src/sig_handlers.c

   1 /* the Music Player Daemon (MPD)
   2  * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
   3  * (c) 2004 Nick Welch (mack@incise.org)
   4  * This project's homepage is: http://www.musicpd.org
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 #include "sig_handlers.h"
  21 #include "player.h"
  22 #include "playerData.h"
  23 #include "playlist.h"
  24 #include "directory.h"
  25 #include "command.h"
  26 #include "signal_check.h"
  27 #include "log.h"
  28 #include "player.h"
  29 #include "decode.h"
  30
  31 #include <signal.h>
  32 #include <sys/types.h>
  33 #include <sys/time.h>
  34 #include <sys/resource.h>
  35 #include <sys/wait.h>
  36 #include <errno.h>
  37 #include <unistd.h>
  38
  39 int handlePendingSignals(void)
  40 {
  41         if (signal_is_pending(SIGINT) || signal_is_pending(SIGTERM)) {
  42                 DEBUG("main process got SIGINT or SIGTERM, exiting\n");
  43                 return COMMAND_RETURN_KILL;
  44         }
  45
  46         if (signal_is_pending(SIGHUP)) {
  47                 DEBUG("got SIGHUP, rereading DB\n");
  48                 signal_clear(SIGHUP);
  49                 if (!isUpdatingDB()) {
  50                         readDirectoryDB();
  51                         playlistVersionChange();
  52                 }
  53                 if (cycle_log_files() < 0)
  54                         return COMMAND_RETURN_KILL;
  55                 playerCycleLogFiles();
  56         }
  57
  58         return 0;
  59 }
  60
  61 static void chldSigHandler(int signal)
  62 {
  63         int status;
  64         int pid;
  65         DEBUG("main process got SIGCHLD\n");
  66         while (0 != (pid = wait3(&status, WNOHANG, NULL))) {
  67                 if (pid < 0) {
  68                         if (errno == EINTR)
  69                                 continue;
  70                         else
  71                                 break;
  72                 }
  73                 player_sigChldHandler(pid, status);
  74                 directory_sigChldHandler(pid, status);
  75         }
  76 }
  77
  78 void initSigHandlers(void)
  79 {
  80         struct sigaction sa;
  81
  82         sa.sa_flags = 0;
  83         sigemptyset(&sa.sa_mask);
  84         sa.sa_handler = SIG_IGN;
  85         while (sigaction(SIGPIPE, &sa, NULL) < 0 && errno == EINTR) ;
  86         sa.sa_handler = chldSigHandler;
  87         while (sigaction(SIGCHLD, &sa, NULL) < 0 && errno == EINTR) ;
  88         signal_handle(SIGUSR1);
  89         signal_handle(SIGINT);
  90         signal_handle(SIGTERM);
  91         signal_handle(SIGHUP);
  92 }
  93
  94 void finishSigHandlers(void)
  95 {
  96         signal_unhandle(SIGINT);
  97         signal_unhandle(SIGUSR1);
  98         signal_unhandle(SIGTERM);
  99         signal_unhandle(SIGHUP);
 100 }
 101
 102 void setSigHandlersForDecoder(void)
 103 {
 104         struct sigaction sa;
 105
 106         finishSigHandlers();
 107
 108         sa.sa_flags = 0;
 109         sigemptyset(&sa.sa_mask);
 110         sa.sa_handler = SIG_IGN;
 111         while (sigaction(SIGHUP, &sa, NULL) < 0 && errno == EINTR) ;
 112         while (sigaction(SIGINT, &sa, NULL) < 0 && errno == EINTR) ;
 113         sa.sa_flags = SA_SIGINFO;
 114         sa.sa_sigaction = decodeSigHandler;
 115         while (sigaction(SIGCHLD, &sa, NULL) < 0 && errno == EINTR) ;
 116         while (sigaction(SIGTERM, &sa, NULL) < 0 && errno == EINTR) ;
 117 }
 118
 119 void ignoreSignals(void)
 120 {
 121         struct sigaction sa;
 122
 123         sa.sa_flags = 0;
 124         sigemptyset(&sa.sa_mask);
 125         sa.sa_handler = SIG_IGN;
 126         sa.sa_sigaction = NULL;
 127         while (sigaction(SIGPIPE, &sa, NULL) < 0 && errno == EINTR) ;
 128         while (sigaction(SIGCHLD, &sa, NULL) < 0 && errno == EINTR) ;
 129         while (sigaction(SIGUSR1, &sa, NULL) < 0 && errno == EINTR) ;
 130         while (sigaction(SIGINT, &sa, NULL) < 0 && errno == EINTR) ;
 131         while (sigaction(SIGTERM, &sa, NULL) < 0 && errno == EINTR) ;
 132         while (sigaction(SIGHUP, &sa, NULL) < 0 && errno == EINTR) ;
 133 }
 134
 135 void blockSignals(void)
 136 {
 137         sigset_t sset;
 138
 139         sigemptyset(&sset);
 140         sigaddset(&sset, SIGCHLD);
 141         sigaddset(&sset, SIGUSR1);
 142         sigaddset(&sset, SIGHUP);
 143         sigaddset(&sset, SIGINT);
 144         sigaddset(&sset, SIGTERM);
 145         while (sigprocmask(SIG_BLOCK, &sset, NULL) < 0 && errno == EINTR) ;
 146 }
 147
 148 void unblockSignals(void)
 149 {
 150         sigset_t sset;
 151
 152         sigemptyset(&sset);
 153         sigaddset(&sset, SIGCHLD);
 154         sigaddset(&sset, SIGUSR1);
 155         sigaddset(&sset, SIGHUP);
 156         sigaddset(&sset, SIGINT);
 157         sigaddset(&sset, SIGTERM);
 158         while (sigprocmask(SIG_UNBLOCK, &sset, NULL) < 0 && errno == EINTR) ;
 159 }