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-rw-r--r--condvar.c1259
1 files changed, 11 insertions, 1248 deletions
diff --git a/condvar.c b/condvar.c
index 32fee38..59878b2 100644
--- a/condvar.c
+++ b/condvar.c
@@ -34,1256 +34,19 @@
* if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*
- *
- * -------------------------------------------------------------
- * Algorithm:
- * The algorithm used in this implementation is that developed by
- * Alexander Terekhov in colaboration with Louis Thomas. The bulk
- * of the discussion is recorded in the file README.CV, which contains
- * several generations of both colaborators original algorithms. The final
- * algorithm used here is the one referred to as
- *
- * Algorithm 8a / IMPL_SEM,UNBLOCK_STRATEGY == UNBLOCK_ALL
- *
- * presented below in pseudo-code as it appeared:
- *
- *
- * given:
- * semBlockLock - bin.semaphore
- * semBlockQueue - semaphore
- * mtxExternal - mutex or CS
- * mtxUnblockLock - mutex or CS
- * nWaitersGone - int
- * nWaitersBlocked - int
- * nWaitersToUnblock - int
- *
- * wait( timeout ) {
- *
- * [auto: register int result ] // error checking omitted
- * [auto: register int nSignalsWasLeft ]
- * [auto: register int nWaitersWasGone ]
- *
- * sem_wait( semBlockLock );
- * nWaitersBlocked++;
- * sem_post( semBlockLock );
- *
- * unlock( mtxExternal );
- * bTimedOut = sem_wait( semBlockQueue,timeout );
- *
- * lock( mtxUnblockLock );
- * if ( 0 != (nSignalsWasLeft = nWaitersToUnblock) ) {
- * if ( bTimeout ) { // timeout (or canceled)
- * if ( 0 != nWaitersBlocked ) {
- * nWaitersBlocked--;
- * }
- * else {
- * nWaitersGone++; // count spurious wakeups.
- * }
- * }
- * if ( 0 == --nWaitersToUnblock ) {
- * if ( 0 != nWaitersBlocked ) {
- * sem_post( semBlockLock ); // open the gate.
- * nSignalsWasLeft = 0; // do not open the gate
- * // below again.
- * }
- * else if ( 0 != (nWaitersWasGone = nWaitersGone) ) {
- * nWaitersGone = 0;
- * }
- * }
- * }
- * else if ( INT_MAX/2 == ++nWaitersGone ) { // timeout/canceled or
- * // spurious semaphore :-)
- * sem_wait( semBlockLock );
- * nWaitersBlocked -= nWaitersGone; // something is going on here
- * // - test of timeouts? :-)
- * sem_post( semBlockLock );
- * nWaitersGone = 0;
- * }
- * unlock( mtxUnblockLock );
- *
- * if ( 1 == nSignalsWasLeft ) {
- * if ( 0 != nWaitersWasGone ) {
- * // sem_adjust( semBlockQueue,-nWaitersWasGone );
- * while ( nWaitersWasGone-- ) {
- * sem_wait( semBlockQueue ); // better now than spurious later
- * }
- * } sem_post( semBlockLock ); // open the gate
- * }
- *
- * lock( mtxExternal );
- *
- * return ( bTimedOut ) ? ETIMEOUT : 0;
- * }
- *
- * signal(bAll) {
- *
- * [auto: register int result ]
- * [auto: register int nSignalsToIssue]
- *
- * lock( mtxUnblockLock );
- *
- * if ( 0 != nWaitersToUnblock ) { // the gate is closed!!!
- * if ( 0 == nWaitersBlocked ) { // NO-OP
- * return unlock( mtxUnblockLock );
- * }
- * if (bAll) {
- * nWaitersToUnblock += nSignalsToIssue=nWaitersBlocked;
- * nWaitersBlocked = 0;
- * }
- * else {
- * nSignalsToIssue = 1;
- * nWaitersToUnblock++;
- * nWaitersBlocked--;
- * }
- * }
- * else if ( nWaitersBlocked > nWaitersGone ) { // HARMLESS RACE CONDITION!
- * sem_wait( semBlockLock ); // close the gate
- * if ( 0 != nWaitersGone ) {
- * nWaitersBlocked -= nWaitersGone;
- * nWaitersGone = 0;
- * }
- * if (bAll) {
- * nSignalsToIssue = nWaitersToUnblock = nWaitersBlocked;
- * nWaitersBlocked = 0;
- * }
- * else {
- * nSignalsToIssue = nWaitersToUnblock = 1;
- * nWaitersBlocked--;
- * }
- * }
- * else { // NO-OP
- * return unlock( mtxUnblockLock );
- * }
- *
- * unlock( mtxUnblockLock );
- * sem_post( semBlockQueue,nSignalsToIssue );
- * return result;
- * }
- * -------------------------------------------------------------
- *
*/
#include "pthread.h"
#include "implement.h"
-static INLINE int
-ptw32_cond_check_need_init (pthread_cond_t *cond)
-{
- int result = 0;
-
- /*
- * The following guarded test is specifically for statically
- * initialised condition variables (via PTHREAD_OBJECT_INITIALIZER).
- *
- * Note that by not providing this synchronisation we risk
- * introducing race conditions into applications which are
- * correctly written.
- *
- * Approach
- * --------
- * We know that static condition variables will not be PROCESS_SHARED
- * so we can serialise access to internal state using
- * Win32 Critical Sections rather than Win32 Mutexes.
- *
- * If using a single global lock slows applications down too much,
- * multiple global locks could be created and hashed on some random
- * value associated with each mutex, the pointer perhaps. At a guess,
- * a good value for the optimal number of global locks might be
- * the number of processors + 1.
- *
- */
- EnterCriticalSection(&ptw32_cond_test_init_lock);
-
- /*
- * We got here possibly under race
- * conditions. Check again inside the critical section.
- * If a static cv has been destroyed, the application can
- * re-initialise it only by calling pthread_cond_init()
- * explicitly.
- */
- if (*cond == PTHREAD_COND_INITIALIZER)
- {
- result = pthread_cond_init(cond, NULL);
- }
- else if (*cond == NULL)
- {
- /*
- * The cv has been destroyed while we were waiting to
- * initialise it, so the operation that caused the
- * auto-initialisation should fail.
- */
- result = EINVAL;
- }
-
- LeaveCriticalSection(&ptw32_cond_test_init_lock);
-
- return result;
-}
-
-
-int
-pthread_condattr_init (pthread_condattr_t * attr)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * Initializes a condition variable attributes object
- * with default attributes.
- *
- * PARAMETERS
- * attr
- * pointer to an instance of pthread_condattr_t
- *
- *
- * DESCRIPTION
- * Initializes a condition variable attributes object
- * with default attributes.
- *
- * NOTES:
- * 1) Use to define condition variable types
- * 2) It is up to the application to ensure
- * that it doesn't re-init an attribute
- * without destroying it first. Otherwise
- * a memory leak is created.
- *
- * RESULTS
- * 0 successfully initialized attr,
- * ENOMEM insufficient memory for attr.
- *
- * ------------------------------------------------------
- */
-{
- pthread_condattr_t attr_result;
- int result = 0;
-
- attr_result = (pthread_condattr_t) calloc (1, sizeof (*attr_result));
-
- if (attr_result == NULL)
- {
- result = ENOMEM;
- }
-
- *attr = attr_result;
-
- return result;
-
-} /* pthread_condattr_init */
-
-
-int
-pthread_condattr_destroy (pthread_condattr_t * attr)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * Destroys a condition variable attributes object.
- * The object can no longer be used.
- *
- * PARAMETERS
- * attr
- * pointer to an instance of pthread_condattr_t
- *
- *
- * DESCRIPTION
- * Destroys a condition variable attributes object.
- * The object can no longer be used.
- *
- * NOTES:
- * 1) Does not affect condition variables created
- * using 'attr'
- *
- * RESULTS
- * 0 successfully released attr,
- * EINVAL 'attr' is invalid.
- *
- * ------------------------------------------------------
- */
-{
- int result = 0;
-
- if (attr == NULL || *attr == NULL)
- {
- result = EINVAL;
- }
- else
- {
- (void) free (*attr);
-
- *attr = NULL;
- result = 0;
- }
-
- return result;
-
-} /* pthread_condattr_destroy */
-
-
-int
-pthread_condattr_getpshared (const pthread_condattr_t * attr, int *pshared)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * Determine whether condition variables created with 'attr'
- * can be shared between processes.
- *
- * PARAMETERS
- * attr
- * pointer to an instance of pthread_condattr_t
- *
- * pshared
- * will be set to one of:
- *
- * PTHREAD_PROCESS_SHARED
- * May be shared if in shared memory
- *
- * PTHREAD_PROCESS_PRIVATE
- * Cannot be shared.
- *
- *
- * DESCRIPTION
- * Condition Variables created with 'attr' can be shared
- * between processes if pthread_cond_t variable is allocated
- * in memory shared by these processes.
- * NOTES:
- * 1) pshared condition variables MUST be allocated in
- * shared memory.
- *
- * 2) The following macro is defined if shared mutexes
- * are supported:
- * _POSIX_THREAD_PROCESS_SHARED
- *
- * RESULTS
- * 0 successfully retrieved attribute,
- * EINVAL 'attr' or 'pshared' is invalid,
- *
- * ------------------------------------------------------
- */
-{
- int result;
-
- if ((attr != NULL && *attr != NULL) && (pshared != NULL))
- {
- *pshared = (*attr)->pshared;
- result = 0;
- }
- else
- {
- result = EINVAL;
- }
-
- return result;
-
-} /* pthread_condattr_getpshared */
-
-
-int
-pthread_condattr_setpshared (pthread_condattr_t * attr, int pshared)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * Mutexes created with 'attr' can be shared between
- * processes if pthread_mutex_t variable is allocated
- * in memory shared by these processes.
- *
- * PARAMETERS
- * attr
- * pointer to an instance of pthread_mutexattr_t
- *
- * pshared
- * must be one of:
- *
- * PTHREAD_PROCESS_SHARED
- * May be shared if in shared memory
- *
- * PTHREAD_PROCESS_PRIVATE
- * Cannot be shared.
- *
- * DESCRIPTION
- * Mutexes creatd with 'attr' can be shared between
- * processes if pthread_mutex_t variable is allocated
- * in memory shared by these processes.
- *
- * NOTES:
- * 1) pshared mutexes MUST be allocated in shared
- * memory.
- *
- * 2) The following macro is defined if shared mutexes
- * are supported:
- * _POSIX_THREAD_PROCESS_SHARED
- *
- * RESULTS
- * 0 successfully set attribute,
- * EINVAL 'attr' or pshared is invalid,
- * ENOSYS PTHREAD_PROCESS_SHARED not supported,
- *
- * ------------------------------------------------------
- */
-{
- int result;
-
- if ((attr != NULL && *attr != NULL)
- && ((pshared == PTHREAD_PROCESS_SHARED)
- || (pshared == PTHREAD_PROCESS_PRIVATE)))
- {
- if (pshared == PTHREAD_PROCESS_SHARED)
- {
-
-#if !defined( _POSIX_THREAD_PROCESS_SHARED )
- result = ENOSYS;
- pshared = PTHREAD_PROCESS_PRIVATE;
-#else
- result = 0;
-
-#endif /* _POSIX_THREAD_PROCESS_SHARED */
-
- }
- else
- {
- result = 0;
- }
-
- (*attr)->pshared = pshared;
- }
- else
- {
- result = EINVAL;
- }
-
- return result;
-
-} /* pthread_condattr_setpshared */
-
-
-int
-pthread_cond_init (pthread_cond_t * cond, const pthread_condattr_t * attr)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * This function initializes a condition variable.
- *
- * PARAMETERS
- * cond
- * pointer to an instance of pthread_cond_t
- *
- * attr
- * specifies optional creation attributes.
- *
- *
- * DESCRIPTION
- * This function initializes a condition variable.
- *
- * RESULTS
- * 0 successfully created condition variable,
- * EINVAL 'attr' is invalid,
- * EAGAIN insufficient resources (other than
- * memory,
- * ENOMEM insufficient memory,
- * EBUSY 'cond' is already initialized,
- *
- * ------------------------------------------------------
- */
-{
- int result;
- pthread_cond_t cv = NULL;
-
- if (cond == NULL)
- {
- return EINVAL;
- }
-
- if ((attr != NULL && *attr != NULL) &&
- ((*attr)->pshared == PTHREAD_PROCESS_SHARED))
- {
- /*
- * Creating condition variable that can be shared between
- * processes.
- */
- result = ENOSYS;
- goto DONE;
- }
-
- cv = (pthread_cond_t) calloc(1, sizeof (*cv));
-
- if (cv == NULL)
- {
- result = ENOMEM;
- goto DONE;
- }
-
- cv->nWaitersBlocked = 0;
- cv->nWaitersToUnblock = 0;
- cv->nWaitersGone = 0;
-
- if (sem_init(&(cv->semBlockLock), 0, 1) != 0)
- {
- result = errno;
- goto FAIL0;
- }
-
- if (sem_init(&(cv->semBlockQueue), 0, 0) != 0)
- {
- result = errno;
- goto FAIL1;
- }
-
- if ((result = pthread_mutex_init(&(cv->mtxUnblockLock), 0)) != 0)
- {
- goto FAIL2;
- }
-
- result = 0;
-
- goto DONE;
-
- /*
- * -------------
- * Failed...
- * -------------
- */
-FAIL2:
- (void) sem_destroy(&(cv->semBlockQueue));
-
-FAIL1:
- (void) sem_destroy(&(cv->semBlockLock));
-
-FAIL0:
- (void) free(cv);
- cv = NULL;
-
-DONE:
- *cond = cv;
-
- return result;
-
-} /* pthread_cond_init */
-
-
-int
-pthread_cond_destroy (pthread_cond_t * cond)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * This function destroys a condition variable
- *
- *
- * PARAMETERS
- * cond
- * pointer to an instance of pthread_cond_t
- *
- *
- * DESCRIPTION
- * This function destroys a condition variable.
- *
- * NOTES:
- * 1) A condition variable can be destroyed
- * immediately after all the threads that
- * are blocked on it are awakened. e.g.
- *
- * struct list {
- * pthread_mutex_t lm;
- * ...
- * }
- *
- * struct elt {
- * key k;
- * int busy;
- * pthread_cond_t notbusy;
- * ...
- * }
- *
- *
- * struct elt *
- * list_find(struct list *lp, key k)
- * {
- * struct elt *ep;
- *
- * pthread_mutex_lock(&lp->lm);
- * while ((ep = find_elt(l,k) != NULL) && ep->busy)
- * pthread_cond_wait(&ep->notbusy, &lp->lm);
- * if (ep != NULL)
- * ep->busy = 1;
- * pthread_mutex_unlock(&lp->lm);
- * return(ep);
- * }
- *
- * delete_elt(struct list *lp, struct elt *ep)
- * {
- * pthread_mutex_lock(&lp->lm);
- * assert(ep->busy);
- * ... remove ep from list ...
- * ep->busy = 0;
- * (A) pthread_cond_broadcast(&ep->notbusy);
- * pthread_mutex_unlock(&lp->lm);
- * (B) pthread_cond_destroy(&rp->notbusy);
- * free(ep);
- * }
- *
- * In this example, the condition variable
- * and its list element may be freed (line B)
- * immediately after all threads waiting for
- * it are awakened (line A), since the mutex
- * and the code ensure that no other thread
- * can touch the element to be deleted.
- *
- * RESULTS
- * 0 successfully released condition variable,
- * EINVAL 'cond' is invalid,
- * EBUSY 'cond' is in use,
- *
- * ------------------------------------------------------
- */
-{
- pthread_cond_t cv;
- int result = 0, result1 = 0, result2 = 0;
-
- /*
- * Assuming any race condition here is harmless.
- */
- if (cond == NULL
- || *cond == NULL)
- {
- return EINVAL;
- }
-
- if (*cond != PTHREAD_COND_INITIALIZER)
- {
- cv = *cond;
-
- /*
- * Close the gate; this will synchronize this thread with
- * all already signaled waiters to let them retract their
- * waiter status - SEE NOTE 1 ABOVE!!!
- */
- if (sem_wait(&(cv->semBlockLock)) != 0)
- {
- return errno;
- }
-
- /*
- * !TRY! lock mtxUnblockLock; try will detect busy condition
- * and will not course a deadlock with respect to concurrent
- * signal/broadcast.
- */
- if ((result = pthread_mutex_trylock(&(cv->mtxUnblockLock))) != 0)
- {
- (void) sem_post(&(cv->semBlockLock));
- return result;
- }
-
- /*
- * Check whether cv is still busy (still has waiters)
- */
- if (cv->nWaitersBlocked > cv->nWaitersGone)
- {
- if (sem_post(&(cv->semBlockLock)) != 0)
- {
- result = errno;
- }
- result1 = pthread_mutex_unlock(&(cv->mtxUnblockLock));
- result2 = EBUSY;
- }
- else
- {
- /*
- * Now it is safe to destroy
- */
- *cond = NULL;
- if (sem_destroy(&(cv->semBlockLock)) != 0)
- {
- result = errno;
- }
- if (sem_destroy(&(cv->semBlockQueue)) != 0)
- {
- result1 = errno;
- }
- if ((result2 = pthread_mutex_unlock(&(cv->mtxUnblockLock))) == 0)
- {
- result2 = pthread_mutex_destroy(&(cv->mtxUnblockLock));
- }
-
- (void) free(cv);
- }
- }
- else
- {
- /*
- * See notes in ptw32_cond_check_need_init() above also.
- */
- EnterCriticalSection(&ptw32_cond_test_init_lock);
-
- /*
- * Check again.
- */
- if (*cond == PTHREAD_COND_INITIALIZER)
- {
- /*
- * This is all we need to do to destroy a statically
- * initialised cond that has not yet been used (initialised).
- * If we get to here, another thread waiting to initialise
- * this cond will get an EINVAL. That's OK.
- */
- *cond = NULL;
- }
- else
- {
- /*
- * The cv has been initialised while we were waiting
- * so assume it's in use.
- */
- result = EBUSY;
- }
-
- LeaveCriticalSection(&ptw32_cond_test_init_lock);
- }
-
- return ((result != 0) ? result : ((result1 != 0) ? result1 : result2));
-
-}
-
-
-/*
- * Arguments for cond_wait_cleanup, since we can only pass a
- * single void * to it.
- */
-typedef struct {
- pthread_mutex_t * mutexPtr;
- pthread_cond_t cv;
- int * resultPtr;
- int signaled;
-} ptw32_cond_wait_cleanup_args_t;
-
-static void
-ptw32_cond_wait_cleanup(void * args)
-{
- ptw32_cond_wait_cleanup_args_t * cleanup_args = (ptw32_cond_wait_cleanup_args_t *) args;
- pthread_cond_t cv = cleanup_args->cv;
- int * resultPtr = cleanup_args->resultPtr;
- int nSignalsWasLeft;
- int nWaitersWasGone = 0; /* Initialised to quell warnings. */
- int result;
-
- /*
- * Whether we got here as a result of signal/broadcast or because of
- * timeout on wait or thread cancellation we indicate that we are no
- * longer waiting. The waiter is responsible for adjusting waiters
- * (to)unblock(ed) counts (protected by unblock lock).
- */
- if ((result = pthread_mutex_lock(&(cv->mtxUnblockLock))) != 0)
- {
- *resultPtr = result;
- return;
- }
-
- if ( 0 != (nSignalsWasLeft = cv->nWaitersToUnblock) )
- {
- if ( !cleanup_args->signaled )
- {
- if ( 0 != cv->nWaitersBlocked )
- {
- (cv->nWaitersBlocked)--;
- }
- else
- {
- (cv->nWaitersGone)++;
- }
- }
- if ( 0 == --(cv->nWaitersToUnblock) )
- {
- if ( 0 != cv->nWaitersBlocked )
- {
- if (sem_post( &(cv->semBlockLock) ) != 0)
- {
- *resultPtr = errno;
- /*
- * This is a fatal error for this CV,
- * so we deliberately don't unlock
- * cv->mtxUnblockLock before returning.
- */
- return;
- }
- nSignalsWasLeft = 0;
- }
- else if ( 0 != (nWaitersWasGone = cv->nWaitersGone) )
- {
- cv->nWaitersGone = 0;
- }
- }
- }
- else if ( INT_MAX/2 == ++(cv->nWaitersGone) )
- {
- if (sem_wait( &(cv->semBlockLock) ) != 0)
- {
- *resultPtr = errno;
- /*
- * This is a fatal error for this CV,
- * so we deliberately don't unlock
- * cv->mtxUnblockLock before returning.
- */
- return;
- }
- cv->nWaitersBlocked -= cv->nWaitersGone;
- if (sem_post( &(cv->semBlockLock) ) != 0)
- {
- *resultPtr = errno;
- /*
- * This is a fatal error for this CV,
- * so we deliberately don't unlock
- * cv->mtxUnblockLock before returning.
- */
- return;
- }
- cv->nWaitersGone = 0;
- }
-
- if ((result = pthread_mutex_unlock(&(cv->mtxUnblockLock))) != 0)
- {
- *resultPtr = result;
- return;
- }
-
- if ( 1 == nSignalsWasLeft )
- {
- if ( 0 != nWaitersWasGone )
- {
- // sem_adjust( &(cv->semBlockQueue), -nWaitersWasGone );
- while ( nWaitersWasGone-- )
- {
- if (sem_wait( &(cv->semBlockQueue)) != 0 )
- {
- *resultPtr = errno;
- return;
- }
- }
- }
- if (sem_post(&(cv->semBlockLock)) != 0)
- {
- *resultPtr = errno;
- return;
- }
- }
-
- /*
- * XSH: Upon successful return, the mutex has been locked and is owned
- * by the calling thread
- */
- if ((result = pthread_mutex_lock(cleanup_args->mutexPtr)) != 0)
- {
- *resultPtr = result;
- }
-
-} /* ptw32_cond_wait_cleanup */
-
-static INLINE int
-ptw32_cond_timedwait (pthread_cond_t * cond,
- pthread_mutex_t * mutex,
- const struct timespec *abstime)
-{
- int result = 0;
- pthread_cond_t cv;
- ptw32_cond_wait_cleanup_args_t cleanup_args;
-
- if (cond == NULL || *cond == NULL)
- {
- return EINVAL;
- }
-
- /*
- * We do a quick check to see if we need to do more work
- * to initialise a static condition variable. We check
- * again inside the guarded section of ptw32_cond_check_need_init()
- * to avoid race conditions.
- */
- if (*cond == PTHREAD_COND_INITIALIZER)
- {
- result = ptw32_cond_check_need_init(cond);
- }
-
- if (result != 0 && result != EBUSY)
- {
- return result;
- }
-
- cv = *cond;
-
- if (sem_wait(&(cv->semBlockLock)) != 0)
- {
- return errno;
- }
-
- cv->nWaitersBlocked++;
-
- if (sem_post(&(cv->semBlockLock)) != 0)
- {
- return errno;
- }
-
- /*
- * Setup this waiter cleanup handler
- */
- cleanup_args.mutexPtr = mutex;
- cleanup_args.cv = cv;
- cleanup_args.resultPtr = &result;
- /*
- * If we're canceled, or the cancelable wait fails for any reason,
- * including a timeout, then tell the cleanup routine that we
- * have not been signaled.
- */
- cleanup_args.signaled = 0;
-
-#ifdef _MSC_VER
-#pragma inline_depth(0)
-#endif
- pthread_cleanup_push(ptw32_cond_wait_cleanup, (void *) &cleanup_args);
-
- /*
- * Now we can release 'mutex' and...
- */
- if ((result = pthread_mutex_unlock(mutex)) == 0)
- {
-
- /*
- * ...wait to be awakened by
- * pthread_cond_signal, or
- * pthread_cond_broadcast, or
- * timeout, or
- * thread cancellation
- *
- * Note:
- *
- * sem_timedwait is a cancellation point,
- * hence providing the mechanism for making
- * pthread_cond_wait a cancellation point.
- * We use the cleanup mechanism to ensure we
- * re-lock the mutex and adjust (to)unblock(ed) waiters
- * counts if we are cancelled, timed out or signalled.
- */
- if (sem_timedwait(&(cv->semBlockQueue), abstime) != 0)
- {
- result = errno;
- }
- }
-
- /*
- * Not executed if we're canceled. Signaled is false if we timed out.
- */
- cleanup_args.signaled = (result == 0);
-
- /*
- * Always cleanup
- */
- pthread_cleanup_pop(1);
-#ifdef _MSC_VER
-#pragma inline_depth()
-#endif
-
- /*
- * "result" can be modified by the cleanup handler.
- */
- return result;
-
-} /* ptw32_cond_timedwait */
-
-
-static INLINE int
-ptw32_cond_unblock (pthread_cond_t * cond,
- int unblockAll)
- /*
- * Notes.
- *
- * Does not use the external mutex for synchronisation,
- * therefore semBlockLock is needed.
- * mtxUnblockLock is for LEVEL-2 synch. LEVEL-2 is the
- * state where the external mutex is not necessarily locked by
- * any thread, ie. between cond_wait unlocking and re-acquiring
- * the lock after having been signaled or a timeout or
- * cancellation.
- *
- * Uses the following CV elements:
- * nWaitersBlocked
- * nWaitersToUnblock
- * nWaitersGone
- * mtxUnblockLock
- * semBlockLock
- * semBlockQueue
- */
-{
- int result;
- pthread_cond_t cv;
- int nSignalsToIssue;
-
- if (cond == NULL || *cond == NULL)
- {
- return EINVAL;
- }
-
- cv = *cond;
-
- /*
- * No-op if the CV is static and hasn't been initialised yet.
- * Assuming that any race condition is harmless.
- */
- if (cv == PTHREAD_COND_INITIALIZER)
- {
- return 0;
- }
-
- if ((result = pthread_mutex_lock(&(cv->mtxUnblockLock))) != 0)
- {
- return result;
- }
-
- if ( 0 != cv->nWaitersToUnblock )
- {
- if ( 0 == cv->nWaitersBlocked )
- {
- return pthread_mutex_unlock( &(cv->mtxUnblockLock) );
- }
- if (unblockAll)
- {
- cv->nWaitersToUnblock += (nSignalsToIssue = cv->nWaitersBlocked);
- cv->nWaitersBlocked = 0;
- }
- else
- {
- nSignalsToIssue = 1;
- cv->nWaitersToUnblock++;
- cv->nWaitersBlocked--;
- }
- }
- else if ( cv->nWaitersBlocked > cv->nWaitersGone )
- {
- if (sem_wait( &(cv->semBlockLock) ) != 0)
- {
- result = errno;
- (void) pthread_mutex_unlock( &(cv->mtxUnblockLock) );
- return result;
- }
- if ( 0 != cv->nWaitersGone )
- {
- cv->nWaitersBlocked -= cv->nWaitersGone;
- cv->nWaitersGone = 0;
- }
- if (unblockAll)
- {
- nSignalsToIssue = cv->nWaitersToUnblock = cv->nWaitersBlocked;
- cv->nWaitersBlocked = 0;
- }
- else
- {
- nSignalsToIssue = cv->nWaitersToUnblock = 1;
- cv->nWaitersBlocked--;
- }
- }
- else
- {
- return pthread_mutex_unlock( &(cv->mtxUnblockLock) );
- }
-
- if ((result = pthread_mutex_unlock( &(cv->mtxUnblockLock) )) == 0)
- {
- if (sem_post_multiple( &(cv->semBlockQueue), nSignalsToIssue ) != 0)
- {
- result = errno;
- }
- }
-
- return result;
-
-} /* ptw32_cond_unblock */
-
-int
-pthread_cond_wait (pthread_cond_t * cond,
- pthread_mutex_t * mutex)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * This function waits on a condition variable until
- * awakened by a signal or broadcast.
- *
- * Caller MUST be holding the mutex lock; the
- * lock is released and the caller is blocked waiting
- * on 'cond'. When 'cond' is signaled, the mutex
- * is re-acquired before returning to the caller.
- *
- * PARAMETERS
- * cond
- * pointer to an instance of pthread_cond_t
- *
- * mutex
- * pointer to an instance of pthread_mutex_t
- *
- *
- * DESCRIPTION
- * This function waits on a condition variable until
- * awakened by a signal or broadcast.
- *
- * NOTES:
- *
- * 1) The function must be called with 'mutex' LOCKED
- * by the calling thread, or undefined behaviour
- * will result.
- *
- * 2) This routine atomically releases 'mutex' and causes
- * the calling thread to block on the condition variable.
- * The blocked thread may be awakened by
- * pthread_cond_signal or
- * pthread_cond_broadcast.
- *
- * Upon successful completion, the 'mutex' has been locked and
- * is owned by the calling thread.
- *
- *
- * RESULTS
- * 0 caught condition; mutex released,
- * EINVAL 'cond' or 'mutex' is invalid,
- * EINVAL different mutexes for concurrent waits,
- * EINVAL mutex is not held by the calling thread,
- *
- * ------------------------------------------------------
- */
-{
- /*
- * The NULL abstime arg means INFINITE waiting.
- */
- return (ptw32_cond_timedwait(cond, mutex, NULL));
-
-} /* pthread_cond_wait */
-
-
-int
-pthread_cond_timedwait (pthread_cond_t * cond,
- pthread_mutex_t * mutex,
- const struct timespec *abstime)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * This function waits on a condition variable either until
- * awakened by a signal or broadcast; or until the time
- * specified by abstime passes.
- *
- * PARAMETERS
- * cond
- * pointer to an instance of pthread_cond_t
- *
- * mutex
- * pointer to an instance of pthread_mutex_t
- *
- * abstime
- * pointer to an instance of (const struct timespec)
- *
- *
- * DESCRIPTION
- * This function waits on a condition variable either until
- * awakened by a signal or broadcast; or until the time
- * specified by abstime passes.
- *
- * NOTES:
- * 1) The function must be called with 'mutex' LOCKED
- * by the calling thread, or undefined behaviour
- * will result.
- *
- * 2) This routine atomically releases 'mutex' and causes
- * the calling thread to block on the condition variable.
- * The blocked thread may be awakened by
- * pthread_cond_signal or
- * pthread_cond_broadcast.
- *
- *
- * RESULTS
- * 0 caught condition; mutex released,
- * EINVAL 'cond', 'mutex', or abstime is invalid,
- * EINVAL different mutexes for concurrent waits,
- * EINVAL mutex is not held by the calling thread,
- * ETIMEDOUT abstime ellapsed before cond was signaled.
- *
- * ------------------------------------------------------
- */
-{
- if (abstime == NULL)
- {
- return EINVAL;
- }
-
- return (ptw32_cond_timedwait(cond, mutex, abstime));
-
-} /* pthread_cond_timedwait */
-
-
-int
-pthread_cond_signal (pthread_cond_t * cond)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * This function signals a condition variable, waking
- * one waiting thread.
- * If SCHED_FIFO or SCHED_RR policy threads are waiting
- * the highest priority waiter is awakened; otherwise,
- * an unspecified waiter is awakened.
- *
- * PARAMETERS
- * cond
- * pointer to an instance of pthread_cond_t
- *
- *
- * DESCRIPTION
- * This function signals a condition variable, waking
- * one waiting thread.
- * If SCHED_FIFO or SCHED_RR policy threads are waiting
- * the highest priority waiter is awakened; otherwise,
- * an unspecified waiter is awakened.
- *
- * NOTES:
- *
- * 1) Use when any waiter can respond and only one need
- * respond (all waiters being equal).
- *
- * RESULTS
- * 0 successfully signaled condition,
- * EINVAL 'cond' is invalid,
- *
- * ------------------------------------------------------
- */
-{
- /*
- * The '0'(FALSE) unblockAll arg means unblock ONE waiter.
- */
- return (ptw32_cond_unblock(cond, 0));
-
-} /* pthread_cond_signal */
-
-int
-pthread_cond_broadcast (pthread_cond_t * cond)
- /*
- * ------------------------------------------------------
- * DOCPUBLIC
- * This function broadcasts the condition variable,
- * waking all current waiters.
- *
- * PARAMETERS
- * cond
- * pointer to an instance of pthread_cond_t
- *
- *
- * DESCRIPTION
- * This function signals a condition variable, waking
- * all waiting threads.
- *
- * NOTES:
- *
- * 1) Use when more than one waiter may respond to
- * predicate change or if any waiting thread may
- * not be able to respond
- *
- * RESULTS
- * 0 successfully signalled condition to all
- * waiting threads,
- * EINVAL 'cond' is invalid
- * ENOSPC a required resource has been exhausted,
- *
- * ------------------------------------------------------
- */
-{
- /*
- * The '1'(TRUE) unblockAll arg means unblock ALL waiters.
- */
- return (ptw32_cond_unblock(cond, 1));
-
-} /* pthread_cond_broadcast */
+#include "condvar_check_need_init.c"
+#include "condvar_attr_init.c"
+#include "condvar_attr_destroy.c"
+#include "condvar_attr_getpshared.c"
+#include "condvar_attr_setpshared.c"
+#include "condvar_init.c"
+#include "condvar_destroy.c"
+#include "condvar_wait.c"
+#include "condvar_timedwait.c"
+#include "condvar_signal.c"
+#include "condvar_broadcast.c"
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-04 14:56:27 +0000