1 /* 2 * Copyright (c) 1989 The Regents of the University of California. 3 * 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 = "from: @(#)sleep.c 5.6 (Berkeley) 2/23/91";*/ 36 static char *rcsid = "$Id: sleep.c,v 1.3 1993/08/26 00:45:11 jtc Exp $"; 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include <sys/time.h> 40 #include <sys/signal.h> 41 #include <unistd.h> 42 43 #define setvec(vec, a) \ 44 vec.sv_handler = a; vec.sv_mask = vec.sv_onstack = 0 45 46 static int ringring; 47 48 unsigned int 49 sleep(seconds) 50 unsigned int seconds; 51 { 52 register struct itimerval *itp; 53 struct itimerval itv, oitv; 54 struct sigvec vec, ovec; 55 long omask; 56 static void sleephandler(); 57 58 itp = &itv; 59 if (!seconds) 60 return 0; 61 timerclear(&itp->it_interval); 62 timerclear(&itp->it_value); 63 if (setitimer(ITIMER_REAL, itp, &oitv) < 0) 64 return seconds; 65 itp->it_value.tv_sec = seconds; 66 if (timerisset(&oitv.it_value)) { 67 if (timercmp(&oitv.it_value, &itp->it_value, >)) 68 oitv.it_value.tv_sec -= itp->it_value.tv_sec; 69 else { 70 itp->it_value = oitv.it_value; 71 /* 72 * This is a hack, but we must have time to return 73 * from the setitimer after the alarm or else it'll 74 * be restarted. And, anyway, sleep never did 75 * anything more than this before. 76 */ 77 oitv.it_value.tv_sec = 1; 78 oitv.it_value.tv_usec = 0; 79 } 80 } 81 setvec(vec, sleephandler); 82 (void) sigvec(SIGALRM, &vec, &ovec); 83 omask = sigblock(sigmask(SIGALRM)); 84 ringring = 0; 85 (void) setitimer(ITIMER_REAL, itp, (struct itimerval *)0); 86 while (!ringring) 87 sigpause(omask &~ sigmask(SIGALRM)); 88 (void) sigvec(SIGALRM, &ovec, (struct sigvec *)0); 89 (void) sigsetmask(omask); 90 (void) setitimer(ITIMER_REAL, &oitv, (struct itimerval *)0); 91 return 0; 92 } 93 94 static void 95 sleephandler() 96 { 97 ringring = 1; 98 } 99