git.m6w6.name Git - m6w6/libmemcached/blob - src/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 "mem_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 #if HAVE_SYS_WAIT_H
  46 #include <sys/wait.h>
  47 #include <signal.h>
  48 #if HAVE_UNISTD_H
  49 #  include <unistd.h>
  50 #endif
  51 #include <sys/select.h>
  52
  53 #include <util/daemon.hpp>
  54
  55 #include <iostream>
  56
  57 namespace datadifferential {
  58 namespace util {
  59
  60 pid_t parent_pid;
  61
  62 extern "C"
  63 {
  64
  65 static void sigusr1_handler(int sig)
  66 {
  67   if (sig == SIGUSR1)
  68   {
  69     _exit(EXIT_SUCCESS);
  70   }
  71 }
  72
  73 }
  74
  75 bool daemon_is_ready(bool close_io)
  76 {
  77   if (kill(parent_pid, SIGUSR1) == -1)
  78   {
  79     perror("kill");
  80     return false;
  81   }
  82
  83   if (close_io == false)
  84   {
  85     return true;;
  86   }
  87
  88   int fd;
  89   if ((fd = open("/dev/null", O_RDWR, 0)) < 0)
  90   {
  91     perror("open");
  92     return false;
  93   }
  94   else
  95   {
  96     if (dup2(fd, STDIN_FILENO) < 0)
  97     {
  98       perror("dup2 stdin");
  99       return false;
 100     }
 101
 102     if (dup2(fd, STDOUT_FILENO) < 0)
 103     {
 104       perror("dup2 stdout");
 105       return false;
 106     }
 107
 108     if (dup2(fd, STDERR_FILENO) < 0)
 109     {
 110       perror("dup2 stderr");
 111       return false;
 112     }
 113
 114     if (fd > STDERR_FILENO)
 115     {
 116       if (close(fd) < 0)
 117       {
 118         perror("close");
 119         return false;
 120       }
 121     }
 122   }
 123
 124   return true;
 125 }
 126
 127 #ifndef __INTEL_COMPILER
 128 #pragma GCC diagnostic ignored "-Wold-style-cast"
 129 #endif
 130
 131 bool daemonize(bool is_chdir, bool wait_sigusr1)
 132 {
 133   struct sigaction new_action;
 134
 135   new_action.sa_handler= sigusr1_handler;
 136   sigemptyset(&new_action.sa_mask);
 137   new_action.sa_flags= 0;
 138   sigaction(SIGUSR1, &new_action, NULL);
 139
 140   parent_pid= getpid();
 141
 142   pid_t child= fork();
 143
 144   switch (child)
 145   {
 146   case -1:
 147     return false;
 148
 149   case 0:
 150     break;
 151
 152   default:
 153     if (wait_sigusr1)
 154     {
 155       /* parent */
 156       int exit_code= EXIT_FAILURE;
 157       int status;
 158       while (waitpid(child, &status, 0) != child)
 159       { }
 160
 161       if (WIFEXITED(status))
 162       {
 163         exit_code= WEXITSTATUS(status);
 164       }
 165       if (WIFSIGNALED(status))
 166       {
 167         exit_code= EXIT_FAILURE;
 168       }
 169       _exit(exit_code);
 170     }
 171     else
 172     {
 173       _exit(EXIT_SUCCESS);
 174     }
 175   }
 176
 177   /* child */
 178   if (setsid() == -1)
 179   {
 180     perror("setsid");
 181     return false;
 182   }
 183
 184   if (is_chdir)
 185   {
 186     if (chdir("/") < 0)
 187     {
 188       perror("chdir");
 189       return false;
 190     }
 191   }
 192
 193   return true;
 194 }
 195
 196 } /* namespace util */
 197 } /* namespace datadifferential */