Content-type: text/html Manpage of PTHREAD_JOIN

PTHREAD_JOIN

Section: C Library Functions (3)
Updated: LinuxThreads
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NAME

pthread_join - wait for termination of another thread

SYNOPSIS

#include <pthread.h>

int pthread_join(pthread_t th, void **thread_return);

DESCRIPTION

pthread_join suspends the execution of the calling thread until the thread identified by th terminates, either by calling pthread_exit(3) or by being cancelled.

If thread_return is not NULL, the return value of th is stored in the location pointed to by thread_return. The return value of th is either the argument it gave to pthread_exit(3), or PTHREAD_CANCELED if th was cancelled.

The joined thread th must be in the joinable state: it must not have been detached using pthread_detach(3) or the PTHREAD_CREATE_DETACHED attribute to pthread_create(3).

When a joinable thread terminates, its memory resources (thread descriptor and stack) are not deallocated until another thread performs pthread_join on it. Therefore, pthread_join must be called once for each joinable thread created to avoid memory leaks.

At most one thread can wait for the termination of a given thread. Calling pthread_join on a thread th on which another thread is already waiting for termination returns an error.

CANCELLATION

pthread_join is a cancellation point. If a thread is canceled while suspended in pthread_join, the thread execution resumes immediately and the cancellation is executed without waiting for the th thread to terminate. If cancellation occurs during pthread_join, the th thread remains not joined.

RETURN VALUE

On success, the return value of th is stored in the location pointed to by thread_return, and 0 is returned. On error, a non-zero error code is returned.

ERRORS

ESRCH: No thread could be found corresponding to that specified by th.
EINVAL: The th thread has been detached.
EINVAL: Another thread is already waiting on termination of th.
EDEADLK: The th argument refers to the calling thread.

AUTHOR

Xavier Leroy <Xavier.Leroy@inria.fr>

This document was created by man2html, using the manual pages.
Time: 09:41:15 GMT, November 29, 2004