BackgroundMusic/BGMApp/PublicUtility/CAMutex.cpp
2016-02-19 16:25:34 +11:00

345 lines
12 KiB
C++

/*
File: CAMutex.cpp
Abstract: CAMutex.h
Version: 1.1
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//==================================================================================================
// Includes
//==================================================================================================
// Self Include
#include "CAMutex.h"
#if TARGET_OS_MAC
#include <errno.h>
#endif
// PublicUtility Includes
#include "CADebugMacros.h"
#include "CAException.h"
#include "CAHostTimeBase.h"
//==================================================================================================
// Logging
//==================================================================================================
#if CoreAudio_Debug
// #define Log_Ownership 1
// #define Log_Errors 1
// #define Log_LongLatencies 1
// #define LongLatencyThreshholdNS 1000000ULL // nanoseconds
#endif
//==================================================================================================
// CAMutex
//==================================================================================================
CAMutex::CAMutex(const char* inName)
:
mName(inName),
mOwner(0)
{
#if TARGET_OS_MAC
OSStatus theError = pthread_mutex_init(&mMutex, NULL);
ThrowIf(theError != 0, CAException(theError), "CAMutex::CAMutex: Could not init the mutex");
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%p %.4f: CAMutex::CAMutex: creating %s, owner: %p\n", pthread_self(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), mName, mOwner);
#endif
#elif TARGET_OS_WIN32
mMutex = CreateMutex(NULL, false, NULL);
ThrowIfNULL(mMutex, CAException(GetLastError()), "CAMutex::CAMutex: could not create the mutex.");
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%lu %.4f: CAMutex::CAMutex: creating %s, owner: %lu\n", GetCurrentThreadId(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), mName, mOwner);
#endif
#endif
}
CAMutex::~CAMutex()
{
#if TARGET_OS_MAC
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%p %.4f: CAMutex::~CAMutex: destroying %s, owner: %p\n", pthread_self(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), mName, mOwner);
#endif
pthread_mutex_destroy(&mMutex);
#elif TARGET_OS_WIN32
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%lu %.4f: CAMutex::~CAMutex: destroying %s, owner: %lu\n", GetCurrentThreadId(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), mName, mOwner);
#endif
if(mMutex != NULL)
{
CloseHandle(mMutex);
}
#endif
}
bool CAMutex::Lock()
{
bool theAnswer = false;
#if TARGET_OS_MAC
pthread_t theCurrentThread = pthread_self();
if(!pthread_equal(theCurrentThread, mOwner))
{
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%p %.4f: CAMutex::Lock: thread %p is locking %s, owner: %p\n", theCurrentThread, ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), theCurrentThread, mName, mOwner);
#endif
#if Log_LongLatencies
UInt64 lockTryTime = CAHostTimeBase::GetCurrentTimeInNanos();
#endif
OSStatus theError = pthread_mutex_lock(&mMutex);
ThrowIf(theError != 0, CAException(theError), "CAMutex::Lock: Could not lock the mutex");
mOwner = theCurrentThread;
theAnswer = true;
#if Log_LongLatencies
UInt64 lockAcquireTime = CAHostTimeBase::GetCurrentTimeInNanos();
if (lockAcquireTime - lockTryTime >= LongLatencyThresholdNS)
DebugPrintfRtn(DebugPrintfFileComma "Thread %p took %.6fs to acquire the lock %s\n", theCurrentThread, (lockAcquireTime - lockTryTime) * 1.0e-9 /* nanos to seconds */, mName);
#endif
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%p %.4f: CAMutex::Lock: thread %p has locked %s, owner: %p\n", pthread_self(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), pthread_self(), mName, mOwner);
#endif
}
#elif TARGET_OS_WIN32
if(mOwner != GetCurrentThreadId())
{
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%lu %.4f: CAMutex::Lock: thread %lu is locking %s, owner: %lu\n", GetCurrentThreadId(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), GetCurrentThreadId(), mName, mOwner);
#endif
OSStatus theError = WaitForSingleObject(mMutex, INFINITE);
ThrowIfError(theError, CAException(theError), "CAMutex::Lock: could not lock the mutex");
mOwner = GetCurrentThreadId();
theAnswer = true;
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%lu %.4f: CAMutex::Lock: thread %lu has locked %s, owner: %lu\n", GetCurrentThreadId(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), GetCurrentThreadId(), mName, mOwner);
#endif
}
#endif
return theAnswer;
}
void CAMutex::Unlock()
{
#if TARGET_OS_MAC
if(pthread_equal(pthread_self(), mOwner))
{
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%p %.4f: CAMutex::Unlock: thread %p is unlocking %s, owner: %p\n", pthread_self(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), pthread_self(), mName, mOwner);
#endif
mOwner = 0;
OSStatus theError = pthread_mutex_unlock(&mMutex);
ThrowIf(theError != 0, CAException(theError), "CAMutex::Unlock: Could not unlock the mutex");
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%p %.4f: CAMutex::Unlock: thread %p has unlocked %s, owner: %p\n", pthread_self(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), pthread_self(), mName, mOwner);
#endif
}
else
{
DebugMessage("CAMutex::Unlock: A thread is attempting to unlock a Mutex it doesn't own");
}
#elif TARGET_OS_WIN32
if(mOwner == GetCurrentThreadId())
{
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%lu %.4f: CAMutex::Unlock: thread %lu is unlocking %s, owner: %lu\n", GetCurrentThreadId(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), GetCurrentThreadId(), mName, mOwner);
#endif
mOwner = 0;
bool wasReleased = ReleaseMutex(mMutex);
ThrowIf(!wasReleased, CAException(GetLastError()), "CAMutex::Unlock: Could not unlock the mutex");
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%lu %.4f: CAMutex::Unlock: thread %lu has unlocked %s, owner: %lu\n", GetCurrentThreadId(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), GetCurrentThreadId(), mName, mOwner);
#endif
}
else
{
DebugMessage("CAMutex::Unlock: A thread is attempting to unlock a Mutex it doesn't own");
}
#endif
}
bool CAMutex::Try(bool& outWasLocked)
{
bool theAnswer = false;
outWasLocked = false;
#if TARGET_OS_MAC
pthread_t theCurrentThread = pthread_self();
if(!pthread_equal(theCurrentThread, mOwner))
{
// this means the current thread doesn't already own the lock
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%p %.4f: CAMutex::Try: thread %p is try-locking %s, owner: %p\n", theCurrentThread, ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), theCurrentThread, mName, mOwner);
#endif
// go ahead and call trylock to see if we can lock it.
int theError = pthread_mutex_trylock(&mMutex);
if(theError == 0)
{
// return value of 0 means we successfully locked the lock
mOwner = theCurrentThread;
theAnswer = true;
outWasLocked = true;
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%p %.4f: CAMutex::Try: thread %p has locked %s, owner: %p\n", theCurrentThread, ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), theCurrentThread, mName, mOwner);
#endif
}
else if(theError == EBUSY)
{
// return value of EBUSY means that the lock was already locked by another thread
theAnswer = false;
outWasLocked = false;
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%p %.4f: CAMutex::Try: thread %p failed to lock %s, owner: %p\n", theCurrentThread, ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), theCurrentThread, mName, mOwner);
#endif
}
else
{
// any other return value means something really bad happenned
ThrowIfError(theError, CAException(theError), "CAMutex::Try: call to pthread_mutex_trylock failed");
}
}
else
{
// this means the current thread already owns the lock
theAnswer = true;
outWasLocked = false;
}
#elif TARGET_OS_WIN32
if(mOwner != GetCurrentThreadId())
{
// this means the current thread doesn't own the lock
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%lu %.4f: CAMutex::Try: thread %lu is try-locking %s, owner: %lu\n", GetCurrentThreadId(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), GetCurrentThreadId(), mName, mOwner);
#endif
// try to acquire the mutex
OSStatus theError = WaitForSingleObject(mMutex, 0);
if(theError == WAIT_OBJECT_0)
{
// this means we successfully locked the lock
mOwner = GetCurrentThreadId();
theAnswer = true;
outWasLocked = true;
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%lu %.4f: CAMutex::Try: thread %lu has locked %s, owner: %lu\n", GetCurrentThreadId(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), GetCurrentThreadId(), mName, mOwner);
#endif
}
else if(theError == WAIT_TIMEOUT)
{
// this means that the lock was already locked by another thread
theAnswer = false;
outWasLocked = false;
#if Log_Ownership
DebugPrintfRtn(DebugPrintfFileComma "%lu %.4f: CAMutex::Try: thread %lu failed to lock %s, owner: %lu\n", GetCurrentThreadId(), ((Float64)(CAHostTimeBase::GetCurrentTimeInNanos()) / 1000000.0), GetCurrentThreadId(), mName, mOwner);
#endif
}
else
{
// any other return value means something really bad happenned
ThrowIfError(theError, CAException(GetLastError()), "CAMutex::Try: call to lock the mutex failed");
}
}
else
{
// this means the current thread already owns the lock
theAnswer = true;
outWasLocked = false;
}
#endif
return theAnswer;
}
bool CAMutex::IsFree() const
{
return mOwner == 0;
}
bool CAMutex::IsOwnedByCurrentThread() const
{
bool theAnswer = true;
#if TARGET_OS_MAC
theAnswer = pthread_equal(pthread_self(), mOwner);
#elif TARGET_OS_WIN32
theAnswer = (mOwner == GetCurrentThreadId());
#endif
return theAnswer;
}
CAMutex::Unlocker::Unlocker(CAMutex& inMutex)
: mMutex(inMutex),
mNeedsLock(false)
{
Assert(mMutex.IsOwnedByCurrentThread(), "Major problem: Unlocker attempted to unlock a mutex not owned by the current thread!");
mMutex.Unlock();
mNeedsLock = true;
}
CAMutex::Unlocker::~Unlocker()
{
if(mNeedsLock)
{
mMutex.Lock();
}
}