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 sun.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 ---