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thr_suspend(3c) [opensolaris man page]

thr_suspend(3C) 					   Standard C Library Functions 					   thr_suspend(3C)

thr_suspend, thr_continue - suspend or continue thread execution SYNOPSIS
cc -mt [ flag... ] file...[ library... ] #include <thread.h> int thr_suspend(thread_t target_thread); int thr_continue(thread_t target_thread); DESCRIPTION
The thr_suspend() function immediately suspends the execution of the thread specified by target_thread. On successful return from thr_sus- pend(), the suspended thread is no longer executing. Once a thread is suspended, subsequent calls to thr_suspend() have no effect. The thr_continue() function resumes the execution of a suspended thread. Once a suspended thread is continued, subsequent calls to thr_con- tinue() have no effect. A suspended thread will not be awakened by any mechanism other than a call to thr_continue(). Signals and the effect of calls tomu- tex_unlock(3C), rw_unlock(3C), sema_post(3C), cond_signal(3C), and cond_broadcast(3C) remain pending until the execution of the thread is resumed by thr_continue(). RETURN VALUES
If successful, the thr_suspend() and thr_continue() functions return 0. Otherwise, a non-zero value is returned to indicate the error. ERRORS
The thr_suspend() and thr_continue() functions will fail if: ESRCH The target_thread cannot be found in the current process. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ SEE ALSO
thr_create(3C), thr_join(3C), attributes(5), standards(5) WARNINGS
The thr_suspend() function is extremely difficult to use safely because it suspends the target thread with no concern for the target thread's state. The target thread could be holding locks, waiting for a lock, or waiting on a condition variable when it is unconditionally suspended. The thread will not run until thr_continue() is applied, regardless of any calls to mutex_unlock(), cond_signal(), or cond_broadcast() by other threads. Its existence on a sleep queue can interfere with the waking up of other threads that are on the same sleep queue. The thr_suspend() and thr_continue() functions should be avoided. Mechanisms that involve the cooperation of the targeted thread, such as mutex locks and condition variables, should be employed instead. SunOS 5.11 22 Mar 2002 thr_suspend(3C)

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thr_join(3C)						   Standard C Library Functions 					      thr_join(3C)

thr_join - wait for thread termination SYNOPSIS
cc -mt [ flag... ] file...[ library... ] #include <thread.h> int thr_join(thread_t thread, thread_t *departed, void **status); DESCRIPTION
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_create(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 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 argument, 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. RETURN VALUES
If successful, thr_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, or the calling thread is waiting for any thread to exit and only daemon threads or waiting threads exist in the process. ESRCH No undetached thread could be found corresponding to the given thread ID. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |MT-Level |MT-Safe | +-----------------------------+-----------------------------+ SEE ALSO
thr_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(). SunOS 5.11 27 Mar 2000 thr_join(3C)

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