| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package org.apache.tomcat.jni; |
| |
| /** Lock |
| * |
| * @author Mladen Turk |
| */ |
| public class Lock { |
| |
| /** |
| * Enumerated potential types for APR process locking methods |
| * <br><b>Warning :</b> Check APR_HAS_foo_SERIALIZE defines to see if the platform supports |
| * APR_LOCK_foo. Only APR_LOCK_DEFAULT is portable. |
| */ |
| |
| public static final int APR_LOCK_FCNTL = 0; /** fcntl() */ |
| public static final int APR_LOCK_FLOCK = 1; /** flock() */ |
| public static final int APR_LOCK_SYSVSEM = 2; /** System V Semaphores */ |
| public static final int APR_LOCK_PROC_PTHREAD = 3; /** POSIX pthread process-based locking */ |
| public static final int APR_LOCK_POSIXSEM = 4; /** POSIX semaphore process-based locking */ |
| public static final int APR_LOCK_DEFAULT = 5; /** Use the default process lock */ |
| |
| /** |
| * Create and initialize a mutex that can be used to synchronize processes. |
| * <br><b>Warning :</b> Check APR_HAS_foo_SERIALIZE defines to see if the platform supports |
| * APR_LOCK_foo. Only APR_LOCK_DEFAULT is portable. |
| * @param fname A file name to use if the lock mechanism requires one. This |
| * argument should always be provided. The lock code itself will |
| * determine if it should be used. |
| * @param mech The mechanism to use for the interprocess lock, if any; one of |
| * <PRE> |
| * APR_LOCK_FCNTL |
| * APR_LOCK_FLOCK |
| * APR_LOCK_SYSVSEM |
| * APR_LOCK_POSIXSEM |
| * APR_LOCK_PROC_PTHREAD |
| * APR_LOCK_DEFAULT pick the default mechanism for the platform |
| * </PRE> |
| * @param pool the pool from which to allocate the mutex. |
| * @return Newly created mutex. |
| */ |
| public static native long create(String fname, int mech, long pool) |
| throws Error; |
| |
| /** |
| * Re-open a mutex in a child process. |
| * This function must be called to maintain portability, even |
| * if the underlying lock mechanism does not require it. |
| * @param fname A file name to use if the mutex mechanism requires one. This |
| * argument should always be provided. The mutex code itself will |
| * determine if it should be used. This filename should be the |
| * same one that was passed to apr_proc_mutex_create(). |
| * @param pool The pool to operate on. |
| * @return Newly opened mutex. |
| */ |
| public static native long childInit(String fname, long pool) |
| throws Error; |
| |
| /** |
| * Acquire the lock for the given mutex. If the mutex is already locked, |
| * the current thread will be put to sleep until the lock becomes available. |
| * @param mutex the mutex on which to acquire the lock. |
| */ |
| public static native int lock(long mutex); |
| |
| /** |
| * Attempt to acquire the lock for the given mutex. If the mutex has already |
| * been acquired, the call returns immediately with APR_EBUSY. Note: it |
| * is important that the APR_STATUS_IS_EBUSY(s) macro be used to determine |
| * if the return value was APR_EBUSY, for portability reasons. |
| * @param mutex the mutex on which to attempt the lock acquiring. |
| */ |
| public static native int trylock(long mutex); |
| |
| /** |
| * Release the lock for the given mutex. |
| * @param mutex the mutex from which to release the lock. |
| */ |
| public static native int unlock(long mutex); |
| |
| /** |
| * Destroy the mutex and free the memory associated with the lock. |
| * @param mutex the mutex to destroy. |
| */ |
| public static native int destroy(long mutex); |
| |
| /** |
| * Return the name of the lockfile for the mutex, or NULL |
| * if the mutex doesn't use a lock file |
| */ |
| public static native String lockfile(long mutex); |
| |
| /** |
| * Display the name of the mutex, as it relates to the actual method used. |
| * This matches the valid options for Apache's AcceptMutex directive |
| * @param mutex the name of the mutex |
| */ |
| public static native String name(long mutex); |
| |
| /** |
| * Display the name of the default mutex: APR_LOCK_DEFAULT |
| */ |
| public static native String defname(); |
| |
| } |