Wait for Thread Termination

Use thr_join(3C) to wait for a target thread to terminate. For POSIX threads, see pthread_join Syntax.

thr_join Syntax

#include <thread.h>

int thr_join(thread_t tid, thread_t *departedid, void **status);

The target thread must be a member of the current process. The target thread cannot be a detached thread or a daemon thread.

Several threads cannot wait for the same thread to complete. One thread will complete successfully. The others will terminate with an ESRCH error.

thr_join() will not block processing of the calling thread if the target thread has already terminated.

thr_join, Join Specific

#include <thread.h>

thread_t tid;
thread_t departedid;
int ret;
void *status;

/* waiting to join thread "tid" with status */
ret = thr_join(tid, &departedid, &status);

/* waiting to join thread "tid" without status */
ret = thr_join(tid, &departedid, NULL);

/* waiting to join thread "tid" without return id and status */
ret = thr_join(tid, NULL, NULL); 

When the tid is (thread_t)0, then thread_join() waits for any undetached thread in the process to terminate. In other words, when no thread identifier is specified, any undetached thread that exits causes thread_join() to return.

thr_join, Join Any

#include <thread.h>

thread_t tid;
thread_t departedid;
int ret;
void *status;

/* waiting to join any non-detached thread with status */
ret = thr_join(0, &departedid, &status); 

By indicating 0 as the thread ID in the Solaris thr_join(), a join takes place when any non detached thread in the process exits. The departedid indicates the thread ID of the exiting thread.

thr_join Return Values

thr_join() returns 0 if successful. When any of the following conditions is detected, thr_join() fails and returns the corresponding value.

ESRCH

Description:

No undetached thread is found which corresponds to the target thread ID.

EDEADLK

Description:

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