/*
 *  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;

/**
 * Poll.
 *
 * @deprecated The scope of the APR/Native Library will be reduced in Tomcat 9.1.x / Tomcat Native 2.x and has been
 *                 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 Poll {

    /*
     * Poll return values
     */
    /** Can read without blocking */
    public static final int APR_POLLIN = 0x001;
    /** Priority data available */
    public static final int APR_POLLPRI = 0x002;
    /** Can write without blocking */
    public static final int APR_POLLOUT = 0x004;
    /** Pending error */
    public static final int APR_POLLERR = 0x010;
    /** Hangup occurred */
    public static final int APR_POLLHUP = 0x020;
    /** Descriptor invalid */
    public static final int APR_POLLNVAL = 0x040;

    /*
     * Pollset Flags
     */
    /** Adding or Removing a Descriptor is thread safe */
    public static final int APR_POLLSET_THREADSAFE = 0x001;


    /*
     * Used in apr_pollfd_t to determine what the apr_descriptor is apr_datatype_e enum
     */
    /** nothing here */
    public static final int APR_NO_DESC = 0;
    /** descriptor refers to a socket */
    public static final int APR_POLL_SOCKET = 1;
    /** descriptor refers to a file */
    public static final int APR_POLL_FILE = 2;
    /** descriptor is the last one in the list */
    public static final int APR_POLL_LASTDESC = 3;

    /**
     * Setup a pollset object. If flags equals APR_POLLSET_THREADSAFE, then a pollset is created on which it is safe to
     * make concurrent calls to apr_pollset_add(), apr_pollset_remove() and apr_pollset_poll() from separate threads.
     * This feature is only supported on some platforms; the apr_pollset_create() call will fail with APR_ENOTIMPL on
     * platforms where it is not supported.
     *
     * @param size  The maximum number of descriptors that this pollset can hold
     * @param p     The pool from which to allocate the pollset
     * @param flags Optional flags to modify the operation of the pollset.
     * @param ttl   Maximum time to live for a particular socket.
     *
     * @return The pointer in which to return the newly created object
     *
     * @throws Error Pollset creation failed
     */
    public static native long create(int size, long p, int flags, long ttl) throws Error;

    /**
     * Destroy a pollset object
     *
     * @param pollset The pollset to destroy
     *
     * @return the operation status
     */
    public static native int destroy(long pollset);

    /**
     * Add a socket to a pollset with the default timeout.
     *
     * @param pollset   The pollset to which to add the socket
     * @param sock      The sockets to add
     * @param reqevents requested events
     *
     * @return the operation status
     */
    public static native int add(long pollset, long sock, int reqevents);

    /**
     * Add a socket to a pollset with a specific timeout.
     *
     * @param pollset   The pollset to which to add the socket
     * @param sock      The sockets to add
     * @param reqevents requested events
     * @param timeout   requested timeout in microseconds (-1 for infinite)
     *
     * @return the operation status
     */
    public static native int addWithTimeout(long pollset, long sock, int reqevents, long timeout);

    /**
     * Remove a descriptor from a pollset
     *
     * @param pollset The pollset from which to remove the descriptor
     * @param sock    The socket to remove
     *
     * @return the operation status
     */
    public static native int remove(long pollset, long sock);

    /**
     * Block for activity on the descriptor(s) in a pollset
     *
     * @param pollset     The pollset to use
     * @param timeout     Timeout in microseconds
     * @param descriptors Array of signaled descriptors (output parameter) The descriptor array must be two times the
     *                        size of pollset. and are populated as follows:
     *
     *                        <PRE>
     * descriptors[2n + 0] -&gt; returned events
     * descriptors[2n + 1] -&gt; socket
     *                        </PRE>
     *
     * @param remove      Remove signaled descriptors from pollset
     *
     * @return Number of signaled descriptors (output parameter) or negative APR error code.
     */
    public static native int poll(long pollset, long timeout, long[] descriptors, boolean remove);

    /**
     * Maintain on the descriptor(s) in a pollset
     *
     * @param pollset     The pollset to use
     * @param descriptors Array of signaled descriptors (output parameter) The descriptor array must be the size of
     *                        pollset. and are populated as follows:
     *
     *                        <PRE>
     * descriptors[n] -&gt; socket
     *                        </PRE>
     *
     * @param remove      Remove signaled descriptors from pollset
     *
     * @return Number of signaled descriptors (output parameter) or negative APR error code.
     */
    public static native int maintain(long pollset, long[] descriptors, boolean remove);

    /**
     * Set the socket time to live.
     *
     * @param pollset The pollset to use
     * @param ttl     Timeout in microseconds
     */
    public static native void setTtl(long pollset, long ttl);

    /**
     * Get the socket time to live.
     *
     * @param pollset The pollset to use
     *
     * @return Timeout in microseconds
     */
    public static native long getTtl(long pollset);

    /**
     * Return all descriptor(s) in a pollset
     *
     * @param pollset     The pollset to use
     * @param descriptors Array of descriptors (output parameter) The descriptor array must be two times the size of
     *                        pollset. and are populated as follows:
     *
     *                        <PRE>
     * descriptors[2n + 0] -&gt; returned events
     * descriptors[2n + 1] -&gt; socket
     *                        </PRE>
     *
     * @return Number of descriptors (output parameter) in the Poll or negative APR error code.
     */
    public static native int pollset(long pollset, long[] descriptors);

    /**
     * Make poll() return.
     *
     * @param pollset The pollset to use
     *
     * @return Negative APR error code
     */
    public static native int interrupt(long pollset);

    /**
     * Check if interrupt() is allowed.
     *
     * @param pollset The pollset to use
     *
     * @return <code>true</code> if {@link #interrupt(long)} is allowed, else <code>false</code>
     */
    public static native boolean wakeable(long pollset);
}