THR_JOIN(3C)THR_JOIN(3C)NAMEthr_join - wait for thread termination
cc -mt [ flag... ] file...[ library... ]
int thr_join(thread_t thread, thread_t *departed, void **status);
The thr_join() function suspends processing of the calling thread until
the target thread completes. The thread argument must be a member of
the current process and cannot be a detached thread. See thr_cre‐
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 thr_join() function will not block processing of the calling
thread if the target thread has already terminated.
If a thr_join() call returns successfully with a non-null status argu‐
ment, the value passed to thr_exit(3C) by the terminating thread will
be placed in the location referenced by status.
If the target thread ID is 0, thr_join() finds and returns the status
of a terminated undetached thread in the process. If no such thread
exists, it suspends processing of the calling thread until a thread for
which no other thread is waiting enters that state, at which time it
returns successfully, or until all other threads in the process are
either daemon threads or threads waiting in thr_join(), in which case
it returns EDEADLK. See NOTES.
If departed is not NULL, it points to a location that is set to the ID
of the terminated thread if thr_join() returns successfully.
If successful, thr_join() returns 0. Otherwise, an error number is
returned to indicate the error.
A joining deadlock would occur, such as when a thread
attempts to wait for itself, or the calling thread is wait‐
ing for any thread to exit and only daemon threads or wait‐
ing threads exist in the process.
No undetached thread could be found corresponding to the
given thread ID.
See attributes(5) for descriptions of the following attributes:
│ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
│MT-Level │ MT-Safe │
SEE ALSOthr_create(3C), thr_exit(3C), wait(3C), attributes(5), standards(5)NOTES
Using thr_join(3C) in the following syntax,
while (thr_join(0, NULL, NULL) == 0);
will wait for the termination of all non-daemon threads, excluding
threads that are themselves waiting in thr_join().
Mar 27, 2000 THR_JOIN(3C)