Mutex Class Reference

#include <Mutex.h>

Public Member Functions
	Mutex ()
int	init ()
int	init (char *name)
int	tryLock (int tries=0, int waitmsecs=0)
int	getLock (int procSlot, bool procAccount=true)
int	releaseLock (int procSlot, bool procAccount=true)
int	destroy ()
Data Fields
char	name [20]

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Detailed Description

Definition at line 24 of file Mutex.h.

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Constructor & Destructor Documentation

Mutex::Mutex

(

)

Definition at line 22 of file Mutex.cxx.

{
#if defined(sparc) || defined(i686)
    lock =0;
#else
    pthread_mutexattr_t attr;
    pthread_mutexattr_init(&attr);
    pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
    pthread_mutex_init(&mutex_, &attr);
#endif
}

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Member Function Documentation

int Mutex::destroy

(

)

Definition at line 205 of file Mutex.cxx.

{
#if defined(sparc) || defined(i686)
#else
    return pthread_mutex_destroy(&mutex_);
#endif
    return 0;
}

int Mutex::getLock	(	int	procSlot,
		bool	procAccount = true
	)

Definition at line 164 of file Mutex.cxx.

References ProcessManager::addMutex(), and tryLock().

Referenced by DatabaseManagerImpl::closeDatabase(), ProcessManager::deregisterThread(), Database::getAllocDatabaseMutex(), Database::getDatabaseMutex(), LockManager::getExclusiveLock(), UniqueID::getID(), Database::getProcessTableMutex(), LockManager::getSharedLock(), Database::getTransTableMutex(), HashIndex::insert(), LockManager::isExclusiveLocked(), TupleIterator::open(), DatabaseManagerImpl::openDatabase(), ProcessManager::registerThread(), LockManager::releaseLock(), HashIndex::remove(), and HashIndex::update().

{
    int ret=0;
#if defined(sparc) || defined(i686)
    ret = tryLock();
    //add it to the has_ of the ThreadInfo
    if (ret ==0 && procAccount) ProcessManager::addMutex(this, procSlot);

    return ret;
#else
    ret = pthread_mutex_lock(&mutex_);
#endif
    if (ret == 0) return 0;
    else
        return 1;
}

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int Mutex::init

(

char *

name

)

Definition at line 48 of file Mutex.cxx.

References init(), and name.

{
    if (strlen(mname) > 19 ) return 0;
    init();
    strcpy(name, mname);
    return 0;

}

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int Mutex::init

(

)

Definition at line 34 of file Mutex.cxx.

Referenced by init(), Database::initAllocDatabaseMutex(), Database::initDatabaseMutex(), Database::initProcessTableMutex(), Database::initTransTableMutex(), and UniqueID::UniqueID().

{
#if defined(sparc) || defined(i686)
    lock = 0;
#else
    pthread_mutexattr_t attr;
    pthread_mutexattr_init(&attr);
    int ret = pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
    printf("pthread_mutexattr_setpshared Returned %d\n", ret);
    pthread_mutex_init(&mutex_, &attr);
    pthread_mutexattr_destroy(&attr);
#endif
    return 0;
}

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int Mutex::releaseLock	(	int	procSlot,
		bool	procAccount = true
	)

Definition at line 181 of file Mutex.cxx.

References ProcessManager::removeMutex().

Referenced by DatabaseManagerImpl::closeDatabase(), ProcessManager::deregisterThread(), LockManager::getExclusiveLock(), UniqueID::getID(), LockManager::getSharedLock(), HashIndex::insert(), LockManager::isExclusiveLocked(), TupleIterator::open(), DatabaseManagerImpl::openDatabase(), ProcessManager::registerThread(), Database::releaseAllocDatabaseMutex(), Database::releaseDatabaseMutex(), LockManager::releaseLock(), Database::releaseProcessTableMutex(), Database::releaseTransTableMutex(), HashIndex::remove(), and HashIndex::update().

{
    int ret=0;
#if defined(sparc) || defined(i686)
    /*int *lw = &lock;
    if (*lw == 0) return 0;
    __asm__ __volatile__("movl $0, %%eax; xchgl (%%ecx), %%eax" :
                      "=m" (*lw) :
                      "ecx" (lw) :
                      "eax");   
    */
    lock = 0;
#else
    ret = pthread_mutex_unlock(&mutex_);
#endif
    if (ret == 0 && procAccount) 
    {
        ProcessManager::removeMutex(this, procSlot);
        return ret;
    }
    else
        return 1;
}

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int Mutex::tryLock	(	int	tries = 0,
		int	waitmsecs = 0
	)

Definition at line 131 of file Mutex.cxx.

References Conf::config, ErrLockTimeOut, Config::getMutexRetries(), Config::getMutexSecs(), Config::getMutexUSecs(), printError, and os::select().

Referenced by getLock().

{
    int tries = 0;
    int ret = 0;
    struct timeval timeout;
    timeout.tv_sec = 0;
    timeout.tv_usec = waitmsecs;
    if (tryTimes == 0 && waitmsecs == 0)
    {
        timeout.tv_sec = Conf::config.getMutexSecs();
        timeout.tv_usec = Conf::config.getMutexUSecs();
        tryTimes = Conf::config.getMutexRetries();
    }
    while (tries < tryTimes)
    {
#if defined(sparc) || defined(i686)
    if (TSL(&lock) == 0) 
    {
        return 0; 
    }
#else
    ret = pthread_mutex_trylock(&mutex_);
    if (EBUSY  != ret) return 0;

#endif
        os::select(0, 0, 0, 0, &timeout);
        tries++;
    }
    printError(ErrLockTimeOut, "Unable to get the mutex , tried %d times", tries);
    return 1;
}

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Field Documentation

char Mutex::name[20]

Definition at line 33 of file Mutex.h.

Referenced by ProcessManager::addMutex(), ProcessManager::deregisterThread(), init(), releaseAllResources(), and ProcessManager::removeMutex().

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The documentation for this class was generated from the following files:

• include/Mutex.h
• src/server/Mutex.cxx

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