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 "autoload.php";
  13         require_once "functions.php";
  14         require_once "config.php";
  15
  16         // defaults
  17         define_default('PURGE_INTERVAL', 3600); // seconds
  18         define_default('MAX_CHILD_RUNTIME', 1800); // seconds
  19         define_default('MAX_JOBS', 2);
  20         define_default('SPAWN_INTERVAL', DAEMON_SLEEP_INTERVAL); // seconds
  21
  22         require_once "sanity_check.php";
  23         require_once "db.php";
  24         require_once "db-prefs.php";
  25
  26         if (!function_exists('pcntl_fork')) {
  27                 die("error: This script requires PHP compiled with PCNTL module.\n");
  28         }
  29
  30         $options = getopt("");
  31
  32         if (!is_array($options)) {
  33                 die("error: getopt() failed. ".
  34                         "Most probably you are using PHP CGI to run this script ".
  35                         "instead of required PHP CLI. Check tt-rss wiki page on updating feeds for ".
  36                         "additional information.\n");
  37         }
  38
  39
  40         $master_handlers_installed = false;
  41
  42         $children = array();
  43         $ctimes = array();
  44
  45         $last_checkpoint = -1;
  46
  47         /**
  48          * @SuppressWarnings(unused)
  49          */
  50         function reap_children() {
  51                 global $children;
  52                 global $ctimes;
  53
  54                 $tmp = array();
  55
  56                 foreach ($children as $pid) {
  57                         if (pcntl_waitpid($pid, $status, WNOHANG) != $pid) {
  58
  59                                 if (file_is_locked("update_daemon-$pid.lock")) {
  60                                         array_push($tmp, $pid);
  61                                 } else {
  62                                         _debug("[reap_children] child $pid seems active but lockfile is unlocked.");
  63                                         unset($ctimes[$pid]);
  64
  65                                 }
  66                         } else {
  67                                 _debug("[reap_children] child $pid reaped.");
  68                                 unset($ctimes[$pid]);
  69                         }
  70                 }
  71
  72                 $children = $tmp;
  73
  74                 return count($tmp);
  75         }
  76
  77         function check_ctimes() {
  78                 global $ctimes;
  79
  80                 foreach (array_keys($ctimes) as $pid) {
  81                         $started = $ctimes[$pid];
  82
  83                         if (time() - $started > MAX_CHILD_RUNTIME) {
  84                                 _debug("[MASTER] child process $pid seems to be stuck, aborting...");
  85                                 posix_kill($pid, SIGKILL);
  86                         }
  87                 }
  88         }
  89
  90         /**
  91         * @SuppressWarnings(unused)
  92         */
  93         function sigchld_handler($signal) {
  94                 $running_jobs = reap_children();
  95
  96                 _debug("[SIGCHLD] jobs left: $running_jobs");
  97
  98                 pcntl_waitpid(-1, $status, WNOHANG);
  99         }
 100
 101         function shutdown($caller_pid) {
 102                 if ($caller_pid == posix_getpid()) {
 103                         if (file_exists(LOCK_DIRECTORY . "/update_daemon.lock")) {
 104                                 _debug("removing lockfile (master)...");
 105                                 unlink(LOCK_DIRECTORY . "/update_daemon.lock");
 106                         }
 107                 }
 108         }
 109
 110         function task_shutdown() {
 111                 $pid = posix_getpid();
 112
 113                 if (file_exists(LOCK_DIRECTORY . "/update_daemon-$pid.lock")) {
 114                         _debug("removing lockfile ($pid)...");
 115                         unlink(LOCK_DIRECTORY . "/update_daemon-$pid.lock");
 116                 }
 117         }
 118
 119         function sigint_handler() {
 120                 _debug("[MASTER] SIG_INT received.\n");
 121                 shutdown(posix_getpid());
 122                 die;
 123         }
 124
 125         function task_sigint_handler() {
 126                 _debug("[TASK] SIG_INT received.\n");
 127                 task_shutdown();
 128                 die;
 129         }
 130
 131         pcntl_signal(SIGCHLD, 'sigchld_handler');
 132
 133         $longopts = array("log:",
 134                         "tasks:",
 135                         "interval:",
 136                         "quiet",
 137                         "help");
 138
 139         $options = getopt("", $longopts);
 140
 141         if (isset($options["help"]) ) {
 142                 print "Tiny Tiny RSS update daemon.\n\n";
 143                 print "Options:\n";
 144                 print "  --log FILE           - log messages to FILE\n";
 145                 print "  --tasks N            - amount of update tasks to spawn\n";
 146                 print "                         default: " . MAX_JOBS . "\n";
 147                 print "  --interval N         - task spawn interval\n";
 148                 print "                         default: " . SPAWN_INTERVAL . " seconds.\n";
 149                 print "  --quiet              - don't output messages to stdout\n";
 150                 return;
 151         }
 152
 153         define('QUIET', isset($options['quiet']));
 154
 155         if (isset($options["tasks"])) {
 156                 _debug("Set to spawn " . $options["tasks"] . " children.");
 157                 $max_jobs = $options["tasks"];
 158         } else {
 159                 $max_jobs = MAX_JOBS;
 160         }
 161
 162         if (isset($options["interval"])) {
 163                 _debug("Spawn interval: " . $options["interval"] . " seconds.");
 164                 $spawn_interval = $options["interval"];
 165         } else {
 166                 $spawn_interval = SPAWN_INTERVAL;
 167         }
 168
 169         // let's enforce a minimum spawn interval as to not forkbomb the host
 170         $spawn_interval = max(60, $spawn_interval);
 171         _debug("Spawn interval: $spawn_interval sec");
 172
 173         if (isset($options["log"])) {
 174                 _debug("Logging to " . $options["log"]);
 175                 define('LOGFILE', $options["log"]);
 176         }
 177
 178         if (file_is_locked("update_daemon.lock")) {
 179                 die("error: Can't create lockfile. ".
 180                         "Maybe another daemon is already running.\n");
 181         }
 182
 183         // Try to lock a file in order to avoid concurrent update.
 184         $lock_handle = make_lockfile("update_daemon.lock");
 185
 186         if (!$lock_handle) {
 187                 die("error: Can't create lockfile. ".
 188                         "Maybe another daemon is already running.\n");
 189         }
 190
 191         $schema_version = get_schema_version();
 192
 193         if ($schema_version != SCHEMA_VERSION) {
 194                 die("Schema version is wrong, please upgrade the database.\n");
 195         }
 196
 197         // Protip: children close shared database handle when terminating, it's a bad idea to
 198         // do database stuff on main process from now on.
 199
 200         while (true) {
 201
 202                 // Since sleep is interupted by SIGCHLD, we need another way to
 203                 // respect the spawn interval
 204                 $next_spawn = $last_checkpoint + $spawn_interval - time();
 205
 206                 if ($next_spawn % 60 == 0) {
 207                         $running_jobs = count($children);
 208                         _debug("[MASTER] active jobs: $running_jobs, next spawn at $next_spawn sec.");
 209                 }
 210
 211                 if ($last_checkpoint + $spawn_interval < time()) {
 212                         check_ctimes();
 213                         reap_children();
 214
 215                         for ($j = count($children); $j < $max_jobs; $j++) {
 216                                 $pid = pcntl_fork();
 217                                 if ($pid == -1) {
 218                                         die("fork failed!\n");
 219                                 } else if ($pid) {
 220
 221                                         if (!$master_handlers_installed) {
 222                                                 _debug("[MASTER] installing shutdown handlers");
 223                                                 pcntl_signal(SIGINT, 'sigint_handler');
 224                                                 pcntl_signal(SIGTERM, 'sigint_handler');
 225                                                 register_shutdown_function('shutdown', posix_getpid());
 226                                                 $master_handlers_installed = true;
 227                                         }
 228
 229                                         _debug("[MASTER] spawned client $j [PID:$pid]...");
 230                                         array_push($children, $pid);
 231                                         $ctimes[$pid] = time();
 232                                 } else {
 233                                         pcntl_signal(SIGCHLD, SIG_IGN);
 234                                         pcntl_signal(SIGINT, 'task_sigint_handler');
 235
 236                                         register_shutdown_function('task_shutdown');
 237
 238                                         $quiet = (isset($options["quiet"])) ? "--quiet" : "";
 239                                         $log = function_exists("flock") && isset($options['log']) ? '--log '.$options['log'] : '';
 240
 241                                         $my_pid = posix_getpid();
 242
 243                                         passthru(PHP_EXECUTABLE . " update.php --daemon-loop $quiet $log --task $j --pidlock $my_pid");
 244
 245                                         sleep(1);
 246
 247                                         // We exit in order to avoid fork bombing.
 248                                         exit(0);
 249                                 }
 250                         }
 251                         $last_checkpoint = time();
 252                 }
 253                 sleep(1);
 254         }
 255
 256 ?>