1 files changed, 97 insertions, 0 deletions

diff --git a/lib/libc/gen/sleep.c b/lib/libc/gen/sleep.c
new file mode 100644
index 000000000000..3c0b8fa31efa
--- /dev/null
+++ b/lib/libc/gen/sleep.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  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 the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)sleep.c	8.1 (Berkeley) 6/4/93";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/time.h>
+#include <sys/signal.h>
+#include <unistd.h>
+
+#define	setvec(vec, a) \
+	vec.sv_handler = a; vec.sv_mask = vec.sv_onstack = 0
+
+static int ringring;
+
+unsigned int
+sleep(seconds)
+	unsigned int seconds;
+{
+	register struct itimerval *itp;
+	struct itimerval itv, oitv;
+	struct sigvec vec, ovec;
+	long omask;
+	static void sleephandler();
+
+	itp = &itv;
+	if (!seconds)
+		return 0;
+	timerclear(&itp->it_interval);
+	timerclear(&itp->it_value);
+	if (setitimer(ITIMER_REAL, itp, &oitv) < 0)
+		return seconds;
+	itp->it_value.tv_sec = seconds;
+	if (timerisset(&oitv.it_value)) {
+		if (timercmp(&oitv.it_value, &itp->it_value, >))
+			oitv.it_value.tv_sec -= itp->it_value.tv_sec;
+		else {
+			itp->it_value = oitv.it_value;
+			/*
+			 * This is a hack, but we must have time to return
+			 * from the setitimer after the alarm or else it'll
+			 * be restarted.  And, anyway, sleep never did
+			 * anything more than this before.
+			 */
+			oitv.it_value.tv_sec = 1;
+			oitv.it_value.tv_usec = 0;
+		}
+	}
+	setvec(vec, sleephandler);
+	(void) sigvec(SIGALRM, &vec, &ovec);
+	omask = sigblock(sigmask(SIGALRM));
+	ringring = 0;
+	(void) setitimer(ITIMER_REAL, itp, (struct itimerval *)0);
+	while (!ringring)
+		sigpause(omask &~ sigmask(SIGALRM));
+	(void) sigvec(SIGALRM, &ovec, (struct sigvec *)0);
+	(void) sigsetmask(omask);
+	(void) setitimer(ITIMER_REAL, &oitv, (struct itimerval *)0);
+	return 0;
+}
+
+static void
+sleephandler()
+{
+	ringring = 1;
+}