попытаться присоединиться к завершенному потоку (try to join with a terminated thread)
Имя (Name)
pthread_tryjoin_np, pthread_timedjoin_np - try to join with a
terminated thread
Синопсис (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);
Compile and link with -pthread.
Описание (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
structure of the following form, specifying an absolute time
measured since the Epoch (see time(2)):
struct timespec {
time_t tv_sec; /* seconds */
long tv_nsec; /* nanoseconds */
};
Возвращаемое значение (Return value)
On success, these functions return 0; on error, they return an
error number.
Ошибки (Error)
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.
Версии (Versions)
These functions first appeared in glibc in version 2.3.3.
Атрибуты (Attributes)
For an explanation of the terms used in this section, see
attributes(7).
┌──────────────────────────────────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├──────────────────────────────────────┼───────────────┼─────────┤
│pthread_tryjoin_np(), │ Thread safety │ MT-Safe │
│pthread_timedjoin_np() │ │ │
└──────────────────────────────────────┴───────────────┴─────────┘
Стандарты (Conforming to)
These functions are nonstandard GNU extensions; hence the suffix
"_np" (nonportable) in the names.
Ошибки (баги) (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.
Примеры (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 */
}
Смотри также (See also)
clock_gettime(2), pthread_exit(3), pthread_join(3), pthreads(7)
