2 // This file is part of Moodle - http://moodle.org/
4 // Moodle is free software: you can redistribute it and/or modify
5 // it under the terms of the GNU General Public License as published by
6 // the Free Software Foundation, either version 3 of the License, or
7 // (at your option) any later version.
9 // Moodle is distributed in the hope that it will be useful,
10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 // GNU General Public License for more details.
14 // You should have received a copy of the GNU General Public License
15 // along with Moodle. If not, see <http://www.gnu.org/licenses/>.
18 * Shutdown management class.
21 * @copyright 2013 Petr Skoda {@link http://skodak.org}
22 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
25 defined('MOODLE_INTERNAL') ||
die();
28 * Shutdown management class.
31 * @copyright 2013 Petr Skoda {@link http://skodak.org}
32 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
34 class core_shutdown_manager
{
35 /** @var array list of custom callbacks */
36 protected static $callbacks = [];
37 /** @var array list of custom signal callbacks */
38 protected static $signalcallbacks = [];
39 /** @var bool is this manager already registered? */
40 protected static $registered = false;
43 * Register self as main shutdown handler.
45 * @private to be called from lib/setup.php only!
47 public static function initialize() {
48 if (self
::$registered) {
49 debugging('Shutdown manager is already initialised!');
51 self
::$registered = true;
52 register_shutdown_function(array('core_shutdown_manager', 'shutdown_handler'));
54 // Signal handlers should only be used when dealing with a CLI script.
55 // In the case of PHP called in a web server the server is the owning process and should handle the signal chain
57 // The 'pcntl' extension is optional and not available on Windows.
58 if (CLI_SCRIPT
&& extension_loaded('pcntl') && function_exists('pcntl_async_signals')) {
59 // We capture and handle SIGINT (Ctrl+C) and SIGTERM (termination requested).
60 pcntl_async_signals(true);
61 pcntl_signal(SIGINT
, ['core_shutdown_manager', 'signal_handler']);
62 pcntl_signal(SIGTERM
, ['core_shutdown_manager', 'signal_handler']);
67 * Signal handler for SIGINT, and SIGTERM.
69 * @param int $signo The signal being handled
71 public static function signal_handler(int $signo) {
72 // Note: There is no need to manually call the shutdown handler.
73 // The fact that we are calling exit() in this script means that the standard shutdown handling is performed
77 // Replicate native behaviour.
78 echo "Terminated: {$signo}\n";
80 // The standard exit code for SIGTERM is 143.
84 // Replicate native behaviour.
87 // The standard exit code for SIGINT (Ctrl+C) is 130.
91 // The signal handler was called with a signal it was not expecting.
92 // We should exit and complain.
93 echo "Warning: \core_shutdown_manager::signal_handler() was called with an unexpected signal ({$signo}).\n";
97 // Normally we should exit unless a callback tells us to wait.
99 foreach (self
::$signalcallbacks as $data) {
100 list($callback, $params) = $data;
102 array_unshift($params, $signo);
103 $shouldexit = call_user_func_array($callback, $params) && $shouldexit;
104 } catch (Throwable
$e) {
106 error_log('Exception ignored in signal function ' . get_callable_name($callback) . ': ' . $e->getMessage());
116 * Register custom signal handler function.
118 * If a handler returns false the signal will be ignored.
120 * @param callable $callback
121 * @param array $params
124 public static function register_signal_handler($callback, ?
array $params = null): void
{
125 if (!is_callable($callback)) {
126 error_log('Invalid custom signal function detected ' . var_export($callback, true)); // phpcs:ignore
128 self
::$signalcallbacks[] = [$callback, $params ??
[]];
132 * Register custom shutdown function.
134 * @param callable $callback
135 * @param array $params
138 public static function register_function($callback, ?
array $params = null): void
{
139 if (!is_callable($callback)) {
140 error_log('Invalid custom shutdown function detected '.var_export($callback, true)); // phpcs:ignore
142 self
::$callbacks[] = [$callback, $params ?
array_values($params) : []];
146 * @private - do NOT call directly.
148 public static function shutdown_handler() {
151 // In case we caught an out of memory shutdown we increase memory limit to unlimited, so we can gracefully shut down.
152 raise_memory_limit(MEMORY_UNLIMITED
);
154 // Always ensure we know who the user is in access logs even if they
155 // were logged in a weird way midway through the request.
156 set_access_log_user();
158 // Custom stuff first.
159 foreach (self
::$callbacks as $data) {
160 list($callback, $params) = $data;
162 call_user_func_array($callback, $params);
163 } catch (Throwable
$e) {
165 error_log('Exception ignored in shutdown function '.get_callable_name($callback).': '.$e->getMessage());
169 // Handle DB transactions, session need to be written afterwards
170 // in order to maintain consistency in all session handlers.
171 if ($DB->is_transaction_started()) {
172 if (!defined('PHPUNIT_TEST') or !PHPUNIT_TEST
) {
173 // This should not happen, it usually indicates wrong catching of exceptions,
174 // because all transactions should be finished manually or in default exception handler.
175 $backtrace = $DB->get_transaction_start_backtrace();
176 error_log('Potential coding error - active database transaction detected during request shutdown:'."\n".format_backtrace($backtrace, true));
178 $DB->force_transaction_rollback();
181 // Close sessions - do it here to make it consistent for all session handlers.
182 \core\session\manager
::write_close();
185 self
::request_shutdown();
188 if (function_exists('profiling_is_running')) {
189 if (profiling_is_running()) {
194 // NOTE: do not dispose $DB and MUC here, they might be used from legacy shutdown functions.
198 * Standard shutdown sequence.
200 protected static function request_shutdown() {
201 global $CFG, $OUTPUT, $PERF;
203 // Help apache server if possible.
204 $apachereleasemem = false;
205 if (function_exists('apache_child_terminate') && function_exists('memory_get_usage') && ini_get_bool('child_terminate')) {
206 $limit = (empty($CFG->apachemaxmem
) ?
64*1024*1024 : $CFG->apachemaxmem
); // 64MB default.
207 if (memory_get_usage() > get_real_size($limit)) {
208 $apachereleasemem = $limit;
209 @apache_child_terminate
();
213 // Deal with perf logging.
214 if (MDL_PERF ||
(!empty($CFG->perfdebug
) && $CFG->perfdebug
> 7)) {
215 if ($apachereleasemem) {
216 error_log('Mem usage over '.$apachereleasemem.': marking Apache child for reaping.');
219 $perf = get_performance_info();
220 error_log("PERF: " . $perf['txt']);
222 if (!empty($PERF->perfdebugdeferred
)) {
223 $perf = get_performance_info();
224 echo $OUTPUT->select_element_for_replace('#perfdebugfooter', $perf['html']);
227 $inc = get_included_files();
229 foreach ($inc as $f) {
230 if (preg_match(':^/:', $f)) {
233 $hfs = display_size($fs);
234 error_log(substr($f, strlen($CFG->dirroot
)) . " size: $fs ($hfs)");
240 $hts = display_size($ts);
241 error_log("Total size of files included: $ts ($hts)");
246 // Close the current streaming element if any.
247 if ($OUTPUT->has_started()) {
248 echo $OUTPUT->close_element_for_append();
251 // Print any closing buffered tags.
252 if (!empty($CFG->closingtags
)) {
253 echo $CFG->closingtags
;