Poll


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3    *  contributor license agreements.  See the NOTICE file distributed with
4    *  this work for additional information regarding copyright ownership.
5    *  The ASF licenses this file to You under the Apache License, Version 2.0
6    *  (the "License"); you may not use this file except in compliance with
7    *  the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   *  Unless required by applicable law or agreed to in writing, software
12   *  distributed under the License is distributed on an "AS IS" BASIS,
13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   *  See the License for the specific language governing permissions and
15   *  limitations under the License.
16   */
17  
18  package org.apache.tomcat.jni;
19  
20  /** Poll
21   *
22   * @author Mladen Turk
23   * @version $Revision: 467222 $, $Date: 2006-10-24 05:17:11 +0200 (mar., 24 oct. 2006) $
24   */
25  
26  public class Poll {
27  
28      /**
29       * Poll options
30       */
31      public static final int APR_POLLIN   = 0x001; /** Can read without blocking */
32      public static final int APR_POLLPRI  = 0x002; /** Priority data available */
33      public static final int APR_POLLOUT  = 0x004; /** Can write without blocking */
34      public static final int APR_POLLERR  = 0x010; /** Pending error */
35      public static final int APR_POLLHUP  = 0x020; /** Hangup occurred */
36      public static final int APR_POLLNVAL = 0x040; /** Descriptior invalid */
37  
38      /**
39       * Pollset Flags
40       */
41      /** Adding or Removing a Descriptor is thread safe */
42      public static final int APR_POLLSET_THREADSAFE = 0x001;
43  
44  
45      /** Used in apr_pollfd_t to determine what the apr_descriptor is
46       * apr_datatype_e enum
47       */
48      public static final int APR_NO_DESC       = 0; /** nothing here */
49      public static final int APR_POLL_SOCKET   = 1; /** descriptor refers to a socket */
50      public static final int APR_POLL_FILE     = 2; /** descriptor refers to a file */
51      public static final int APR_POLL_LASTDESC = 3; /** descriptor is the last one in the list */
52  
53      /**
54       * Setup a pollset object.
55       * If flags equals APR_POLLSET_THREADSAFE, then a pollset is
56       * created on which it is safe to make concurrent calls to
57       * apr_pollset_add(), apr_pollset_remove() and apr_pollset_poll() from
58       * separate threads.  This feature is only supported on some
59       * platforms; the apr_pollset_create() call will fail with
60       * APR_ENOTIMPL on platforms where it is not supported.
61       * @param size The maximum number of descriptors that this pollset can hold
62       * @param p The pool from which to allocate the pollset
63       * @param flags Optional flags to modify the operation of the pollset.
64       * @param ttl Maximum time to live for a particular socket.
65       * @return  The pointer in which to return the newly created object
66       */
67      public static native long create(int size, long p, int flags, long ttl)
68          throws Error  ;
69      /**
70       * Destroy a pollset object
71       * @param pollset The pollset to destroy
72       */
73      public static native int destroy(long pollset);
74  
75      /**
76       * Add a socket or to a pollset
77       * If you set client_data in the descriptor, that value
78       * will be returned in the client_data field whenever this
79       * descriptor is signalled in apr_pollset_poll().
80       * @param pollset The pollset to which to add the descriptor
81       * @param sock The sockets to add
82       * @param data Client data to add
83       * @param reqevents requested events
84       */
85      public static native int add(long pollset, long sock,
86                                   int reqevents);
87  
88      /**
89       * Remove a descriptor from a pollset
90       * @param pollset The pollset from which to remove the descriptor
91       * @param sock The socket to remove
92       */
93      public static native int remove(long pollset, long sock);
94  
95      /**
96       * Block for activity on the descriptor(s) in a pollset
97       * @param pollset The pollset to use
98       * @param timeout Timeout in microseconds
99       * @param descriptors Array of signalled descriptors (output parameter)
100      *        The desctiptor array must be two times the size of pollset.
101      *        and are populated as follows:
102      * <PRE>
103      * descriptors[n + 0] -> returned events
104      * descriptors[n + 1] -> socket
105      * </PRE>
106      * @param remove Remove signaled descriptors from pollset
107      * @return Number of signalled descriptors (output parameter)
108      *         or negative APR error code.
109      */
110     public static native int poll(long pollset, long timeout,
111                                   long [] descriptors, boolean remove);
112 
113     /**
114      * Maintain on the descriptor(s) in a pollset
115      * @param pollset The pollset to use
116      * @param descriptors Array of signalled descriptors (output parameter)
117      *        The desctiptor array must be the size of pollset.
118      *        and are populated as follows:
119      * <PRE>
120      * descriptors[n] -> socket
121      * </PRE>
122      * @param remove Remove signaled descriptors from pollset
123      * @return Number of signalled descriptors (output parameter)
124      *         or negative APR error code.
125      */
126     public static native int maintain(long pollset, long [] descriptors,
127                                       boolean remove);
128 
129     /**
130      * Set the socket time to live.
131      * @param pollset The pollset to use
132      * @param ttl Timeout in microseconds
133      */
134     public static native void setTtl(long pollset, long ttl);
135 
136     /**
137      * Get the socket time to live.
138      * @param pollset The pollset to use
139      * @return Timeout in microseconds
140      */
141     public static native long getTtl(long pollset);
142 
143     /**
144      * Return all descriptor(s) in a pollset
145      * @param pollset The pollset to use
146      * @param descriptors Array of descriptors (output parameter)
147      *        The desctiptor array must be two times the size of pollset.
148      *        and are populated as follows:
149      * <PRE>
150      * descriptors[n + 0] -> returned events
151      * descriptors[n + 1] -> socket
152      * </PRE>
153      * @return Number of descriptors (output parameter) in the Poll
154      *         or negative APR error code.
155      */
156     public static native int pollset(long pollset, long [] descriptors);
157 
158 }
159
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