rev 12972 : 8140606: Update library code to use internal Unsafe
Reviewed-by: duke
1 /*
2 * Copyright (c) 2008, 2015, 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 java.lang.invoke.MethodHandles.Lookup;
29 import java.lang.reflect.Field;
30 import static java.lang.invoke.MethodHandleNatives.Constants.*;
31 import static java.lang.invoke.MethodHandleStatics.*;
32 import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
33 import sun.misc.Cleaner;
34
35 /**
36 * The JVM interface for the method handles package is all here.
37 * This is an interface internal and private to an implementation of JSR 292.
38 * <em>This class is not part of the JSR 292 standard.</em>
39 * @author jrose
40 */
41 class MethodHandleNatives {
42
43 private MethodHandleNatives() { } // static only
44
45 /// MemberName support
46
47 static native void init(MemberName self, Object ref);
48 static native void expand(MemberName self);
49 static native MemberName resolve(MemberName self, Class<?> caller) throws LinkageError;
50 static native int getMembers(Class<?> defc, String matchName, String matchSig,
51 int matchFlags, Class<?> caller, int skip, MemberName[] results);
52
53 /// Field layout queries parallel to jdk.internal.misc.Unsafe:
54 static native long objectFieldOffset(MemberName self); // e.g., returns vmindex
55 static native long staticFieldOffset(MemberName self); // e.g., returns vmindex
56 static native Object staticFieldBase(MemberName self); // e.g., returns clazz
57 static native Object getMemberVMInfo(MemberName self); // returns {vmindex,vmtarget}
58
59 /// CallSite support
60
61 /** Tell the JVM that we need to change the target of a CallSite. */
62 static native void setCallSiteTargetNormal(CallSite site, MethodHandle target);
63 static native void setCallSiteTargetVolatile(CallSite site, MethodHandle target);
64
65 /** Represents a context to track nmethod dependencies on CallSite instance target. */
66 static class CallSiteContext implements Runnable {
67 //@Injected JVM_nmethodBucket* vmdependencies;
68
69 static CallSiteContext make(CallSite cs) {
70 final CallSiteContext newContext = new CallSiteContext();
71 // Cleaner is attached to CallSite instance and it clears native structures allocated for CallSite context.
72 // Though the CallSite can become unreachable, its Context is retained by the Cleaner instance (which is
73 // referenced from Cleaner class) until cleanup is performed.
74 Cleaner.create(cs, newContext);
75 return newContext;
76 }
77
78 @Override
79 public void run() {
80 MethodHandleNatives.clearCallSiteContext(this);
81 }
82 }
83
84 /** Invalidate all recorded nmethods. */
85 private static native void clearCallSiteContext(CallSiteContext context);
86
87 private static native void registerNatives();
88 static {
89 registerNatives();
90
91 // The JVM calls MethodHandleNatives.<clinit>. Cascade the <clinit> calls as needed:
92 MethodHandleImpl.initStatics();
93 }
94
95 /**
96 * Compile-time constants go here. This collection exists not only for
97 * reference from clients, but also for ensuring the VM and JDK agree on the
98 * values of these constants (see {@link #verifyConstants()}).
99 */
100 static class Constants {
101 Constants() { } // static only
102
103 static final int
104 MN_IS_METHOD = 0x00010000, // method (not constructor)
105 MN_IS_CONSTRUCTOR = 0x00020000, // constructor
106 MN_IS_FIELD = 0x00040000, // field
107 MN_IS_TYPE = 0x00080000, // nested type
108 MN_CALLER_SENSITIVE = 0x00100000, // @CallerSensitive annotation detected
109 MN_REFERENCE_KIND_SHIFT = 24, // refKind
110 MN_REFERENCE_KIND_MASK = 0x0F000000 >> MN_REFERENCE_KIND_SHIFT,
111 // The SEARCH_* bits are not for MN.flags but for the matchFlags argument of MHN.getMembers:
112 MN_SEARCH_SUPERCLASSES = 0x00100000,
113 MN_SEARCH_INTERFACES = 0x00200000;
114
115 /**
116 * Constant pool reference-kind codes, as used by CONSTANT_MethodHandle CP entries.
117 */
118 static final byte
119 REF_NONE = 0, // null value
120 REF_getField = 1,
121 REF_getStatic = 2,
122 REF_putField = 3,
123 REF_putStatic = 4,
124 REF_invokeVirtual = 5,
125 REF_invokeStatic = 6,
126 REF_invokeSpecial = 7,
127 REF_newInvokeSpecial = 8,
128 REF_invokeInterface = 9,
129 REF_LIMIT = 10;
130 }
131
132 static boolean refKindIsValid(int refKind) {
133 return (refKind > REF_NONE && refKind < REF_LIMIT);
134 }
135 static boolean refKindIsField(byte refKind) {
136 assert(refKindIsValid(refKind));
137 return (refKind <= REF_putStatic);
138 }
139 static boolean refKindIsGetter(byte refKind) {
140 assert(refKindIsValid(refKind));
141 return (refKind <= REF_getStatic);
142 }
143 static boolean refKindIsSetter(byte refKind) {
144 return refKindIsField(refKind) && !refKindIsGetter(refKind);
145 }
146 static boolean refKindIsMethod(byte refKind) {
147 return !refKindIsField(refKind) && (refKind != REF_newInvokeSpecial);
148 }
149 static boolean refKindIsConstructor(byte refKind) {
150 return (refKind == REF_newInvokeSpecial);
151 }
152 static boolean refKindHasReceiver(byte refKind) {
153 assert(refKindIsValid(refKind));
154 return (refKind & 1) != 0;
155 }
156 static boolean refKindIsStatic(byte refKind) {
157 return !refKindHasReceiver(refKind) && (refKind != REF_newInvokeSpecial);
158 }
159 static boolean refKindDoesDispatch(byte refKind) {
160 assert(refKindIsValid(refKind));
161 return (refKind == REF_invokeVirtual ||
162 refKind == REF_invokeInterface);
163 }
164 static {
165 final int HR_MASK = ((1 << REF_getField) |
166 (1 << REF_putField) |
167 (1 << REF_invokeVirtual) |
168 (1 << REF_invokeSpecial) |
169 (1 << REF_invokeInterface)
170 );
171 for (byte refKind = REF_NONE+1; refKind < REF_LIMIT; refKind++) {
172 assert(refKindHasReceiver(refKind) == (((1<<refKind) & HR_MASK) != 0)) : refKind;
173 }
174 }
175 static String refKindName(byte refKind) {
176 assert(refKindIsValid(refKind));
177 switch (refKind) {
178 case REF_getField: return "getField";
179 case REF_getStatic: return "getStatic";
180 case REF_putField: return "putField";
181 case REF_putStatic: return "putStatic";
182 case REF_invokeVirtual: return "invokeVirtual";
183 case REF_invokeStatic: return "invokeStatic";
184 case REF_invokeSpecial: return "invokeSpecial";
185 case REF_newInvokeSpecial: return "newInvokeSpecial";
186 case REF_invokeInterface: return "invokeInterface";
187 default: return "REF_???";
188 }
189 }
190
191 private static native int getNamedCon(int which, Object[] name);
192 static boolean verifyConstants() {
193 Object[] box = { null };
194 for (int i = 0; ; i++) {
195 box[0] = null;
196 int vmval = getNamedCon(i, box);
197 if (box[0] == null) break;
198 String name = (String) box[0];
199 try {
200 Field con = Constants.class.getDeclaredField(name);
201 int jval = con.getInt(null);
202 if (jval == vmval) continue;
203 String err = (name+": JVM has "+vmval+" while Java has "+jval);
204 if (name.equals("CONV_OP_LIMIT")) {
205 System.err.println("warning: "+err);
206 continue;
207 }
208 throw new InternalError(err);
209 } catch (NoSuchFieldException | IllegalAccessException ex) {
210 String err = (name+": JVM has "+vmval+" which Java does not define");
211 // ignore exotic ops the JVM cares about; we just wont issue them
212 //System.err.println("warning: "+err);
213 continue;
214 }
215 }
216 return true;
217 }
218 static {
219 assert(verifyConstants());
220 }
221
222 // Up-calls from the JVM.
223 // These must NOT be public.
224
225 /**
226 * The JVM is linking an invokedynamic instruction. Create a reified call site for it.
227 */
228 static MemberName linkCallSite(Object callerObj,
229 Object bootstrapMethodObj,
230 Object nameObj, Object typeObj,
231 Object staticArguments,
232 Object[] appendixResult) {
233 MethodHandle bootstrapMethod = (MethodHandle)bootstrapMethodObj;
234 Class<?> caller = (Class<?>)callerObj;
235 String name = nameObj.toString().intern();
236 MethodType type = (MethodType)typeObj;
237 if (!TRACE_METHOD_LINKAGE)
238 return linkCallSiteImpl(caller, bootstrapMethod, name, type,
239 staticArguments, appendixResult);
240 return linkCallSiteTracing(caller, bootstrapMethod, name, type,
241 staticArguments, appendixResult);
242 }
243 static MemberName linkCallSiteImpl(Class<?> caller,
244 MethodHandle bootstrapMethod,
245 String name, MethodType type,
246 Object staticArguments,
247 Object[] appendixResult) {
248 CallSite callSite = CallSite.makeSite(bootstrapMethod,
249 name,
250 type,
251 staticArguments,
252 caller);
253 if (callSite instanceof ConstantCallSite) {
254 appendixResult[0] = callSite.dynamicInvoker();
255 return Invokers.linkToTargetMethod(type);
256 } else {
257 appendixResult[0] = callSite;
258 return Invokers.linkToCallSiteMethod(type);
259 }
260 }
261 // Tracing logic:
262 static MemberName linkCallSiteTracing(Class<?> caller,
263 MethodHandle bootstrapMethod,
264 String name, MethodType type,
265 Object staticArguments,
266 Object[] appendixResult) {
267 Object bsmReference = bootstrapMethod.internalMemberName();
268 if (bsmReference == null) bsmReference = bootstrapMethod;
269 Object staticArglist = (staticArguments instanceof Object[] ?
270 java.util.Arrays.asList((Object[]) staticArguments) :
271 staticArguments);
272 System.out.println("linkCallSite "+caller.getName()+" "+
273 bsmReference+" "+
274 name+type+"/"+staticArglist);
275 try {
276 MemberName res = linkCallSiteImpl(caller, bootstrapMethod, name, type,
277 staticArguments, appendixResult);
278 System.out.println("linkCallSite => "+res+" + "+appendixResult[0]);
279 return res;
280 } catch (Throwable ex) {
281 System.out.println("linkCallSite => throw "+ex);
282 throw ex;
283 }
284 }
285
286 /**
287 * The JVM wants a pointer to a MethodType. Oblige it by finding or creating one.
288 */
289 static MethodType findMethodHandleType(Class<?> rtype, Class<?>[] ptypes) {
290 return MethodType.makeImpl(rtype, ptypes, true);
291 }
292
293 /**
294 * The JVM wants to link a call site that requires a dynamic type check.
295 * Name is a type-checking invoker, invokeExact or invoke.
296 * Return a JVM method (MemberName) to handle the invoking.
297 * The method assumes the following arguments on the stack:
298 * 0: the method handle being invoked
299 * 1-N: the arguments to the method handle invocation
300 * N+1: an optional, implicitly added argument (typically the given MethodType)
301 * <p>
302 * The nominal method at such a call site is an instance of
303 * a signature-polymorphic method (see @PolymorphicSignature).
304 * Such method instances are user-visible entities which are
305 * "split" from the generic placeholder method in {@code MethodHandle}.
306 * (Note that the placeholder method is not identical with any of
307 * its instances. If invoked reflectively, is guaranteed to throw an
308 * {@code UnsupportedOperationException}.)
309 * If the signature-polymorphic method instance is ever reified,
310 * it appears as a "copy" of the original placeholder
311 * (a native final member of {@code MethodHandle}) except
312 * that its type descriptor has shape required by the instance,
313 * and the method instance is <em>not</em> varargs.
314 * The method instance is also marked synthetic, since the
315 * method (by definition) does not appear in Java source code.
316 * <p>
317 * The JVM is allowed to reify this method as instance metadata.
318 * For example, {@code invokeBasic} is always reified.
319 * But the JVM may instead call {@code linkMethod}.
320 * If the result is an * ordered pair of a {@code (method, appendix)},
321 * the method gets all the arguments (0..N inclusive)
322 * plus the appendix (N+1), and uses the appendix to complete the call.
323 * In this way, one reusable method (called a "linker method")
324 * can perform the function of any number of polymorphic instance
325 * methods.
326 * <p>
327 * Linker methods are allowed to be weakly typed, with any or
328 * all references rewritten to {@code Object} and any primitives
329 * (except {@code long}/{@code float}/{@code double})
330 * rewritten to {@code int}.
331 * A linker method is trusted to return a strongly typed result,
332 * according to the specific method type descriptor of the
333 * signature-polymorphic instance it is emulating.
334 * This can involve (as necessary) a dynamic check using
335 * data extracted from the appendix argument.
336 * <p>
337 * The JVM does not inspect the appendix, other than to pass
338 * it verbatim to the linker method at every call.
339 * This means that the JDK runtime has wide latitude
340 * for choosing the shape of each linker method and its
341 * corresponding appendix.
342 * Linker methods should be generated from {@code LambdaForm}s
343 * so that they do not become visible on stack traces.
344 * <p>
345 * The {@code linkMethod} call is free to omit the appendix
346 * (returning null) and instead emulate the required function
347 * completely in the linker method.
348 * As a corner case, if N==255, no appendix is possible.
349 * In this case, the method returned must be custom-generated to
350 * to perform any needed type checking.
351 * <p>
352 * If the JVM does not reify a method at a call site, but instead
353 * calls {@code linkMethod}, the corresponding call represented
354 * in the bytecodes may mention a valid method which is not
355 * representable with a {@code MemberName}.
356 * Therefore, use cases for {@code linkMethod} tend to correspond to
357 * special cases in reflective code such as {@code findVirtual}
358 * or {@code revealDirect}.
359 */
360 static MemberName linkMethod(Class<?> callerClass, int refKind,
361 Class<?> defc, String name, Object type,
362 Object[] appendixResult) {
363 if (!TRACE_METHOD_LINKAGE)
364 return linkMethodImpl(callerClass, refKind, defc, name, type, appendixResult);
365 return linkMethodTracing(callerClass, refKind, defc, name, type, appendixResult);
366 }
367 static MemberName linkMethodImpl(Class<?> callerClass, int refKind,
368 Class<?> defc, String name, Object type,
369 Object[] appendixResult) {
370 try {
371 if (defc == MethodHandle.class && refKind == REF_invokeVirtual) {
372 return Invokers.methodHandleInvokeLinkerMethod(name, fixMethodType(callerClass, type), appendixResult);
373 }
374 } catch (Throwable ex) {
375 if (ex instanceof LinkageError)
376 throw (LinkageError) ex;
377 else
378 throw new LinkageError(ex.getMessage(), ex);
379 }
380 throw new LinkageError("no such method "+defc.getName()+"."+name+type);
381 }
382 private static MethodType fixMethodType(Class<?> callerClass, Object type) {
383 if (type instanceof MethodType)
384 return (MethodType) type;
385 else
386 return MethodType.fromDescriptor((String)type, callerClass.getClassLoader());
387 }
388 // Tracing logic:
389 static MemberName linkMethodTracing(Class<?> callerClass, int refKind,
390 Class<?> defc, String name, Object type,
391 Object[] appendixResult) {
392 System.out.println("linkMethod "+defc.getName()+"."+
393 name+type+"/"+Integer.toHexString(refKind));
394 try {
395 MemberName res = linkMethodImpl(callerClass, refKind, defc, name, type, appendixResult);
396 System.out.println("linkMethod => "+res+" + "+appendixResult[0]);
397 return res;
398 } catch (Throwable ex) {
399 System.out.println("linkMethod => throw "+ex);
400 throw ex;
401 }
402 }
403
404
405 /**
406 * The JVM is resolving a CONSTANT_MethodHandle CP entry. And it wants our help.
407 * It will make an up-call to this method. (Do not change the name or signature.)
408 * The type argument is a Class for field requests and a MethodType for non-fields.
409 * <p>
410 * Recent versions of the JVM may also pass a resolved MemberName for the type.
411 * In that case, the name is ignored and may be null.
412 */
413 static MethodHandle linkMethodHandleConstant(Class<?> callerClass, int refKind,
414 Class<?> defc, String name, Object type) {
415 try {
416 Lookup lookup = IMPL_LOOKUP.in(callerClass);
417 assert(refKindIsValid(refKind));
418 return lookup.linkMethodHandleConstant((byte) refKind, defc, name, type);
419 } catch (IllegalAccessException ex) {
420 Throwable cause = ex.getCause();
421 if (cause instanceof AbstractMethodError) {
422 throw (AbstractMethodError) cause;
423 } else {
424 Error err = new IllegalAccessError(ex.getMessage());
425 throw initCauseFrom(err, ex);
426 }
427 } catch (NoSuchMethodException ex) {
428 Error err = new NoSuchMethodError(ex.getMessage());
429 throw initCauseFrom(err, ex);
430 } catch (NoSuchFieldException ex) {
431 Error err = new NoSuchFieldError(ex.getMessage());
432 throw initCauseFrom(err, ex);
433 } catch (ReflectiveOperationException ex) {
434 Error err = new IncompatibleClassChangeError();
435 throw initCauseFrom(err, ex);
436 }
437 }
438
439 /**
440 * Use best possible cause for err.initCause(), substituting the
441 * cause for err itself if the cause has the same (or better) type.
442 */
443 private static Error initCauseFrom(Error err, Exception ex) {
444 Throwable th = ex.getCause();
445 if (err.getClass().isInstance(th))
446 return (Error) th;
447 err.initCause(th == null ? ex : th);
448 return err;
449 }
450
451 /**
452 * Is this method a caller-sensitive method?
453 * I.e., does it call Reflection.getCallerClass or a similar method
454 * to ask about the identity of its caller?
455 */
456 static boolean isCallerSensitive(MemberName mem) {
457 if (!mem.isInvocable()) return false; // fields are not caller sensitive
458
459 return mem.isCallerSensitive() || canBeCalledVirtual(mem);
460 }
461
462 static boolean canBeCalledVirtual(MemberName mem) {
463 assert(mem.isInvocable());
464 Class<?> defc = mem.getDeclaringClass();
465 switch (mem.getName()) {
466 case "checkMemberAccess":
467 return canBeCalledVirtual(mem, java.lang.SecurityManager.class);
468 case "getContextClassLoader":
469 return canBeCalledVirtual(mem, java.lang.Thread.class);
470 }
471 return false;
472 }
473
474 static boolean canBeCalledVirtual(MemberName symbolicRef, Class<?> definingClass) {
475 Class<?> symbolicRefClass = symbolicRef.getDeclaringClass();
476 if (symbolicRefClass == definingClass) return true;
477 if (symbolicRef.isStatic() || symbolicRef.isPrivate()) return false;
478 return (definingClass.isAssignableFrom(symbolicRefClass) || // Msym overrides Mdef
479 symbolicRefClass.isInterface()); // Mdef implements Msym
480 }
481 }
--- EOF ---