update_daemon2.php

   1 #!/usr/bin/env php
   2 <?php
   3         set_include_path(dirname(__FILE__) ."/include" . PATH_SEPARATOR .
   4                 get_include_path());
   5
   6         declare(ticks = 1);
   7         chdir(dirname(__FILE__));
   8
   9         define('DISABLE_SESSIONS', true);
  10
  11         require_once "version.php";
  12         require_once "config.php";
  13         require_once "autoload.php";
  14         require_once "functions.php";
  15         require_once "rssfuncs.php";
  16
  17         // defaults
  18         define_default('PURGE_INTERVAL', 3600); // seconds
  19         define_default('MAX_CHILD_RUNTIME', 1800); // seconds
  20         define_default('MAX_JOBS', 2);
  21         define_default('SPAWN_INTERVAL', DAEMON_SLEEP_INTERVAL); // seconds
  22
  23         require_once "sanity_check.php";
  24         require_once "db.php";
  25         require_once "db-prefs.php";
  26
  27
  28         if (!function_exists('pcntl_fork')) {
  29                 die("error: This script requires PHP compiled with PCNTL module.\n");
  30         }
  31
  32         $children = array();
  33         $ctimes = array();
  34
  35         $last_checkpoint = -1;
  36
  37         function reap_children() {
  38                 global $children;
  39                 global $ctimes;
  40
  41                 $tmp = array();
  42
  43                 foreach ($children as $pid) {
  44                         if (pcntl_waitpid($pid, $status, WNOHANG) != $pid) {
  45
  46                                 if (file_is_locked("update_daemon-$pid.lock")) {
  47                                         array_push($tmp, $pid);
  48                                 } else {
  49                                         _debug("[reap_children] child $pid seems active but lockfile is unlocked.");
  50                                         unset($ctimes[$pid]);
  51
  52                                 }
  53                         } else {
  54                                 _debug("[reap_children] child $pid reaped.");
  55                                 unset($ctimes[$pid]);
  56                         }
  57                 }
  58
  59                 $children = $tmp;
  60
  61                 return count($tmp);
  62         }
  63
  64         function check_ctimes() {
  65                 global $ctimes;
  66
  67                 foreach (array_keys($ctimes) as $pid) {
  68                         $started = $ctimes[$pid];
  69
  70                         if (time() - $started > MAX_CHILD_RUNTIME) {
  71                                 _debug("[MASTER] child process $pid seems to be stuck, aborting...");
  72                                 posix_kill($pid, SIGKILL);
  73                         }
  74                 }
  75         }
  76
  77         function sigchld_handler($signal) {
  78                 $running_jobs = reap_children();
  79
  80                 _debug("[SIGCHLD] jobs left: $running_jobs");
  81
  82                 pcntl_waitpid(-1, $status, WNOHANG);
  83         }
  84
  85         pcntl_signal(SIGCHLD, 'sigchld_handler');
  86
  87         $longopts = array("log:",
  88                         "tasks:",
  89                         "interval:",
  90                         "quiet",
  91                         "help");
  92
  93         $options = getopt("", $longopts);
  94
  95         if (isset($options["help"]) ) {
  96                 print "Tiny Tiny RSS update daemon.\n\n";
  97                 print "Options:\n";
  98                 print "  --log FILE           - log messages to FILE\n";
  99                 print "  --tasks N            - amount of update tasks to spawn\n";
 100                 print "                         default: " . MAX_JOBS . "\n";
 101                 print "  --interval N         - task spawn interval\n";
 102                 print "                         default: " . SPAWN_INTERVAL . " seconds.\n";
 103                 print "  --quiet              - don't output messages to stdout\n";
 104                 return;
 105         }
 106
 107         define('QUIET', isset($options['quiet']));
 108
 109         if (isset($options["tasks"])) {
 110                 _debug("Set to spawn " . $options["tasks"] . " children.");
 111                 $max_jobs = $options["tasks"];
 112         } else {
 113                 $max_jobs = MAX_JOBS;
 114         }
 115
 116         if (isset($options["interval"])) {
 117                 _debug("Spawn interval: " . $options["interval"] . " seconds.");
 118                 $spawn_interval = $options["interval"];
 119         } else {
 120                 $spawn_interval = SPAWN_INTERVAL;
 121         }
 122
 123         if (isset($options["log"])) {
 124                 _debug("Logging to " . $options["log"]);
 125                 define('LOGFILE', $options["log"]);
 126         }
 127
 128         if (file_is_locked("update_daemon.lock")) {
 129                 die("error: Can't create lockfile. ".
 130                         "Maybe another daemon is already running.\n");
 131         }
 132
 133         // Try to lock a file in order to avoid concurrent update.
 134         $lock_handle = make_lockfile("update_daemon.lock");
 135
 136         if (!$lock_handle) {
 137                 die("error: Can't create lockfile. ".
 138                         "Maybe another daemon is already running.\n");
 139         }
 140
 141         $schema_version = get_schema_version();
 142
 143         if ($schema_version != SCHEMA_VERSION) {
 144                 die("Schema version is wrong, please upgrade the database.\n");
 145         }
 146
 147         // Protip: children close shared database handle when terminating, it's a bad idea to
 148         // do database stuff on main process from now on.
 149
 150         while (true) {
 151
 152                 // Since sleep is interupted by SIGCHLD, we need another way to
 153                 // respect the spawn interval
 154                 $next_spawn = $last_checkpoint + $spawn_interval - time();
 155
 156                 if ($next_spawn % 60 == 0) {
 157                         $running_jobs = count($children);
 158                         _debug("[MASTER] active jobs: $running_jobs, next spawn at $next_spawn sec.");
 159                 }
 160
 161                 if ($last_checkpoint + $spawn_interval < time()) {
 162                         check_ctimes();
 163                         reap_children();
 164
 165                         for ($j = count($children); $j < $max_jobs; $j++) {
 166                                 $pid = pcntl_fork();
 167                                 if ($pid == -1) {
 168                                         die("fork failed!\n");
 169                                 } else if ($pid) {
 170                                         _debug("[MASTER] spawned client $j [PID:$pid]...");
 171                                         array_push($children, $pid);
 172                                         $ctimes[$pid] = time();
 173                                 } else {
 174                                         pcntl_signal(SIGCHLD, SIG_IGN);
 175
 176                                         $quiet = (isset($options["quiet"])) ? "--quiet" : "";
 177
 178                                         $my_pid = posix_getpid();
 179
 180                                         passthru(PHP_EXECUTABLE . " update.php --daemon-loop $quiet --task $j --pidlock $my_pid");
 181
 182                                         sleep(1);
 183
 184                                         // We exit in order to avoid fork bombing.
 185                                         exit(0);
 186                                 }
 187                         }
 188                         $last_checkpoint = time();
 189                 }
 190                 sleep(1);
 191         }
 192
 193 ?>