CompiledFunction.java revision 953:221a84ef44c0
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 */ 25package jdk.nashorn.internal.runtime; 26 27import static jdk.nashorn.internal.lookup.Lookup.MH; 28import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT; 29import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.isValid; 30 31import java.lang.invoke.CallSite; 32import java.lang.invoke.MethodHandle; 33import java.lang.invoke.MethodHandles; 34import java.lang.invoke.MethodType; 35import java.lang.invoke.MutableCallSite; 36import java.lang.invoke.SwitchPoint; 37import java.util.Iterator; 38import java.util.Map; 39import java.util.TreeMap; 40import java.util.logging.Level; 41import jdk.nashorn.internal.codegen.Compiler; 42import jdk.nashorn.internal.codegen.Compiler.CompilationPhases; 43import jdk.nashorn.internal.codegen.types.ArrayType; 44import jdk.nashorn.internal.codegen.types.Type; 45import jdk.nashorn.internal.ir.FunctionNode; 46import jdk.nashorn.internal.runtime.events.RecompilationEvent; 47import jdk.nashorn.internal.runtime.linker.Bootstrap; 48import jdk.nashorn.internal.runtime.logging.DebugLogger; 49 50/** 51 * An version of a JavaScript function, native or JavaScript. 52 * Supports lazily generating a constructor version of the invocation. 53 */ 54final class CompiledFunction { 55 56 private static final MethodHandle NEWFILTER = findOwnMH("newFilter", Object.class, Object.class, Object.class); 57 private static final MethodHandle RELINK_COMPOSABLE_INVOKER = findOwnMH("relinkComposableInvoker", void.class, CallSite.class, CompiledFunction.class, boolean.class); 58 private static final MethodHandle HANDLE_REWRITE_EXCEPTION = findOwnMH("handleRewriteException", MethodHandle.class, CompiledFunction.class, OptimismInfo.class, RewriteException.class); 59 private static final MethodHandle RESTOF_INVOKER = MethodHandles.exactInvoker(MethodType.methodType(Object.class, RewriteException.class)); 60 61 private final DebugLogger log; 62 63 /** 64 * The method type may be more specific than the invoker, if. e.g. 65 * the invoker is guarded, and a guard with a generic object only 66 * fallback, while the target is more specific, we still need the 67 * more specific type for sorting 68 */ 69 private MethodHandle invoker; 70 private MethodHandle constructor; 71 private OptimismInfo optimismInfo; 72 private int flags; // from FunctionNode 73 74 CompiledFunction(final MethodHandle invoker) { 75 this(invoker, null); 76 } 77 78 static CompiledFunction createBuiltInConstructor(final MethodHandle invoker) { 79 return new CompiledFunction(MH.insertArguments(invoker, 0, false), createConstructorFromInvoker(MH.insertArguments(invoker, 0, true))); 80 } 81 82 CompiledFunction(final MethodHandle invoker, final MethodHandle constructor) { 83 this(invoker, constructor, DebugLogger.DISABLED_LOGGER); 84 } 85 86 CompiledFunction(final MethodHandle invoker, final MethodHandle constructor, final DebugLogger log) { 87 this.invoker = invoker; 88 this.constructor = constructor; 89 this.log = log; 90 } 91 92 CompiledFunction(final MethodHandle invoker, final RecompilableScriptFunctionData functionData, 93 final Map<Integer, Type> invalidatedProgramPoints, final int flags) { 94 this(invoker, null, functionData.getLogger()); 95 this.flags = flags; 96 if ((flags & FunctionNode.IS_DEOPTIMIZABLE) != 0) { 97 optimismInfo = new OptimismInfo(functionData, invalidatedProgramPoints); 98 } else { 99 optimismInfo = null; 100 } 101 } 102 103 int getFlags() { 104 return flags; 105 } 106 107 boolean isApplyToCall() { 108 return (flags & FunctionNode.HAS_APPLY_TO_CALL_SPECIALIZATION) != 0; 109 } 110 111 boolean isVarArg() { 112 return isVarArgsType(invoker.type()); 113 } 114 115 @Override 116 public String toString() { 117 return "[invokerType=" + invoker.type() + " ctor=" + constructor + " weight=" + weight() + " isApplyToCall=" + isApplyToCall() + "]"; 118 } 119 120 boolean needsCallee() { 121 return ScriptFunctionData.needsCallee(invoker); 122 } 123 124 /** 125 * Returns an invoker method handle for this function. Note that the handle is safely composable in 126 * the sense that you can compose it with other handles using any combinators even if you can't affect call site 127 * invalidation. If this compiled function is non-optimistic, then it returns the same value as 128 * {@link #getInvoker()}. However, if the function is optimistic, then this handle will incur an overhead as it will 129 * add an intermediate internal call site that can relink itself when the function needs to regenerate its code to 130 * always point at the latest generated code version. 131 * @return a guaranteed composable invoker method handle for this function. 132 */ 133 MethodHandle createComposableInvoker() { 134 return createComposableInvoker(false); 135 } 136 137 /** 138 * Returns an invoker method handle for this function when invoked as a constructor. Note that the handle should be 139 * considered non-composable in the sense that you can only compose it with other handles using any combinators if 140 * you can ensure that the composition is guarded by {@link #getOptimisticAssumptionsSwitchPoint()} if it's 141 * non-null, and that you can relink the call site it is set into as a target if the switch point is invalidated. In 142 * all other cases, use {@link #createComposableConstructor()}. 143 * @return a direct constructor method handle for this function. 144 */ 145 MethodHandle getConstructor() { 146 if (constructor == null) { 147 constructor = createConstructorFromInvoker(createInvokerForPessimisticCaller()); 148 } 149 150 return constructor; 151 } 152 153 /** 154 * Creates a version of the invoker intended for a pessimistic caller (return type is Object, no caller optimistic 155 * program point available). 156 * @return a version of the invoker intended for a pessimistic caller. 157 */ 158 private MethodHandle createInvokerForPessimisticCaller() { 159 return createInvoker(Object.class, INVALID_PROGRAM_POINT); 160 } 161 162 /** 163 * Compose a constructor from an invoker. 164 * 165 * @param invoker invoker 166 * @param needsCallee do we need to pass a callee 167 * 168 * @return the composed constructor 169 */ 170 private static MethodHandle createConstructorFromInvoker(final MethodHandle invoker) { 171 final boolean needsCallee = ScriptFunctionData.needsCallee(invoker); 172 // If it was (callee, this, args...), permute it to (this, callee, args...). We're doing this because having 173 // "this" in the first argument position is what allows the elegant folded composition of 174 // (newFilter x constructor x allocator) further down below in the code. Also, ensure the composite constructor 175 // always returns Object. 176 final MethodHandle swapped = needsCallee ? swapCalleeAndThis(invoker) : invoker; 177 178 final MethodHandle returnsObject = MH.asType(swapped, swapped.type().changeReturnType(Object.class)); 179 180 final MethodType ctorType = returnsObject.type(); 181 182 // Construct a dropping type list for NEWFILTER, but don't include constructor "this" into it, so it's actually 183 // captured as "allocation" parameter of NEWFILTER after we fold the constructor into it. 184 // (this, [callee, ]args...) => ([callee, ]args...) 185 final Class<?>[] ctorArgs = ctorType.dropParameterTypes(0, 1).parameterArray(); 186 187 // Fold constructor into newFilter that replaces the return value from the constructor with the originally 188 // allocated value when the originally allocated value is a JS primitive (String, Boolean, Number). 189 // (result, this, [callee, ]args...) x (this, [callee, ]args...) => (this, [callee, ]args...) 190 final MethodHandle filtered = MH.foldArguments(MH.dropArguments(NEWFILTER, 2, ctorArgs), returnsObject); 191 192 // allocate() takes a ScriptFunction and returns a newly allocated ScriptObject... 193 if (needsCallee) { 194 // ...we either fold it into the previous composition, if we need both the ScriptFunction callee object and 195 // the newly allocated object in the arguments, so (this, callee, args...) x (callee) => (callee, args...), 196 // or... 197 return MH.foldArguments(filtered, ScriptFunction.ALLOCATE); 198 } 199 200 // ...replace the ScriptFunction argument with the newly allocated object, if it doesn't need the callee 201 // (this, args...) filter (callee) => (callee, args...) 202 return MH.filterArguments(filtered, 0, ScriptFunction.ALLOCATE); 203 } 204 205 /** 206 * Permutes the parameters in the method handle from {@code (callee, this, ...)} to {@code (this, callee, ...)}. 207 * Used when creating a constructor handle. 208 * @param mh a method handle with order of arguments {@code (callee, this, ...)} 209 * @return a method handle with order of arguments {@code (this, callee, ...)} 210 */ 211 private static MethodHandle swapCalleeAndThis(final MethodHandle mh) { 212 final MethodType type = mh.type(); 213 assert type.parameterType(0) == ScriptFunction.class : type; 214 assert type.parameterType(1) == Object.class : type; 215 final MethodType newType = type.changeParameterType(0, Object.class).changeParameterType(1, ScriptFunction.class); 216 final int[] reorder = new int[type.parameterCount()]; 217 reorder[0] = 1; 218 assert reorder[1] == 0; 219 for (int i = 2; i < reorder.length; ++i) { 220 reorder[i] = i; 221 } 222 return MethodHandles.permuteArguments(mh, newType, reorder); 223 } 224 225 /** 226 * Returns an invoker method handle for this function when invoked as a constructor. Note that the handle is safely 227 * composable in the sense that you can compose it with other handles using any combinators even if you can't affect 228 * call site invalidation. If this compiled function is non-optimistic, then it returns the same value as 229 * {@link #getConstructor()}. However, if the function is optimistic, then this handle will incur an overhead as it 230 * will add an intermediate internal call site that can relink itself when the function needs to regenerate its code 231 * to always point at the latest generated code version. 232 * @return a guaranteed composable constructor method handle for this function. 233 */ 234 MethodHandle createComposableConstructor() { 235 return createComposableInvoker(true); 236 } 237 238 boolean hasConstructor() { 239 return constructor != null; 240 } 241 242 MethodType type() { 243 return invoker.type(); 244 } 245 246 int weight() { 247 return weight(type()); 248 } 249 250 private static int weight(final MethodType type) { 251 if (isVarArgsType(type)) { 252 return Integer.MAX_VALUE; //if there is a varargs it should be the heavist and last fallback 253 } 254 255 int weight = Type.typeFor(type.returnType()).getWeight(); 256 for (int i = 0 ; i < type.parameterCount() ; i++) { 257 final Class<?> paramType = type.parameterType(i); 258 final int pweight = Type.typeFor(paramType).getWeight() * 2; //params are more important than call types as return values are always specialized 259 weight += pweight; 260 } 261 262 weight += type.parameterCount(); //more params outweigh few parameters 263 264 return weight; 265 } 266 267 static boolean isVarArgsType(final MethodType type) { 268 assert type.parameterCount() >= 1 : type; 269 return type.parameterType(type.parameterCount() - 1) == Object[].class; 270 } 271 272 static boolean moreGenericThan(final MethodType mt0, final MethodType mt1) { 273 return weight(mt0) > weight(mt1); 274 } 275 276 boolean betterThanFinal(final CompiledFunction other, final MethodType callSiteMethodType) { 277 // Prefer anything over nothing, as we can't compile new versions. 278 if (other == null) { 279 return true; 280 } 281 return betterThanFinal(type(), other.type(), callSiteMethodType); 282 } 283 284 static boolean betterThanFinal(final MethodType thisMethodType, final MethodType otherMethodType, final MethodType callSiteMethodType) { 285 final int thisParamCount = getParamCount(thisMethodType); 286 final int otherParamCount = getParamCount(otherMethodType); 287 final int callSiteRawParamCount = getParamCount(callSiteMethodType); 288 final boolean csVarArg = callSiteRawParamCount == Integer.MAX_VALUE; 289 // Subtract 1 for callee for non-vararg call sites 290 final int callSiteParamCount = csVarArg ? callSiteRawParamCount : callSiteRawParamCount - 1; 291 292 // Prefer the function that discards less parameters 293 final int thisDiscardsParams = Math.max(callSiteParamCount - thisParamCount, 0); 294 final int otherDiscardsParams = Math.max(callSiteParamCount - otherParamCount, 0); 295 if(thisDiscardsParams < otherDiscardsParams) { 296 return true; 297 } 298 if(thisDiscardsParams > otherDiscardsParams) { 299 return false; 300 } 301 302 final boolean thisVarArg = thisParamCount == Integer.MAX_VALUE; 303 final boolean otherVarArg = otherParamCount == Integer.MAX_VALUE; 304 if(!(thisVarArg && otherVarArg && csVarArg)) { 305 // At least one of them isn't vararg 306 final Type[] thisType = toTypeWithoutCallee(thisMethodType, 0); // Never has callee 307 final Type[] otherType = toTypeWithoutCallee(otherMethodType, 0); // Never has callee 308 final Type[] callSiteType = toTypeWithoutCallee(callSiteMethodType, 1); // Always has callee 309 310 int narrowWeightDelta = 0; 311 int widenWeightDelta = 0; 312 final int minParamsCount = Math.min(Math.min(thisParamCount, otherParamCount), callSiteParamCount); 313 for(int i = 0; i < minParamsCount; ++i) { 314 final int callSiteParamWeight = getParamType(i, callSiteType, csVarArg).getWeight(); 315 // Delta is negative for narrowing, positive for widening 316 final int thisParamWeightDelta = getParamType(i, thisType, thisVarArg).getWeight() - callSiteParamWeight; 317 final int otherParamWeightDelta = getParamType(i, otherType, otherVarArg).getWeight() - callSiteParamWeight; 318 // Only count absolute values of narrowings 319 narrowWeightDelta += Math.max(-thisParamWeightDelta, 0) - Math.max(-otherParamWeightDelta, 0); 320 // Only count absolute values of widenings 321 widenWeightDelta += Math.max(thisParamWeightDelta, 0) - Math.max(otherParamWeightDelta, 0); 322 } 323 324 // If both functions accept more arguments than what is passed at the call site, account for ability 325 // to receive Undefined un-narrowed in the remaining arguments. 326 if(!thisVarArg) { 327 for(int i = callSiteParamCount; i < thisParamCount; ++i) { 328 narrowWeightDelta += Math.max(Type.OBJECT.getWeight() - thisType[i].getWeight(), 0); 329 } 330 } 331 if(!otherVarArg) { 332 for(int i = callSiteParamCount; i < otherParamCount; ++i) { 333 narrowWeightDelta -= Math.max(Type.OBJECT.getWeight() - otherType[i].getWeight(), 0); 334 } 335 } 336 337 // Prefer function that narrows less 338 if(narrowWeightDelta < 0) { 339 return true; 340 } 341 if(narrowWeightDelta > 0) { 342 return false; 343 } 344 345 // Prefer function that widens less 346 if(widenWeightDelta < 0) { 347 return true; 348 } 349 if(widenWeightDelta > 0) { 350 return false; 351 } 352 } 353 354 // Prefer the function that exactly matches the arity of the call site. 355 if(thisParamCount == callSiteParamCount && otherParamCount != callSiteParamCount) { 356 return true; 357 } 358 if(thisParamCount != callSiteParamCount && otherParamCount == callSiteParamCount) { 359 return false; 360 } 361 362 // Otherwise, neither function matches arity exactly. We also know that at this point, they both can receive 363 // more arguments than call site, otherwise we would've already chosen the one that discards less parameters. 364 // Note that variable arity methods are preferred, as they actually match the call site arity better, since they 365 // really have arbitrary arity. 366 if(thisVarArg) { 367 if(!otherVarArg) { 368 return true; // 369 } 370 } else if(otherVarArg) { 371 return false; 372 } 373 374 // Neither is variable arity; chose the one that has less extra parameters. 375 final int fnParamDelta = thisParamCount - otherParamCount; 376 if(fnParamDelta < 0) { 377 return true; 378 } 379 if(fnParamDelta > 0) { 380 return false; 381 } 382 383 final int callSiteRetWeight = Type.typeFor(callSiteMethodType.returnType()).getWeight(); 384 // Delta is negative for narrower return type, positive for wider return type 385 final int thisRetWeightDelta = Type.typeFor(thisMethodType.returnType()).getWeight() - callSiteRetWeight; 386 final int otherRetWeightDelta = Type.typeFor(otherMethodType.returnType()).getWeight() - callSiteRetWeight; 387 388 // Prefer function that returns a less wide return type 389 final int widenRetDelta = Math.max(thisRetWeightDelta, 0) - Math.max(otherRetWeightDelta, 0); 390 if(widenRetDelta < 0) { 391 return true; 392 } 393 if(widenRetDelta > 0) { 394 return false; 395 } 396 397 // Prefer function that returns a less narrow return type 398 final int narrowRetDelta = Math.max(-thisRetWeightDelta, 0) - Math.max(-otherRetWeightDelta, 0); 399 if(narrowRetDelta < 0) { 400 return true; 401 } 402 if(narrowRetDelta > 0) { 403 return false; 404 } 405 406 throw new AssertionError(thisMethodType + " identically applicable to " + otherMethodType + " for " + callSiteMethodType); // Signatures are identical 407 } 408 409 private static Type[] toTypeWithoutCallee(final MethodType type, final int thisIndex) { 410 final int paramCount = type.parameterCount(); 411 final Type[] t = new Type[paramCount - thisIndex]; 412 for(int i = thisIndex; i < paramCount; ++i) { 413 t[i - thisIndex] = Type.typeFor(type.parameterType(i)); 414 } 415 return t; 416 } 417 418 private static Type getParamType(final int i, final Type[] paramTypes, final boolean isVarArg) { 419 final int fixParamCount = paramTypes.length - (isVarArg ? 1 : 0); 420 if(i < fixParamCount) { 421 return paramTypes[i]; 422 } 423 assert isVarArg; 424 return ((ArrayType)paramTypes[paramTypes.length - 1]).getElementType(); 425 } 426 427 boolean matchesCallSite(final MethodType callSiteType, final boolean pickVarArg) { 428 final MethodType type = type(); 429 final int fnParamCount = getParamCount(type); 430 final boolean isVarArg = fnParamCount == Integer.MAX_VALUE; 431 if (isVarArg) { 432 return pickVarArg; 433 } 434 435 final int csParamCount = getParamCount(callSiteType); 436 final boolean csIsVarArg = csParamCount == Integer.MAX_VALUE; 437 final int thisThisIndex = needsCallee() ? 1 : 0; // Index of "this" parameter in this function's type 438 439 final int fnParamCountNoCallee = fnParamCount - thisThisIndex; 440 final int minParams = Math.min(csParamCount - 1, fnParamCountNoCallee); // callSiteType always has callee, so subtract 1 441 // We must match all incoming parameters, except "this". Starting from 1 to skip "this". 442 for(int i = 1; i < minParams; ++i) { 443 final Type fnType = Type.typeFor(type.parameterType(i + thisThisIndex)); 444 final Type csType = csIsVarArg ? Type.OBJECT : Type.typeFor(callSiteType.parameterType(i + 1)); 445 if(!fnType.isEquivalentTo(csType)) { 446 return false; 447 } 448 } 449 450 // Must match any undefined parameters to Object type. 451 for(int i = minParams; i < fnParamCountNoCallee; ++i) { 452 if(!Type.typeFor(type.parameterType(i + thisThisIndex)).isEquivalentTo(Type.OBJECT)) { 453 return false; 454 } 455 } 456 457 return true; 458 } 459 460 private static int getParamCount(final MethodType type) { 461 final int paramCount = type.parameterCount(); 462 return type.parameterType(paramCount - 1).isArray() ? Integer.MAX_VALUE : paramCount; 463 } 464 465 /** 466 * Returns the switch point embodying the optimistic assumptions in this compiled function. It should be used to 467 * guard any linking to the function's invoker or constructor. 468 * @return the switch point embodying the optimistic assumptions in this compiled function. Null is returned if the 469 * function has no optimistic assumptions. 470 */ 471 SwitchPoint getOptimisticAssumptionsSwitchPoint() { 472 return canBeDeoptimized() ? optimismInfo.optimisticAssumptions : null; 473 } 474 475 boolean canBeDeoptimized() { 476 return optimismInfo != null; 477 } 478 479 private MethodHandle createComposableInvoker(final boolean isConstructor) { 480 final MethodHandle handle = getInvokerOrConstructor(isConstructor); 481 482 // If compiled function is not optimistic, it can't ever change its invoker/constructor, so just return them 483 // directly. 484 if(!canBeDeoptimized()) { 485 return handle; 486 } 487 488 // Otherwise, we need a new level of indirection; need to introduce a mutable call site that can relink itslef 489 // to the compiled function's changed target whenever the optimistic assumptions are invalidated. 490 final CallSite cs = new MutableCallSite(handle.type()); 491 relinkComposableInvoker(cs, this, isConstructor); 492 return cs.dynamicInvoker(); 493 } 494 private static void relinkComposableInvoker(final CallSite cs, final CompiledFunction inv, final boolean constructor) { 495 final MethodHandle handle = inv.getInvokerOrConstructor(constructor); 496 final SwitchPoint assumptions = inv.getOptimisticAssumptionsSwitchPoint(); 497 final MethodHandle target; 498 if(assumptions == null) { 499 target = handle; 500 } else { 501 // This assertion can obviously fail in a multithreaded environment, as we can be in a situation where 502 // one thread is in the middle of a deoptimizing compilation when we hit this and thus, it has invalidated 503 // the old switch point, but hasn't created the new one yet. Note that the behavior of invalidating the old 504 // switch point before recompilation, and only creating the new one after recompilation is by design. 505 // TODO: We need to think about thread safety of CompiledFunction objects. 506 assert !assumptions.hasBeenInvalidated(); 507 final MethodHandle relink = MethodHandles.insertArguments(RELINK_COMPOSABLE_INVOKER, 0, cs, inv, constructor); 508 target = assumptions.guardWithTest(handle, MethodHandles.foldArguments(cs.dynamicInvoker(), relink)); 509 } 510 cs.setTarget(target.asType(cs.type())); 511 } 512 513 private MethodHandle getInvokerOrConstructor(final boolean selectCtor) { 514 return selectCtor ? getConstructor() : createInvokerForPessimisticCaller(); 515 } 516 517 MethodHandle createInvoker(final Class<?> callSiteReturnType, final int callerProgramPoint) { 518 final boolean isOptimistic = canBeDeoptimized(); 519 MethodHandle handleRewriteException = isOptimistic ? createRewriteExceptionHandler() : null; 520 521 MethodHandle inv = invoker; 522 if(isValid(callerProgramPoint)) { 523 inv = OptimisticReturnFilters.filterOptimisticReturnValue(inv, callSiteReturnType, callerProgramPoint); 524 inv = changeReturnType(inv, callSiteReturnType); 525 if(callSiteReturnType.isPrimitive() && handleRewriteException != null) { 526 // because handleRewriteException always returns Object 527 handleRewriteException = OptimisticReturnFilters.filterOptimisticReturnValue(handleRewriteException, 528 callSiteReturnType, callerProgramPoint); 529 } 530 } else if(isOptimistic) { 531 // Required so that rewrite exception has the same return type. It'd be okay to do it even if we weren't 532 // optimistic, but it isn't necessary as the linker upstream will eventually convert the return type. 533 inv = changeReturnType(inv, callSiteReturnType); 534 } 535 536 if(isOptimistic) { 537 assert handleRewriteException != null; 538 final MethodHandle typedHandleRewriteException = changeReturnType(handleRewriteException, inv.type().returnType()); 539 return MH.catchException(inv, RewriteException.class, typedHandleRewriteException); 540 } 541 return inv; 542 } 543 544 private MethodHandle createRewriteExceptionHandler() { 545 return MH.foldArguments(RESTOF_INVOKER, MH.insertArguments(HANDLE_REWRITE_EXCEPTION, 0, this, optimismInfo)); 546 } 547 548 private static MethodHandle changeReturnType(final MethodHandle mh, final Class<?> newReturnType) { 549 return Bootstrap.getLinkerServices().asType(mh, mh.type().changeReturnType(newReturnType)); 550 } 551 552 @SuppressWarnings("unused") 553 private static MethodHandle handleRewriteException(final CompiledFunction function, final OptimismInfo oldOptimismInfo, final RewriteException re) { 554 return function.handleRewriteException(oldOptimismInfo, re); 555 } 556 557 /** 558 * Debug function for printing out all invalidated program points and their 559 * invalidation mapping to next type 560 * @param ipp 561 * @return string describing the ipp map 562 */ 563 private static String toStringInvalidations(final Map<Integer, Type> ipp) { 564 if (ipp == null) { 565 return ""; 566 } 567 568 final StringBuilder sb = new StringBuilder(); 569 570 for (final Iterator<Map.Entry<Integer, Type>> iter = ipp.entrySet().iterator(); iter.hasNext(); ) { 571 final Map.Entry<Integer, Type> entry = iter.next(); 572 final char bct = entry.getValue().getBytecodeStackType(); 573 574 sb.append('['). 575 append(entry.getKey()). 576 append("->"). 577 append(bct == 'A' ? 'O' : bct). 578 append(']'); 579 580 if (iter.hasNext()) { 581 sb.append(' '); 582 } 583 } 584 585 return sb.toString(); 586 } 587 588 private void logRecompile(final String reason, final FunctionNode fn, final MethodType callSiteType, final Map<Integer, Type> ipp) { 589 if (log.isEnabled()) { 590 log.info(reason, DebugLogger.quote(fn.getName()), " signature: ", callSiteType, " ", toStringInvalidations(ipp)); 591 } 592 } 593 594 /** 595 * Handles a {@link RewriteException} raised during the execution of this function by recompiling (if needed) the 596 * function with an optimistic assumption invalidated at the program point indicated by the exception, and then 597 * executing a rest-of method to complete the execution with the deoptimized version. 598 * @param oldOptInfo the optimism info of this function. We must store it explicitly as a bound argument in the 599 * method handle, otherwise it could be null for handling a rewrite exception in an outer invocation of a recursive 600 * function when recursive invocations of the function have completely deoptimized it. 601 * @param re the rewrite exception that was raised 602 * @return the method handle for the rest-of method, for folding composition. 603 */ 604 private MethodHandle handleRewriteException(final OptimismInfo oldOptInfo, final RewriteException re) { 605 if (log.isEnabled()) { 606 log.info(new RecompilationEvent(Level.INFO, re, re.getReturnValueNonDestructive()), "RewriteException ", re.getMessageShort()); 607 } 608 609 final MethodType type = type(); 610 611 // Compiler needs a call site type as its input, which always has a callee parameter, so we must add it if 612 // this function doesn't have a callee parameter. 613 final MethodType callSiteType = type.parameterType(0) == ScriptFunction.class ? 614 type : 615 type.insertParameterTypes(0, ScriptFunction.class); 616 final OptimismInfo currentOptInfo = optimismInfo; 617 final boolean shouldRecompile = currentOptInfo != null && currentOptInfo.requestRecompile(re); 618 619 // Effective optimism info, for subsequent use. We'll normally try to use the current (latest) one, but if it 620 // isn't available, we'll use the old one bound into the call site. 621 final OptimismInfo effectiveOptInfo = currentOptInfo != null ? currentOptInfo : oldOptInfo; 622 FunctionNode fn = effectiveOptInfo.reparse(); 623 final Compiler compiler = effectiveOptInfo.getCompiler(fn, callSiteType, re); //set to non rest-of 624 625 if (!shouldRecompile) { 626 // It didn't necessarily recompile, e.g. for an outer invocation of a recursive function if we already 627 // recompiled a deoptimized version for an inner invocation. 628 // We still need to do the rest of from the beginning 629 logRecompile("Rest-of compilation [STANDALONE] ", fn, callSiteType, effectiveOptInfo.invalidatedProgramPoints); 630 return restOfHandle(effectiveOptInfo, compiler.compile(fn, CompilationPhases.COMPILE_ALL_RESTOF), currentOptInfo != null); 631 } 632 633 logRecompile("Deoptimizing recompilation (up to bytecode) ", fn, callSiteType, effectiveOptInfo.invalidatedProgramPoints); 634 fn = compiler.compile(fn, CompilationPhases.COMPILE_UPTO_BYTECODE); 635 log.info("Reusable IR generated"); 636 637 // compile the rest of the function, and install it 638 log.info("Generating and installing bytecode from reusable IR..."); 639 logRecompile("Rest-of compilation [CODE PIPELINE REUSE] ", fn, callSiteType, effectiveOptInfo.invalidatedProgramPoints); 640 final FunctionNode normalFn = compiler.compile(fn, CompilationPhases.COMPILE_FROM_BYTECODE); 641 642 FunctionNode fn2 = effectiveOptInfo.reparse(); 643 fn2 = compiler.compile(fn2, CompilationPhases.COMPILE_UPTO_BYTECODE); 644 log.info("Done."); 645 646 final boolean canBeDeoptimized = normalFn.canBeDeoptimized(); 647 648 if (log.isEnabled()) { 649 log.info("Recompiled '", fn.getName(), "' (", Debug.id(this), ") ", canBeDeoptimized ? " can still be deoptimized." : " is completely deoptimized."); 650 } 651 652 log.info("Looking up invoker..."); 653 654 final MethodHandle newInvoker = effectiveOptInfo.data.lookup(fn); 655 invoker = newInvoker.asType(type.changeReturnType(newInvoker.type().returnType())); 656 constructor = null; // Will be regenerated when needed 657 658 log.info("Done: ", invoker); 659 final MethodHandle restOf = restOfHandle(effectiveOptInfo, compiler.compile(fn, CompilationPhases.COMPILE_FROM_BYTECODE_RESTOF), canBeDeoptimized); 660 661 // Note that we only adjust the switch point after we set the invoker/constructor. This is important. 662 if (canBeDeoptimized) { 663 effectiveOptInfo.newOptimisticAssumptions(); // Otherwise, set a new switch point. 664 } else { 665 optimismInfo = null; // If we got to a point where we no longer have optimistic assumptions, let the optimism info go. 666 } 667 668 return restOf; 669 } 670 671 private MethodHandle restOfHandle(final OptimismInfo info, final FunctionNode restOfFunction, final boolean canBeDeoptimized) { 672 assert info != null; 673 assert restOfFunction.getCompileUnit().getUnitClassName().indexOf("restOf") != -1; 674 final MethodHandle restOf = 675 changeReturnType( 676 info.data.lookupWithExplicitType( 677 restOfFunction, 678 MH.type(restOfFunction.getReturnType().getTypeClass(), 679 RewriteException.class)), 680 Object.class); 681 682 if (!canBeDeoptimized) { 683 return restOf; 684 } 685 686 // If rest-of is itself optimistic, we must make sure that we can repeat a deoptimization if it, too hits an exception. 687 return MH.catchException(restOf, RewriteException.class, createRewriteExceptionHandler()); 688 689 } 690 691 private static class OptimismInfo { 692 // TODO: this is pointing to its owning ScriptFunctionData. Re-evaluate if that's okay. 693 private final RecompilableScriptFunctionData data; 694 private final Map<Integer, Type> invalidatedProgramPoints; 695 private SwitchPoint optimisticAssumptions; 696 private final DebugLogger log; 697 698 OptimismInfo(final RecompilableScriptFunctionData data, final Map<Integer, Type> invalidatedProgramPoints) { 699 this.data = data; 700 this.log = data.getLogger(); 701 this.invalidatedProgramPoints = invalidatedProgramPoints == null ? new TreeMap<Integer, Type>() : invalidatedProgramPoints; 702 newOptimisticAssumptions(); 703 } 704 705 private void newOptimisticAssumptions() { 706 optimisticAssumptions = new SwitchPoint(); 707 } 708 709 boolean requestRecompile(final RewriteException e) { 710 final Type retType = e.getReturnType(); 711 final Type previousFailedType = invalidatedProgramPoints.put(e.getProgramPoint(), retType); 712 713 if (previousFailedType != null && !previousFailedType.narrowerThan(retType)) { 714 final StackTraceElement[] stack = e.getStackTrace(); 715 final String functionId = stack.length == 0 ? 716 data.getName() : 717 stack[0].getClassName() + "." + stack[0].getMethodName(); 718 719 log.info("RewriteException for an already invalidated program point ", e.getProgramPoint(), " in ", functionId, ". This is okay for a recursive function invocation, but a bug otherwise."); 720 721 return false; 722 } 723 724 SwitchPoint.invalidateAll(new SwitchPoint[] { optimisticAssumptions }); 725 726 return true; 727 } 728 729 Compiler getCompiler(final FunctionNode fn, final MethodType actualCallSiteType, final RewriteException e) { 730 return data.getCompiler(fn, actualCallSiteType, e.getRuntimeScope(), invalidatedProgramPoints, getEntryPoints(e)); 731 } 732 733 private static int[] getEntryPoints(final RewriteException e) { 734 final int[] prevEntryPoints = e.getPreviousContinuationEntryPoints(); 735 final int[] entryPoints; 736 if (prevEntryPoints == null) { 737 entryPoints = new int[1]; 738 } else { 739 final int l = prevEntryPoints.length; 740 entryPoints = new int[l + 1]; 741 System.arraycopy(prevEntryPoints, 0, entryPoints, 1, l); 742 } 743 entryPoints[0] = e.getProgramPoint(); 744 return entryPoints; 745 } 746 747 FunctionNode reparse() { 748 return data.reparse(); 749 } 750 } 751 752 @SuppressWarnings("unused") 753 private static Object newFilter(final Object result, final Object allocation) { 754 return (result instanceof ScriptObject || !JSType.isPrimitive(result))? result : allocation; 755 } 756 757 private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) { 758 return MH.findStatic(MethodHandles.lookup(), CompiledFunction.class, name, MH.type(rtype, types)); 759 } 760} 761