PTHREAD_JOIN(3C)PTHREAD_JOIN(3C)NAMEpthread_join - wait for thread termination
SYNOPSIS
cc -mt [ flag... ] file... -lpthread [ library... ]
#include <pthread.h>
int pthread_join(pthread_t thread, void **status);
DESCRIPTION
The pthread_join() function suspends processing of the calling thread
until the target thread completes. thread must be a member of the cur‐
rent process and it cannot be a detached thread. See pthread_cre‐
ate(3C).
If two or more threads wait for the same thread to complete, all will
suspend processing until the thread has terminated, and then one thread
will return successfully and the others will return with an error of
ESRCH. The pthread_join() function will not block processing of the
calling thread if the target thread has already terminated.
If a pthread_join() call returns successfully with a non-null status
argument, the value passed to pthread_exit(3C) by the terminating
thread will be placed in the location referenced by status.
If the pthread_join() calling thread is cancelled, then the target
thread will remain joinable by pthread_join(). However, the calling
thread may set up a cancellation cleanup handler on thread prior to the
join call, which may detach the target thread by calling
pthread_detach(3C). See pthread_detach(3C) and pthread_cancel(3C).
RETURN VALUES
If successful, pthread_join() returns 0. Otherwise, an error number is
returned to indicate the error.
ERRORS
EDEADLK
A joining deadlock would occur, such as when a thread
attempts to wait for itself.
EINVAL
The thread corresponding to the given thread ID is a
detached thread.
ESRCH
No thread could be found corresponding to the given thread
ID.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌────────────────────┬─────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────┤
│Interface Stability │ Standard │
├────────────────────┼─────────────────┤
│MT-Level │ MT-Safe │
└────────────────────┴─────────────────┘
SEE ALSOpthread_cancel(3C), pthread_create(3C), pthread_detach(3C),
pthread_exit(3C), wait(3C), attributes(5), standards(5)NOTES
The pthread_join(3C) function must specify the thread ID for whose ter‐
mination it will wait.
Calling pthread_join() also "detaches" the thread; that is,
pthread_join() includes the effect of the pthread_detach() function. If
a thread were to be cancelled when blocked in pthread_join(), an
explicit detach would have to be performed in the cancellation cleanup
handler. The pthread_detach() function exists primarily for this pur‐
pose.
Mar 23, 2005 PTHREAD_JOIN(3C)
