PTHREAD_JOIN(3)

NAME
pthread_join, pthread_timedjoin_np - wait for thread termination

LIBRARY
libpthread

SYNOPSIS
#include <pthread.h>
int
pthread_join(pthread_t thread, void **value_ptr);
#include <pthread_np.h>
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 p1003.1-96. The pthread_timedjoin_np() function is a FreeBSD extension which was added to DragonFly 1.3.