Merge working tree with build tree.
[awesomized/libmemcached] / util / pidfile.cc
1 /* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
2 *
3 * DataDifferential Utility Library
4 *
5 * Copyright (C) 2011 Data Differential, http://datadifferential.com/
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are
10 * met:
11 *
12 * * Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * * Redistributions in binary form must reproduce the above
16 * copyright notice, this list of conditions and the following disclaimer
17 * in the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * * The names of its contributors may not be used to endorse or
21 * promote products derived from this software without specific prior
22 * written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
27 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
28 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
30 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
31 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
34 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 *
36 */
37
38 #include "config.h"
39
40 #include "util/pidfile.hpp"
41
42 #include <cstdio>
43 #include <cstdlib>
44 #include <cstring>
45 #include <cerrno>
46 #include <fcntl.h>
47 #include <iostream>
48 #include <sstream>
49 #include <sys/stat.h>
50 #include <sys/types.h>
51 #include <unistd.h>
52
53 extern "C" {
54
55 char pid_file[1024 * 4]= { 0 };
56
57 static void remove_pidfile(void)
58 {
59 if (pid_file[0])
60 {
61 if (unlink(pid_file) == -1)
62 {
63 std::cerr << "Could not remove pidfile: " << pid_file << "(" << strerror(errno) << ")" << std::endl;
64 }
65
66 pid_file[0]= 0;
67 }
68 }
69
70 }
71
72 namespace datadifferential {
73 namespace util {
74
75 Pidfile::Pidfile(const std::string &arg) :
76 _last_errno(0),
77 _filename(arg)
78 {
79 }
80
81
82 Pidfile::~Pidfile()
83 {
84 if (not _filename.empty())
85 {
86 if (access(_filename.c_str(), F_OK) == -1)
87 {
88 std::stringstream error_stream;
89 error_stream << "Could not access the pid file: " << _filename << "(" << strerror(errno) << ")";
90 _error_message= error_stream.str();
91 }
92 else if (unlink(_filename.c_str()) == -1)
93 {
94 std::stringstream error_stream;
95 error_stream << "Could not remove the pid file: " << _filename << "(" << strerror(errno) << ")";
96 _error_message= error_stream.str();
97 }
98 }
99 pid_file[0]= 0;
100 }
101
102 bool Pidfile::create()
103 {
104 if (_filename.empty())
105 {
106 return true;
107 }
108
109 if (access(_filename.c_str(), F_OK) == 0)
110 {
111 if (unlink(_filename.c_str()) == -1)
112 {
113 std::stringstream error_stream;
114 error_stream << "Unable to remove exisiting file:" << _filename << "(" << strerror(errno) << ")";
115 _error_message= error_stream.str();
116
117 return false;
118 }
119 }
120
121 int file;
122 if ((file = open(_filename.c_str(), O_CREAT|O_WRONLY|O_TRUNC, S_IRWXU|S_IRGRP|S_IROTH)) < 0)
123 {
124 std::stringstream error_stream;
125 error_stream << "Could not open pid file for writing: " << _filename << "(" << strerror(errno) << ")";
126 _error_message= error_stream.str();
127
128 return false;
129 }
130
131 char buffer[BUFSIZ];
132 unsigned long temp= static_cast<unsigned long>(getpid());
133 int length= snprintf(buffer, sizeof(buffer), "%lu\n", temp);
134 if (write(file, buffer, length) != length)
135 {
136 std::stringstream error_stream;
137 error_stream << "Could not write pid to file: " << _filename << "(" << strerror(errno) << ")";
138 _error_message= error_stream.str();
139 close(file);
140
141 return false;
142 }
143
144 if (close(file) < 0)
145 {
146 _error_message+= "Could not close() file after writing pid to it: ";
147 _error_message+= _filename;
148 return false;
149 }
150 snprintf(pid_file, sizeof(pid_file), "%s", _filename.c_str());
151 atexit(remove_pidfile);
152
153 return true;
154 }
155
156 } /* namespace util */
157 } /* namespace datadifferential */