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