git.m6w6.name Git - awesomized/libmemcached/blob - util/daemon.cc

   1 /*    $Header: /cvsroot/wikipedia/willow/src/bin/willow/daemon.c,v 1.1 2005/05/02 19:15:21 kateturner Exp $    */
   2 /*    $NetBSD: daemon.c,v 1.9 2003/08/07 16:42:46 agc Exp $    */
   3 /*-
   4  * Copyright (c) 1990, 1993
   5  *    The Regents of the University of California.  All rights reserved.
   6  * Copyright (c) 2010
   7  *    Stewart Smith
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. 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 #include <config.h>
  35
  36 #if defined __SUNPRO_C || defined __DECC || defined __HP_cc
  37 # pragma ident "@(#)$Header: /cvsroot/wikipedia/willow/src/bin/willow/daemon.c,v 1.1 2005/05/02 19:15:21 kateturner Exp $"
  38 # pragma ident "$NetBSD: daemon.c,v 1.9 2003/08/07 16:42:46 agc Exp $"
  39 #endif
  40
  41 #include <fcntl.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <sys/types.h>
  45 #include <sys/wait.h>
  46 #include <signal.h>
  47 #include <unistd.h>
  48 #include <sys/select.h>
  49
  50 #include <util/daemon.hpp>
  51
  52 #include <iostream>
  53
  54 namespace datadifferential {
  55 namespace util {
  56
  57 pid_t parent_pid;
  58
  59 extern "C"
  60 {
  61
  62 static void sigusr1_handler(int sig)
  63 {
  64   if (sig == SIGUSR1)
  65   {
  66     _exit(EXIT_SUCCESS);
  67   }
  68 }
  69
  70 }
  71
  72 bool daemon_is_ready(bool close_io)
  73 {
  74   if (kill(parent_pid, SIGUSR1) == -1)
  75   {
  76     perror("kill");
  77     return false;
  78   }
  79
  80   if (not close_io)
  81   {
  82     return true;;
  83   }
  84
  85   int fd;
  86   if ((fd = open("/dev/null", O_RDWR, 0)) < 0)
  87   {
  88     perror("open");
  89     return false;
  90   }
  91   else
  92   {
  93     if (dup2(fd, STDIN_FILENO) < 0)
  94     {
  95       perror("dup2 stdin");
  96       return false;
  97     }
  98
  99     if (dup2(fd, STDOUT_FILENO) < 0)
 100     {
 101       perror("dup2 stdout");
 102       return false;
 103     }
 104
 105     if (dup2(fd, STDERR_FILENO) < 0)
 106     {
 107       perror("dup2 stderr");
 108       return false;
 109     }
 110
 111     if (fd > STDERR_FILENO)
 112     {
 113       if (close(fd) < 0)
 114       {
 115         perror("close");
 116         return false;
 117       }
 118     }
 119   }
 120
 121   return true;
 122 }
 123
 124 #ifndef __INTEL_COMPILER
 125 #pragma GCC diagnostic ignored "-Wold-style-cast"
 126 #endif
 127
 128 bool daemonize(bool is_chdir, bool wait_sigusr1)
 129 {
 130   struct sigaction new_action;
 131
 132   new_action.sa_handler= sigusr1_handler;
 133   sigemptyset(&new_action.sa_mask);
 134   new_action.sa_flags= 0;
 135   sigaction(SIGUSR1, &new_action, NULL);
 136
 137   parent_pid= getpid();
 138
 139   pid_t child= fork();
 140
 141   switch (child)
 142   {
 143   case -1:
 144     return false;
 145
 146   case 0:
 147     break;
 148
 149   default:
 150     if (wait_sigusr1)
 151     {
 152       /* parent */
 153       int exit_code= EXIT_FAILURE;
 154       int status;
 155       while (waitpid(child, &status, 0) != child)
 156       { }
 157
 158       if (WIFEXITED(status))
 159       {
 160         exit_code= WEXITSTATUS(status);
 161       }
 162       if (WIFSIGNALED(status))
 163       {
 164         exit_code= EXIT_FAILURE;
 165       }
 166       _exit(exit_code);
 167     }
 168     else
 169     {
 170       _exit(EXIT_SUCCESS);
 171     }
 172   }
 173
 174   /* child */
 175   if (setsid() == -1)
 176   {
 177     perror("setsid");
 178     return false;
 179   }
 180
 181   if (is_chdir)
 182   {
 183     if (chdir("/") < 0)
 184     {
 185       perror("chdir");
 186       return false;
 187     }
 188   }
 189
 190   return true;
 191 }
 192
 193 } /* namespace util */
 194 } /* namespace datadifferential */