pthread_tryjoin_np
Section: C Library Functions (3)
Updated: 2022-12-15
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NAME
pthread_tryjoin_np, pthread_timedjoin_np - try to join with a
terminated thread
LIBRARY
POSIX threads library
(libpthread, -lpthread)
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <pthread.h>
int pthread_tryjoin_np(pthread_t thread, void **retval);
int pthread_timedjoin_np(pthread_t thread, void **retval,
const struct timespec *abstime);
DESCRIPTION
These functions operate in the same way as
pthread_join(3),
except for the differences described on this page.
The
pthread_tryjoin_np()
function performs a nonblocking join with the thread
thread,
returning the exit status of the thread in
*retval.
If
thread
has not yet terminated, then instead of blocking, as is done by
pthread_join(3),
the call returns an error.
The
pthread_timedjoin_np()
function performs a join-with-timeout.
If
thread
has not yet terminated,
then the call blocks until a maximum time, specified in
abstime,
measured against the
CLOCK_REALTIME
clock.
If the timeout expires before
thread
terminates,
the call returns an error.
The
abstime
argument is a
timespec(3)
structure,
specifying an absolute time measured since the Epoch (see
time(2)).
RETURN VALUE
On success,
these functions return 0;
on error, they return an error number.
ERRORS
These functions can fail with the same errors as
pthread_join(3).
pthread_tryjoin_np()
can in addition fail with the following error:
- EBUSY
-
thread
had not yet terminated at the time of the call.
pthread_timedjoin_np()
can in addition fail with the following errors:
- EINVAL
-
abstime
value is invalid
(tv_sec
is less than 0 or
tv_nsec
is greater than 1e9).
- ETIMEDOUT
-
The call timed out before
thread
terminated.
pthread_timedjoin_np()
never returns the error
EINTR.
VERSIONS
These functions were added in glibc 2.3.3.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
Interface | Attribute | Value
|
pthread_tryjoin_np(),
pthread_timedjoin_np()
| Thread safety | MT-Safe
|
STANDARDS
These functions are nonstandard GNU extensions;
hence the suffix "_np" (nonportable) in the names.
BUGS
The
pthread_timedjoin_np()
function measures time by internally calculating a relative sleep interval
that is then measured against the
CLOCK_MONOTONIC
clock instead of the
CLOCK_REALTIME
clock.
Consequently, the timeout is unaffected by discontinuous changes to the
CLOCK_REALTIME
clock.
EXAMPLES
The following code waits to join for up to 5 seconds:
struct timespec ts;
int s;
...
if (clock_gettime(CLOCK_REALTIME, &ts) == -1) {
/* Handle error */
}
ts.tv_sec += 5;
s = pthread_timedjoin_np(thread, NULL, &ts);
if (s != 0) {
/* Handle error */
}
SEE ALSO
clock_gettime(2),
pthread_exit(3),
pthread_join(3),
timespec(3),
pthreads(7)
Index
- NAME
-
- LIBRARY
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- VERSIONS
-
- ATTRIBUTES
-
- STANDARDS
-
- BUGS
-
- EXAMPLES
-
- SEE ALSO
-
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Time: 15:22:40 GMT, May 23, 2024