update_daemon2.php

   1 #!/usr/bin/php
   2 <?php
   3         // This is an experimental multiprocess update daemon.
   4         // Some configurable variable may be found below.
   5
   6         // define('DEFAULT_ERROR_LEVEL', E_ALL);
   7         define('DEFAULT_ERROR_LEVEL', E_ERROR | E_WARNING | E_PARSE);
   8
   9         declare(ticks = 1);
  10
  11         define('DISABLE_SESSIONS', true);
  12
  13         require_once "version.php";
  14
  15         if (strpos(VERSION, ".99") !== false || getenv('DAEMON_XDEBUG')) {
  16                 define('DAEMON_EXTENDED_DEBUG', true);
  17         }
  18
  19         define('PURGE_INTERVAL', 3600); // seconds
  20         define('MAX_CHILD_RUNTIME', 600); // seconds
  21
  22         require_once "sanity_check.php";
  23         require_once "config.php";
  24
  25         define('MAX_JOBS', 2);
  26         define('SPAWN_INTERVAL', DAEMON_SLEEP_INTERVAL);
  27
  28         if (!function_exists('pcntl_fork')) {
  29                 die("error: This script requires PHP compiled with PCNTL module.\n");
  30         }
  31
  32         if (!ENABLE_UPDATE_DAEMON) {
  33                 die("error: Please enable option ENABLE_UPDATE_DAEMON in config.php\n");
  34         }
  35
  36         require_once "db.php";
  37         require_once "db-prefs.php";
  38         require_once "functions.php";
  39         require_once "lib/magpierss/rss_fetch.inc";
  40
  41         error_reporting(DEFAULT_ERROR_LEVEL);
  42
  43         $children = array();
  44         $ctimes = array();
  45
  46         $last_checkpoint = -1;
  47
  48         function reap_children() {
  49                 global $children;
  50
  51                 $tmp = array();
  52
  53                 foreach ($children as $pid) {
  54                         if (pcntl_waitpid($pid, $status, WNOHANG) != $pid) {
  55                                 array_push($tmp, $pid);
  56                         } else {
  57                                 _debug("[SIGCHLD] child $pid reaped.");
  58                                 unset($ctimes[$pid]);
  59                         }
  60                 }
  61
  62                 $children = $tmp;
  63
  64                 return count($tmp);
  65         }
  66
  67         function check_ctimes() {
  68                 global $ctimes;
  69
  70                 foreach (array_keys($ctimes) as $pid) {
  71                         $started = $ctimes[$pid];
  72
  73                         if (time() - $started > MAX_CHILD_RUNTIME) {
  74                                 _debug("[MASTER] child process $pid seems to be stuck, aborting...");
  75                                 posix_kill($pid, SIGINT);
  76                         }
  77                 }
  78         }
  79
  80         function sigchld_handler($signal) {
  81                 $running_jobs = reap_children();
  82
  83                 _debug("[SIGCHLD] jobs left: $running_jobs");
  84
  85                 pcntl_waitpid(-1, $status, WNOHANG);
  86         }
  87
  88         function sigint_handler() {
  89                 unlink(LOCK_DIRECTORY . "/update_daemon.lock");
  90                 die("[SIGINT] removing lockfile and exiting.\n");
  91         }
  92
  93         pcntl_signal(SIGCHLD, 'sigchld_handler');
  94
  95         if (file_is_locked("update_daemon.lock")) {
  96                 die("error: Can't create lockfile. ".
  97                         "Maybe another daemon is already running.\n");
  98         }
  99
 100         if (!pcntl_fork()) {
 101                 pcntl_signal(SIGINT, 'sigint_handler');
 102
 103                 // Try to lock a file in order to avoid concurrent update.
 104                 $lock_handle = make_lockfile("update_daemon.lock");
 105
 106                 if (!$lock_handle) {
 107                         die("error: Can't create lockfile. ".
 108                                 "Maybe another daemon is already running.\n");
 109                 }
 110
 111                 while (true) { sleep(100); }
 112         }
 113
 114         // Testing database connection.
 115         // It is unnecessary to start the fork loop if database is not ok.
 116         $link = db_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);
 117
 118         if (!$link) {
 119                 if (DB_TYPE == "mysql") {
 120                         print mysql_error();
 121                 }
 122                 // PG seems to display its own errors just fine by default.
 123                 return;
 124         }
 125
 126         db_close($link);
 127
 128         while (true) {
 129
 130                 // Since sleep is interupted by SIGCHLD, we need another way to
 131                 // respect the SPAWN_INTERVAL
 132                 $next_spawn = $last_checkpoint + SPAWN_INTERVAL - time();
 133
 134                 if ($next_spawn % 10 == 0) {
 135                         $running_jobs = count($children);
 136                         _debug("[MASTER] active jobs: $running_jobs, next spawn at $next_spawn sec.");
 137                 }
 138
 139                 if ($last_checkpoint + SPAWN_INTERVAL < time()) {
 140
 141                         check_ctimes();
 142                         reap_children();
 143
 144                         for ($j = count($children); $j < MAX_JOBS; $j++) {
 145                                 $pid = pcntl_fork();
 146                                 if ($pid == -1) {
 147                                         die("fork failed!\n");
 148                                 } else if ($pid) {
 149                                         _debug("[MASTER] spawned client $j [PID:$pid]...");
 150                                         array_push($children, $pid);
 151                                         $ctimes[$pid] = time();
 152                                 } else {
 153                                         pcntl_signal(SIGCHLD, SIG_IGN);
 154                                         pcntl_signal(SIGINT, SIG_DFL);
 155
 156                                         // ****** Updating RSS code *******
 157                                         // Only run in fork process.
 158
 159                                         $start_timestamp = time();
 160
 161                                         $link = db_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);
 162
 163                                         if (!$link) {
 164                                                 if (DB_TYPE == "mysql") {
 165                                                         print mysql_error();
 166                                                 }
 167                                                 // PG seems to display its own errors just fine by default.
 168                                                 return;
 169                                         }
 170
 171                                         init_connection($link);
 172
 173                                         // We disable stamp file, since it is of no use in a multiprocess update.
 174                                         // not really, tho for the time being -fox
 175                                         if (!make_stampfile('update_daemon.stamp')) {
 176                                                 print "warning: unable to create stampfile";
 177                                         }
 178
 179                                         // FIXME : $last_purge is of no use in a multiprocess update.
 180                                         // FIXME : We ALWAYS purge old posts.
 181                                         //_debug("Purging old posts (random 30 feeds)...");
 182                                         //global_purge_old_posts($link, true, 30);
 183
 184                                         // Call to the feed batch update function
 185                                         // or regenerate feedbrowser cache
 186
 187                                         if (rand(0,100) > 50) {
 188                                                 update_daemon_common($link);
 189                                         } else {
 190                                                 $count = update_feedbrowser_cache($link);
 191                                                 _debug("Finished, $count feeds processed.");
 192                                         }
 193
 194                                         _debug("Elapsed time: " . (time() - $start_timestamp) . " second(s)");
 195
 196                                         db_close($link);
 197
 198                                         // We are in a fork.
 199                                         // We wait a little before exiting to avoid to be faster than our parent process.
 200                                         sleep(1);
 201                                         // We exit in order to avoid fork bombing.
 202                                         exit(0);
 203                                 }
 204
 205                                 // We wait a little time before the next fork, in order to let the first fork
 206                                 // mark the feeds it update :
 207                                 sleep(1);
 208                         }
 209                         $last_checkpoint = time();
 210                 }
 211                 sleep(1);
 212         }
 213
 214 ?>