mirror of https://github.com/friendica/friendica
86 lines
1.7 KiB
PHP
86 lines
1.7 KiB
PHP
<?php
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namespace Friendica\Util\Lock;
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use Friendica\Core\Cache;
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use dba;
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class MemcacheLockDriver implements ILockDriver
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{
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/**
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*
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* @brief Sets a lock for a given name
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*
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* @param string $key The Name of the lock
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* @param integer $timeout Seconds until we give up
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*
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* @return boolean Was the lock successful?
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*/
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public function acquireLock($key, $timeout = 120)
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{
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$got_lock = false;
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$start = time();
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$cachekey = get_app()->get_hostname() . ";lock:" . $key;
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do {
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// We only lock to be sure that nothing happens at exactly the same time
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dba::lock('locks');
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$lock = Cache::get($cachekey);
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if (!is_bool($lock)) {
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$pid = (int)$lock;
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// When the process id isn't used anymore, we can safely claim the lock for us.
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// Or we do want to lock something that was already locked by us.
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if (!posix_kill($pid, 0) || ($pid == getmypid())) {
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$lock = false;
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}
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}
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if (is_bool($lock)) {
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Cache::set($cachekey, getmypid(), 300);
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$got_lock = true;
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}
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dba::unlock();
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if (!$got_lock && ($timeout > 0)) {
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usleep(rand(10000, 200000));
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}
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} while (!$got_lock && ((time() - $start) < $timeout));
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return $got_lock;
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}
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/**
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* @brief Removes a lock if it was set by us
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*
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* @param string $key Name of the lock
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*
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* @return mixed
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*/
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public function releaseLock($key)
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{
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$cachekey = get_app()->get_hostname() . ";lock:" . $key;
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$lock = Cache::get($cachekey);
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if (!is_bool($lock)) {
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if ((int)$lock == getmypid()) {
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Cache::delete($cachekey);
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}
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}
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return;
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}
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/**
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* @brief Removes all lock that were set by us
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*
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* @return void
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*/
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public function releaseAll()
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{
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// We cannot delete all cache entries, but this doesn't matter with memcache
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return;
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}
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} |