1 /*
2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
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
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /*
27 * This file is available under and governed by the GNU General Public
28 * License version 2 only, as published by the Free Software Foundation.
29 * However, the following notice accompanied the original version of this
30 * file, and Oracle licenses the original version of this file under the BSD
31 * license:
32 */
33 /*
34 Copyright 2009-2013 Attila Szegedi
35
36 Licensed under both the Apache License, Version 2.0 (the "Apache License")
37 and the BSD License (the "BSD License"), with licensee being free to
38 choose either of the two at their discretion.
39
40 You may not use this file except in compliance with either the Apache
41 License or the BSD License.
42
43 If you choose to use this file in compliance with the Apache License, the
44 following notice applies to you:
45
46 You may obtain a copy of the Apache License at
47
48 http://www.apache.org/licenses/LICENSE-2.0
49
50 Unless required by applicable law or agreed to in writing, software
51 distributed under the License is distributed on an "AS IS" BASIS,
52 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
53 implied. See the License for the specific language governing
54 permissions and limitations under the License.
55
56 If you choose to use this file in compliance with the BSD License, the
57 following notice applies to you:
58
59 Redistribution and use in source and binary forms, with or without
60 modification, are permitted provided that the following conditions are
61 met:
62 * Redistributions of source code must retain the above copyright
63 notice, this list of conditions and the following disclaimer.
64 * Redistributions in binary form must reproduce the above copyright
65 notice, this list of conditions and the following disclaimer in the
66 documentation and/or other materials provided with the distribution.
67 * Neither the name of the copyright holder nor the names of
68 contributors may be used to endorse or promote products derived from
69 this software without specific prior written permission.
70
71 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
72 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
73 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
74 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
75 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
76 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
77 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
78 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
79 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
80 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
81 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
82 */
83
84 package jdk.internal.dynalink.linker;
85
86 import static jdk.nashorn.internal.lookup.Lookup.MH;
87
88 import java.lang.invoke.MethodHandle;
89 import java.lang.invoke.MethodHandles;
90 import java.lang.invoke.MethodType;
91 import java.lang.invoke.SwitchPoint;
92 import java.lang.invoke.WrongMethodTypeException;
93 import java.util.List;
94 import jdk.internal.dynalink.CallSiteDescriptor;
95 import jdk.internal.dynalink.support.Guards;
96
97 /**
98 * Represents a conditionally valid method handle. It is an immutable triple of an invocation method handle, a guard
99 * method handle that defines the applicability of the invocation handle, and a switch point that can be used for
100 * external invalidation of the invocation handle. The invocation handle is suitable for invocation if the guard
101 * handle returns true for its arguments, and as long as the switch point is not invalidated. Both the guard and the
102 * switch point are optional; neither, one, or both can be present.
103 *
104 * @author Attila Szegedi
105 */
106 public class GuardedInvocation {
107 private final MethodHandle invocation;
108 private final MethodHandle guard;
109 private final Class<? extends Throwable> exception;
110 private final SwitchPoint[] switchPoints;
111
112 /**
113 * Creates a new guarded invocation. This invocation is unconditional as it has no invalidations.
114 *
115 * @param invocation the method handle representing the invocation. Must not be null.
116 * @throws NullPointerException if invocation is null.
117 */
118 public GuardedInvocation(final MethodHandle invocation) {
119 this(invocation, null, (SwitchPoint)null, null);
120 }
121
122 /**
123 * Creates a new guarded invocation.
124 *
125 * @param invocation the method handle representing the invocation. Must not be null.
126 * @param guard the method handle representing the guard. Must have the same method type as the invocation, except
127 * it must return boolean. For some useful guards, check out the {@link Guards} class. It can be null to represent
128 * an unconditional invocation, although that is unusual.
129 * @throws NullPointerException if invocation is null.
130 */
131 public GuardedInvocation(final MethodHandle invocation, final MethodHandle guard) {
132 this(invocation, guard, (SwitchPoint)null, null);
133 }
134
135 /**
136 * Creates a new guarded invocation.
137 *
138 * @param invocation the method handle representing the invocation. Must not be null.
139 * @param switchPoint the optional switch point that can be used to invalidate this linkage.
140 * @throws NullPointerException if invocation is null.
141 */
142 public GuardedInvocation(final MethodHandle invocation, final SwitchPoint switchPoint) {
143 this(invocation, null, switchPoint, null);
144 }
145
146 /**
147 * Creates a new guarded invocation.
148 *
149 * @param invocation the method handle representing the invocation. Must not be null.
150 * @param guard the method handle representing the guard. Must have the same method type as the invocation, except
151 * it must return boolean. For some useful guards, check out the {@link Guards} class. It can be null. If both it
152 * and the switch point are null, this represents an unconditional invocation, which is legal but unusual.
153 * @param switchPoint the optional switch point that can be used to invalidate this linkage.
154 * @throws NullPointerException if invocation is null.
155 */
156 public GuardedInvocation(final MethodHandle invocation, final MethodHandle guard, final SwitchPoint switchPoint) {
157 this(invocation, guard, switchPoint, null);
158 }
159
160 /**
161 * Creates a new guarded invocation.
162 *
163 * @param invocation the method handle representing the invocation. Must not be null.
164 * @param guard the method handle representing the guard. Must have the same method type as the invocation, except
165 * it must return boolean. For some useful guards, check out the {@link Guards} class. It can be null. If both it
166 * and the switch point are null, this represents an unconditional invocation, which is legal but unusual.
167 * @param switchPoint the optional switch point that can be used to invalidate this linkage.
168 * @param exception the optional exception type that is expected to be thrown by the invocation and that also
169 * invalidates the linkage.
170 * @throws NullPointerException if invocation is null.
171 */
172 public GuardedInvocation(final MethodHandle invocation, final MethodHandle guard, final SwitchPoint switchPoint, final Class<? extends Throwable> exception) {
173 invocation.getClass(); // NPE check
174 this.invocation = invocation;
175 this.guard = guard;
176 this.switchPoints = switchPoint == null ? null : new SwitchPoint[] { switchPoint };
177 this.exception = exception;
178 }
179
180 /**
181 * Creates a new guarded invocation
182 *
183 * @param invocation the method handle representing the invocation. Must not be null.
184 * @param guard the method handle representing the guard. Must have the same method type as the invocation, except
185 * it must return boolean. For some useful guards, check out the {@link Guards} class. It can be null. If both it
186 * and the switch point are null, this represents an unconditional invocation, which is legal but unusual.
187 * @param switchPoints the optional switch points that can be used to invalidate this linkage.
188 * @param exception the optional exception type that is expected to be thrown by the invocation and that also
189 * invalidates the linkage.
190 * @throws NullPointerException if invocation is null.
191 */
192 public GuardedInvocation(final MethodHandle invocation, final MethodHandle guard, final SwitchPoint[] switchPoints, final Class<? extends Throwable> exception) {
193 invocation.getClass(); // NPE check
194 this.invocation = invocation;
195 this.guard = guard;
196 this.switchPoints = switchPoints == null ? null : switchPoints.clone();
197 this.exception = exception;
198 }
199
200 /**
201 * Returns the invocation method handle.
202 *
203 * @return the invocation method handle. It will never be null.
204 */
205 public MethodHandle getInvocation() {
206 return invocation;
207 }
208
209 /**
210 * Returns the guard method handle.
211 *
212 * @return the guard method handle. Can be null.
213 */
214 public MethodHandle getGuard() {
215 return guard;
216 }
217
218 /**
219 * Returns the switch point that can be used to invalidate the invocation handle.
220 *
221 * @return the switch point that can be used to invalidate the invocation handle. Can be null.
222 */
223 public SwitchPoint[] getSwitchPoints() {
224 return switchPoints == null ? null : switchPoints.clone();
225 }
226
227 /**
228 * Returns the exception type that if thrown should be used to invalidate the linkage.
229 *
230 * @return the exception type that if thrown should be used to invalidate the linkage. Can be null.
231 */
232 public Class<? extends Throwable> getException() {
233 return exception;
234 }
235
236 /**
237 * Returns true if and only if this guarded invocation has a switchpoint, and that switchpoint has been invalidated.
238 * @return true if and only if this guarded invocation has a switchpoint, and that switchpoint has been invalidated.
239 */
240 public boolean hasBeenInvalidated() {
241 if (switchPoints == null) {
242 return false;
243 }
244 for (final SwitchPoint sp : switchPoints) {
245 if (sp.hasBeenInvalidated()) {
246 return true;
247 }
248 }
249 return false;
250 }
251
252 /**
253 * Asserts that the invocation is of the specified type, and the guard (if present) is of the specified type with a
254 * boolean return type.
255 *
256 * @param type the asserted type
257 * @throws WrongMethodTypeException if the invocation and the guard are not of the expected method type.
258 */
259 public void assertType(final MethodType type) {
260 assertType(invocation, type);
261 if (guard != null) {
262 assertType(guard, type.changeReturnType(Boolean.TYPE));
263 }
264 }
265
266 /**
267 * Creates a new guarded invocation with different methods, preserving the switch point.
268 *
269 * @param newInvocation the new invocation
270 * @param newGuard the new guard
271 * @return a new guarded invocation with the replaced methods and the same switch point as this invocation.
272 */
273 public GuardedInvocation replaceMethods(final MethodHandle newInvocation, final MethodHandle newGuard) {
274 return new GuardedInvocation(newInvocation, newGuard, switchPoints, exception);
275 }
276
277 /**
278 * Add a switchpoint to this guarded invocation
279 * @param newSwitchPoint new switchpoint, or null for nop
280 * @return new guarded invocation with the extra switchpoint
281 */
282 public GuardedInvocation addSwitchPoint(final SwitchPoint newSwitchPoint) {
283 if (newSwitchPoint == null) {
284 return this;
285 }
286
287 final SwitchPoint[] newSwitchPoints;
288 if (switchPoints != null) {
289 newSwitchPoints = new SwitchPoint[switchPoints.length + 1];
290 System.arraycopy(switchPoints, 0, newSwitchPoints, 0, switchPoints.length);
291 newSwitchPoints[switchPoints.length] = newSwitchPoint;
292 } else {
293 newSwitchPoints = new SwitchPoint[] { newSwitchPoint };
294 }
295
296 return new GuardedInvocation(invocation, guard, newSwitchPoints, exception);
297 }
298
299 private GuardedInvocation replaceMethodsOrThis(final MethodHandle newInvocation, final MethodHandle newGuard) {
300 if (newInvocation == invocation && newGuard == guard) {
301 return this;
302 }
303 return replaceMethods(newInvocation, newGuard);
304 }
305
306 /**
307 * Changes the type of the invocation, as if {@link MethodHandle#asType(MethodType)} was applied to its invocation
308 * and its guard, if it has one (with return type changed to boolean, and parameter count potentially truncated for
309 * the guard). If the invocation already is of the required type, returns this object.
310 * @param newType the new type of the invocation.
311 * @return a guarded invocation with the new type applied to it.
312 */
313 public GuardedInvocation asType(final MethodType newType) {
314 return replaceMethodsOrThis(invocation.asType(newType), guard == null ? null : Guards.asType(guard, newType));
315 }
316
317 /**
318 * Changes the type of the invocation, as if {@link LinkerServices#asType(MethodHandle, MethodType)} was applied to
319 * its invocation and its guard, if it has one (with return type changed to boolean, and parameter count potentially
320 * truncated for the guard). If the invocation already is of the required type, returns this object.
321 * @param linkerServices the linker services to use for the conversion
322 * @param newType the new type of the invocation.
323 * @return a guarded invocation with the new type applied to it.
324 */
325 public GuardedInvocation asType(final LinkerServices linkerServices, final MethodType newType) {
326 return replaceMethodsOrThis(linkerServices.asType(invocation, newType), guard == null ? null :
327 Guards.asType(linkerServices, guard, newType));
328 }
329
330 /**
331 * Changes the type of the invocation, as if {@link LinkerServices#asTypeLosslessReturn(MethodHandle, MethodType)} was
332 * applied to its invocation and {@link LinkerServices#asType(MethodHandle, MethodType)} applied to its guard, if it
333 * has one (with return type changed to boolean, and parameter count potentially truncated for the guard). If the
334 * invocation doesn't change its type, returns this object.
335 * @param linkerServices the linker services to use for the conversion
336 * @param newType the new type of the invocation.
337 * @return a guarded invocation with the new type applied to it.
338 */
339 public GuardedInvocation asTypeSafeReturn(final LinkerServices linkerServices, final MethodType newType) {
340 return replaceMethodsOrThis(linkerServices.asTypeLosslessReturn(invocation, newType), guard == null ? null :
341 Guards.asType(linkerServices, guard, newType));
342 }
343
344 /**
345 * Changes the type of the invocation, as if {@link MethodHandle#asType(MethodType)} was applied to its invocation
346 * and its guard, if it has one (with return type changed to boolean for guard). If the invocation already is of the
347 * required type, returns this object.
348 * @param desc a call descriptor whose method type is adapted.
349 * @return a guarded invocation with the new type applied to it.
350 */
351 public GuardedInvocation asType(final CallSiteDescriptor desc) {
352 return asType(desc.getMethodType());
353 }
354
355 /**
356 * Applies argument filters to both the invocation and the guard (if there is one).
357 * @param pos the position of the first argumen being filtered
358 * @param filters the argument filters
359 * @return a filtered invocation
360 */
361 public GuardedInvocation filterArguments(final int pos, final MethodHandle... filters) {
362 return replaceMethods(MethodHandles.filterArguments(invocation, pos, filters), guard == null ? null :
363 MethodHandles.filterArguments(guard, pos, filters));
364 }
365
366 /**
367 * Makes an invocation that drops arguments in both the invocation and the guard (if there is one).
368 * @param pos the position of the first argument being dropped
369 * @param valueTypes the types of the values being dropped
370 * @return an invocation that drops arguments
371 */
372 public GuardedInvocation dropArguments(final int pos, final List<Class<?>> valueTypes) {
373 return replaceMethods(MethodHandles.dropArguments(invocation, pos, valueTypes), guard == null ? null :
374 MethodHandles.dropArguments(guard, pos, valueTypes));
375 }
376
377 /**
378 * Makes an invocation that drops arguments in both the invocation and the guard (if there is one).
379 * @param pos the position of the first argument being dropped
380 * @param valueTypes the types of the values being dropped
381 * @return an invocation that drops arguments
382 */
383 public GuardedInvocation dropArguments(final int pos, final Class<?>... valueTypes) {
384 return replaceMethods(MethodHandles.dropArguments(invocation, pos, valueTypes), guard == null ? null :
385 MethodHandles.dropArguments(guard, pos, valueTypes));
386 }
387
388
389 /**
390 * Composes the invocation, switchpoint, and the guard into a composite method handle that knows how to fall back.
391 * @param fallback the fallback method handle in case switchpoint is invalidated or guard returns false.
392 * @return a composite method handle.
393 */
394 public MethodHandle compose(final MethodHandle fallback) {
395 return compose(fallback, fallback, fallback);
396 }
397
398 /**
399 * Composes the invocation, switchpoint, and the guard into a composite method handle that knows how to fall back.
400 * @param switchpointFallback the fallback method handle in case switchpoint is invalidated.
401 * @param guardFallback the fallback method handle in case guard returns false.
402 * @param catchFallback the fallback method in case the exception handler triggers
403 * @return a composite method handle.
404 */
405 public MethodHandle compose(final MethodHandle guardFallback, final MethodHandle switchpointFallback, final MethodHandle catchFallback) {
406 final MethodHandle guarded =
407 guard == null ?
408 invocation :
409 MethodHandles.guardWithTest(
410 guard,
411 invocation,
412 guardFallback);
413
414 final MethodHandle catchGuarded =
415 exception == null ?
416 guarded :
417 MH.catchException(
418 guarded,
419 exception,
420 MethodHandles.dropArguments(
421 catchFallback,
422 0,
423 exception));
424
425 if (switchPoints == null) {
426 return catchGuarded;
427 }
428
429 MethodHandle spGuarded = catchGuarded;
430 for (final SwitchPoint sp : switchPoints) {
431 spGuarded = sp.guardWithTest(spGuarded, switchpointFallback);
432 }
433
434 return spGuarded;
435 }
436
437 private static void assertType(final MethodHandle mh, final MethodType type) {
438 if(!mh.type().equals(type)) {
439 throw new WrongMethodTypeException("Expected type: " + type + " actual type: " + mh.type());
440 }
441 }
442 }