/* 用当前RTSPSession构造一个OSRef实例, 在RTPSession Map(Hash表)中注册并加入该引用OSRef元(其key值唯一),
同时更新qtssSvrClientSessions的属性,及QTSServerInterface中的总RTPSession数 */
QTSS_Error RTPSession::Activate(const StrPtrLen& inSessionID)
{
//Set the session ID for this session
/* 用入参配置fRTSPSessionIDBuf的值(是C-String) */
Assert(inSessionID.Len <= QTSS_MAX_SESSION_ID_LENGTH);
::memcpy(fRTSPSessionIDBuf, inSessionID.Ptr, inSessionID.Len);
fRTSPSessionIDBuf[inSessionID.Len] = '\0';
/* 用C-String的fRTSPSessionIDBuf设置qtssCliSesRTSPSessionID的属性值 */
this->SetVal(qtssCliSesRTSPSessionID, &fRTSPSessionIDBuf[0], inSessionID.Len);
/* 用qtssCliSesRTSPSessionID的属性值来得到一个RTPSession Map的引用OSRef元 */
fRTPMapElem.Set(*this->GetValue(qtssCliSesRTSPSessionID), this);
/* 获取服务器接口 */
QTSServerInterface* theServer = QTSServerInterface::GetServer();
//Activate puts the session into the RTPSession Map
/* 在RTPSession Map(Hash表)中注册并加入一个引用OSRef,若字符串标识唯一,就能成功返回OS_NoErr;若有一个相同key值的元素,就返回错误EPERM */
QTSS_Error err = theServer->GetRTPSessionMap()->Register(&fRTPMapElem);
//若有同名键值,立即返回
if (err == EPERM)
return err;
/* 确保key值唯一 */
Assert(err == QTSS_NoErr);
//
// Adding this session into the qtssSvrClientSessions attr and incrementing the number of sessions must be atomic
/* 锁定服务器对象 */
OSMutexLocker locker(theServer->GetMutex());
//
// Put this session into the qtssSvrClientSessions attribute of the server
#if DEBUG
Assert(theServer->GetNumValues(qtssSvrClientSessions) == theServer->GetNumRTPSessions());//确保属性qtssSvrClientSessions中的RTPSession个数和服务器中实际的个数相同
#endif
/* 设置qtssSvrClientSessions的第GetNumRTPSessions()个RTPSession的属性 */
RTPSession* theSession = this;
err = theServer->SetValue(qtssSvrClientSessions, theServer->GetNumRTPSessions(), &theSession, sizeof(theSession), QTSSDictionary::kDontObeyReadOnly);
Assert(err == QTSS_NoErr);
#if DEBUG
fActivateCalled = true;
#endif
/* 及时更新QTSServerInterface中的总RTPSession数 */
QTSServerInterface::GetServer()->IncrementTotalRTPSessions();
return QTSS_NoErr;
}
QTSS_Error RTPSession::Activate(const StrPtrLen& inSessionID)
{
//Set the session ID for this session
Assert(inSessionID.Len <= QTSS_MAX_SESSION_ID_LENGTH);
::memcpy(fRTSPSessionIDBuf, inSessionID.Ptr, inSessionID.Len);
fRTSPSessionIDBuf[inSessionID.Len] = '\0';
this->SetVal(qtssCliSesRTSPSessionID, &fRTSPSessionIDBuf[0], inSessionID.Len);
fRTPMapElem.Set(*this->GetValue(qtssCliSesRTSPSessionID), this);
QTSServerInterface* theServer = QTSServerInterface::GetServer();
//Activate puts the session into the RTPSession Map
QTSS_Error err = theServer->GetRTPSessionMap()->Register(&fRTPMapElem);
if (err == EPERM)
return err;
Assert(err == QTSS_NoErr);
//
// Adding this session into the qtssSvrClientSessions attr and incrementing the number of sessions must be atomic
OSMutexLocker locker(theServer->GetMutex());
//
// Put this session into the qtssSvrClientSessions attribute of the server
#if DEBUG
Assert(theServer->GetNumValues(qtssSvrClientSessions) == theServer->GetNumRTPSessions());
#endif
RTPSession* theSession = this;
err = theServer->SetValue(qtssSvrClientSessions, theServer->GetNumRTPSessions(), &theSession, sizeof(theSession), QTSSDictionary::kDontObeyReadOnly);
Assert(err == QTSS_NoErr);
#if DEBUG
fActivateCalled = true;
#endif
QTSServerInterface::GetServer()->IncrementTotalRTPSessions();
return QTSS_NoErr;
}
SInt64 RTPStatsUpdaterTask::Run()
{
QTSServerInterface* theServer = QTSServerInterface::sServer;
// All of this must happen atomically wrt dictionary values we are manipulating
OSMutexLocker locker(&theServer->fMutex);
//First update total bytes. This must be done because total bytes is a 64 bit number,
//so no atomic functions can apply.
//
// NOTE: The line below is not thread safe on non-PowerPC platforms. This is
// because the fPeriodicRTPBytes variable is being manipulated from within an
// atomic_add. On PowerPC, assignments are atomic, so the assignment below is ok.
// On a non-PowerPC platform, the following would be thread safe:
//unsigned int periodicBytes = atomic_add(&theServer->fPeriodicRTPBytes, 0);
unsigned int periodicBytes = theServer->fPeriodicRTPBytes;
(void)atomic_sub(&theServer->fPeriodicRTPBytes, periodicBytes);
theServer->fTotalRTPBytes += periodicBytes;
// Same deal for packet totals
unsigned int periodicPackets = theServer->fPeriodicRTPPackets;
(void)atomic_sub(&theServer->fPeriodicRTPPackets, periodicPackets);
theServer->fTotalRTPPackets += periodicPackets;
// ..and for lost packet totals
unsigned int periodicPacketsLost = theServer->fPeriodicRTPPacketsLost;
(void)atomic_sub(&theServer->fPeriodicRTPPacketsLost, periodicPacketsLost);
theServer->fTotalRTPPacketsLost += periodicPacketsLost;
SInt64 curTime = OS::Milliseconds();
//for cpu percent
Float32 cpuTimeInSec = GetCPUTimeInSeconds();
//also update current bandwidth statistic
if (fLastBandwidthTime != 0)
{
Assert(curTime > fLastBandwidthTime);
UInt32 delta = (UInt32)(curTime - fLastBandwidthTime);
if (delta < 1000)
WarnV(delta >= 1000, "Timer is off");
//do the bandwidth computation using floating point divides
//for accuracy and speed.
Float32 bits = (Float32)(periodicBytes * 8);
Float32 theTime = (Float32)delta;
theTime /= 1000;
bits /= theTime;
Assert(bits >= 0);
theServer->fCurrentRTPBandwidthInBits = (UInt32)bits;
// okay let's do it for MP3 bytes now
bits = (Float32)(((SInt64)theServer->fTotalMP3Bytes - fLastTotalMP3Bytes) * 8);
bits /= theTime;
theServer->fCurrentMP3BandwidthInBits = (UInt32)bits;
//do the same computation for packets per second
Float32 packetsPerSecond = (Float32)periodicPackets;
packetsPerSecond /= theTime;
Assert(packetsPerSecond >= 0);
theServer->fRTPPacketsPerSecond = (UInt32)packetsPerSecond;
//do the computation for cpu percent
Float32 diffTime = cpuTimeInSec - theServer->fCPUTimeUsedInSec;
theServer->fCPUPercent = (diffTime/theTime) * 100;
UInt32 numProcessors = OS::GetNumProcessors();
if (numProcessors > 1)
theServer->fCPUPercent /= numProcessors;
}
fLastTotalMP3Bytes = (SInt64)theServer->fTotalMP3Bytes;
fLastBandwidthTime = curTime;
// We use a running average for avg. bandwidth calculations
theServer->fAvgMP3BandwidthInBits = (theServer->fAvgMP3BandwidthInBits
+ theServer->fCurrentMP3BandwidthInBits)/2;
//for cpu percent
theServer->fCPUTimeUsedInSec = cpuTimeInSec;
//also compute average bandwidth, a much more smooth value. This is done with
//the fLastBandwidthAvg, a timestamp of the last time we did an average, and
//fLastBytesSent, the number of bytes sent when we last did an average.
if ((fLastBandwidthAvg != 0) && (curTime > (fLastBandwidthAvg +
(theServer->GetPrefs()->GetAvgBandwidthUpdateTimeInSecs() * 1000))))
{
UInt32 delta = (UInt32)(curTime - fLastBandwidthAvg);
SInt64 bytesSent = theServer->fTotalRTPBytes - fLastBytesSent;
Assert(bytesSent >= 0);
//do the bandwidth computation using floating point divides
//for accuracy and speed.
Float32 bits = (Float32)(bytesSent * 8);
Float32 theAvgTime = (Float32)delta;
theAvgTime /= 1000;
bits /= theAvgTime;
Assert(bits >= 0);
theServer->fAvgRTPBandwidthInBits = (UInt32)bits;
fLastBandwidthAvg = curTime;
fLastBytesSent = theServer->fTotalRTPBytes;
//if the bandwidth is above the bandwidth setting, disconnect 1 user by sending them
//a BYE RTCP packet.
SInt32 maxKBits = theServer->GetPrefs()->GetMaxKBitsBandwidth();
if ((maxKBits > -1) && (theServer->fAvgRTPBandwidthInBits > ((UInt32)maxKBits * 1024)))
{
//we need to make sure that all of this happens atomically wrt the session map
OSMutexLocker locker(theServer->GetRTPSessionMap()->GetMutex());
RTPSessionInterface* theSession = this->GetNewestSession(theServer->fRTPMap);
if (theSession != NULL)
if ((curTime - theSession->GetSessionCreateTime()) <
theServer->GetPrefs()->GetSafePlayDurationInSecs() * 1000)
theSession->Signal(Task::kKillEvent);
}
}
else if (fLastBandwidthAvg == 0)
{
fLastBandwidthAvg = curTime;
fLastBytesSent = theServer->fTotalRTPBytes;
}
(void)this->GetEvents();//we must clear the event mask!
return theServer->GetPrefs()->GetTotalBytesUpdateTimeInSecs() * 1000;
}