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                 global $ctimes;
  51
  52                 $tmp = array();
  53
  54                 foreach ($children as $pid) {
  55                         if (pcntl_waitpid($pid, $status, WNOHANG) != $pid) {
  56                                 array_push($tmp, $pid);
  57                         } else {
  58                                 _debug("[SIGCHLD] child $pid reaped.");
  59                                 unset($ctimes[$pid]);
  60                         }
  61                 }
  62
  63                 $children = $tmp;
  64
  65                 return count($tmp);
  66         }
  67
  68         function check_ctimes() {
  69                 global $ctimes;
  70
  71                 foreach (array_keys($ctimes) as $pid) {
  72                         $started = $ctimes[$pid];
  73
  74                         if (time() - $started > MAX_CHILD_RUNTIME) {
  75                                 _debug("[MASTER] child process $pid seems to be stuck, aborting...");
  76                                 posix_kill($pid, SIGKILL);
  77                         }
  78                 }
  79         }
  80
  81         function sigchld_handler($signal) {
  82                 $running_jobs = reap_children();
  83
  84                 _debug("[SIGCHLD] jobs left: $running_jobs");
  85
  86                 pcntl_waitpid(-1, $status, WNOHANG);
  87         }
  88
  89         function sigint_handler() {
  90                 unlink(LOCK_DIRECTORY . "/update_daemon.lock");
  91                 die("[SIGINT] removing lockfile and exiting.\n");
  92         }
  93
  94         pcntl_signal(SIGCHLD, 'sigchld_handler');
  95
  96         if (file_is_locked("update_daemon.lock")) {
  97                 die("error: Can't create lockfile. ".
  98                         "Maybe another daemon is already running.\n");
  99         }
 100
 101         if (!pcntl_fork()) {
 102                 pcntl_signal(SIGINT, 'sigint_handler');
 103
 104                 // Try to lock a file in order to avoid concurrent update.
 105                 $lock_handle = make_lockfile("update_daemon.lock");
 106
 107                 if (!$lock_handle) {
 108                         die("error: Can't create lockfile. ".
 109                                 "Maybe another daemon is already running.\n");
 110                 }
 111
 112                 while (true) { sleep(100); }
 113         }
 114
 115         // Testing database connection.
 116         // It is unnecessary to start the fork loop if database is not ok.
 117         $link = db_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);
 118
 119         if (!$link) {
 120                 if (DB_TYPE == "mysql") {
 121                         print mysql_error();
 122                 }
 123                 // PG seems to display its own errors just fine by default.
 124                 return;
 125         }
 126
 127         db_close($link);
 128
 129         while (true) {
 130
 131                 // Since sleep is interupted by SIGCHLD, we need another way to
 132                 // respect the SPAWN_INTERVAL
 133                 $next_spawn = $last_checkpoint + SPAWN_INTERVAL - time();
 134
 135                 if ($next_spawn % 10 == 0) {
 136                         $running_jobs = count($children);
 137                         _debug("[MASTER] active jobs: $running_jobs, next spawn at $next_spawn sec.");
 138                 }
 139
 140                 if ($last_checkpoint + SPAWN_INTERVAL < time()) {
 141
 142                         check_ctimes();
 143                         reap_children();
 144
 145                         for ($j = count($children); $j < MAX_JOBS; $j++) {
 146                                 $pid = pcntl_fork();
 147                                 if ($pid == -1) {
 148                                         die("fork failed!\n");
 149                                 } else if ($pid) {
 150                                         _debug("[MASTER] spawned client $j [PID:$pid]...");
 151                                         array_push($children, $pid);
 152                                         $ctimes[$pid] = time();
 153                                 } else {
 154                                         pcntl_signal(SIGCHLD, SIG_IGN);
 155                                         pcntl_signal(SIGINT, SIG_DFL);
 156
 157                                         // ****** Updating RSS code *******
 158                                         // Only run in fork process.
 159
 160                                         $start_timestamp = time();
 161
 162                                         $link = db_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);
 163
 164                                         if (!$link) {
 165                                                 if (DB_TYPE == "mysql") {
 166                                                         print mysql_error();
 167                                                 }
 168                                                 // PG seems to display its own errors just fine by default.
 169                                                 return;
 170                                         }
 171
 172                                         init_connection($link);
 173
 174                                         // We disable stamp file, since it is of no use in a multiprocess update.
 175                                         // not really, tho for the time being -fox
 176                                         if (!make_stampfile('update_daemon.stamp')) {
 177                                                 print "warning: unable to create stampfile";
 178                                         }
 179
 180                                         // FIXME : $last_purge is of no use in a multiprocess update.
 181                                         // FIXME : We ALWAYS purge old posts.
 182                                         //_debug("Purging old posts (random 30 feeds)...");
 183                                         //global_purge_old_posts($link, true, 30);
 184
 185                                         // Call to the feed batch update function
 186                                         // or regenerate feedbrowser cache
 187
 188                                         if (rand(0,100) > 50) {
 189                                                 update_daemon_common($link);
 190                                         } else {
 191                                                 $count = update_feedbrowser_cache($link);
 192                                                 _debug("Finished, $count feeds processed.");
 193                                         }
 194
 195                                         _debug("Elapsed time: " . (time() - $start_timestamp) . " second(s)");
 196
 197                                         db_close($link);
 198
 199                                         // We are in a fork.
 200                                         // We wait a little before exiting to avoid to be faster than our parent process.
 201                                         sleep(1);
 202                                         // We exit in order to avoid fork bombing.
 203                                         exit(0);
 204                                 }
 205
 206                                 // We wait a little time before the next fork, in order to let the first fork
 207                                 // mark the feeds it update :
 208                                 sleep(1);
 209                         }
 210                         $last_checkpoint = time();
 211                 }
 212                 sleep(1);
 213         }
 214
 215 ?>