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) != $pid) {
  56
  57                                 if (file_is_locked("update_daemon-$pid.lock")) {
  58                                         array_push($tmp, $pid);
  59                                 } else {
  60                                         _debug("[reap_children] child $pid seems active but lockfile is unlocked.");
  61                                 }
  62                         } else {
  63                                 _debug("[reap_children] child $pid reaped.");
  64                                 unset($ctimes[$pid]);
  65                         }
  66                 }
  67
  68                 $children = $tmp;
  69
  70                 return count($tmp);
  71         }
  72
  73         function check_ctimes() {
  74                 global $ctimes;
  75
  76                 foreach (array_keys($ctimes) as $pid) {
  77                         $started = $ctimes[$pid];
  78
  79                         if (time() - $started > MAX_CHILD_RUNTIME) {
  80                                 _debug("[MASTER] child process $pid seems to be stuck, aborting...");
  81                                 posix_kill($pid, SIGKILL);
  82                         }
  83                 }
  84         }
  85
  86         function sigchld_handler($signal) {
  87                 $running_jobs = reap_children();
  88
  89                 _debug("[SIGCHLD] jobs left: $running_jobs");
  90
  91                 pcntl_waitpid(-1, $status, WNOHANG);
  92         }
  93
  94         function shutdown() {
  95                 if (file_exists(LOCK_DIRECTORY . "/update_daemon.lock"))
  96                         unlink(LOCK_DIRECTORY . "/update_daemon.lock");
  97         }
  98
  99         function task_shutdown() {
 100                 $pid = posix_getpid();
 101
 102                 if (file_exists(LOCK_DIRECTORY . "/update_daemon-$pid.lock"))
 103                         unlink(LOCK_DIRECTORY . "/update_daemon-$pid.lock");
 104         }
 105
 106         function sigint_handler() {
 107                 shutdown();
 108                 die("[SIGINT] removing lockfile and exiting.\n");
 109         }
 110
 111         function task_sigint_handler() {
 112                 task_shutdown();
 113                 die("[SIGINT] removing lockfile and exiting.\n");
 114         }
 115
 116         pcntl_signal(SIGCHLD, 'sigchld_handler');
 117
 118         if (file_is_locked("update_daemon.lock")) {
 119                 die("error: Can't create lockfile. ".
 120                         "Maybe another daemon is already running.\n");
 121         }
 122
 123         if (!pcntl_fork()) {
 124                 pcntl_signal(SIGINT, 'sigint_handler');
 125                 register_shutdown_function('shutdown');
 126
 127                 // Try to lock a file in order to avoid concurrent update.
 128                 $lock_handle = make_lockfile("update_daemon.lock");
 129
 130                 if (!$lock_handle) {
 131                         die("error: Can't create lockfile. ".
 132                                 "Maybe another daemon is already running.\n");
 133                 }
 134
 135                 while (true) { sleep(100); }
 136         }
 137
 138         // Testing database connection.
 139         // It is unnecessary to start the fork loop if database is not ok.
 140         $link = db_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);
 141
 142         if (!$link) {
 143                 if (DB_TYPE == "mysql") {
 144                         print mysql_error();
 145                 }
 146                 // PG seems to display its own errors just fine by default.
 147                 return;
 148         }
 149
 150         db_close($link);
 151
 152         while (true) {
 153
 154                 // Since sleep is interupted by SIGCHLD, we need another way to
 155                 // respect the SPAWN_INTERVAL
 156                 $next_spawn = $last_checkpoint + SPAWN_INTERVAL - time();
 157
 158                 if ($next_spawn % 10 == 0) {
 159                         $running_jobs = count($children);
 160                         _debug("[MASTER] active jobs: $running_jobs, next spawn at $next_spawn sec.");
 161                 }
 162
 163                 if ($last_checkpoint + SPAWN_INTERVAL < time()) {
 164
 165                         check_ctimes();
 166                         reap_children();
 167
 168                         for ($j = count($children); $j < MAX_JOBS; $j++) {
 169                                 $pid = pcntl_fork();
 170                                 if ($pid == -1) {
 171                                         die("fork failed!\n");
 172                                 } else if ($pid) {
 173                                         _debug("[MASTER] spawned client $j [PID:$pid]...");
 174                                         array_push($children, $pid);
 175                                         $ctimes[$pid] = time();
 176                                 } else {
 177                                         pcntl_signal(SIGCHLD, SIG_IGN);
 178                                         pcntl_signal(SIGINT, 'task_sigint_handler');
 179
 180                                         register_shutdown_function('task_shutdown');
 181
 182                                         $my_pid = posix_getpid();
 183                                         $lock_filename = "update_daemon-$my_pid.lock";
 184
 185                                         $lock_handle = make_lockfile($lock_filename);
 186
 187                                         if (!$lock_handle) {
 188                                                 die("error: Can't create lockfile ($lock_filename). ".
 189                                                 "Maybe another daemon is already running.\n");
 190                                         }
 191
 192                                         // ****** Updating RSS code *******
 193                                         // Only run in fork process.
 194
 195                                         $start_timestamp = time();
 196
 197                                         $link = db_connect(DB_HOST, DB_USER, DB_PASS, DB_NAME);
 198
 199                                         if (!$link) {
 200                                                 if (DB_TYPE == "mysql") {
 201                                                         print mysql_error();
 202                                                 }
 203                                                 // PG seems to display its own errors just fine by default.
 204                                                 return;
 205                                         }
 206
 207                                         init_connection($link);
 208
 209                                         // We disable stamp file, since it is of no use in a multiprocess update.
 210                                         // not really, tho for the time being -fox
 211                                         if (!make_stampfile('update_daemon.stamp')) {
 212                                                 print "warning: unable to create stampfile";
 213                                         }
 214
 215                                         // Call to the feed batch update function
 216                                         // or regenerate feedbrowser cache
 217
 218                                         if (rand(0,100) > 30) {
 219                                                 update_daemon_common($link);
 220                                         } else {
 221                                                 $count = update_feedbrowser_cache($link);
 222                                                 _debug("Finished, $count feeds processed.");
 223                                         }
 224
 225                                         _debug("Elapsed time: " . (time() - $start_timestamp) . " second(s)");
 226
 227                                         db_close($link);
 228
 229                                         // We are in a fork.
 230                                         // We wait a little before exiting to avoid to be faster than our parent process.
 231                                         sleep(1);
 232
 233                                         unlink(LOCK_DIRECTORY . "/$lock_filename");
 234
 235                                         // We exit in order to avoid fork bombing.
 236                                         exit(0);
 237                                 }
 238
 239                                 // We wait a little time before the next fork, in order to let the first fork
 240                                 // mark the feeds it update :
 241                                 sleep(1);
 242                         }
 243                         $last_checkpoint = time();
 244                 }
 245                 sleep(1);
 246         }
 247
 248 ?>