update_daemon2.php

   1 #!/usr/bin/env php
   2 <?php
   3         set_include_path(dirname(__FILE__) ."/include" . PATH_SEPARATOR .
   4                 get_include_path());
   5
   6         declare(ticks = 1);
   7         chdir(dirname(__FILE__));
   8
   9         define('DISABLE_SESSIONS', true);
  10
  11         require_once "version.php";
  12         require_once "config.php";
  13         require_once "autoload.php";
  14         require_once "functions.php";
  15         require_once "rssfuncs.php";
  16
  17         // defaults
  18         define_default('PURGE_INTERVAL', 3600); // seconds
  19         define_default('MAX_CHILD_RUNTIME', 1800); // seconds
  20         define_default('MAX_JOBS', 2);
  21         define_default('SPAWN_INTERVAL', DAEMON_SLEEP_INTERVAL); // seconds
  22
  23         require_once "sanity_check.php";
  24         require_once "db.php";
  25         require_once "db-prefs.php";
  26
  27
  28         if (!function_exists('pcntl_fork')) {
  29                 die("error: This script requires PHP compiled with PCNTL module.\n");
  30         }
  31
  32         $master_handlers_installed = false;
  33
  34         $children = array();
  35         $ctimes = array();
  36
  37         $last_checkpoint = -1;
  38
  39         function reap_children() {
  40                 global $children;
  41                 global $ctimes;
  42
  43                 $tmp = array();
  44
  45                 foreach ($children as $pid) {
  46                         if (pcntl_waitpid($pid, $status, WNOHANG) != $pid) {
  47
  48                                 if (file_is_locked("update_daemon-$pid.lock")) {
  49                                         array_push($tmp, $pid);
  50                                 } else {
  51                                         _debug("[reap_children] child $pid seems active but lockfile is unlocked.");
  52                                         unset($ctimes[$pid]);
  53
  54                                 }
  55                         } else {
  56                                 _debug("[reap_children] child $pid reaped.");
  57                                 unset($ctimes[$pid]);
  58                         }
  59                 }
  60
  61                 $children = $tmp;
  62
  63                 return count($tmp);
  64         }
  65
  66         function check_ctimes() {
  67                 global $ctimes;
  68
  69                 foreach (array_keys($ctimes) as $pid) {
  70                         $started = $ctimes[$pid];
  71
  72                         if (time() - $started > MAX_CHILD_RUNTIME) {
  73                                 _debug("[MASTER] child process $pid seems to be stuck, aborting...");
  74                                 posix_kill($pid, SIGKILL);
  75                         }
  76                 }
  77         }
  78
  79         function sigchld_handler($signal) {
  80                 $running_jobs = reap_children();
  81
  82                 _debug("[SIGCHLD] jobs left: $running_jobs");
  83
  84                 pcntl_waitpid(-1, $status, WNOHANG);
  85         }
  86
  87         function shutdown($caller_pid) {
  88                 if ($caller_pid == posix_getpid()) {
  89                         if (file_exists(LOCK_DIRECTORY . "/update_daemon.lock")) {
  90                                 _debug("removing lockfile (master)...");
  91                                 unlink(LOCK_DIRECTORY . "/update_daemon.lock");
  92                         }
  93                 }
  94         }
  95
  96         function task_shutdown() {
  97                 $pid = posix_getpid();
  98
  99                 if (file_exists(LOCK_DIRECTORY . "/update_daemon-$pid.lock")) {
 100                         _debug("removing lockfile ($pid)...");
 101                         unlink(LOCK_DIRECTORY . "/update_daemon-$pid.lock");
 102                 }
 103         }
 104
 105         function sigint_handler() {
 106                 _debug("[MASTER] SIG_INT received.\n");
 107                 shutdown(posix_getpid());
 108                 die;
 109         }
 110
 111         function task_sigint_handler() {
 112                 _debug("[TASK] SIG_INT received.\n");
 113                 task_shutdown();
 114                 die;
 115         }
 116
 117         pcntl_signal(SIGCHLD, 'sigchld_handler');
 118
 119         $longopts = array("log:",
 120                         "tasks:",
 121                         "interval:",
 122                         "quiet",
 123                         "help");
 124
 125         $options = getopt("", $longopts);
 126
 127         if (isset($options["help"]) ) {
 128                 print "Tiny Tiny RSS update daemon.\n\n";
 129                 print "Options:\n";
 130                 print "  --log FILE           - log messages to FILE\n";
 131                 print "  --tasks N            - amount of update tasks to spawn\n";
 132                 print "                         default: " . MAX_JOBS . "\n";
 133                 print "  --interval N         - task spawn interval\n";
 134                 print "                         default: " . SPAWN_INTERVAL . " seconds.\n";
 135                 print "  --quiet              - don't output messages to stdout\n";
 136                 return;
 137         }
 138
 139         define('QUIET', isset($options['quiet']));
 140
 141         if (isset($options["tasks"])) {
 142                 _debug("Set to spawn " . $options["tasks"] . " children.");
 143                 $max_jobs = $options["tasks"];
 144         } else {
 145                 $max_jobs = MAX_JOBS;
 146         }
 147
 148         if (isset($options["interval"])) {
 149                 _debug("Spawn interval: " . $options["interval"] . " seconds.");
 150                 $spawn_interval = $options["interval"];
 151         } else {
 152                 $spawn_interval = SPAWN_INTERVAL;
 153         }
 154
 155         if (isset($options["log"])) {
 156                 _debug("Logging to " . $options["log"]);
 157                 define('LOGFILE', $options["log"]);
 158         }
 159
 160         if (file_is_locked("update_daemon.lock")) {
 161                 die("error: Can't create lockfile. ".
 162                         "Maybe another daemon is already running.\n");
 163         }
 164
 165         // Try to lock a file in order to avoid concurrent update.
 166         $lock_handle = make_lockfile("update_daemon.lock");
 167
 168         if (!$lock_handle) {
 169                 die("error: Can't create lockfile. ".
 170                         "Maybe another daemon is already running.\n");
 171         }
 172
 173         $schema_version = get_schema_version();
 174
 175         if ($schema_version != SCHEMA_VERSION) {
 176                 die("Schema version is wrong, please upgrade the database.\n");
 177         }
 178
 179         // Protip: children close shared database handle when terminating, it's a bad idea to
 180         // do database stuff on main process from now on.
 181
 182         while (true) {
 183
 184                 // Since sleep is interupted by SIGCHLD, we need another way to
 185                 // respect the spawn interval
 186                 $next_spawn = $last_checkpoint + $spawn_interval - time();
 187
 188                 if ($next_spawn % 60 == 0) {
 189                         $running_jobs = count($children);
 190                         _debug("[MASTER] active jobs: $running_jobs, next spawn at $next_spawn sec.");
 191                 }
 192
 193                 if ($last_checkpoint + $spawn_interval < time()) {
 194                         check_ctimes();
 195                         reap_children();
 196
 197                         for ($j = count($children); $j < $max_jobs; $j++) {
 198                                 $pid = pcntl_fork();
 199                                 if ($pid == -1) {
 200                                         die("fork failed!\n");
 201                                 } else if ($pid) {
 202
 203                                         if (!$master_handlers_installed) {
 204                                                 _debug("[MASTER] installing shutdown handlers");
 205                                                 pcntl_signal(SIGINT, 'sigint_handler');
 206                                                 pcntl_signal(SIGTERM, 'sigint_handler');
 207                                                 register_shutdown_function('shutdown', posix_getpid());
 208                                                 $master_handlers_installed = true;
 209                                         }
 210
 211                                         _debug("[MASTER] spawned client $j [PID:$pid]...");
 212                                         array_push($children, $pid);
 213                                         $ctimes[$pid] = time();
 214                                 } else {
 215                                         pcntl_signal(SIGCHLD, SIG_IGN);
 216                                         pcntl_signal(SIGINT, 'task_sigint_handler');
 217
 218                                         register_shutdown_function('task_shutdown');
 219
 220                                         $quiet = (isset($options["quiet"])) ? "--quiet" : "";
 221
 222                                         $my_pid = posix_getpid();
 223
 224                                         passthru(PHP_EXECUTABLE . " update.php --daemon-loop $quiet --task $j --pidlock $my_pid");
 225
 226                                         sleep(1);
 227
 228                                         // We exit in order to avoid fork bombing.
 229                                         exit(0);
 230                                 }
 231                         }
 232                         $last_checkpoint = time();
 233                 }
 234                 sleep(1);
 235         }
 236
 237 ?>