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