git.m6w6.name Git - m6w6/libmemcached/blob - 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 */