1 /*
2 * Copyright (c) 2008, 2017, 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 package java.lang.invoke;
27
28 import jdk.internal.vm.annotation.Stable;
29 import sun.invoke.util.ValueConversions;
30
31 import java.util.ArrayList;
32 import java.util.List;
33
34 import static java.lang.invoke.LambdaForm.BasicType;
35 import static java.lang.invoke.LambdaForm.BasicType.*;
36 import static java.lang.invoke.LambdaForm.BasicType.V_TYPE_NUM;
37 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
38 import static java.lang.invoke.MethodHandleNatives.Constants.*;
39 import static java.lang.invoke.MethodHandleStatics.newInternalError;
40 import static java.lang.invoke.MethodHandleStatics.uncaughtException;
41
42 /**
43 * The flavor of method handle which emulates an invoke instruction
44 * on a predetermined argument. The JVM dispatches to the correct method
45 * when the handle is created, not when it is invoked.
46 *
47 * All bound arguments are encapsulated in dedicated species.
48 */
49 /*non-public*/ abstract class BoundMethodHandle extends MethodHandle {
50
51 /*non-public*/ BoundMethodHandle(MethodType type, LambdaForm form) {
52 super(type, form);
53 assert(speciesData() == speciesDataFor(form));
54 }
55
56 //
57 // BMH API and internals
58 //
59
60 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, BasicType xtype, Object x) {
61 // for some type signatures, there exist pre-defined concrete BMH classes
62 try {
63 switch (xtype) {
64 case L_TYPE:
65 return bindSingle(type, form, x); // Use known fast path.
66 case I_TYPE:
67 return (BoundMethodHandle) SPECIALIZER.topSpecies().extendWith(I_TYPE_NUM).factory().invokeBasic(type, form, ValueConversions.widenSubword(x));
68 case J_TYPE:
69 return (BoundMethodHandle) SPECIALIZER.topSpecies().extendWith(J_TYPE_NUM).factory().invokeBasic(type, form, (long) x);
70 case F_TYPE:
71 return (BoundMethodHandle) SPECIALIZER.topSpecies().extendWith(F_TYPE_NUM).factory().invokeBasic(type, form, (float) x);
72 case D_TYPE:
73 return (BoundMethodHandle) SPECIALIZER.topSpecies().extendWith(D_TYPE_NUM).factory().invokeBasic(type, form, (double) x);
74 default : throw newInternalError("unexpected xtype: " + xtype);
75 }
76 } catch (Throwable t) {
77 throw uncaughtException(t);
78 }
79 }
80
81 /*non-public*/
82 LambdaFormEditor editor() {
83 return form.editor();
84 }
85
86 static BoundMethodHandle bindSingle(MethodType type, LambdaForm form, Object x) {
87 return Species_L.make(type, form, x);
88 }
89
90 @Override // there is a default binder in the super class, for 'L' types only
91 /*non-public*/
92 BoundMethodHandle bindArgumentL(int pos, Object value) {
93 return editor().bindArgumentL(this, pos, value);
94 }
95
96 /*non-public*/
97 BoundMethodHandle bindArgumentI(int pos, int value) {
98 return editor().bindArgumentI(this, pos, value);
99 }
100 /*non-public*/
101 BoundMethodHandle bindArgumentJ(int pos, long value) {
102 return editor().bindArgumentJ(this, pos, value);
103 }
104 /*non-public*/
105 BoundMethodHandle bindArgumentF(int pos, float value) {
106 return editor().bindArgumentF(this, pos, value);
107 }
108 /*non-public*/
109 BoundMethodHandle bindArgumentD(int pos, double value) {
110 return editor().bindArgumentD(this, pos, value);
111 }
112 @Override
113 BoundMethodHandle rebind() {
114 if (!tooComplex()) {
115 return this;
116 }
117 return makeReinvoker(this);
118 }
119
120 private boolean tooComplex() {
121 return (fieldCount() > FIELD_COUNT_THRESHOLD ||
122 form.expressionCount() > FORM_EXPRESSION_THRESHOLD);
123 }
124 private static final int FIELD_COUNT_THRESHOLD = 12; // largest convenient BMH field count
125 private static final int FORM_EXPRESSION_THRESHOLD = 24; // largest convenient BMH expression count
126
127 /**
128 * A reinvoker MH has this form:
129 * {@code lambda (bmh, arg*) { thismh = bmh[0]; invokeBasic(thismh, arg*) }}
130 */
131 static BoundMethodHandle makeReinvoker(MethodHandle target) {
132 LambdaForm form = DelegatingMethodHandle.makeReinvokerForm(
133 target, MethodTypeForm.LF_REBIND,
134 Species_L.BMH_SPECIES, Species_L.BMH_SPECIES.getterFunction(0));
135 return Species_L.make(target.type(), form, target);
136 }
137
138 /**
139 * Return the {@link BoundMethodHandle.SpeciesData} instance representing this BMH species. All subclasses must provide a
140 * static field containing this value, and they must accordingly implement this method.
141 */
142 /*non-public*/ abstract BoundMethodHandle.SpeciesData speciesData();
143
144 /*non-public*/ static BoundMethodHandle.SpeciesData speciesDataFor(LambdaForm form) {
145 Object c = form.names[0].constraint;
146 if (c instanceof SpeciesData) {
147 return (SpeciesData) c;
148 }
149 // if there is no BMH constraint, then use the null constraint
150 return SPECIALIZER.topSpecies();
151 }
152
153 /**
154 * Return the number of fields in this BMH. Equivalent to speciesData().fieldCount().
155 */
156 /*non-public*/ final int fieldCount() { return speciesData().fieldCount(); }
157
158 @Override
159 Object internalProperties() {
160 return "\n& BMH="+internalValues();
161 }
162
163 @Override
164 final String internalValues() {
165 int count = fieldCount();
166 if (count == 1) {
167 return "[" + arg(0) + "]";
168 }
169 StringBuilder sb = new StringBuilder("[");
170 for (int i = 0; i < count; ++i) {
171 sb.append("\n ").append(i).append(": ( ").append(arg(i)).append(" )");
172 }
173 return sb.append("\n]").toString();
174 }
175
176 /*non-public*/ final Object arg(int i) {
177 try {
178 Class<?> fieldType = speciesData().fieldTypes().get(i);
179 switch (BasicType.basicType(fieldType)) {
180 case L_TYPE: return speciesData().getter(i).invokeBasic(this);
181 case I_TYPE: return (int) speciesData().getter(i).invokeBasic(this);
182 case J_TYPE: return (long) speciesData().getter(i).invokeBasic(this);
183 case F_TYPE: return (float) speciesData().getter(i).invokeBasic(this);
184 case D_TYPE: return (double) speciesData().getter(i).invokeBasic(this);
185 }
186 } catch (Throwable ex) {
187 throw uncaughtException(ex);
188 }
189 throw new InternalError("unexpected type: " + speciesData().key()+"."+i);
190 }
191
192 //
193 // cloning API
194 //
195
196 /*non-public*/ abstract BoundMethodHandle copyWith(MethodType mt, LambdaForm lf);
197 /*non-public*/ abstract BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg);
198 /*non-public*/ abstract BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg);
199 /*non-public*/ abstract BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg);
200 /*non-public*/ abstract BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg);
201 /*non-public*/ abstract BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg);
202
203 //
204 // concrete BMH classes required to close bootstrap loops
205 //
206
207 private // make it private to force users to access the enclosing class first
208 static final class Species_L extends BoundMethodHandle {
209
210 final Object argL0;
211
212 private Species_L(MethodType mt, LambdaForm lf, Object argL0) {
213 super(mt, lf);
214 this.argL0 = argL0;
215 }
216
217 @Override
218 /*non-public*/ SpeciesData speciesData() {
219 return BMH_SPECIES;
220 }
221
222 /*non-public*/ static @Stable SpeciesData BMH_SPECIES;
223
224 /*non-public*/ static BoundMethodHandle make(MethodType mt, LambdaForm lf, Object argL0) {
225 return new Species_L(mt, lf, argL0);
226 }
227 @Override
228 /*non-public*/ final BoundMethodHandle copyWith(MethodType mt, LambdaForm lf) {
229 return new Species_L(mt, lf, argL0);
230 }
231 @Override
232 /*non-public*/ final BoundMethodHandle copyWithExtendL(MethodType mt, LambdaForm lf, Object narg) {
233 try {
234 return (BoundMethodHandle) BMH_SPECIES.extendWith(L_TYPE_NUM).factory().invokeBasic(mt, lf, argL0, narg);
235 } catch (Throwable ex) {
236 throw uncaughtException(ex);
237 }
238 }
239 @Override
240 /*non-public*/ final BoundMethodHandle copyWithExtendI(MethodType mt, LambdaForm lf, int narg) {
241 try {
242 return (BoundMethodHandle) BMH_SPECIES.extendWith(I_TYPE_NUM).factory().invokeBasic(mt, lf, argL0, narg);
243 } catch (Throwable ex) {
244 throw uncaughtException(ex);
245 }
246 }
247 @Override
248 /*non-public*/ final BoundMethodHandle copyWithExtendJ(MethodType mt, LambdaForm lf, long narg) {
249 try {
250 return (BoundMethodHandle) BMH_SPECIES.extendWith(J_TYPE_NUM).factory().invokeBasic(mt, lf, argL0, narg);
251 } catch (Throwable ex) {
252 throw uncaughtException(ex);
253 }
254 }
255 @Override
256 /*non-public*/ final BoundMethodHandle copyWithExtendF(MethodType mt, LambdaForm lf, float narg) {
257 try {
258 return (BoundMethodHandle) BMH_SPECIES.extendWith(F_TYPE_NUM).factory().invokeBasic(mt, lf, argL0, narg);
259 } catch (Throwable ex) {
260 throw uncaughtException(ex);
261 }
262 }
263 @Override
264 /*non-public*/ final BoundMethodHandle copyWithExtendD(MethodType mt, LambdaForm lf, double narg) {
265 try {
266 return (BoundMethodHandle) BMH_SPECIES.extendWith(D_TYPE_NUM).factory().invokeBasic(mt, lf, argL0, narg);
267 } catch (Throwable ex) {
268 throw uncaughtException(ex);
269 }
270 }
271 }
272
273 //
274 // BMH species meta-data
275 //
276
277 /*non-public*/
278 static final class SpeciesData extends ClassSpecializer<BoundMethodHandle, String, SpeciesData>.SpeciesData {
279 // This array is filled in lazily, as new species come into being over time.
280 @Stable final private SpeciesData[] extensions = new SpeciesData[ARG_TYPE_LIMIT];
281
282 public SpeciesData(Specializer outer, String key) {
283 outer.super(key);
284 }
285
286 @Override
287 protected String deriveClassName() {
288 String typeString = deriveTypeString();
289 if (typeString.isEmpty()) {
290 return SimpleMethodHandle.class.getName();
291 }
292 return BoundMethodHandle.class.getName() + "$Species_" + typeString;
293 }
294
295 @Override
296 protected List<Class<?>> deriveFieldTypes(String key) {
297 ArrayList<Class<?>> types = new ArrayList<>(key.length());
298 for (int i = 0; i < key.length(); i++) {
299 types.add(basicType(key.charAt(i)).basicTypeClass());
300 }
301 return types;
302 }
303
304 @Override
305 protected String deriveTypeString() {
306 // (If/when we have to add nominal types, just inherit the more complex default.)
307 return key();
308 }
309
310 @Override
311 protected MethodHandle deriveTransformHelper(MemberName transform, int whichtm) {
312 if (whichtm == Specializer.TN_COPY_NO_EXTEND) {
313 return factory();
314 } else if (whichtm < ARG_TYPE_LIMIT) {
315 return extendWith((byte) whichtm).factory();
316 } else {
317 throw newInternalError("bad transform");
318 }
319 }
320
321 @Override
322 protected <X> List<X> deriveTransformHelperArguments(MemberName transform, int whichtm, List<X> args, List<X> fields) {
323 assert(verifyTHAargs(transform, whichtm, args, fields));
324 // The rule is really simple: Keep the first two arguments
325 // the same, then put in the fields, then put any other argument.
326 args.addAll(2, fields);
327 return args;
328 }
329
330 private boolean verifyTHAargs(MemberName transform, int whichtm, List<?> args, List<?> fields) {
331 assert(transform == Specializer.BMH_TRANSFORMS.get(whichtm));
332 assert(args.size() == transform.getMethodType().parameterCount());
333 assert(fields.size() == this.fieldCount());
334 final int MH_AND_LF = 2;
335 if (whichtm == Specializer.TN_COPY_NO_EXTEND) {
336 assert(transform.getMethodType().parameterCount() == MH_AND_LF);
337 } else if (whichtm < ARG_TYPE_LIMIT) {
338 assert(transform.getMethodType().parameterCount() == MH_AND_LF+1);
339 final BasicType type = basicType((byte) whichtm);
340 assert(transform.getParameterTypes()[MH_AND_LF] == type.basicTypeClass());
341 } else {
342 return false;
343 }
344 return true;
345 }
346
347 /*non-public*/ SpeciesData extendWith(byte typeNum) {
348 SpeciesData sd = extensions[typeNum];
349 if (sd != null) return sd;
350 sd = SPECIALIZER.findSpecies(key() + BasicType.basicType(typeNum).basicTypeChar());
351 extensions[typeNum] = sd;
352 return sd;
353 }
354 }
355
356 /*non-public*/
357 static final Specializer SPECIALIZER = new Specializer();
358 static {
359 SimpleMethodHandle.BMH_SPECIES = BoundMethodHandle.SPECIALIZER.findSpecies("");
360 Species_L.BMH_SPECIES = BoundMethodHandle.SPECIALIZER.findSpecies("L");
361 }
362
363 /*non-public*/
364 static final class Specializer extends ClassSpecializer<BoundMethodHandle, String, SpeciesData> {
365
366 private static final MemberName SPECIES_DATA_ACCESSOR;
367
368 static {
369 try {
370 SPECIES_DATA_ACCESSOR = IMPL_LOOKUP.resolveOrFail(REF_invokeVirtual, BoundMethodHandle.class,
371 "speciesData", MethodType.methodType(BoundMethodHandle.SpeciesData.class));
372 } catch (ReflectiveOperationException ex) {
373 throw newInternalError("Bootstrap link error", ex);
374 }
375 }
376
377 private Specializer() {
378 super( // Reified type parameters:
379 BoundMethodHandle.class, String.class, BoundMethodHandle.SpeciesData.class,
380 // Principal constructor type:
381 MethodType.methodType(void.class, MethodType.class, LambdaForm.class),
382 // Required linkage between class and species:
383 SPECIES_DATA_ACCESSOR,
384 "BMH_SPECIES",
385 BMH_TRANSFORMS);
386 }
387
388 @Override
389 protected String topSpeciesKey() {
390 return "";
391 }
392
393 @Override
394 protected BoundMethodHandle.SpeciesData newSpeciesData(String key) {
395 return new BoundMethodHandle.SpeciesData(this, key);
396 }
397
398 static final List<MemberName> BMH_TRANSFORMS;
399 static final int TN_COPY_NO_EXTEND = V_TYPE_NUM;
400 static {
401 final Class<BoundMethodHandle> BMH = BoundMethodHandle.class;
402 // copyWithExtendLIJFD + copyWith
403 try {
404 BMH_TRANSFORMS = List.of(
405 IMPL_LOOKUP.resolveOrFail(REF_invokeVirtual, BMH, "copyWithExtendL", MethodType.methodType(BMH, MethodType.class, LambdaForm.class, Object.class)),
406 IMPL_LOOKUP.resolveOrFail(REF_invokeVirtual, BMH, "copyWithExtendI", MethodType.methodType(BMH, MethodType.class, LambdaForm.class, int.class)),
407 IMPL_LOOKUP.resolveOrFail(REF_invokeVirtual, BMH, "copyWithExtendJ", MethodType.methodType(BMH, MethodType.class, LambdaForm.class, long.class)),
408 IMPL_LOOKUP.resolveOrFail(REF_invokeVirtual, BMH, "copyWithExtendF", MethodType.methodType(BMH, MethodType.class, LambdaForm.class, float.class)),
409 IMPL_LOOKUP.resolveOrFail(REF_invokeVirtual, BMH, "copyWithExtendD", MethodType.methodType(BMH, MethodType.class, LambdaForm.class, double.class)),
410 IMPL_LOOKUP.resolveOrFail(REF_invokeVirtual, BMH, "copyWith", MethodType.methodType(BMH, MethodType.class, LambdaForm.class))
411 );
412 } catch (ReflectiveOperationException ex) {
413 throw newInternalError("Failed resolving copyWith methods", ex);
414 }
415
416 // as it happens, there is one transform per BasicType including V_TYPE
417 assert(BMH_TRANSFORMS.size() == TYPE_LIMIT);
418 }
419
420 /**
421 * Generation of concrete BMH classes.
422 *
423 * A concrete BMH species is fit for binding a number of values adhering to a
424 * given type pattern. Reference types are erased.
425 *
426 * BMH species are cached by type pattern.
427 *
428 * A BMH species has a number of fields with the concrete (possibly erased) types of
429 * bound values. Setters are provided as an API in BMH. Getters are exposed as MHs,
430 * which can be included as names in lambda forms.
431 */
432 class Factory extends ClassSpecializer<BoundMethodHandle, String, BoundMethodHandle.SpeciesData>.Factory {
433 @Override
434 protected String chooseFieldName(Class<?> type, int index) {
435 return "arg" + super.chooseFieldName(type, index);
436 }
437 }
438
439 @Override
440 protected Factory makeFactory() {
441 return new Factory();
442 }
443 }
444
445 static SpeciesData speciesData_L() { return Species_L.BMH_SPECIES; }
446 static SpeciesData speciesData_LL() { return SPECIALIZER.findSpecies("LL"); }
447 static SpeciesData speciesData_LLL() { return SPECIALIZER.findSpecies("LLL"); }
448 static SpeciesData speciesData_LLLL() { return SPECIALIZER.findSpecies("LLLL"); }
449 static SpeciesData speciesData_LLLLL() { return SPECIALIZER.findSpecies("LLLLL"); }
450 }