1 files changed, 127 insertions, 3 deletions

diff --git a/lib/libpthread/thread/thr_sigwait.c b/lib/libpthread/thread/thr_sigwait.c
index 5364d66..b955251 100644
--- a/lib/libpthread/thread/thr_sigwait.c
+++ b/lib/libpthread/thread/thr_sigwait.c
@@ -42,11 +42,135 @@
 __weak_reference(_sigwait, sigwait);
 
 int
-_sigwait(const sigset_t * __restrict set, int * __restrict sig)
+_sigwait(const sigset_t *set, int *sig)
 {
+	struct pthread	*curthread = _get_curthread();
+	int		ret = 0;
+	int		i;
+	sigset_t	tempset, waitset;
+	struct sigaction act;
+	
+	_thr_enter_cancellation_point(curthread);
 
 	/*
-	 * All signals are invalid for waiting.
+	 * Specify the thread kernel signal handler.
 	 */
-	return (EINVAL);
+	act.sa_handler = (void (*) ()) _thr_sig_handler;
+	act.sa_flags = SA_RESTART | SA_SIGINFO;
+	/* Ensure the signal handler cannot be interrupted by other signals: */
+	sigfillset(&act.sa_mask);
+
+	/*
+	 * Initialize the set of signals that will be waited on:
+	 */
+	waitset = *set;
+
+	/* These signals can't be waited on. */
+	sigdelset(&waitset, SIGKILL);
+	sigdelset(&waitset, SIGSTOP);
+
+	/*
+	 * Check to see if a pending signal is in the wait mask.
+	 * This has to be atomic. */
+	tempset = curthread->sigpend;
+	SIGSETOR(tempset, _thr_proc_sigpending);
+	SIGSETAND(tempset, waitset);
+	if (SIGNOTEMPTY(tempset)) {
+		/* Enter a loop to find a pending signal: */
+		for (i = 1; i < NSIG; i++) {
+			if (sigismember (&tempset, i))
+				break;
+		}
+
+		/* Clear the pending signal: */
+		if (sigismember(&curthread->sigpend,i))
+			sigdelset(&curthread->sigpend,i);
+		else
+			sigdelset(&_thr_proc_sigpending,i);
+
+		/* Return the signal number to the caller: */
+		*sig = i;
+
+		_thr_leave_cancellation_point(curthread);
+		return (0);
+	}
+
+	/*
+	 * Lock the array of SIG_DFL wait counts.
+	 */
+	THR_LOCK_ACQUIRE(curthread, &_thread_signal_lock);
+
+	/*
+	 * Enter a loop to find the signals that are SIG_DFL.  For
+	 * these signals we must install a dummy signal handler in
+	 * order for the kernel to pass them in to us.  POSIX says
+	 * that the _application_ must explicitly install a dummy
+	 * handler for signals that are SIG_IGN in order to sigwait
+	 * on them.  Note that SIG_IGN signals are left in the
+	 * mask because a subsequent sigaction could enable an
+	 * ignored signal.
+	 */
+	sigemptyset(&tempset);
+	for (i = 1; i < NSIG; i++) {
+		if (sigismember(&waitset, i) &&
+		    (_thread_sigact[i - 1].sa_handler == SIG_DFL)) {
+			_thread_dfl_count[i]++;
+			sigaddset(&tempset, i);
+			if (_thread_dfl_count[i] == 1) {
+				if (__sys_sigaction(i, &act, NULL) != 0)
+					ret = -1;
+			}
+		}
+	}
+	/* Done accessing _thread_dfl_count for now. */
+	THR_LOCK_RELEASE(curthread, &_thread_signal_lock);
+
+	if (ret == 0) {
+		/*
+		 * Save the wait signal mask.  The wait signal
+		 * mask is independent of the threads signal mask
+		 * and requires separate storage.
+		 */
+		curthread->data.sigwait = &waitset;
+
+		/* Wait for a signal: */
+		THR_SCHED_LOCK(curthread, curthread);
+		THR_SET_STATE(curthread, PS_SIGWAIT);
+		THR_SCHED_UNLOCK(curthread, curthread);
+		_thr_sched_switch(curthread);
+
+		/* Return the signal number to the caller: */
+		*sig = curthread->signo;
+
+		/*
+		 * Probably unnecessary, but since it's in a union struct
+		 * we don't know how it could be used in the future.
+		 */
+		curthread->data.sigwait = NULL;
+	}
+
+	/*
+	 * Relock the array of SIG_DFL wait counts.
+	 */
+	THR_LOCK_ACQUIRE(curthread, &_thread_signal_lock);
+
+	/* Restore the sigactions: */
+	act.sa_handler = SIG_DFL;
+	for (i = 1; i < NSIG; i++) {
+		if (sigismember(&tempset, i)) {
+			_thread_dfl_count[i]--;
+			if ((_thread_sigact[i - 1].sa_handler == SIG_DFL) &&
+			    (_thread_dfl_count[i] == 0)) {
+				if (__sys_sigaction(i, &act, NULL) != 0)
+					ret = -1;
+			}
+		}
+	}
+	/* Done accessing _thread_dfl_count. */
+	THR_LOCK_RELEASE(curthread, &_thread_signal_lock);
+
+	_thr_leave_cancellation_point(curthread);
+	
+	/* Return the completion status: */
+	return (ret);
 }