git.m6w6.name Git - m6w6/libmemcached/blob - src/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
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  30  *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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  32  *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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  34  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  *
  36  */
  37
  38 #include "mem_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 #if #if HAVE_UNISTD_H
  52 #  include <unistd.h>
  53 #endif
  54
  55 extern "C" {
  56
  57   char pid_file[1024 * 4]= { 0 };
  58
  59   static void remove_pidfile(void)
  60   {
  61     if (pid_file[0])
  62     {
  63       if (unlink(pid_file) == -1)
  64       {
  65         std::cerr << "Could not remove pidfile: " << pid_file << "(" << strerror(errno) << ")" << std::endl;
  66       }
  67
  68       pid_file[0]= 0;
  69     }
  70   }
  71
  72 }
  73
  74 namespace datadifferential {
  75 namespace util {
  76
  77 Pidfile::Pidfile(const std::string &arg) :
  78   _last_errno(0),
  79   _filename(arg)
  80 {
  81 }
  82
  83
  84 Pidfile::~Pidfile()
  85 {
  86   if (not _filename.empty())
  87   {
  88     if (access(_filename.c_str(), F_OK) == -1)
  89     {
  90       std::stringstream error_stream;
  91       error_stream << "Could not access the pid file: " << _filename << "(" << strerror(errno) << ")";
  92       _error_message= error_stream.str();
  93     }
  94     else if (unlink(_filename.c_str()) == -1)
  95     {
  96       std::stringstream error_stream;
  97       error_stream << "Could not remove the pid file: " << _filename << "(" << strerror(errno) << ")";
  98       _error_message= error_stream.str();
  99     }
 100   }
 101   pid_file[0]= 0;
 102 }
 103
 104 bool Pidfile::create()
 105 {
 106   if (_filename.empty())
 107   {
 108     return true;
 109   }
 110
 111   if (access(_filename.c_str(), F_OK) == 0)
 112   {
 113     if (unlink(_filename.c_str()) == -1)
 114     {
 115       std::stringstream error_stream;
 116       error_stream << "Unable to remove exisiting file:" << _filename << "(" << strerror(errno) << ")";
 117       _error_message= error_stream.str();
 118
 119       return false;
 120     }
 121   }
 122
 123   int oflags= O_CREAT|O_WRONLY|O_TRUNC;
 124 #ifdef HAVE_O_CLOEXEC
 125   oflags= oflags | O_CLOEXEC;
 126 #endif
 127
 128   int file;
 129   if ((file = open(_filename.c_str(), oflags, S_IRWXU|S_IRGRP|S_IROTH)) < 0)
 130   {
 131     std::stringstream error_stream;
 132     error_stream << "Could not open pid file for writing: " << _filename << "(" << strerror(errno) << ")";
 133     _error_message= error_stream.str();
 134
 135     return false;
 136   }
 137
 138   char buffer[BUFSIZ];
 139   unsigned long temp= static_cast<unsigned long>(getpid());
 140   int length= snprintf(buffer, sizeof(buffer), "%lu\n", temp);
 141   if (write(file, buffer, length) != length)
 142   {
 143     std::stringstream error_stream;
 144     error_stream << "Could not write pid to file: " << _filename << "(" << strerror(errno) << ")";
 145     _error_message= error_stream.str();
 146     close(file);
 147
 148     return false;
 149   }
 150
 151   if (close(file) < 0)
 152   {
 153     _error_message+= "Could not close() file after writing pid to it: ";
 154     _error_message+= _filename;
 155     return false;
 156   }
 157   snprintf(pid_file, sizeof(pid_file), "%s", _filename.c_str());
 158   atexit(remove_pidfile);
 159
 160   return true;
 161 }
 162
 163 } /* namespace util */
 164 } /* namespace datadifferential */