init

java/org/apache/tomcat/jni/Lock.java

@@ -0,0 +1,131 @@
+/*
+ *  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.
+     * @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();
+
+}