Updating for 1.0.2 release
[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
52 extern "C" {
53
54 char pid_file[1024 * 4]= { 0 };
55
56 static void remove_pidfile(void)
57 {
58 if (pid_file[0])
59 {
60 if (unlink(pid_file) == -1)
61 {
62 std::cerr << "Could not remove pidfile: " << pid_file << "(" << strerror(errno) << ")" << std::endl;
63 }
64
65 pid_file[0]= 0;
66 }
67 }
68
69 }
70
71 namespace datadifferential {
72 namespace util {
73
74 Pidfile::Pidfile(const std::string &arg) :
75 _last_errno(0),
76 _filename(arg)
77 {
78 }
79
80
81 Pidfile::~Pidfile()
82 {
83 if (not _filename.empty())
84 {
85 if (access(_filename.c_str(), F_OK) == -1)
86 {
87 std::stringstream error_stream;
88 error_stream << "Could not access the pid file: " << _filename << "(" << strerror(errno) << ")";
89 _error_message= error_stream.str();
90 }
91 else if (unlink(_filename.c_str()) == -1)
92 {
93 std::stringstream error_stream;
94 error_stream << "Could not remove the pid file: " << _filename << "(" << strerror(errno) << ")";
95 _error_message= error_stream.str();
96 }
97 }
98 pid_file[0]= 0;
99 }
100
101 bool Pidfile::create()
102 {
103 if (_filename.empty())
104 {
105 return true;
106 }
107
108 if (access(_filename.c_str(), F_OK) == 0)
109 {
110 if (unlink(_filename.c_str()) == -1)
111 {
112 std::stringstream error_stream;
113 error_stream << "Unable to remove exisiting file:" << _filename << "(" << strerror(errno) << ")";
114 _error_message= error_stream.str();
115
116 return false;
117 }
118 }
119
120 int file;
121 if ((file = open(_filename.c_str(), O_CREAT|O_WRONLY|O_TRUNC, S_IRWXU|S_IRGRP|S_IROTH)) < 0)
122 {
123 std::stringstream error_stream;
124 error_stream << "Could not open pid file for writing: " << _filename << "(" << strerror(errno) << ")";
125 _error_message= error_stream.str();
126
127 return false;
128 }
129
130 char buffer[BUFSIZ];
131 unsigned long temp= static_cast<unsigned long>(getpid());
132 int length= snprintf(buffer, sizeof(buffer), "%lu\n", temp);
133 if (write(file, buffer, length) != length)
134 {
135 std::stringstream error_stream;
136 error_stream << "Could not write pid to file: " << _filename << "(" << strerror(errno) << ")";
137 _error_message= error_stream.str();
138 close(file);
139
140 return false;
141 }
142
143 if (close(file) < 0)
144 {
145 _error_message+= "Could not close() file after writing pid to it: ";
146 _error_message+= _filename;
147 return false;
148 }
149 snprintf(pid_file, sizeof(pid_file), "%s", _filename.c_str());
150 atexit(remove_pidfile);
151
152 return true;
153 }
154
155 } /* namespace util */
156 } /* namespace datadifferential */