VMS Help
POSIX Threads, TIS routines, tis_cond_timedwait
*Conan The Librarian (sorry for the slow response - running on an old VAX)
|
|
Causes a thread to wait for the specified condition variable
to be signaled or broadcast, such that it will awake after a
specified period of time.
#include <tis.h>
int
tis_cond_timedwait (
pthread_cond_t *cond,
pthread_mutex_t *mutex,
const struct timespec *abstime);
cond
Condition variable that the calling thread waits on.
mutex
Mutex associated with the condition variable specified in cond.
abstime
Absolute time at which the wait expires, if the condition has not
been signaled or broadcast. See the tis_get_expiration() routine,
which is used to obtain a value for this argument.
The abstime argument is specified in Universal Coordinated Time
(UTC). In the UTC-based model, time is represented as seconds
since the Epoch. The Epoch is defined as the time 0 hours, 0
minutes, 0 seconds, January 1st, 1970 UTC.
If threads are not present, this function is equivalent to
sleep().
This routine causes a thread to wait until one of the following
occurs:
o The specified condition variable is signaled or broadcast.
o The current system clock time is greater than or equal to the
time specified by the abstime argument.
This routine is identical to tis_cond_wait(), except that this
routine can return before a condition variable is signaled or
broadcast, specifically, when the specified time expires. For
more information, see the tis_cond_wait() description.
This routine atomically releases the mutex and causes the calling
thread to wait on the condition. When the thread regains control
after calling tis_cond_timedwait(), the mutex is locked and the
thread is the owner. This is true regardless of why the wait
ended. If general cancelability is enabled, the thread reacquires
the mutex (blocking for it if necessary) before the cleanup
handlers are run (or before the exception is raised).
If the current time equals or exceeds the expiration time, this
routine returns immediately, releasing and reacquiring the mutex.
It might cause the calling thread to yield (see the sched_yield()
description). Your code should check the return status whenever
this routine returns and take the appropriate action. Otherwise,
waiting on the condition variable can become a nonblocking loop.
Call this routine after you have locked the mutex specified
in mutex. The results of this routine are unpredictable if
this routine is called without first locking the mutex. The
only routines that are supported for use with asynchronous
cancelability enabled are those that disable asynchronous
cancelability.
If an error condition occurs, this routine returns an integer
indicating the type of error. Possible return values are as
follows:
Return Description
0 Successful completion.
[EINVAL] The value specified by cond, mutex, or abstime is
invalid, or
Different mutexes are supplied for concurrent
tis_cond_timedwait() operations or
tis_cond_wait() operations on the same condition
variable, or
The mutex was not owned by the calling thread at the
time of the call.
[ETIMEDOUT] The time specified by abstime expired.
[ENOMEM] The Threads Library cannot acquire memory needed
to block using a statically initialized condition
variable.
tis_cond_broadcast()
tis_cond_destroy()
tis_cond_init()
tis_cond_signal()
tis_cond_wait()
tis_get_expiration()
[legal]
[privacy]
[GNU]
[policy]
[netiquette]
[sponsors]
[FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.