif defined(WEBRTC_LINUX) || defined(WEBRTC_MAC)
static UnixSystemClock system_clock;
// Keeps the global state for the Windows implementation of RtpRtcpClock.
// Note that this is a POD. Only PODs are allowed to have static storage
// duration according to the Google Style guide.
static WindowsHelpTimer global_help_timer = {0, 0, {{ 0, 0}, 0}, 0};
#endif
RtpRtcpClock* GetSystemClock() {
#if defined(_WIN32)
return new WindowsSystemClock(&global_help_timer);
#elif defined(WEBRTC_LINUX) || defined(WEBRTC_MAC)
return new UnixSystemClock();
#else
return NULL;
#endif
return &system_clock;
}
WebRtc_UWord32 GetCurrentRTP(RtpRtcpClock* clock, WebRtc_UWord32 freq) {
if (clock == NULL)
clock = GetSystemClock();
const bool use_global_clock = (clock == NULL);
RtpRtcpClock* local_clock = clock;
if (use_global_clock) {
local_clock = GetSystemClock();
}
WebRtc_UWord32 secs = 0, frac = 0;
clock->CurrentNTP(secs, frac);
local_clock->CurrentNTP(secs, frac);
if (use_global_clock) {
delete local_clock;
}
return ConvertNTPTimeToRTP(secs, frac, freq);
}

4
src/modules/rtp_rtcp/source/rtp_utility.h
View File

@ -65,6 +65,10 @@ namespace ModuleRTPUtility
// system. The returned instances are guaranteed to read the same
// times; in particular, they return relative times relative to
// the same base.
// Note that even though the instances returned by this function
// read the same times a new object is created every time this
// API is called. The ownership of this object belongs to the
// caller.
RtpRtcpClock* GetSystemClock();
// Return the current RTP timestamp from the NTP timestamp