int
sem_trywait (sem_t * sem)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function tries to wait on a semaphore.
*
* PARAMETERS
* sem
* pointer to an instance of sem_t
*
* DESCRIPTION
* This function tries to wait on a semaphore. If the
* semaphore value is greater than zero, it decreases
* its value by one. If the semaphore value is zero, then
* this function returns immediately with the error EAGAIN
*
* RESULTS
* 0 successfully decreased semaphore,
* -1 failed, error in errno
* ERRNO
* EAGAIN the semaphore was already locked,
* EINVAL 'sem' is not a valid semaphore,
* ENOTSUP sem_trywait is not supported,
* EINTR the function was interrupted by a signal,
* EDEADLK a deadlock condition was detected.
*
* ------------------------------------------------------
*/
{
int result = 0;
sem_t s = *sem;
ptw32_mcs_local_node_t node;
ptw32_mcs_lock_acquire(&s->lock, &node);
if (s->value > 0)
{
s->value--;
}
else
{
result = EAGAIN;
}
ptw32_mcs_lock_release(&node);
if (result != 0)
{
PTW32_SET_ERRNO(result);
return -1;
}
return 0;
} /* sem_trywait */
int
sched_setscheduler (pid_t pid, int policy)
{
/*
* Win32 only has one policy which we call SCHED_OTHER.
* However, we try to provide other valid side-effects
* such as EPERM and ESRCH errors. Choosing to check
* for a valid policy last allows us to get the most value out
* of this function.
*/
if (0 != pid)
{
int selfPid = (int) GetCurrentProcessId ();
if (pid != selfPid)
{
HANDLE h =
OpenProcess (PROCESS_SET_INFORMATION, PTW32_FALSE, (DWORD) pid);
if (NULL == h)
{
PTW32_SET_ERRNO((GetLastError () == (0xFF & ERROR_ACCESS_DENIED)) ? EPERM : ESRCH);
return -1;
}
else
CloseHandle(h);
}
}
if (SCHED_OTHER != policy)
{
PTW32_SET_ERRNO(ENOSYS);
return -1;
}
/*
* Don't set anything because there is nothing to set.
* Just return the current (the only possible) value.
*/
return SCHED_OTHER;
}
int
sched_setaffinity (pid_t pid, size_t cpusetsize, cpu_set_t *set)
/*
* ------------------------------------------------------
* DOCPUBLIC
* Sets the CPU affinity mask of the process whose ID is pid
* to the value specified by mask. If pid is zero, then the
* calling process is used. The argument cpusetsize is the
* length (in bytes) of the data pointed to by mask. Normally
* this argument would be specified as sizeof(cpu_set_t).
*
* If the process specified by pid is not currently running on
* one of the CPUs specified in mask, then that process is
* migrated to one of the CPUs specified in mask.
*
* PARAMETERS
* pid
* Process ID
*
* cpusetsize
* Currently ignored in pthreads4w.
* Usually set to sizeof(cpu_set_t)
*
* mask
* Pointer to the CPU mask to set (cpu_set_t).
*
* DESCRIPTION
* Sets the CPU affinity mask of the process whose ID is pid
* to the value specified by mask. If pid is zero, then the
* calling process is used. The argument cpusetsize is the
* length (in bytes) of the data pointed to by mask. Normally
* this argument would be specified as sizeof(cpu_set_t).
*
* If the process specified by pid is not currently running on
* one of the CPUs specified in mask, then that process is
* migrated to one of the CPUs specified in mask.
*
* RESULTS
* 0 successfully created semaphore,
* EFAULT 'mask' is a NULL pointer.
* EINVAL '*mask' contains no CPUs in the set
* of available CPUs.
* EAGAIN The system available CPUs could not
* be obtained.
* EPERM The process referred to by 'pid' is
* not modifiable by us.
* ESRCH The process referred to by 'pid' was
* not found.
* ENOSYS Function not supported.
*
* ------------------------------------------------------
*/
{
#if ! defined(NEED_PROCESS_AFFINITY_MASK)
DWORD_PTR vProcessMask;
DWORD_PTR vSystemMask;
HANDLE h;
int targetPid = (int)(size_t) pid;
int result = 0;
if (NULL == set)
{
result = EFAULT;
}
else
{
if (0 == targetPid)
{
targetPid = (int) GetCurrentProcessId ();
}
h = OpenProcess (PROCESS_QUERY_INFORMATION|PROCESS_SET_INFORMATION, PTW32_FALSE, (DWORD) targetPid);
if (NULL == h)
{
result = (((0xFF & ERROR_ACCESS_DENIED) == GetLastError()) ? EPERM : ESRCH);
}
else
{
if (GetProcessAffinityMask (h, &vProcessMask, &vSystemMask))
{
/*
* Result is the intersection of available CPUs and the mask.
*/
DWORD_PTR newMask = vSystemMask & ((_sched_cpu_set_vector_*)set)->_cpuset;
if (newMask)
{
if (SetProcessAffinityMask(h, newMask) == 0)
{
switch (GetLastError())
{
case (0xFF & ERROR_ACCESS_DENIED):
result = EPERM;
break;
case (0xFF & ERROR_INVALID_PARAMETER):
result = EINVAL;
break;
default:
result = EAGAIN;
break;
}
}
}
else
{
/*
* Mask does not contain any CPUs currently available on the system.
*/
result = EINVAL;
}
}
else
{
result = EAGAIN;
}
}
CloseHandle(h);
}
if (result != 0)
{
PTW32_SET_ERRNO(result);
return -1;
}
else
{
return 0;
}
#else
PTW32_SET_ERRNO(ENOSYS);
return -1;
#endif
}
int
sched_getaffinity (pid_t pid, size_t cpusetsize, cpu_set_t *set)
/*
* ------------------------------------------------------
* DOCPUBLIC
* Gets the CPU affinity mask of the process whose ID is pid
* to the value specified by mask. If pid is zero, then the
* calling process is used. The argument cpusetsize is the
* length (in bytes) of the data pointed to by mask. Normally
* this argument would be specified as sizeof(cpu_set_t).
*
* PARAMETERS
* pid
* Process ID
*
* cpusetsize
* Currently ignored in pthreads4w.
* Usually set to sizeof(cpu_set_t)
*
* mask
* Pointer to the CPU mask to set (cpu_set_t).
*
* DESCRIPTION
* Sets the CPU affinity mask of the process whose ID is pid
* to the value specified by mask. If pid is zero, then the
* calling process is used. The argument cpusetsize is the
* length (in bytes) of the data pointed to by mask. Normally
* this argument would be specified as sizeof(cpu_set_t).
*
* RESULTS
* 0 successfully created semaphore,
* EFAULT 'mask' is a NULL pointer.
* EAGAIN The system available CPUs could not
* be obtained.
* EPERM The process referred to by 'pid' is
* not modifiable by us.
* ESRCH The process referred to by 'pid' was
* not found.
*
* ------------------------------------------------------
*/
{
DWORD_PTR vProcessMask;
DWORD_PTR vSystemMask;
HANDLE h;
int targetPid = (int)(size_t) pid;
int result = 0;
if (NULL == set)
{
result = EFAULT;
}
else
{
#if ! defined(NEED_PROCESS_AFFINITY_MASK)
if (0 == targetPid)
{
targetPid = (int) GetCurrentProcessId ();
}
h = OpenProcess (PROCESS_QUERY_INFORMATION, PTW32_FALSE, (DWORD) targetPid);
if (NULL == h)
{
result = (((0xFF & ERROR_ACCESS_DENIED) == GetLastError()) ? EPERM : ESRCH);
}
else
{
if (GetProcessAffinityMask (h, &vProcessMask, &vSystemMask))
{
((_sched_cpu_set_vector_*)set)->_cpuset = vProcessMask;
}
else
{
result = EAGAIN;
}
}
CloseHandle(h);
#else
((_sched_cpu_set_vector_*)set)->_cpuset = (size_t)0x1;
#endif
}
if (result != 0)
{
PTW32_SET_ERRNO(result);
return -1;
}
else
{
return 0;
}
}
int
sem_timedwait (sem_t * sem, const struct timespec *abstime)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function waits on a semaphore possibly until
* 'abstime' time.
*
* PARAMETERS
* sem
* pointer to an instance of sem_t
*
* abstime
* pointer to an instance of struct timespec
*
* DESCRIPTION
* This function waits on a semaphore. If the
* semaphore value is greater than zero, it decreases
* its value by one. If the semaphore value is zero, then
* the calling thread (or process) is blocked until it can
* successfully decrease the value or until interrupted by
* a signal.
*
* If 'abstime' is a NULL pointer then this function will
* block until it can successfully decrease the value or
* until interrupted by a signal.
*
* RESULTS
* 0 successfully decreased semaphore,
* -1 failed, error in errno
* ERRNO
* EINVAL 'sem' is not a valid semaphore,
* ENOSYS semaphores are not supported,
* EINTR the function was interrupted by a signal,
* EDEADLK a deadlock condition was detected.
* ETIMEDOUT abstime elapsed before success.
*
* ------------------------------------------------------
*/
{
ptw32_mcs_local_node_t node;
DWORD milliseconds;
int v;
int result = 0;
sem_t s = *sem;
pthread_testcancel();
if (abstime == NULL)
{
milliseconds = INFINITE;
}
else
{
/*
* Calculate timeout as milliseconds from current system time.
*/
milliseconds = ptw32_relmillisecs (abstime);
}
ptw32_mcs_lock_acquire(&s->lock, &node);
v = --s->value;
ptw32_mcs_lock_release(&node);
if (v < 0)
{
#if defined(NEED_SEM)
int timedout;
#endif
sem_timedwait_cleanup_args_t cleanup_args;
cleanup_args.sem = s;
cleanup_args.resultPtr = &result;
#if defined(PTW32_CONFIG_MSVC7)
#pragma inline_depth(0)
#endif
/* Must wait */
pthread_cleanup_push(ptw32_sem_timedwait_cleanup, (void *) &cleanup_args);
#if defined(NEED_SEM)
timedout =
#endif
result = pthreadCancelableTimedWait (s->sem, milliseconds);
pthread_cleanup_pop(result);
#if defined(PTW32_CONFIG_MSVC7)
#pragma inline_depth()
#endif
#if defined(NEED_SEM)
if (!timedout)
{
ptw32_mcs_lock_acquire(&s->lock, &node);
if (s->leftToUnblock > 0)
{
--s->leftToUnblock;
SetEvent(s->sem);
}
ptw32_mcs_lock_release(&node);
}
#endif /* NEED_SEM */
}
if (result != 0)
{
PTW32_SET_ERRNO(result);
return -1;
}
return 0;
} /* sem_timedwait */
int
sem_init (sem_t * sem, int pshared, unsigned int value)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function initializes a semaphore. The
* initial value of the semaphore is 'value'
*
* PARAMETERS
* sem
* pointer to an instance of sem_t
*
* pshared
* if zero, this semaphore may only be shared between
* threads in the same process.
* if nonzero, the semaphore can be shared between
* processes
*
* value
* initial value of the semaphore counter
*
* DESCRIPTION
* This function initializes a semaphore. The
* initial value of the semaphore is set to 'value'.
*
* RESULTS
* 0 successfully created semaphore,
* -1 failed, error in errno
* ERRNO
* EINVAL 'sem' is not a valid semaphore, or
* 'value' >= SEM_VALUE_MAX
* ENOMEM out of memory,
* ENOSPC a required resource has been exhausted,
* ENOSYS semaphores are not supported,
* EPERM the process lacks appropriate privilege
*
* ------------------------------------------------------
*/
{
int result = 0;
sem_t s = NULL;
if (pshared != 0)
{
/*
* Creating a semaphore that can be shared between
* processes
*/
result = EPERM;
}
else if (value > (unsigned int)SEM_VALUE_MAX)
{
result = EINVAL;
}
else
{
s = (sem_t) calloc (1, sizeof (*s));
if (NULL == s)
{
result = ENOMEM;
}
else
{
s->value = value;
if (pthread_mutex_init(&s->lock, NULL) == 0)
{
#if defined(NEED_SEM)
s->sem = CreateEvent (NULL,
PTW32_FALSE, /* auto (not manual) reset */
PTW32_FALSE, /* initial state is unset */
NULL);
if (0 == s->sem)
{
(void) pthread_mutex_destroy(&s->lock);
result = ENOSPC;
}
else
{
s->leftToUnblock = 0;
}
#else /* NEED_SEM */
if ((s->sem = CreateSemaphore (NULL, /* Always NULL */
(long) 0, /* Force threads to wait */
(long) SEM_VALUE_MAX, /* Maximum value */
NULL)) == 0) /* Name */
{
(void) pthread_mutex_destroy(&s->lock);
result = ENOSPC;
}
#endif /* NEED_SEM */
}
else
{
result = ENOSPC;
}
if (result != 0)
{
free(s);
}
}
}
if (result != 0)
{
PTW32_SET_ERRNO(result);
return -1;
}
*sem = s;
return 0;
} /* sem_init */
int
sem_open (const char *name, int oflag, mode_t mode, unsigned int value)
{
PTW32_SET_ERRNO(ENOSYS);
return -1;
} /* sem_open */
int
sem_destroy (sem_t * sem)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function destroys an unnamed semaphore.
*
* PARAMETERS
* sem
* pointer to an instance of sem_t
*
* DESCRIPTION
* This function destroys an unnamed semaphore.
*
* RESULTS
* 0 successfully destroyed semaphore,
* -1 failed, error in errno
* ERRNO
* EINVAL 'sem' is not a valid semaphore,
* ENOSYS semaphores are not supported,
* EBUSY threads (or processes) are currently
* blocked on 'sem'
*
* ------------------------------------------------------
*/
{
int result = 0;
sem_t s = NULL;
if (sem == NULL || *sem == NULL)
{
result = EINVAL;
}
else
{
s = *sem;
if ((result = pthread_mutex_lock (&s->lock)) == 0)
{
if (s->value < 0)
{
(void) pthread_mutex_unlock (&s->lock);
result = EBUSY;
}
else
{
/* There are no threads currently blocked on this semaphore. */
if (!CloseHandle (s->sem))
{
(void) pthread_mutex_unlock (&s->lock);
result = EINVAL;
}
else
{
/*
* Invalidate the semaphore handle when we have the lock.
* Other sema operations should test this after acquiring the lock
* to check that the sema is still valid, i.e. before performing any
* operations. This may only be necessary before the sema op routine
* returns so that the routine can return EINVAL - e.g. if setting
* s->value to SEM_VALUE_MAX below does force a fall-through.
*/
*sem = NULL;
/* Prevent anyone else actually waiting on or posting this sema.
*/
s->value = SEM_VALUE_MAX;
(void) pthread_mutex_unlock (&s->lock);
do
{
/* Give other threads a chance to run and exit any sema op
* routines. Due to the SEM_VALUE_MAX value, if sem_post or
* sem_wait were blocked by us they should fall through.
*/
Sleep(0);
}
while (pthread_mutex_destroy (&s->lock) == EBUSY);
}
}
}
}
if (result != 0)
{
PTW32_SET_ERRNO(result);
return -1;
}
free (s);
return 0;
} /* sem_destroy */
int
sem_destroy (sem_t * sem)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function destroys an unnamed semaphore.
*
* PARAMETERS
* sem
* pointer to an instance of sem_t
*
* DESCRIPTION
* This function destroys an unnamed semaphore.
*
* RESULTS
* 0 successfully destroyed semaphore,
* -1 failed, error in errno
* ERRNO
* EINVAL 'sem' is not a valid semaphore,
* ENOSYS semaphores are not supported,
* EBUSY threads (or processes) are currently
* blocked on 'sem'
*
* ------------------------------------------------------
*/
{
int result = 0;
sem_t s = NULL;
if (sem == NULL || *sem == NULL)
{
result = EINVAL;
}
else
{
ptw32_mcs_local_node_t node;
s = *sem;
if ((result = ptw32_mcs_lock_try_acquire(&s->lock, &node)) == 0)
{
if (s->value < 0)
{
result = EBUSY;
}
else
{
/*
* There are no threads currently blocked on this semaphore
* however there could be threads about to wait behind us.
* It is up to the application to ensure this is not the case.
*/
if (!CloseHandle (s->sem))
{
result = EINVAL;
}
}
ptw32_mcs_lock_release(&node);
}
}
if (result != 0)
{
PTW32_SET_ERRNO(result);
return -1;
}
free (s);
return 0;
} /* sem_destroy */
int
ptw32_semwait (sem_t * sem)
/*
* ------------------------------------------------------
* DESCRIPTION
* This function waits on a POSIX semaphore. If the
* semaphore value is greater than zero, it decreases
* its value by one. If the semaphore value is zero, then
* the calling thread (or process) is blocked until it can
* successfully decrease the value.
*
* Unlike sem_wait(), this routine is non-cancelable.
*
* RESULTS
* 0 successfully decreased semaphore,
* -1 failed, error in errno.
* ERRNO
* EINVAL 'sem' is not a valid semaphore,
* ENOSYS semaphores are not supported,
* EINTR the function was interrupted by a signal,
* EDEADLK a deadlock condition was detected.
*
* ------------------------------------------------------
*/
{
int result = 0;
sem_t s = *sem;
if (s == NULL)
{
result = EINVAL;
}
else
{
if ((result = pthread_mutex_lock (&s->lock)) == 0)
{
int v;
/* See sem_destroy.c
*/
if (*sem == NULL)
{
(void) pthread_mutex_unlock (&s->lock);
PTW32_SET_ERRNO(EINVAL);
return -1;
}
v = --s->value;
(void) pthread_mutex_unlock (&s->lock);
if (v < 0)
{
/* Must wait */
if (WaitForSingleObject (s->sem, INFINITE) == WAIT_OBJECT_0)
{
#if defined(NEED_SEM)
if (pthread_mutex_lock (&s->lock) == 0)
{
if (*sem == NULL)
{
(void) pthread_mutex_unlock (&s->lock);
PTW32_SET_ERRNO(EINVAL);
return -1;
}
if (s->leftToUnblock > 0)
{
--s->leftToUnblock;
SetEvent(s->sem);
}
(void) pthread_mutex_unlock (&s->lock);
}
#endif
return 0;
}
}
else
{
return 0;
}
}
}
if (result != 0)
{
PTW32_SET_ERRNO(result);
return -1;
}
return 0;
} /* ptw32_semwait */
