org.apache.tomcat.jni.Global 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;
/** Global
*
* @author Mladen Turk
*/
public class Global {
/**
* Create and initialize a mutex that can be used to synchronize both
* processes and threads. Note: There is considerable overhead in using
* this API if only cross-process or cross-thread mutual exclusion is
* required. See apr_proc_mutex.h and apr_thread_mutex.h for more
* specialized lock routines.
*
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 If an error occurred
*/
public static native long create(String fname, int mech, long pool)
throws Error;
/**
* Re-open a mutex in a child process.
* @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.
* This function must be called to maintain portability, even
* if the underlying lock mechanism does not require it.
* @return Newly opened mutex.
* @throws Error If 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);
}