Merging bzr://gaz.tangent.org/libmemcached/build/ to Build branch
[awesomized/libmemcached] / 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 (close_io == false)
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 */