[c3e3bf]: mutex.c  Maximize  Restore  History

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/*
* mutex.c
*
* Description:
* This translation unit implements mutual exclusion (mutex) primitives.
*/
#include <errno.h>
#include "pthread.h"
#include "implement.h"
int
pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)
{
if (mutex == NULL)
{
return EINVAL;
}
/* Create a critical section. */
InitializeCriticalSection(&mutex->cs);
/* Mark as valid. */
mutex->valid = 1;
return 0;
}
int
pthread_mutex_destroy(pthread_mutex_t *mutex)
{
if (mutex == NULL)
{
return EINVAL;
}
DeleteCriticalSection(&mutex->cs);
/* Mark as invalid. */
mutex->valid = 0;
return 0;
}
int
pthread_mutexattr_init(pthread_mutexattr_t *attr)
{
if (attr == NULL)
{
/* This is disallowed. */
return EINVAL;
}
/* None of the optional attributes are supported yet. */
return 0;
}
int
pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
{
/* Nothing to do. */
return 0;
}
int
pthread_mutex_lock(pthread_mutex_t *mutex)
{
if (!mutex->valid)
{
pthread_mutex_init(mutex, NULL);
}
EnterCriticalSection(&mutex->cs);
return 0;
}
int
pthread_mutex_unlock(pthread_mutex_t *mutex)
{
if (!mutex->valid)
{
return EINVAL;
}
LeaveCriticalSection(&mutex->cs);
return 0;
}
int
pthread_mutex_trylock(pthread_mutex_t *mutex)
{
if (_pthread_try_enter_critical_section == NULL)
{
/* TryEnterCriticalSection does not exist in the OS; return ENOSYS. */
return ENOSYS;
}
if (mutex == NULL)
{
return EINVAL;
}
if (!mutex->valid)
{
pthread_mutex_init(mutex, NULL);
}
return ((*_pthread_try_enter_critical_section)(&mutex->cs) != TRUE) ? EBUSY : 0;
}