1 /* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char sccsid[] = "@(#)sleep.c 8.1 (Berkeley) 6/4/93"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <sys/time.h> 39 #include <sys/signal.h> 40 #include <unistd.h> 41 42 #define setvec(vec, a) \ 43 vec.sv_handler = a; vec.sv_mask = vec.sv_onstack = 0 44 45 static int ringring; 46 47 unsigned int 48 sleep(seconds) 49 unsigned int seconds; 50 { 51 register struct itimerval *itp; 52 struct itimerval itv, oitv; 53 struct sigvec vec, ovec; 54 long omask; 55 static void sleephandler(); 56 57 itp = &itv; 58 if (!seconds) 59 return 0; 60 timerclear(&itp->it_interval); 61 timerclear(&itp->it_value); 62 if (setitimer(ITIMER_REAL, itp, &oitv) < 0) 63 return seconds; 64 itp->it_value.tv_sec = seconds; 65 if (timerisset(&oitv.it_value)) { 66 if (timercmp(&oitv.it_value, &itp->it_value, >)) 67 oitv.it_value.tv_sec -= itp->it_value.tv_sec; 68 else { 69 itp->it_value = oitv.it_value; 70 /* 71 * This is a hack, but we must have time to return 72 * from the setitimer after the alarm or else it'll 73 * be restarted. And, anyway, sleep never did 74 * anything more than this before. 75 */ 76 oitv.it_value.tv_sec = 1; 77 oitv.it_value.tv_usec = 0; 78 } 79 } 80 setvec(vec, sleephandler); 81 (void) sigvec(SIGALRM, &vec, &ovec); 82 omask = sigblock(sigmask(SIGALRM)); 83 ringring = 0; 84 (void) setitimer(ITIMER_REAL, itp, (struct itimerval *)0); 85 while (!ringring) 86 sigpause(omask &~ sigmask(SIGALRM)); 87 (void) sigvec(SIGALRM, &ovec, (struct sigvec *)0); 88 (void) sigsetmask(omask); 89 (void) setitimer(ITIMER_REAL, &oitv, (struct itimerval *)0); 90 return 0; 91 } 92 93 static void 94 sleephandler() 95 { 96 ringring = 1; 97 } 98