update_daemon2.php

   1 #!/usr/bin/php
   2 <?php
   3         // This is an experimental multiprocess update daemon
   4         // It consists of the master server (this file) and
   5         // client batch script (update_daemon2_client.php) which
   6         // should only be run by the server process
   7
   8         declare(ticks = 1);
   9
  10         require "config.php";
  11
  12         define('MAX_JOBS', 2);
  13         define('CLIENT_PROCESS', './update_daemon2_client.php SRV_RUN_OK');
  14         define('SPAWN_INTERVAL', DAEMON_SLEEP_INTERVAL);
  15
  16         $running_jobs = 0;
  17         $last_checkpoint = -1;
  18
  19         function sigchld_handler($signal) {
  20                 global $running_jobs;
  21                 if ($running_jobs > 0) $running_jobs--;
  22                 print posix_getpid() . ": SIGCHLD received, jobs left: $running_jobs\n";
  23                 pcntl_waitpid(-1, $status, WNOHANG);
  24         }
  25
  26         pcntl_signal(SIGCHLD, 'sigchld_handler');
  27
  28         while (true) {
  29
  30                 $next_spawn = $last_checkpoint + SPAWN_INTERVAL - time();
  31
  32                 print "[MASTER] active jobs: $running_jobs, next spawn at $next_spawn sec\n";
  33
  34                 if ($last_checkpoint + SPAWN_INTERVAL < time()) {
  35
  36                         for ($j = $running_jobs; $j < MAX_JOBS; $j++) {
  37                                 print "[MASTER] spawning client $j...";
  38                                 $pid = pcntl_fork();
  39                                 if ($pid == -1) {
  40                                         die("fork failed!\n");
  41                                 } else if ($pid) {
  42                                         $running_jobs++;
  43                                         print "OK [$running_jobs]\n";
  44                                 } else {
  45                                         pcntl_signal(SIGCHLD, SIG_IGN);
  46                                         passthru(CLIENT_PROCESS);
  47                                         exit(0);
  48                                 }
  49                         }
  50                         $last_checkpoint = time();
  51                 }
  52                 sleep(1);
  53         }
  54
  55 ?>