update_daemon2.php

   1 #!/usr/bin/php
   2 <?php
   3         set_include_path(get_include_path() . PATH_SEPARATOR . "include");
   4
   5         // This is an experimental multiprocess update daemon.
   6         // Some configurable variable may be found below.
   7
   8         declare(ticks = 1);
   9         chdir(dirname(__FILE__));
  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         require_once "db.php";
  33         require_once "db-prefs.php";
  34         require_once "functions.php";
  35         require_once "lib/magpierss/rss_fetch.inc";
  36
  37         $children = array();
  38         $ctimes = array();
  39
  40         $last_checkpoint = -1;
  41
  42         function reap_children() {
  43                 global $children;
  44                 global $ctimes;
  45
  46                 $tmp = array();
  47
  48                 foreach ($children as $pid) {
  49                         if (pcntl_waitpid($pid, $status, WNOHANG) != $pid) {
  50
  51                                 if (file_is_locked("update_daemon-$pid.lock")) {
  52                                         array_push($tmp, $pid);
  53                                 } else {
  54                                         _debug("[reap_children] child $pid seems active but lockfile is unlocked.");
  55                                 }
  56                         } else {
  57                                 _debug("[reap_children] 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, SIGKILL);
  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 shutdown() {
  89                 if (file_exists(LOCK_DIRECTORY . "/update_daemon.lock"))
  90                         unlink(LOCK_DIRECTORY . "/update_daemon.lock");
  91         }
  92
  93         function task_shutdown() {
  94                 $pid = posix_getpid();
  95
  96                 if (file_exists(LOCK_DIRECTORY . "/update_daemon-$pid.lock"))
  97                         unlink(LOCK_DIRECTORY . "/update_daemon-$pid.lock");
  98         }
  99
 100         function sigint_handler() {
 101                 shutdown();
 102                 die("[SIGINT] removing lockfile and exiting.\n");
 103         }
 104
 105         function task_sigint_handler() {
 106                 task_shutdown();
 107                 die("[SIGINT] removing lockfile and exiting.\n");
 108         }
 109
 110         pcntl_signal(SIGCHLD, 'sigchld_handler');
 111
 112         if (file_is_locked("update_daemon.lock")) {
 113                 die("error: Can't create lockfile. ".
 114                         "Maybe another daemon is already running.\n");
 115         }
 116
 117         if (!pcntl_fork()) {
 118                 pcntl_signal(SIGINT, 'sigint_handler');
 119                 register_shutdown_function('shutdown');
 120
 121                 // Try to lock a file in order to avoid concurrent update.
 122                 $lock_handle = make_lockfile("update_daemon.lock");
 123
 124                 if (!$lock_handle) {
 125                         die("error: Can't create lockfile. ".
 126                                 "Maybe another daemon is already running.\n");
 127                 }
 128
 129                 while (true) { sleep(100); }
 130         }
 131
 132         // Testing database connection.
 133         // It is unnecessary to start the fork loop if database is not ok.
 134         $link = db_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);
 135
 136         if (!init_connection($link)) return;
 137
 138         db_close($link);
 139
 140         while (true) {
 141
 142                 // Since sleep is interupted by SIGCHLD, we need another way to
 143                 // respect the SPAWN_INTERVAL
 144                 $next_spawn = $last_checkpoint + SPAWN_INTERVAL - time();
 145
 146                 if ($next_spawn % 10 == 0) {
 147                         $running_jobs = count($children);
 148                         _debug("[MASTER] active jobs: $running_jobs, next spawn at $next_spawn sec.");
 149                 }
 150
 151                 if ($last_checkpoint + SPAWN_INTERVAL < time()) {
 152
 153                         check_ctimes();
 154                         reap_children();
 155
 156                         for ($j = count($children); $j < MAX_JOBS; $j++) {
 157                                 $pid = pcntl_fork();
 158                                 if ($pid == -1) {
 159                                         die("fork failed!\n");
 160                                 } else if ($pid) {
 161                                         _debug("[MASTER] spawned client $j [PID:$pid]...");
 162                                         array_push($children, $pid);
 163                                         $ctimes[$pid] = time();
 164                                 } else {
 165                                         pcntl_signal(SIGCHLD, SIG_IGN);
 166                                         pcntl_signal(SIGINT, 'task_sigint_handler');
 167
 168                                         register_shutdown_function('task_shutdown');
 169
 170                                         $my_pid = posix_getpid();
 171                                         $lock_filename = "update_daemon-$my_pid.lock";
 172
 173                                         $lock_handle = make_lockfile($lock_filename);
 174
 175                                         if (!$lock_handle) {
 176                                                 die("error: Can't create lockfile ($lock_filename). ".
 177                                                 "Maybe another daemon is already running.\n");
 178                                         }
 179
 180                                         // ****** Updating RSS code *******
 181                                         // Only run in fork process.
 182
 183                                         $start_timestamp = time();
 184
 185                                         $link = db_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);
 186
 187                                         if (!init_connection($link)) return;
 188
 189                                         // We disable stamp file, since it is of no use in a multiprocess update.
 190                                         // not really, tho for the time being -fox
 191                                         if (!make_stampfile('update_daemon.stamp')) {
 192                                                 print "warning: unable to create stampfile";
 193                                         }
 194
 195                                         // Call to the feed batch update function
 196                                         // or regenerate feedbrowser cache
 197
 198                                         if (rand(0,100) > 30) {
 199                                                 update_daemon_common($link);
 200                                         } else {
 201                                                 $count = update_feedbrowser_cache($link);
 202                                                 _debug("Feedbrowser updated, $count feeds processed.");
 203
 204                                                 purge_orphans($link, true);
 205
 206                                                 $rc = cleanup_tags($link, 14, 50000);
 207
 208                                                 _debug("Cleaned $rc cached tags.");
 209
 210                                                 _debug("Updating linked feeds...");
 211                                                 get_linked_feeds($link);
 212
 213                                         }
 214
 215                                         _debug("Elapsed time: " . (time() - $start_timestamp) . " second(s)");
 216
 217                                         db_close($link);
 218
 219                                         // We are in a fork.
 220                                         // We wait a little before exiting to avoid to be faster than our parent process.
 221                                         sleep(1);
 222
 223                                         unlink(LOCK_DIRECTORY . "/$lock_filename");
 224
 225                                         // We exit in order to avoid fork bombing.
 226                                         exit(0);
 227                                 }
 228
 229                                 // We wait a little time before the next fork, in order to let the first fork
 230                                 // mark the feeds it update :
 231                                 sleep(1);
 232                         }
 233                         $last_checkpoint = time();
 234                 }
 235                 sleep(1);
 236         }
 237
 238 ?>