--- /dev/null
+<?php
+/**
+ * Zend Framework
+ *
+ * LICENSE
+ *
+ * This source file is subject to the new BSD license that is bundled
+ * with this package in the file LICENSE.txt.
+ * It is also available through the world-wide-web at this URL:
+ * http://framework.zend.com/license/new-bsd
+ * If you did not receive a copy of the license and are unable to
+ * obtain it through the world-wide-web, please send an email
+ * to license@zend.com so we can send you a copy immediately.
+ *
+ * @category Zend
+ * @package Zend_Search_Lucene
+ * @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license http://framework.zend.com/license/new-bsd New BSD License
+ * @version $Id: LockManager.php 16971 2009-07-22 18:05:45Z mikaelkael $
+ */
+
+/** Zend_Search_Lucene_Storage_Directory */
+require_once 'Zend/Search/Lucene/Storage/Directory.php';
+
+/** Zend_Search_Lucene_Storage_File */
+require_once 'Zend/Search/Lucene/Storage/File.php';
+
+/**
+ * This is an utility class which provides index locks processing functionality
+ *
+ * @category Zend
+ * @package Zend_Search_Lucene
+ * @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license http://framework.zend.com/license/new-bsd New BSD License
+ */
+class Zend_Search_Lucene_LockManager
+{
+ /**
+ * consts for name of file to show lock status
+ */
+ const WRITE_LOCK_FILE = 'write.lock.file';
+ const READ_LOCK_FILE = 'read.lock.file';
+ const READ_LOCK_PROCESSING_LOCK_FILE = 'read-lock-processing.lock.file';
+ const OPTIMIZATION_LOCK_FILE = 'optimization.lock.file';
+
+ /**
+ * Obtain exclusive write lock on the index
+ *
+ * @param Zend_Search_Lucene_Storage_Directory $lockDirectory
+ * @return Zend_Search_Lucene_Storage_File
+ * @throws Zend_Search_Lucene_Exception
+ */
+ public static function obtainWriteLock(Zend_Search_Lucene_Storage_Directory $lockDirectory)
+ {
+ $lock = $lockDirectory->createFile(self::WRITE_LOCK_FILE);
+ if (!$lock->lock(LOCK_EX)) {
+ require_once 'Zend/Search/Lucene/Exception.php';
+ throw new Zend_Search_Lucene_Exception('Can\'t obtain exclusive index lock');
+ }
+ return $lock;
+ }
+
+ /**
+ * Release exclusive write lock
+ *
+ * @param Zend_Search_Lucene_Storage_Directory $lockDirectory
+ */
+ public static function releaseWriteLock(Zend_Search_Lucene_Storage_Directory $lockDirectory)
+ {
+ $lock = $lockDirectory->getFileObject(self::WRITE_LOCK_FILE);
+ $lock->unlock();
+ }
+
+ /**
+ * Obtain the exclusive "read escalation/de-escalation" lock
+ *
+ * Required to protect the escalate/de-escalate read lock process
+ * on GFS (and potentially other) mounted filesystems.
+ *
+ * Why we need this:
+ * While GFS supports cluster-wide locking via flock(), it's
+ * implementation isn't quite what it should be. The locking
+ * semantics that work consistently on a local filesystem tend to
+ * fail on GFS mounted filesystems. This appears to be a design defect
+ * in the implementation of GFS. How this manifests itself is that
+ * conditional promotion of a shared lock to exclusive will always
+ * fail, lock release requests are honored but not immediately
+ * processed (causing erratic failures of subsequent conditional
+ * requests) and the releasing of the exclusive lock before the
+ * shared lock is set when a lock is demoted (which can open a window
+ * of opportunity for another process to gain an exclusive lock when
+ * it shoudln't be allowed to).
+ *
+ * @param Zend_Search_Lucene_Storage_Directory $lockDirectory
+ * @return Zend_Search_Lucene_Storage_File
+ * @throws Zend_Search_Lucene_Exception
+ */
+ private static function _startReadLockProcessing(Zend_Search_Lucene_Storage_Directory $lockDirectory)
+ {
+ $lock = $lockDirectory->createFile(self::READ_LOCK_PROCESSING_LOCK_FILE);
+ if (!$lock->lock(LOCK_EX)) {
+ require_once 'Zend/Search/Lucene/Exception.php';
+ throw new Zend_Search_Lucene_Exception('Can\'t obtain exclusive lock for the read lock processing file');
+ }
+ return $lock;
+ }
+
+ /**
+ * Release the exclusive "read escalation/de-escalation" lock
+ *
+ * Required to protect the escalate/de-escalate read lock process
+ * on GFS (and potentially other) mounted filesystems.
+ *
+ * @param Zend_Search_Lucene_Storage_Directory $lockDirectory
+ */
+ private static function _stopReadLockProcessing(Zend_Search_Lucene_Storage_Directory $lockDirectory)
+ {
+ $lock = $lockDirectory->getFileObject(self::READ_LOCK_PROCESSING_LOCK_FILE);
+ $lock->unlock();
+ }
+
+
+ /**
+ * Obtain shared read lock on the index
+ *
+ * It doesn't block other read or update processes, but prevent index from the premature cleaning-up
+ *
+ * @param Zend_Search_Lucene_Storage_Directory $defaultLockDirectory
+ * @return Zend_Search_Lucene_Storage_File
+ * @throws Zend_Search_Lucene_Exception
+ */
+ public static function obtainReadLock(Zend_Search_Lucene_Storage_Directory $lockDirectory)
+ {
+ $lock = $lockDirectory->createFile(self::READ_LOCK_FILE);
+ if (!$lock->lock(LOCK_SH)) {
+ require_once 'Zend/Search/Lucene/Exception.php';
+ throw new Zend_Search_Lucene_Exception('Can\'t obtain shared reading index lock');
+ }
+ return $lock;
+ }
+
+ /**
+ * Release shared read lock
+ *
+ * @param Zend_Search_Lucene_Storage_Directory $lockDirectory
+ */
+ public static function releaseReadLock(Zend_Search_Lucene_Storage_Directory $lockDirectory)
+ {
+ $lock = $lockDirectory->getFileObject(self::READ_LOCK_FILE);
+ $lock->unlock();
+ }
+
+ /**
+ * Escalate Read lock to exclusive level
+ *
+ * @param Zend_Search_Lucene_Storage_Directory $lockDirectory
+ * @return boolean
+ */
+ public static function escalateReadLock(Zend_Search_Lucene_Storage_Directory $lockDirectory)
+ {
+ self::_startReadLockProcessing($lockDirectory);
+
+ $lock = $lockDirectory->getFileObject(self::READ_LOCK_FILE);
+
+ // First, release the shared lock for the benefit of GFS since
+ // it will fail the conditional request to promote the lock to
+ // "exclusive" while the shared lock is held (even when we are
+ // the only holder).
+ $lock->unlock();
+
+ // GFS is really poor. While the above "unlock" returns, GFS
+ // doesn't clean up it's tables right away (which will potentially
+ // cause the conditional locking for the "exclusive" lock to fail.
+ // We will retry the conditional lock request several times on a
+ // failure to get past this. The performance hit is negligible
+ // in the grand scheme of things and only will occur with GFS
+ // filesystems or if another local process has the shared lock
+ // on local filesystems.
+ for ($retries = 0; $retries < 10; $retries++) {
+ if ($lock->lock(LOCK_EX, true)) {
+ // Exclusive lock is obtained!
+ self::_stopReadLockProcessing($lockDirectory);
+ return true;
+ }
+
+ // wait 1 microsecond
+ usleep(1);
+ }
+
+ // Restore lock state
+ $lock->lock(LOCK_SH);
+
+ self::_stopReadLockProcessing($lockDirectory);
+ return false;
+ }
+
+ /**
+ * De-escalate Read lock to shared level
+ *
+ * @param Zend_Search_Lucene_Storage_Directory $lockDirectory
+ */
+ public static function deEscalateReadLock(Zend_Search_Lucene_Storage_Directory $lockDirectory)
+ {
+ $lock = $lockDirectory->getFileObject(self::READ_LOCK_FILE);
+ $lock->lock(LOCK_SH);
+ }
+
+ /**
+ * Obtain exclusive optimization lock on the index
+ *
+ * Returns lock object on success and false otherwise (doesn't block execution)
+ *
+ * @param Zend_Search_Lucene_Storage_Directory $lockDirectory
+ * @return mixed
+ */
+ public static function obtainOptimizationLock(Zend_Search_Lucene_Storage_Directory $lockDirectory)
+ {
+ $lock = $lockDirectory->createFile(self::OPTIMIZATION_LOCK_FILE);
+ if (!$lock->lock(LOCK_EX, true)) {
+ return false;
+ }
+ return $lock;
+ }
+
+ /**
+ * Release exclusive optimization lock
+ *
+ * @param Zend_Search_Lucene_Storage_Directory $lockDirectory
+ */
+ public static function releaseOptimizationLock(Zend_Search_Lucene_Storage_Directory $lockDirectory)
+ {
+ $lock = $lockDirectory->getFileObject(self::OPTIMIZATION_LOCK_FILE);
+ $lock->unlock();
+ }
+
+}
projects / web.mtrack / blobdiff