NAME

     thr_wake — wake up the suspended thread

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <sys/thr.h>

     int
     thr_wake(long id);

DESCRIPTION

     This function is intended for implementing threading.  Normal applications should use
     pthread_cond_timedwait(3) together with pthread_cond_broadcast(3) for typical safe
     suspension with cooperation of the thread being suspended, or pthread_suspend_np(3) and
     pthread_resume_np(3) in some specific situations, instead.

     Passing the thread identifier of the calling thread (see thr_self(2)) to thr_wake() sets a
     thread's flag to cause the next signal-interruptible sleep of that thread in the kernel to
     fail immediately with the EINTR error.  The flag is cleared by an interruptible sleep
     attempt or by a call to thr_suspend(2.) This is used by the system threading library to
     implement cancellation.

     If id is not equal to the current thread identifier, the specified thread is woken up if
     suspended by the thr_suspend system call.  If the thread is not suspended at the time of the
     thr_wake call, the wake is remembered and the next attempt of the thread to suspend itself
     with the thr_suspend(2) results in immediate return with success.  Only one wake is
     remembered.

RETURN VALUES

     The thr_wake() function returns the value 0 if successful; otherwise the value -1 is
     returned and the global variable errno is set to indicate the error.

ERRORS

     The thr_wake() operation returns these errors:

     [ESRCH]            The specified thread was not found or does not belong to the process of
                        the calling thread.

SEE ALSO

     ps(1), thr_self(2) thr_suspend(2), pthread_cancel(3), pthread_resume_np(3),
     pthread_suspend_np(3)

STANDARDS

     The thr_suspend() system call is non-standard and is used by 1:1 Threading Library (libthr,
     -lthr) to implement IEEE Std 1003.1-2001 (“POSIX.1”) pthread(3) functionality.