org.apache.tomcat.jni.Lock Maven / Gradle / Ivy
/*
* 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
*
* @deprecated The scope of the APR/Native Library will be reduced in Tomcat
* 10.1.x / Tomcat Native 2.x onwards to only include those
* components required to provide OpenSSL integration with the NIO
* and NIO2 connectors.
*/
@Deprecated
public class Lock {
/**
* Enumerated potential types for APR process locking methods
*
Warning : 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.
*
Warning : 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
*
* 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
*
* @param pool the pool from which to allocate the mutex.
* @return Newly created mutex.
* @throws Error An error occurred
*/
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.
* @throws Error An error occurred
*/
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.
* @return the operation status
*/
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.
* @return the operation status
*/
public static native int trylock(long mutex);
/**
* Release the lock for the given mutex.
* @param mutex the mutex from which to release the lock.
* @return the operation status
*/
public static native int unlock(long mutex);
/**
* Destroy the mutex and free the memory associated with the lock.
* @param mutex the mutex to destroy.
* @return the operation status
*/
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
* @param mutex the name of the mutex
* @return the name of the 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
* @return the name of the mutex
*/
public static native String name(long mutex);
/**
* Display the name of the default mutex: APR_LOCK_DEFAULT
* @return the default name
*/
public static native String defname();
}