NAME

pthread_join, pthread_timedjoin_np — wait for thread termination

LIBRARY

POSIX Threads Library (libpthread, -lpthread)

SYNOPSIS

#include < pthread.h>

int
pthread_join( pthread_t thread, void **value_ptr);

int
pthread_timedjoin_np( pthread_t thread, void **value_ptr, const struct timespec *abstime);

DESCRIPTION

The pthread_join() function suspends execution of the calling thread until the target thread terminates unless the target thread has already terminated.

On return from a successful pthread_join() call with a non-NULL value_ptr argument, the value passed to pthread_exit() by the terminating thread is stored in the location referenced by value_ptr. When a pthread_join() returns successfully, the target thread has been terminated. The results of multiple simultaneous calls to pthread_join() specifying the same target thread are undefined. If the thread calling pthread_join() is cancelled, then the target thread is not detached.

The pthread_timedjoin_np() function is equivalent to the pthread_join() function except it will return ETIMEDOUT if target thread does not exit before specified absolute time passes.

A thread that has exited but remains unjoined counts against [_POSIX_THREAD_THREADS_MAX].

RETURN VALUES

If successful, the pthread_join() and pthread_timedjoin_np() functions will return zero. Otherwise an error number will be returned to indicate the error.

ERRORS

The pthread_join() and pthread_timedjoin_np() functions will fail if:

[ EINVAL]

The implementation has detected that the value specified by thread does not refer to a joinable thread.

[ ESRCH]

No thread could be found corresponding to that specified by the given thread ID, thread.

[ EDEADLK]

A deadlock was detected or the value of thread specifies the calling thread.

[ EOPNOTSUPP]

The implementation detected that another caller is already waiting on thread.

Additionally, the pthread_timedjoin_np() function will fail if:

[ ETIMEDOUT]

The specified absolute time passed while pthread_timedjoin_np() waited for thread exit.

SEE ALSO

wait(2), pthread_create(3)

STANDARDS

The pthread_join() function conforms to ISO/IEC 9945-1:1996 (“POSIX.1”). The pthread_timedjoin_np() is a FreeBSD extension which first appeared in FreeBSD 6.1.