1 /* |
1 /* |
2 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. |
2 * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. |
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 * |
4 * |
5 * This code is free software; you can redistribute it and/or modify it |
5 * This code is free software; you can redistribute it and/or modify it |
6 * under the terms of the GNU General Public License version 2 only, as |
6 * under the terms of the GNU General Public License version 2 only, as |
7 * published by the Free Software Foundation. Oracle designates this |
7 * published by the Free Software Foundation. Oracle designates this |
115 * |
115 * |
116 * @return The valid-operation set |
116 * @return The valid-operation set |
117 */ |
117 */ |
118 public abstract int validOps(); |
118 public abstract int validOps(); |
119 |
119 |
120 // Internal state: |
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121 // keySet, may be empty but is never null, typ. a tiny array |
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122 // boolean isRegistered, protected by key set |
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123 // regLock, lock object to prevent duplicate registrations |
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124 // blocking mode, protected by regLock |
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125 |
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126 /** |
120 /** |
127 * Tells whether or not this channel is currently registered with any |
121 * Tells whether or not this channel is currently registered with any |
128 * selectors. A newly-created channel is not registered. |
122 * selectors. A newly-created channel is not registered. |
129 * |
123 * |
130 * <p> Due to the inherent delay between key cancellation and channel |
124 * <p> Due to the inherent delay between key cancellation and channel |
133 * for some time after it is closed. </p> |
127 * for some time after it is closed. </p> |
134 * |
128 * |
135 * @return {@code true} if, and only if, this channel is registered |
129 * @return {@code true} if, and only if, this channel is registered |
136 */ |
130 */ |
137 public abstract boolean isRegistered(); |
131 public abstract boolean isRegistered(); |
138 // |
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139 // sync(keySet) { return isRegistered; } |
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140 |
132 |
141 /** |
133 /** |
142 * Retrieves the key representing the channel's registration with the given |
134 * Retrieves the key representing the channel's registration with the given |
143 * selector. |
135 * selector. |
144 * |
136 * |
148 * @return The key returned when this channel was last registered with the |
140 * @return The key returned when this channel was last registered with the |
149 * given selector, or {@code null} if this channel is not |
141 * given selector, or {@code null} if this channel is not |
150 * currently registered with that selector |
142 * currently registered with that selector |
151 */ |
143 */ |
152 public abstract SelectionKey keyFor(Selector sel); |
144 public abstract SelectionKey keyFor(Selector sel); |
153 // |
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154 // sync(keySet) { return findKey(sel); } |
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155 |
145 |
156 /** |
146 /** |
157 * Registers this channel with the given selector, returning a selection |
147 * Registers this channel with the given selector, returning a selection |
158 * key. |
148 * key. |
159 * |
149 * |
169 * selector, so it is registered and the resulting new key is returned. |
159 * selector, so it is registered and the resulting new key is returned. |
170 * The key's initial interest set will be {@code ops} and its attachment |
160 * The key's initial interest set will be {@code ops} and its attachment |
171 * will be {@code att}. |
161 * will be {@code att}. |
172 * |
162 * |
173 * <p> This method may be invoked at any time. If this method is invoked |
163 * <p> This method may be invoked at any time. If this method is invoked |
174 * while another invocation of this method or of the {@link |
164 * while a selection operation is in progress then it has no effect upon |
175 * #configureBlocking(boolean) configureBlocking} method is in progress |
165 * that operation; the new registration or change to the key's interest set |
176 * then it will first block until the other operation is complete. This |
166 * will be seen by the next selection operation. If this method is invoked |
177 * method will then synchronize on the selector's key set and therefore may |
167 * while an invocation of {@link #configureBlocking(boolean) configureBlocking} |
178 * block if invoked concurrently with another registration or selection |
168 * is in progress then it will block until the channel's blocking mode has |
179 * operation involving the same selector. </p> |
169 * been adjusted. |
180 * |
170 * |
181 * <p> If this channel is closed while this operation is in progress then |
171 * <p> If this channel is closed while this operation is in progress then |
182 * the key returned by this method will have been cancelled and will |
172 * the key returned by this method will have been cancelled and will |
183 * therefore be invalid. </p> |
173 * therefore be invalid. </p> |
184 * |
174 * |
216 * @return A key representing the registration of this channel with |
206 * @return A key representing the registration of this channel with |
217 * the given selector |
207 * the given selector |
218 */ |
208 */ |
219 public abstract SelectionKey register(Selector sel, int ops, Object att) |
209 public abstract SelectionKey register(Selector sel, int ops, Object att) |
220 throws ClosedChannelException; |
210 throws ClosedChannelException; |
221 // |
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222 // sync(regLock) { |
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223 // sync(keySet) { look for selector } |
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224 // if (channel found) { set interest ops -- may block in selector; |
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225 // return key; } |
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226 // create new key -- may block somewhere in selector; |
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227 // sync(keySet) { add key; } |
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228 // attach(attachment); |
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229 // return key; |
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230 // } |
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231 |
211 |
232 /** |
212 /** |
233 * Registers this channel with the given selector, returning a selection |
213 * Registers this channel with the given selector, returning a selection |
234 * key. |
214 * key. |
235 * |
215 * |
312 * @throws IOException |
292 * @throws IOException |
313 * If an I/O error occurs |
293 * If an I/O error occurs |
314 */ |
294 */ |
315 public abstract SelectableChannel configureBlocking(boolean block) |
295 public abstract SelectableChannel configureBlocking(boolean block) |
316 throws IOException; |
296 throws IOException; |
317 // |
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318 // sync(regLock) { |
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319 // sync(keySet) { throw IBME if block && isRegistered; } |
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320 // change mode; |
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321 // } |
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322 |
297 |
323 /** |
298 /** |
324 * Tells whether or not every I/O operation on this channel will block |
299 * Tells whether or not every I/O operation on this channel will block |
325 * until it completes. A newly-created channel is always in blocking mode. |
300 * until it completes. A newly-created channel is always in blocking mode. |
326 * |
301 * |