Leaked source code of windows server 2003
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/*
Copyright (c) 1998-1999 Microsoft Corporation
*/
#include "stdafx.h"
#include "atlconv.h"
#include "termmgr.h"
#include "meterf.h"
#include "medpump.h"
#include <stdio.h>
#include <limits.h>
#include <tchar.h>
//
// the default value for maximum number of filters serviced by a single
// pump. can also be configurable through registry.
//
#define DEFAULT_MAX_FILTER_PER_PUMP (20)
//
// registry location where max number of filters per pump is configured
//
#define MST_REGISTRY_PATH _T("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Telephony\\MST")
#define MAX_FILTERS_PER_PUMP_KEY _T("MaximumFiltersPerPump")
DWORD WINAPI WriteMediaPumpThreadStart(void *pvPump)
{
return ((CMediaPump *)pvPump)->PumpMainLoop();
}
CMediaPump::CMediaPump(
)
: m_hThread(NULL),
m_hRegisterBeginSemaphore(NULL),
m_hRegisterEndSemaphore(NULL)
{
HRESULT hr;
LOG((MSP_TRACE, "CMediaPump::CMediaPump - enter"));
// create semaphores for registration signaling and completion -
// m_hRegisterBeginSemaphore is signaled before the Register call tries to acquire
// the critical section and m_hRegisterEndSemaphore is signaled when the Register
// call completes
// NOTE the names must be NULL, otherwise they will conflict when multiple pump threads
// are created
TCHAR *ptszSemaphoreName = NULL;
#if DBG
//
// in debug build, use named semaphores.
//
TCHAR tszSemaphoreNameString[MAX_PATH];
_stprintf(tszSemaphoreNameString, _T("RegisterBeginSemaphore_pid[0x%lx]_MediaPump[%p]_"), GetCurrentProcessId(), this);
LOG((MSP_TRACE, "CMediaPump::CMediaPump - creating semaphore[%S]", tszSemaphoreNameString));
ptszSemaphoreName = &tszSemaphoreNameString[0];
#endif
//
// create the beginning semaphore
//
m_hRegisterBeginSemaphore = CreateSemaphore(NULL, 0, LONG_MAX, ptszSemaphoreName);
if ( NULL == m_hRegisterBeginSemaphore ) goto cleanup;
#if DBG
//
// construct a name for registration end semaphore
//
_stprintf(tszSemaphoreNameString,
_T("RegisterEndSemaphore_pid[0x%lx]_MediaPump[%p]"),
GetCurrentProcessId(), this);
LOG((MSP_TRACE, "CMediaPump::CMediaPump - creating semaphore[%S]", tszSemaphoreNameString));
ptszSemaphoreName = &tszSemaphoreNameString[0];
#endif
//
// create the end semaphore
//
m_hRegisterEndSemaphore = CreateSemaphore(NULL, 0, LONG_MAX, ptszSemaphoreName);
if ( NULL == m_hRegisterEndSemaphore ) goto cleanup;
// insert the register event and the filter info to the arrays
// NOTE: we have to close and null the event in case of failure
// so that we can just check the register event handle value in
// Register to check if initialization was successful
hr = m_EventArray.Add(m_hRegisterBeginSemaphore);
if ( FAILED(hr) ) goto cleanup;
// add a corresponding NULL filter info entry
hr = m_FilterInfoArray.Add(NULL);
if ( FAILED(hr) )
{
m_EventArray.Remove(m_EventArray.GetSize()-1);
goto cleanup;
}
LOG((MSP_TRACE, "CMediaPump::CMediaPump - exit"));
return;
cleanup:
if ( NULL != m_hRegisterBeginSemaphore )
{
CloseHandle(m_hRegisterBeginSemaphore);
m_hRegisterBeginSemaphore = NULL;
}
if ( NULL != m_hRegisterEndSemaphore )
{
CloseHandle(m_hRegisterEndSemaphore);
m_hRegisterEndSemaphore = NULL;
}
LOG((MSP_TRACE, "CMediaPump::CMediaPump - cleanup exit"));
}
CMediaPump::~CMediaPump(void)
{
LOG((MSP_TRACE, "CMediaPump::~CMediaPump - enter"));
if ( NULL != m_hThread )
{
// when decommit is called on all the write terminals, the thread
// will return. this will signal the thread handle
WaitForSingleObject(m_hThread, INFINITE);
CloseHandle(m_hThread);
m_hThread = NULL;
}
if ( NULL != m_hRegisterBeginSemaphore )
{
CloseHandle(m_hRegisterBeginSemaphore);
m_hRegisterBeginSemaphore = NULL;
}
if ( NULL != m_hRegisterEndSemaphore )
{
CloseHandle(m_hRegisterEndSemaphore);
m_hRegisterEndSemaphore = NULL;
}
LOG((MSP_TRACE, "CMediaPump::~CMediaPump - exit"));
}
HRESULT
CMediaPump::CreateThreadPump(void)
{
LOG((MSP_TRACE, "CMediaPump::CreateThreadPump - enter"));
// release resources for any previous thread
if (NULL != m_hThread)
{
// when decommit is called on all the write terminals, the thread
// will return. this will signal the thread handle
// NOTE: this wait cannot cause a deadlock as we know that the
// number of entries in the array had dropped to 0 and only thread
// that can remove entries is the pump. this means that the pump thread
// must have detected that and returned
WaitForSingleObject(m_hThread, INFINITE);
CloseHandle(m_hThread);
m_hThread = NULL;
}
// create new thread
m_hThread = CreateThread(
NULL, 0, WriteMediaPumpThreadStart,
(void *)this, 0, NULL
);
if (NULL == m_hThread)
{
DWORD WinErrorCode = GetLastError();
LOG((MSP_TRACE,
"CMediaPump::CreateThreadPump - failed to create thread. LastError = 0x%lx",
WinErrorCode));
return HRESULT_FROM_ERROR_CODE(WinErrorCode);
}
LOG((MSP_TRACE, "CMediaPump::CreateThreadPump - finish"));
return S_OK;
}
// add this filter to its wait array
HRESULT
CMediaPump::Register(
IN CMediaTerminalFilter *pFilter,
IN HANDLE hWaitEvent
)
{
LOG((MSP_TRACE, "CMediaPump::Register - enter"));
TM_ASSERT(NULL != pFilter);
TM_ASSERT(NULL != hWaitEvent);
BAIL_IF_NULL(pFilter, E_INVALIDARG);
BAIL_IF_NULL(hWaitEvent, E_INVALIDARG);
// check if the register event
if ( NULL == m_hRegisterBeginSemaphore )
{
LOG((MSP_ERROR,
"CMediaPump::Register - m_hRegisterBeginSemaphore is NULL"));
return E_FAIL;
}
LONG lDebug;
// signal the register event, the pump thread will come out of the
// critical section and wait on m_hRegisterEndSemaphore
if ( !ReleaseSemaphore(m_hRegisterBeginSemaphore, 1, &lDebug) )
{
DWORD WinErrorCode = GetLastError();
LOG((MSP_ERROR,
"CMediaPump::Register - failed to release m_hRegisterBeginSemaphore. LastError = 0x%lx",
WinErrorCode));
return HRESULT_FROM_ERROR_CODE(WinErrorCode);
}
LOG((MSP_TRACE, "CMediaPump::Register - released begin semaphore - old count was %d", lDebug));
// when this SignalRegisterEnd instance is destroyed, it'll signal
// the end of registration and unblock the thread pump
//
// NOTE this releases the semaphore on DESTRUCTION of the class instance
RELEASE_SEMAPHORE_ON_DEST SignalRegisterEnd(m_hRegisterEndSemaphore);
HRESULT hr;
PUMP_LOCK LocalLock(&m_CritSec);
TM_ASSERT(m_EventArray.GetSize() == m_FilterInfoArray.GetSize());
// its possible that there is a duplicate in the array
// scenario - decommit signals the wait event but commit-register
// calls enter the critical section before the pump
DWORD Index;
if ( m_EventArray.Find(hWaitEvent, Index) )
{
LOG((MSP_TRACE, "CMediaPump::Register - event already registered"));
return S_OK;
}
// check if we have reached the maximum allowed filters
// if we overflow, we must return a very specific error code here
// (See CMediaPumpPool)
if ( m_EventArray.GetSize() >= MAX_FILTERS )
{
LOG((MSP_ERROR, "CMediaPump::Register - reached max number of filters for this[%p] pump", this));
return TAPI_E_ALLOCATED;
}
// create CFilterInfo for holding the call parameters
CFilterInfo *pFilterInfo = new CFilterInfo(pFilter, hWaitEvent);
if (NULL == pFilterInfo)
{
LOG((MSP_ERROR, "CMediaPump::Register - failed to allocate CFilterInfo"));
return E_OUTOFMEMORY;
}
//
// addref so the filterinfo structure we place into the array has refcount
// of one
//
pFilterInfo->AddRef();
// insert wait event into the array
hr = m_EventArray.Add(hWaitEvent);
if ( FAILED(hr) )
{
pFilterInfo->Release();
LOG((MSP_ERROR, "CMediaPump::Register - m_EventArray.Add failed hr = %lx", hr));
return hr;
}
// add a corresponding filter info entry
hr = m_FilterInfoArray.Add(pFilterInfo);
if ( FAILED(hr) )
{
m_EventArray.Remove(m_EventArray.GetSize()-1);
pFilterInfo->Release();
LOG((MSP_ERROR, "CMediaPump::Register - m_FilterInfoArray.Add failed hr = %lx", hr));
return hr;
}
// if this is the first entry into the array (beside the
// m_hRegisterBeginSemaphore, we need to create a thread pump
if (m_EventArray.GetSize() == 2)
{
hr = CreateThreadPump();
if ( FAILED(hr) )
{
RemoveFilter(m_EventArray.GetSize()-1);
LOG((MSP_ERROR, "CMediaPump::Register - CreateThreadPump failed hr = %lx", hr));
return hr;
}
}
// ignore error code. if we have been decommitted in between, it will
// signal us through the wait event
pFilter->SignalRegisteredAtPump();
TM_ASSERT(m_EventArray.GetSize() == m_FilterInfoArray.GetSize());
LOG((MSP_TRACE, "CMediaPump::Register - exit"));
return S_OK;
}
// remove this filter from wait array
HRESULT
CMediaPump::UnRegister(
IN HANDLE hWaitEvent
)
{
LOG((MSP_TRACE, "CMediaPump::Unregister[%p] - enter. Event[%p]",
this, hWaitEvent));
//
// if we did not get a valid event handle, debug
//
TM_ASSERT(NULL != hWaitEvent);
BAIL_IF_NULL(hWaitEvent, E_INVALIDARG);
//
// if we don't have register event, the pump is not properly initialized
//
if ( NULL == m_hRegisterBeginSemaphore )
{
LOG((MSP_ERROR,
"CMediaPump::Unregister[%p] - m_hRegisterBeginSemaphore is nUll. "
"pump is not initialized. returning E_FAIL - hWaitEvent=[%p]",
this, hWaitEvent));
return E_FAIL;
}
LONG lDebugSemaphoreCount = 0;
// signal the register event, the pump thread will come out of the
// critical section and wait on m_hRegisterEndSemaphore
if ( !ReleaseSemaphore(m_hRegisterBeginSemaphore, 1, &lDebugSemaphoreCount) )
{
DWORD WinErrorCode = GetLastError();
LOG((MSP_ERROR,
"CMediaPump::Unregister - ReleaseSemaphore failed with LastError 0x%lx",
WinErrorCode));
return HRESULT_FROM_ERROR_CODE(WinErrorCode);
}
LOG((MSP_TRACE, "CMediaPump::UnRegister - released begin semaphore - old count was %d", lDebugSemaphoreCount));
// when this SignalRegisterEnd instance is destroyed, it'll signal
// the end of registration and unblock the thread pump
//
// NOTE this releases the semaphore on DESTRUCTION of the class instance
RELEASE_SEMAPHORE_ON_DEST SignalRegisterEnd(m_hRegisterEndSemaphore);
PUMP_LOCK LocalLock(&m_CritSec);
TM_ASSERT(m_EventArray.GetSize() == m_FilterInfoArray.GetSize());
//
// has this event been registered before
//
DWORD Index;
if ( !m_EventArray.Find(hWaitEvent, Index) )
{
LOG((MSP_TRACE,
"CMediaPump::UnRegister - event is not ours. returning E_FAIL. not an error."));
return E_FAIL;
}
//
// found the filter that matches the event. remove the filter.
//
RemoveFilter(Index);
TM_ASSERT(m_EventArray.GetSize() == m_FilterInfoArray.GetSize());
LOG((MSP_TRACE, "CMediaPump::Unregister - finish."));
return S_OK;
}
void
CMediaPump::RemoveFilter(
IN DWORD Index
)
{
PUMP_LOCK LocalLock(&m_CritSec);
//
// event array and filterinfo arrays must always be consistent
//
TM_ASSERT(m_EventArray.GetSize() == m_FilterInfoArray.GetSize());
//
// find the filter that needs to be removed -- it must exist
//
CFilterInfo *pFilterInfo = m_FilterInfoArray.Get(Index);
if (NULL == pFilterInfo)
{
LOG((MSP_ERROR,
"CMediaPump::RemoveFilter - filter %ld not found in filter array",
Index));
TM_ASSERT(FALSE);
return;
}
//
// remove event and filter from the corresponding arrays
//
m_EventArray.Remove(Index);
m_FilterInfoArray.Remove(Index);
//
// remove filter from timer q and destroy it
//
LOG((MSP_TRACE,
"CMediaPump::RemoveFilter - removing filter[%ld] filterinfo[%p] from timerq",
Index,
pFilterInfo
));
m_TimerQueue.Remove(pFilterInfo);
pFilterInfo->Release();
TM_ASSERT(m_EventArray.GetSize() == m_FilterInfoArray.GetSize());
}
void
CMediaPump::RemoveFilter(
IN CFilterInfo *pFilterInfo
)
{
//
// find and remove should be atomic and need to be done in a lock
//
PUMP_LOCK LocalLock(&m_CritSec);
//
// find the array index
//
DWORD Index = 0;
if ( !m_FilterInfoArray.Find(pFilterInfo, Index) )
{
LOG((MSP_ERROR,
"CMediaPump::RemoveFilter - filter[%p] is not in the filterinfo array",
pFilterInfo));
return;
}
//
// index found, remove the filter
//
RemoveFilter(Index);
}
void
CMediaPump::ServiceFilter(
IN CFilterInfo *pFilterInfo
)
{
if (NULL == pFilterInfo)
{
LOG((MSP_ERROR,
"CMediaPump::ServiceFilter - pFilterInfo is NULL"));
TM_ASSERT(FALSE);
return;
}
if (NULL == pFilterInfo->m_pFilter)
{
LOG((MSP_ERROR,
"CMediaPump::ServiceFilter - pFilterInfo->m_pFilter is NULL"));
TM_ASSERT(FALSE);
return;
}
DWORD dwTimeBeforeGetFilledBuffer = timeGetTime();
IMediaSample *pMediaSample;
DWORD NextTimeout;
CMediaTerminalFilter *pFilter = pFilterInfo->m_pFilter;
HRESULT hr = pFilter->GetFilledBuffer(
pMediaSample, NextTimeout
);
if ( SUCCEEDED(hr) )
{
// if S_FALSE, nothing needs to be done
// its returned when we were signaled but there is no sample in
// the filter pool now.
// just continue to wait on event, no timeout needs to be scheduled
if ( S_FALSE == hr )
{
return;
}
// if GetFilledBuffer could not get an output buffer from the sample
// queue, then there is no sample to deliver just yet, but we do
// need to schedule the next timeout.
if ( VFW_S_NO_MORE_ITEMS != hr )
{
LOG((MSP_TRACE, "CMediaPump::ServiceFilter - calling Receive on downstream filter"));
//
// ask filter to process this sample. if everything goes ok, the
// filter will pass the sample to a downstream connected pin
//
HRESULT hrReceived = pFilter->ProcessSample(pMediaSample);
LOG((MSP_TRACE, "CMediaPump::ServiceFilter - returned from Receive on downstream filter"));
if ( pFilter->m_bUsingMyAllocator )
{
CSample *pSample = ((CMediaSampleTM *)pMediaSample)->m_pSample;
pSample->m_bReceived = true;
if (hrReceived != S_OK)
{
LOG((MSP_TRACE,
"CMediaPump::ServiceFilter - downstream filter's ProcessSample returned 0x%08x. "
"Aborting I/O operation",
hrReceived));
pSample->m_MediaSampleIoStatus = E_ABORT;
}
}
pMediaSample->Release();
//
// Account for how long it took to get the buffer and call Receive
// on the sample.
//
DWORD dwTimeAfterReceive = timeGetTime();
DWORD dwServiceDuration;
if ( dwTimeAfterReceive >= dwTimeBeforeGetFilledBuffer )
{
dwServiceDuration =
dwTimeAfterReceive - dwTimeBeforeGetFilledBuffer;
}
else
{
dwServiceDuration = ( (DWORD) -1 )
- dwTimeBeforeGetFilledBuffer + dwTimeAfterReceive;
}
//
// Give it an extra 1 ms, just so we err on the side of caution.
// This won't cause us to fill up the buffers anytime soon.
//
dwServiceDuration++;
//
// Adjust the timeout.
//
if ( dwServiceDuration >= NextTimeout )
{
NextTimeout = 0;
}
else
{
NextTimeout -= dwServiceDuration;
}
LOG((MSP_TRACE, "CMediaPump::ServiceFilter - "
"timeout adjusted by %d ms; resulting timeout is %d ms",
dwServiceDuration, NextTimeout));
}
// if there is a valid timeout, schedule next timeout.
// otherwise, we'll get only signaled if a new sample is added or
// the filter is decommitted
//
// need to do this in a lock
//
PUMP_LOCK LocalLock(&m_CritSec);
//
// if the filter has not yet been unregistered, schedule next timeout
//
DWORD Index = 0;
if ( m_FilterInfoArray.Find(pFilterInfo, Index) )
{
//
// filter is still registered, schedule next timeout
//
pFilterInfo->ScheduleNextTimeout(m_TimerQueue, NextTimeout);
}
else
{
//
// filter was unregistered while we held critical section. this is
// ok, but we should no longer schedule the filter, since it will
// be deleted when this call returns and the filter is released.
//
LOG((MSP_TRACE,
"CMediaPump::ServiceFilter - filter[%p] is not in the filterinfo array",
pFilterInfo));
}
}
else
{
TM_ASSERT(FAILED(hr));
RemoveFilter(pFilterInfo);
}
return;
}
void
CMediaPump::DestroyFilterInfoArray(
)
{
for(DWORD i=1; i < m_FilterInfoArray.GetSize(); i++)
{
CFilterInfo *pFilterInfo = m_FilterInfoArray.Get(i);
TM_ASSERT(NULL != pFilterInfo);
delete pFilterInfo;
m_FilterInfoArray.Remove(i);
}
}
// waits for filter events to be activated. also waits
// for registration calls and timer events
HRESULT
CMediaPump::PumpMainLoop(
)
{
HRESULT hr;
// wait in a loop for the filter events to be set or for the timer
// events to be fired
DWORD TimeToWait = INFINITE;
DWORD ErrorCode;
BOOL InRegisterCall = FALSE;
SetThreadPriority(
GetCurrentThread(),
THREAD_PRIORITY_TIME_CRITICAL
);
do
{
// if a register call is in progress, wait for the call to signal
// us before proceeding to acquire the critical section
if ( InRegisterCall )
{
LOG((MSP_TRACE, "CMediaPump::PumpMainLoop - waiting for end semaphore"));
InRegisterCall = FALSE;
DWORD EndErrorCode = WaitForSingleObject(
m_hRegisterEndSemaphore,
INFINITE
);
if ( WAIT_OBJECT_0 != EndErrorCode )
{
LOG((MSP_ERROR,
"CMediaPump::PumpMainLoop - failed waiting for m_hRegisterEndSemaphore"));
return E_UNEXPECTED;
}
//
// lock before accessing array
//
m_CritSec.Lock();
//
// see if the last filter was unregistered... if so, exit the thread.
//
if ( (1 == m_EventArray.GetSize()) )
{
m_CritSec.Unlock();
LOG((MSP_TRACE,
"CMediaPump::PumpMainLoop - a filter was unregistered. "
"no more filters. exiting thread"));
return S_OK;
}
//
// if did not exit, keeping the lock
//
LOG((MSP_TRACE, "CMediaPump::PumpMainLoop - finished waiting for end semaphore"));
}
else
{
//
// grab pump lock before starting to wait for events
//
m_CritSec.Lock();
}
//
// we should have a lock at this point
//
TM_ASSERT(m_EventArray.GetSize() > 0);
TM_ASSERT(m_EventArray.GetSize() == \
m_FilterInfoArray.GetSize());
//
// calculate time until the thread should wake up
//
TimeToWait = m_TimerQueue.GetTimeToTimeout();
LOG((MSP_TRACE,
"CMediaPump::PumpMainLoop - starting waiting for array. timeout %lu",
TimeToWait));
//
// wait to be signaled or until a timeout
//
ErrorCode = WaitForMultipleObjects(
m_EventArray.GetSize(),
m_EventArray.GetData(),
FALSE, // don't wait for all
TimeToWait
);
C_ASSERT(WAIT_OBJECT_0 == 0);
if (WAIT_TIMEOUT == ErrorCode)
{
//
// filter timeout
//
TM_ASSERT(INFINITE != TimeToWait);
TM_ASSERT(!m_TimerQueue.IsEmpty());
LOG((MSP_TRACE, "CMediaPump::PumpMainLoop - timeout"));
CFilterInfo *pFilterInfo = m_TimerQueue.RemoveFirst();
if (NULL == pFilterInfo)
{
LOG((MSP_ERROR,
"CMediaPump::PumpMainLoop - m_TimerQueue.RemoveFirst returned NULL"));
TM_ASSERT(FALSE);
}
else
{
pFilterInfo->AddRef();
//
// release the lock while in ServiceFilter to avoid deadlock with
// CMediaPump__UnRegister
//
m_CritSec.Unlock();
ServiceFilter(pFilterInfo);
pFilterInfo->Release();
m_CritSec.Lock();
}
}
else if ( ErrorCode < (WAIT_OBJECT_0 + m_EventArray.GetSize()) )
{
LOG((MSP_TRACE, "CMediaPump::PumpMainLoop - signaled"));
DWORD nFilterInfoIndex = ErrorCode - WAIT_OBJECT_0;
if (0 == nFilterInfoIndex)
{
//
// m_hRegisterBeginSemaphore was signaled
//
InRegisterCall = TRUE;
}
else
{
//
// one of the filters was signaled
//
CFilterInfo *pFilterInfo = m_FilterInfoArray.Get(nFilterInfoIndex);
if (NULL == pFilterInfo)
{
LOG((MSP_ERROR,
"CMediaPump::PumpMainLoop - pFilterInfo at index %ld is NULL",
nFilterInfoIndex));
TM_ASSERT(FALSE);
}
else
{
pFilterInfo->AddRef();
//
// unlock while in ServiceFilter. we don't want to service
// filter in a lock to avoid deadlocks.
//
m_CritSec.Unlock();
ServiceFilter(pFilterInfo);
pFilterInfo->Release();
m_CritSec.Lock();
}
}
}
else if ( (WAIT_ABANDONED_0 <= ErrorCode) &&
(ErrorCode < (WAIT_ABANDONED_0 + m_EventArray.GetSize()) ) )
{
DWORD nFilterIndex = ErrorCode - WAIT_OBJECT_0;
LOG((MSP_TRACE,
"CMediaPump::PumpMainLoop - event 0x%lx abandoned. removing filter",
nFilterIndex));
// remove item from the arrays
RemoveFilter(nFilterIndex);
}
else
{
//
// something bad happened
//
DestroyFilterInfoArray();
m_CritSec.Unlock();
DWORD WinErrorCode = GetLastError();
LOG((MSP_ERROR,
"CMediaPump::PumpMainLoop - error %ld... exiting",
WinErrorCode));
return HRESULT_FROM_ERROR_CODE(WinErrorCode);
}
//
// this check is performed here so that we detect the empty
// array and return, thus signaling the thread handle
//
// the case when InRegisterCall is on is not handled here -- we will
// check for the number of filters left after we have waited for the
// end event
//
if ( (1 == m_EventArray.GetSize()) && !InRegisterCall)
{
LOG((MSP_TRACE,
"CMediaPump::PumpMainLoop - no more filters in the array. exiting thread"));
m_CritSec.Unlock();
return S_OK;
}
m_CritSec.Unlock();
}
while(1);
}
int CMediaPump::CountFilters()
{
LOG((MSP_TRACE, "CMediaPump::CountFilters[%p] - enter", this));
//
// one of the events is the registration event -- we need to account for
// it -- hence the -1
//
//
// note: it is ok to do this without locking media pump.
//
// the getsize operation is purely get, and it is ok if the value is
// sometimes misread -- this would lead to the new filter being distributed
// not in the most optimal fashion on extremely rare occasions. this slight
// abnormality in distribution will be corrected later as new filters are
// coming in.
//
// on the other hand, locking media pump to get filter count will lead to
// "deadlocks" (when main pump loop is sleeping, and nothing happens to
// wake it up), and it is not trivial to get around this deadlock condition
// without affecting performance. not locking the pump is a simple and very
// inexpensive way to accomplish the objective, with an acceptable
// trade-off.
//
int nFilters = m_EventArray.GetSize() - 1;
LOG((MSP_TRACE, "CMediaPump::CountFilters - exit. [%d] filters", nFilters));
return nFilters;
}
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
//
// ZoltanS: non-optimal, but relatively painless way to get around scalability
// limitation of 63 filters per pump thread. This class presents the same
// external interface as the single thread pump, but creates as many pump
// threads as are needed to serve the filters that are in use.
//
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
CMediaPumpPool::CMediaPumpPool()
{
LOG((MSP_TRACE, "CMediaPumpPool::CMediaPumpPool - enter"));
//
// setting the default value. registry setting, if present, overwrites this
//
m_dwMaxNumberOfFilterPerPump = DEFAULT_MAX_FILTER_PER_PUMP;
LOG((MSP_TRACE, "CMediaPumpPool::CMediaPumpPool - exit"));
}
//////////////////////////////////////////////////////////////////////////////
//
// Destructor: This destroys the individual pumps.
//
CMediaPumpPool::~CMediaPumpPool(void)
{
LOG((MSP_TRACE, "CMediaPumpPool::~CMediaPumpPool - enter"));
CLock lock(m_CritSection);
//
// Shut down and delete each CMediaPump; the array itself is
// cleaned up in its destructor.
//
int iSize = m_aPumps.GetSize();
for (int i = 0; i < iSize; i++ )
{
delete m_aPumps[i];
}
LOG((MSP_TRACE, "CMediaPumpPool::~CMediaPumpPool - exit"));
}
//////////////////////////////////////////////////////////////////////////////
//
// CMediaPumpPool::CreatePumps
//
// this function creates the media pumps, the number of which is passed as an
// argument
//
HRESULT CMediaPumpPool::CreatePumps(int nPumpsToCreate)
{
LOG((MSP_TRACE, "CMediaPumpPool::CreatePumps - enter. nPumpsToCreate = [%d]", nPumpsToCreate));
for (int i = 0; i < nPumpsToCreate; i++)
{
//
// attempt to create a media pump
//
CMediaPump * pNewPump = new CMediaPump;
if ( pNewPump == NULL )
{
LOG((MSP_ERROR, "CMediaPumpPool::CreatePumps - "
"cannot create new media pump - "
"exit E_OUTOFMEMORY"));
//
// delete all the pumps we have created in this call
//
for (int j = i - 1; j >= 0; j--)
{
delete m_aPumps[j];
m_aPumps.RemoveAt(j);
}
return E_OUTOFMEMORY;
}
//
// attempt to add the new media pump to the array of media pumps.
//
if ( ! m_aPumps.Add(pNewPump) )
{
LOG((MSP_ERROR, "CMediaPumpPool::CreatePumps - cannot add new media pump to array - exit E_OUTOFMEMORY"));
//
// delete all the pumps we have created in this call
//
delete pNewPump;
for (int j = i - 1; j >= 0; j--)
{
delete m_aPumps[j];
m_aPumps.RemoveAt(j);
}
return E_OUTOFMEMORY;
}
}
LOG((MSP_TRACE, "CMediaPumpPool::CreatePumps - finished."));
return S_OK;
}
///////////////////////////////////////////////////////////////////////////////
//
// CMediaPumpPool::ReadRegistryValuesIfNeeded
//
// this function reads the registry setting for max number of filters per pump
// and in case of success, keeps the new value.
//
// this function is not thread safe. the caller must guarantee thread safety
//
HRESULT CMediaPumpPool::ReadRegistryValuesIfNeeded()
{
//
// we don't want to access registry more than once. so we have this static
// flag that helps us limit registry access
//
static bRegistryChecked = FALSE;
if (TRUE == bRegistryChecked)
{
//
// checked registry before. no need to do (or log) anything here
//
return S_OK;
}
//
// we don't want to log until we know we will try to read registry
//
LOG((MSP_TRACE, "CMediaPumpPool::ReadRegistryValuesIfNeeded - enter"));
//
// whether we will succeed or fail, do not check the registry again
//
bRegistryChecked = TRUE;
//
// Open the registry key
//
HKEY hKey = 0;
LONG lResult = RegOpenKeyEx(HKEY_LOCAL_MACHINE,
MST_REGISTRY_PATH,
0,
KEY_READ,
&hKey);
//
// did we manage to open the key?
//
if( ERROR_SUCCESS != lResult )
{
LOG((MSP_WARN, "CPTUtil::ReadRegistryValuesIfNeeded - "
"RegOpenKeyEx failed, returns E_FAIL"));
return E_FAIL;
}
//
// read the value
//
DWORD dwMaxFiltersPerPump = 0;
DWORD dwDataSize = sizeof(DWORD);
lResult = RegQueryValueEx(
hKey,
MAX_FILTERS_PER_PUMP_KEY,
NULL,
NULL,
(LPBYTE) &dwMaxFiltersPerPump,
&dwDataSize
);
//
// don't need the key anymore
//
RegCloseKey(hKey);
hKey = NULL;
//
// any luck reading the value?
//
if( ERROR_SUCCESS != lResult )
{
LOG((MSP_WARN, "CPTUtil::ReadRegistryValuesIfNeeded - RegQueryValueEx failed, return E_FAIL"));
return E_FAIL;
}
//
// got the value, keeping it.
//
m_dwMaxNumberOfFilterPerPump = dwMaxFiltersPerPump;
LOG((MSP_TRACE,
"CMediaPumpPool::ReadRegistryValuesIfNeeded - exit. MaxNumberOfFilterPerPump = %lx",
m_dwMaxNumberOfFilterPerPump));
return S_OK;
}
//////////////////////////////////////////////////////////////////////////////
//
// CMediaPumpPool::GetOptimalNumberOfPumps
//
// this function returns the number of pumps required to process all the
// filters that are currently being handled, plus the filter that is about to
// be registered
//
HRESULT CMediaPumpPool::GetOptimalNumberOfPumps(int *pnPumpsNeeded)
{
LOG((MSP_TRACE, "CMediaPumpPool::GetOptimalNumberOfPumps - enter"));
//
// if the argument is bad, it's a bug
//
if (IsBadWritePtr(pnPumpsNeeded, sizeof(int)))
{
LOG((MSP_ERROR,
"CMediaPumpPool::GetOptimalNumberOfPumps - pnPumpsNeeded[%p] is bad",
pnPumpsNeeded));
TM_ASSERT(FALSE);
return E_POINTER;
}
//
// calculate the total number of service filters
//
int nTotalExistingPumps = m_aPumps.GetSize();
//
// start with one filter (to adjust for the filter we are adding)
//
int nTotalFilters = 1;
for (int i = 0; i < nTotalExistingPumps; i++)
{
//
// note that the number of filters we get could be slightly higher then
// the real number, since the filters can be removed without involving
// pump pool (and thus getting its critical section). this is ok --
// the worst that will happen is that we will sometimes have more pumps
// then we really need.
//
nTotalFilters += m_aPumps[i]->CountFilters();
}
//
// calculated how many filters are being serviced
//
//
// what is the max number of filters a pump can service
//
DWORD dwMaxNumberOfFilterPerPump = GetMaxNumberOfFiltersPerPump();
//
// find the number of pumps needed to service all our filters
//
*pnPumpsNeeded = nTotalFilters / dwMaxNumberOfFilterPerPump;
//
// if the number of filters is not evenly divisible by the max number of
// filters serviced by a pump, we need to round up.
//
if ( 0 != (nTotalFilters % dwMaxNumberOfFilterPerPump) )
{
//
// uneven divide, roundup adjustment is necessary
//
*pnPumpsNeeded += 1;
}
//
// we have calculated the number of pumps needed to process all our filters
//
LOG((MSP_TRACE,
"CMediaPumpPool::GetOptimalNumberOfPumps - exit. [%d] filters should be serviced by [%d] pump(s)",
nTotalFilters, *pnPumpsNeeded));
return S_OK;
}
/////////////////////////////////////////////////////////////////////////////
//
// CMediaPumpPool::PickThePumpToUse
//
// this method chooses the pump that should be used to service the new filter
// the pump is picked based on the load and the number of pumps needed to
// service all pf the current filters
//
HRESULT CMediaPumpPool::PickThePumpToUse(int *pPumpToUse)
{
LOG((MSP_TRACE, "CMediaPumpPool::PickThePumpToUse - enter"));
//
// if the argument is bad, it's a bug
//
if (IsBadWritePtr(pPumpToUse, sizeof(int)))
{
LOG((MSP_ERROR, "CMediaPumpPool::PickThePumpToUse - pPumpToUse[%p] is bad", pPumpToUse));
TM_ASSERT(FALSE);
return E_POINTER;
}
//
// calculate the optimal number of pumps needed for the current number of filters
//
int nPumpsNeeded = 0;
HRESULT hr = GetOptimalNumberOfPumps(&nPumpsNeeded);
if (FAILED(hr))
{
LOG((MSP_ERROR,
"CMediaPumpPool::PickThePumpToUse - GetOptimalNumberOfPumps failed hr = [%lx]",
hr));
return hr;
}
//
// if we don't have enough pumps, create more
//
int nTotalExistingPumps = m_aPumps.GetSize();
if (nTotalExistingPumps < nPumpsNeeded)
{
//
// this is how many more pumps we need to create
//
int nNewPumpsToCreate = nPumpsNeeded - nTotalExistingPumps;
//
// we will never need to create more than one new pump at a time
//
TM_ASSERT(1 == nNewPumpsToCreate);
//
// special case if we currently don't have any pumps -- create one pump
// for each processor. this will help us scale on symmetric
// multiprocessor machines.
//
if (0 == nTotalExistingPumps)
{
//
// get the number of processors. according to documentation,
// GetSystemInfo cannot fail, so there is return code to check
//
SYSTEM_INFO SystemInfo;
GetSystemInfo(&SystemInfo);
//
// we will want to create at least as many new pumps as we have
// processors, but maybe more if needed
//
//
// note: we may also want to look at the affinity mask, it may
// tell us how many CPUs are actually used
//
int nNumberOfProcessors = SystemInfo.dwNumberOfProcessors;
if (nNewPumpsToCreate < nNumberOfProcessors)
{
nNewPumpsToCreate = SystemInfo.dwNumberOfProcessors;
}
}
//
// we now have all the information needed to create the pumps we need.
//
hr = CreatePumps(nNewPumpsToCreate);
if (FAILED(hr))
{
LOG((MSP_ERROR,
"CMediaPumpPool::PickThePumpToUse - CreatePumps failed hr = [%lx]",
hr));
return hr;
}
LOG((MSP_TRACE, "CMediaPumpPool::PickThePumpToUse - create [%d] pumps", nNewPumpsToCreate));
}
//
// walk trough the pumps (only use pumps starting from the first N pumps,
// N being the number of pumps needed to service the number of filters that
// we are servicing
//
nTotalExistingPumps = m_aPumps.GetSize();
int nLowestLoad = INT_MAX;
int nLowestLoadPumpIndex = -1;
for (int nPumpIndex = 0; nPumpIndex < nTotalExistingPumps; nPumpIndex++)
{
int nNumberOfFiltersAtPump = 0;
//
// how many filters is this pump serving?
//
nNumberOfFiltersAtPump = m_aPumps[nPumpIndex]->CountFilters();
//
// if the pump we are looking at has less load then any of the
// previously evaluated pumps, remember it. if we don't find anything
// better, this is what we will use.
//
if (nNumberOfFiltersAtPump < nLowestLoad)
{
nLowestLoadPumpIndex = nPumpIndex;
nLowestLoad = nNumberOfFiltersAtPump;
}
}
//
// we had to get something!
//
if (-1 == nLowestLoadPumpIndex)
{
LOG((MSP_ERROR,
"CMediaPumpPool::PickThePumpToUse - did not find a pump to use"));
//
// we have a bug -- need to investigate
//
TM_ASSERT(FALSE);
return E_UNEXPECTED;
}
//
// we found a pump to use
//
*pPumpToUse = nLowestLoadPumpIndex;
LOG((MSP_TRACE,
"CMediaPumpPool::PickThePumpToUse - finish. using pump %d, current load %d",
*pPumpToUse, nLowestLoad));
return S_OK;
}
//////////////////////////////////////////////////////////////////////////////
//
// Register: This delegates to the individual pumps, creating new ones as
// needed.
//
HRESULT CMediaPumpPool::Register(
IN CMediaTerminalFilter *pFilter,
IN HANDLE hWaitEvent
)
{
LOG((MSP_TRACE, "CMediaPumpPool::Register - enter"));
CLock lock(m_CritSection);
//
// find the pump with which to register filter
//
int nPumpToUse = 0;
HRESULT hr = PickThePumpToUse(&nPumpToUse);
if (FAILED(hr))
{
LOG((MSP_ERROR,
"CMediaPumpPool::Register - failed to find the pump to be used to service the new filter, hr = [%lx]",
hr));
return hr;
}
//
// just to be on the safe side, make sure the index we got makes sense
//
int nTotalPumps = m_aPumps.GetSize();
if (nTotalPumps - 1 < nPumpToUse)
{
LOG((MSP_ERROR,
"CMediaPumpPool::Register - PickThePumpToUse return bad pump index [%d]",
nPumpToUse));
TM_ASSERT(FALSE);
return E_UNEXPECTED;
}
//
// ok, all is well, register with the pump
//
hr = m_aPumps[nPumpToUse]->Register(pFilter, hWaitEvent);
if (FAILED(hr))
{
LOG((MSP_ERROR,
"CMediaPumpPool::Register - failed to register with pump [%d] at [%p]",
nPumpToUse, m_aPumps[nPumpToUse]));
return hr;
}
LOG((MSP_TRACE, "CMediaPumpPool::Register - finished"));
return S_OK;
}
//////////////////////////////////////////////////////////////////////////////
//
// UnRegister: Unregister filter. This delegates to the individual pumps
//
HRESULT CMediaPumpPool::UnRegister(
IN HANDLE hWaitEvent
)
{
LOG((MSP_TRACE, "CMediaPumpPool::UnRegister - enter"));
HRESULT hr = E_FAIL;
//
// All of this is done within a single critical section, to
// synchronize access to our array
//
CLock lock(m_CritSection);
//
// try to unregister from a pump thread in the array
//
int iSize = m_aPumps.GetSize();
for (int i = 0; i < iSize; i++ )
{
//
// Try to unregister from this pump thread.
//
hr = m_aPumps[i]->UnRegister(hWaitEvent);
//
// If succeeded unregistering from this pump, then we are done.
// Otherwise just try the next one.
//
if ( hr == S_OK )
{
LOG((MSP_TRACE,
"CMediaPumpPool::UnRegister - unregistered with media pump %d",
i));
break;
}
}
LOG((MSP_TRACE,
"CMediaPumpPool::UnRegister - exit. hr = 0x%08x", hr));
return hr;
}
//
// eof
//