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         declare(ticks = 1);
   7         chdir(dirname(__FILE__));
   8
   9         define('DISABLE_SESSIONS', true);
  10
  11         require_once "version.php";
  12
  13         if (strpos(VERSION, ".99") !== false || getenv('DAEMON_XDEBUG')) {
  14                 define('DAEMON_EXTENDED_DEBUG', true);
  15         }
  16
  17         define('PURGE_INTERVAL', 3600); // seconds
  18         define('MAX_CHILD_RUNTIME', 600); // seconds
  19
  20         require_once "sanity_check.php";
  21         require_once "config.php";
  22
  23         define('MAX_JOBS', 2);
  24         define('SPAWN_INTERVAL', DAEMON_SLEEP_INTERVAL);
  25
  26         if (!function_exists('pcntl_fork')) {
  27                 die("error: This script requires PHP compiled with PCNTL module.\n");
  28         }
  29
  30         require_once "db.php";
  31         require_once "db-prefs.php";
  32         require_once "functions.php";
  33         require_once "lib/magpierss/rss_fetch.inc";
  34
  35         $children = array();
  36         $ctimes = array();
  37
  38         $last_checkpoint = -1;
  39
  40         function reap_children() {
  41                 global $children;
  42                 global $ctimes;
  43
  44                 $tmp = array();
  45
  46                 foreach ($children as $pid) {
  47                         if (pcntl_waitpid($pid, $status, WNOHANG) != $pid) {
  48
  49                                 if (file_is_locked("update_daemon-$pid.lock")) {
  50                                         array_push($tmp, $pid);
  51                                 } else {
  52                                         _debug("[reap_children] child $pid seems active but lockfile is unlocked.");
  53                                 }
  54                         } else {
  55                                 _debug("[reap_children] child $pid reaped.");
  56                                 unset($ctimes[$pid]);
  57                         }
  58                 }
  59
  60                 $children = $tmp;
  61
  62                 return count($tmp);
  63         }
  64
  65         function check_ctimes() {
  66                 global $ctimes;
  67
  68                 foreach (array_keys($ctimes) as $pid) {
  69                         $started = $ctimes[$pid];
  70
  71                         if (time() - $started > MAX_CHILD_RUNTIME) {
  72                                 _debug("[MASTER] child process $pid seems to be stuck, aborting...");
  73                                 posix_kill($pid, SIGKILL);
  74                         }
  75                 }
  76         }
  77
  78         function sigchld_handler($signal) {
  79                 $running_jobs = reap_children();
  80
  81                 _debug("[SIGCHLD] jobs left: $running_jobs");
  82
  83                 pcntl_waitpid(-1, $status, WNOHANG);
  84         }
  85
  86         function shutdown() {
  87                 if (file_exists(LOCK_DIRECTORY . "/update_daemon.lock"))
  88                         unlink(LOCK_DIRECTORY . "/update_daemon.lock");
  89         }
  90
  91         function task_shutdown() {
  92                 $pid = posix_getpid();
  93
  94                 if (file_exists(LOCK_DIRECTORY . "/update_daemon-$pid.lock"))
  95                         unlink(LOCK_DIRECTORY . "/update_daemon-$pid.lock");
  96         }
  97
  98         function sigint_handler() {
  99                 shutdown();
 100                 die("[SIGINT] removing lockfile and exiting.\n");
 101         }
 102
 103         function task_sigint_handler() {
 104                 task_shutdown();
 105                 die("[SIGINT] removing lockfile and exiting.\n");
 106         }
 107
 108         pcntl_signal(SIGCHLD, 'sigchld_handler');
 109
 110         if (file_is_locked("update_daemon.lock")) {
 111                 die("error: Can't create lockfile. ".
 112                         "Maybe another daemon is already running.\n");
 113         }
 114
 115         if (!pcntl_fork()) {
 116                 pcntl_signal(SIGINT, 'sigint_handler');
 117                 register_shutdown_function('shutdown');
 118
 119                 // Try to lock a file in order to avoid concurrent update.
 120                 $lock_handle = make_lockfile("update_daemon.lock");
 121
 122                 if (!$lock_handle) {
 123                         die("error: Can't create lockfile. ".
 124                                 "Maybe another daemon is already running.\n");
 125                 }
 126
 127                 while (true) { sleep(100); }
 128         }
 129
 130         // Testing database connection.
 131         // It is unnecessary to start the fork loop if database is not ok.
 132         $link = db_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);
 133
 134         if (!$link) {
 135                 if (DB_TYPE == "mysql") {
 136                         print mysql_error();
 137                 }
 138                 // PG seems to display its own errors just fine by default.
 139                 return;
 140         }
 141
 142         db_close($link);
 143
 144         while (true) {
 145
 146                 // Since sleep is interupted by SIGCHLD, we need another way to
 147                 // respect the SPAWN_INTERVAL
 148                 $next_spawn = $last_checkpoint + SPAWN_INTERVAL - time();
 149
 150                 if ($next_spawn % 10 == 0) {
 151                         $running_jobs = count($children);
 152                         _debug("[MASTER] active jobs: $running_jobs, next spawn at $next_spawn sec.");
 153                 }
 154
 155                 if ($last_checkpoint + SPAWN_INTERVAL < time()) {
 156
 157                         check_ctimes();
 158                         reap_children();
 159
 160                         for ($j = count($children); $j < MAX_JOBS; $j++) {
 161                                 $pid = pcntl_fork();
 162                                 if ($pid == -1) {
 163                                         die("fork failed!\n");
 164                                 } else if ($pid) {
 165                                         _debug("[MASTER] spawned client $j [PID:$pid]...");
 166                                         array_push($children, $pid);
 167                                         $ctimes[$pid] = time();
 168                                 } else {
 169                                         pcntl_signal(SIGCHLD, SIG_IGN);
 170                                         pcntl_signal(SIGINT, 'task_sigint_handler');
 171
 172                                         register_shutdown_function('task_shutdown');
 173
 174                                         $my_pid = posix_getpid();
 175                                         $lock_filename = "update_daemon-$my_pid.lock";
 176
 177                                         $lock_handle = make_lockfile($lock_filename);
 178
 179                                         if (!$lock_handle) {
 180                                                 die("error: Can't create lockfile ($lock_filename). ".
 181                                                 "Maybe another daemon is already running.\n");
 182                                         }
 183
 184                                         // ****** Updating RSS code *******
 185                                         // Only run in fork process.
 186
 187                                         $start_timestamp = time();
 188
 189                                         $link = db_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);
 190
 191                                         if (!$link) {
 192                                                 if (DB_TYPE == "mysql") {
 193                                                         print mysql_error();
 194                                                 }
 195                                                 // PG seems to display its own errors just fine by default.
 196                                                 return;
 197                                         }
 198
 199                                         init_connection($link);
 200
 201                                         // We disable stamp file, since it is of no use in a multiprocess update.
 202                                         // not really, tho for the time being -fox
 203                                         if (!make_stampfile('update_daemon.stamp')) {
 204                                                 print "warning: unable to create stampfile";
 205                                         }
 206
 207                                         // Call to the feed batch update function
 208                                         // or regenerate feedbrowser cache
 209
 210                                         if (rand(0,100) > 30) {
 211                                                 update_daemon_common($link);
 212                                         } else {
 213                                                 $count = update_feedbrowser_cache($link);
 214                                                 _debug("Feedbrowser updated, $count feeds processed.");
 215
 216                                                 purge_orphans($link, true);
 217
 218                                                 $rc = cleanup_tags($link, 14, 50000);
 219
 220                                                 _debug("Cleaned $rc cached tags.");
 221
 222                                         }
 223
 224                                         _debug("Elapsed time: " . (time() - $start_timestamp) . " second(s)");
 225
 226                                         db_close($link);
 227
 228                                         // We are in a fork.
 229                                         // We wait a little before exiting to avoid to be faster than our parent process.
 230                                         sleep(1);
 231
 232                                         unlink(LOCK_DIRECTORY . "/$lock_filename");
 233
 234                                         // We exit in order to avoid fork bombing.
 235                                         exit(0);
 236                                 }
 237
 238                                 // We wait a little time before the next fork, in order to let the first fork
 239                                 // mark the feeds it update :
 240                                 sleep(1);
 241                         }
 242                         $last_checkpoint = time();
 243                 }
 244                 sleep(1);
 245         }
 246
 247 ?>