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/*
* misc.c
*
* Description:
* This translation unit implements miscellaneous thread functions.
*/
#include <errno.h>
#include "pthread.h"
int
pthread_once(pthread_once_t *once_control,
void (*init_routine)(void))
{
/* A flag, allocated per invocation, that indicates if the atomic
test-and-set occured. */
unsigned short flag = 0;
if (once_control == NULL || init_routine == NULL)
{
return EINVAL;
}
/* An atomic test-and-set of the "once" flag. */
pthread_mutex_lock(&once_control->lock);
if (once_control->flag == 0)
{
flag = once_control->flag = 1;
}
pthread_mutex_unlock(&once_control->lock);
if (flag)
{
/* Run the init routine. */
init_routine();
}
return 0;
}
/*
* Code contributed by John E. Bossom <JEB>.
*/
pthread_t
pthread_self (void)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function returns a reference to the current running
* thread.
*
* PARAMETERS
* N/A
*
*
* DESCRIPTION
* This function returns a reference to the current running
* thread.
*
* RESULTS
* pthread_t reference to the current thread
*
* ------------------------------------------------------
*/
{
pthread_t self = NULL;
/*
* need to ensure there always is a self
*/
if ((self = pthread_getspecific (_pthread_selfThreadKey)) == NULL)
{
/*
* Need to create an implicit 'self' for the currently
* executing thread.
*/
self = (pthread_t) calloc (1, sizeof (*self));
if (self != NULL)
{
self->implicit = 1;
self->detachState = PTHREAD_CREATE_DETACHED;
self->thread = GetCurrentThreadId ();
self->threadH = GetCurrentThread ();
}
pthread_setspecific (_pthread_selfThreadKey, self);
}
return (self);
} /* pthread_self */
int
pthread_equal (pthread_t t1, pthread_t t2)
/*
* ------------------------------------------------------
* DOCPUBLIC
* This function returns zero if t1 and t2 are equal, else
* returns nonzero
*
* PARAMETERS
* t1,
* t2
* references to an instances of thread_t
*
*
* DESCRIPTION
* This function returns zero if t1 and t2 are equal, else
* returns nonzero.
*
* RESULTS
* 0 if t1 and t2 refer to the same thread,
* non-zero t1 and t2 do not refer to the same thread
*
* ------------------------------------------------------
*/
{
int result;
result = !((t1 == t2) || (t1->thread == t2->thread));
return (result);
} /* pthread_equal */
int
pthreadCancelableWait (HANDLE waitHandle)
/*
* -------------------------------------------------------------------
* This provides an extra hook into the pthread_cancel
* mechanism that will allow you to wait on a Windows handle and make it a
* cancellation point. This function blocks until the given WIN32 handle is
* signaled or pthread_cancel has been called. It is implemented using
* WaitForMultipleObjects on 'waitHandle' and a manually reset WIN32
* event used to implement pthread_cancel.
*
* Given this hook it would be possible to implement more of the cancellation
* points.
* -------------------------------------------------------------------
*/
{
int result;
pthread_t self;
HANDLE handles[2];
DWORD nHandles = 1;
DWORD status;
handles[0] = waitHandle;
if ((self = pthread_getspecific (_pthread_selfThreadKey)) != NULL)
{
/*
* Get cancelEvent handle
*/
if (self->cancelState == PTHREAD_CANCEL_ENABLE)
{
if ((handles[1] = self->cancelEvent) != NULL)
{
nHandles++;
}
}
}
else
{
handles[1] = NULL;
}
status = WaitForMultipleObjects (
nHandles,
handles,
FALSE,
INFINITE);
if (status == WAIT_FAILED)
{
result = EINVAL;
}
else if (status == WAIT_ABANDONED_0)
{
result = EINVAL;
}
else
{
/*
* Either got the mutex or the cancel event
* was signaled
*/
switch (status - WAIT_OBJECT_0)
{
case 0:
/*
* Got the mutex
*/
result = 0;
break;
case 1:
/*
* Got cancel request
*/
ResetEvent (handles[1]);
if (self != NULL && !self->implicit)
{
/*
* Thread started with pthread_create
*/
DWORD exceptionInformation[3];
exceptionInformation[0] = (DWORD) (0);
exceptionInformation[1] = (DWORD) (0);
RaiseException (
EXCEPTION_PTHREAD_SERVICES,
0,
3,
exceptionInformation);
}
((void *) -1);
break;
default:
result = EINVAL;
break;
}
}
return (result);
} /* pthreadCancelableWait */
/* </JEB> */
#if 0 /* Pre Bossom */
pthread_t
pthread_self(void)
{
pthread_t ret;
/* This TLS index is allocated on DLL load by dll.c */
extern DWORD _pthread_threadID_TlsIndex;
ret = (pthread_t) TlsGetValue(_pthread_threadID_TlsIndex);
if (ret == 0)
{
/* FIXME: Oh no! This can't happen. */
}
return ret;
}
int
pthread_equal(pthread_t t1, pthread_t t2)
{
return (t1 == t2);
}
#endif /* Pre Bossom */
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