pthread_join - wait for termination of another thread
#include <pthread.h>
int pthread_join(pthread_t th, void **thread_return);
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.
pthread_join is a cancellation point. If a thread is cancelled 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.
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.
Xavier Leroy <[email protected]>
pthread_exit(3) , pthread_detach(3) , pthread_create(3) , pthread_attr_setdetachstate(3) , pthread_cleanup_push(3) , pthread_key_create(3) .