1 /*- 2 * Copyright (c) 1997 Brian Somers <brian@Awfulhak.org> 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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $Id: sig.c,v 1.13 1998/05/21 21:48:20 brian Exp $ 27 */ 28 29 #include <sys/types.h> 30 31 #include <signal.h> 32 33 #include "log.h" 34 #include "sig.h" 35 36 static int caused[NSIG]; /* An array of pending signals */ 37 static int necessary; /* Anything set ? */ 38 static sig_type handler[NSIG]; /* all start at SIG_DFL */ 39 40 41 /* Record a signal in the "caused" array */ 42 43 static void 44 signal_recorder(int sig) 45 { 46 caused[sig - 1]++; 47 necessary = 1; 48 } 49 50 51 /* 52 * Set up signal_recorder, and record handler as the function to ultimately 53 * call in handle_signal() 54 */ 55 56 sig_type 57 sig_signal(int sig, sig_type fn) 58 { 59 sig_type Result; 60 61 if (sig <= 0 || sig > NSIG) { 62 /* Oops - we must be a bit out of date (too many sigs ?) */ 63 log_Printf(LogALERT, "Eeek! %s:%d: I must be out of date!\n", 64 __FILE__, __LINE__); 65 return signal(sig, fn); 66 } 67 Result = handler[sig - 1]; 68 if (fn == SIG_DFL || fn == SIG_IGN) { 69 signal(sig, fn); 70 handler[sig - 1] = (sig_type) 0; 71 } else { 72 handler[sig - 1] = fn; 73 signal(sig, signal_recorder); 74 } 75 caused[sig - 1] = 0; 76 return Result; 77 } 78 79 80 /* Call the handlers for any pending signals */ 81 82 int 83 sig_Handle() 84 { 85 int sig; 86 int got; 87 int result; 88 89 result = 0; 90 if (necessary) { 91 /* We've *probably* got something in `caused' set */ 92 necessary = 0; 93 /* `necessary' might go back to 1 while we're in here.... */ 94 do { 95 got = 0; 96 for (sig = 0; sig < NSIG; sig++) 97 if (caused[sig]) { 98 caused[sig]--; 99 got++; 100 result++; 101 (*handler[sig])(sig + 1); 102 } 103 } while (got); 104 } 105 106 return result; 107 } 108