experimental threaded libc - kernel only

1 files changed, 112 insertions, 0 deletions

diff --git a/lib/libpthread/uthread/uthread_sigwait.c b/lib/libpthread/uthread/uthread_sigwait.c
new file mode 100644
index 00000000000..f441fa3b731
--- /dev/null
+++ b/lib/libpthread/uthread/uthread_sigwait.c
@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 1997 John Birrell <jb@cimlogic.com.au>.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by John Birrell.
+ * 4. Neither the name of the author nor the names of any co-contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+#include <signal.h>
+#include <errno.h>
+#ifdef _THREAD_SAFE
+#include <pthread.h>
+#include "pthread_private.h"
+
+int
+sigwait(const sigset_t * set, int *sig)
+{
+	int		ret = 0;
+	int		i;
+	sigset_t	oset;
+	struct sigaction act;
+	
+	/*
+	 * Specify the thread kernel signal handler.
+	 */
+	act.sa_handler = (void (*) ()) _thread_sig_handler;
+	act.sa_flags = SA_RESTART;
+	act.sa_mask = *set;
+
+	/*
+	 * These signals can't be waited on.
+	 */
+	sigdelset(&act.sa_mask, SIGKILL);
+	sigdelset(&act.sa_mask, SIGSTOP);
+	sigdelset(&act.sa_mask, SIGVTALRM);
+	sigdelset(&act.sa_mask, SIGCHLD);
+	sigdelset(&act.sa_mask, SIGINFO);
+
+	/*
+	 * 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, so we ignore SIG_IGN signals.
+	 */
+	for (i = 1; i < NSIG; i++) {
+		if (sigismember(&act.sa_mask, i)) {
+			if (_thread_sigact[i - 1].sa_handler == SIG_DFL) {
+				if (_thread_sys_sigaction(i,&act,NULL) != 0)
+					ret = -1;
+			}
+			else if (_thread_sigact[i - 1].sa_handler == SIG_IGN)
+				sigdelset(&act.sa_mask, i);
+		}
+	}
+	if (ret == 0) {
+
+		/* Save the current signal mask: */
+		oset = _thread_run->sigmask;
+
+		/* Combine the caller's mask with the current one: */
+		_thread_run->sigmask |= act.sa_mask;
+
+		/* Wait for a signal: */
+		_thread_kern_sched_state(PS_SIGWAIT, __FILE__, __LINE__);
+
+		/* Return the signal number to the caller: */
+		*sig = _thread_run->signo;
+
+		/* Restore the signal mask: */
+		_thread_run->sigmask = oset;
+	}
+
+	/* Restore the sigactions: */
+	act.sa_handler = SIG_DFL;
+	for (i = 1; i < NSIG; i++) {
+		if (sigismember(&act.sa_mask, i) &&
+		    (_thread_sigact[i - 1].sa_handler == SIG_DFL)) {
+			if (_thread_sys_sigaction(i,&act,NULL) != 0)
+				ret = -1;
+		}
+	}
+
+	/* Return the completion status: */
+	return (ret);
+}
+#endif