CompiledFunction.java revision 1006:f04f14587586
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; 30import java.lang.invoke.CallSite; 31import java.lang.invoke.MethodHandle; 32import java.lang.invoke.MethodHandles; 33import java.lang.invoke.MethodType; 34import java.lang.invoke.MutableCallSite; 35import java.lang.invoke.SwitchPoint; 36import java.util.Iterator; 37import java.util.Map; 38import java.util.TreeMap; 39import java.util.function.Supplier; 40import java.util.logging.Level; 41import jdk.internal.dynalink.linker.GuardedInvocation; 42import jdk.nashorn.internal.codegen.Compiler; 43import jdk.nashorn.internal.codegen.Compiler.CompilationPhases; 44import jdk.nashorn.internal.codegen.TypeMap; 45import jdk.nashorn.internal.codegen.types.ArrayType; 46import jdk.nashorn.internal.codegen.types.Type; 47import jdk.nashorn.internal.ir.FunctionNode; 48import jdk.nashorn.internal.runtime.events.RecompilationEvent; 49import jdk.nashorn.internal.runtime.linker.Bootstrap; 50import jdk.nashorn.internal.runtime.logging.DebugLogger; 51 52/** 53 * An version of a JavaScript function, native or JavaScript. 54 * Supports lazily generating a constructor version of the invocation. 55 */ 56final class CompiledFunction { 57 58 private static final MethodHandle NEWFILTER = findOwnMH("newFilter", Object.class, Object.class, Object.class); 59 private static final MethodHandle RELINK_COMPOSABLE_INVOKER = findOwnMH("relinkComposableInvoker", void.class, CallSite.class, CompiledFunction.class, boolean.class); 60 private static final MethodHandle HANDLE_REWRITE_EXCEPTION = findOwnMH("handleRewriteException", MethodHandle.class, CompiledFunction.class, OptimismInfo.class, RewriteException.class); 61 private static final MethodHandle RESTOF_INVOKER = MethodHandles.exactInvoker(MethodType.methodType(Object.class, RewriteException.class)); 62 63 private final DebugLogger log; 64 65 /** 66 * The method type may be more specific than the invoker, if. e.g. 67 * the invoker is guarded, and a guard with a generic object only 68 * fallback, while the target is more specific, we still need the 69 * more specific type for sorting 70 */ 71 private MethodHandle invoker; 72 private MethodHandle constructor; 73 private OptimismInfo optimismInfo; 74 private final int flags; // from FunctionNode 75 private final MethodType callSiteType; 76 77 CompiledFunction(final MethodHandle invoker) { 78 this(invoker, null); 79 } 80 81 static CompiledFunction createBuiltInConstructor(final MethodHandle invoker) { 82 return new CompiledFunction(MH.insertArguments(invoker, 0, false), createConstructorFromInvoker(MH.insertArguments(invoker, 0, true))); 83 } 84 85 CompiledFunction(final MethodHandle invoker, final MethodHandle constructor) { 86 this(invoker, constructor, 0, null, DebugLogger.DISABLED_LOGGER); 87 } 88 89 CompiledFunction(final MethodHandle invoker, final MethodHandle constructor, final int flags, final MethodType callSiteType, final DebugLogger log) { 90 this.invoker = invoker; 91 this.constructor = constructor; 92 this.flags = flags; 93 this.callSiteType = callSiteType; 94 this.log = log; 95 } 96 97 CompiledFunction(final MethodHandle invoker, final RecompilableScriptFunctionData functionData, 98 final Map<Integer, Type> invalidatedProgramPoints, final MethodType callSiteType, final int flags) { 99 this(invoker, null, flags, callSiteType, functionData.getLogger()); 100 if ((flags & FunctionNode.IS_DEOPTIMIZABLE) != 0) { 101 optimismInfo = new OptimismInfo(functionData, invalidatedProgramPoints); 102 } else { 103 optimismInfo = null; 104 } 105 } 106 107 int getFlags() { 108 return flags; 109 } 110 111 boolean isApplyToCall() { 112 return (flags & FunctionNode.HAS_APPLY_TO_CALL_SPECIALIZATION) != 0; 113 } 114 115 boolean isVarArg() { 116 return isVarArgsType(invoker.type()); 117 } 118 119 @Override 120 public String toString() { 121 return "[invokerType=" + invoker.type() + " ctor=" + constructor + " weight=" + weight() + " isApplyToCall=" + isApplyToCall() + "]"; 122 } 123 124 boolean needsCallee() { 125 return ScriptFunctionData.needsCallee(invoker); 126 } 127 128 /** 129 * Returns an invoker method handle for this function. Note that the handle is safely composable in 130 * the sense that you can compose it with other handles using any combinators even if you can't affect call site 131 * invalidation. If this compiled function is non-optimistic, then it returns the same value as 132 * {@link #getInvokerOrConstructor(boolean)}. However, if the function is optimistic, then this handle will 133 * incur an overhead as it will add an intermediate internal call site that can relink itself when the function 134 * needs to regenerate its code to always point at the latest generated code version. 135 * @return a guaranteed composable invoker method handle for this function. 136 */ 137 MethodHandle createComposableInvoker() { 138 return createComposableInvoker(false); 139 } 140 141 /** 142 * Returns an invoker method handle for this function when invoked as a constructor. Note that the handle should be 143 * considered non-composable in the sense that you can only compose it with other handles using any combinators if 144 * you can ensure that the composition is guarded by {@link #getOptimisticAssumptionsSwitchPoint()} if it's 145 * non-null, and that you can relink the call site it is set into as a target if the switch point is invalidated. In 146 * all other cases, use {@link #createComposableConstructor()}. 147 * @return a direct constructor method handle for this function. 148 */ 149 private MethodHandle getConstructor() { 150 if (constructor == null) { 151 constructor = createConstructorFromInvoker(createInvokerForPessimisticCaller()); 152 } 153 154 return constructor; 155 } 156 157 /** 158 * Creates a version of the invoker intended for a pessimistic caller (return type is Object, no caller optimistic 159 * program point available). 160 * @return a version of the invoker intended for a pessimistic caller. 161 */ 162 private MethodHandle createInvokerForPessimisticCaller() { 163 return createInvoker(Object.class, INVALID_PROGRAM_POINT); 164 } 165 166 /** 167 * Compose a constructor from an invoker. 168 * 169 * @param invoker invoker 170 * @return the composed constructor 171 */ 172 private static MethodHandle createConstructorFromInvoker(final MethodHandle invoker) { 173 final boolean needsCallee = ScriptFunctionData.needsCallee(invoker); 174 // If it was (callee, this, args...), permute it to (this, callee, args...). We're doing this because having 175 // "this" in the first argument position is what allows the elegant folded composition of 176 // (newFilter x constructor x allocator) further down below in the code. Also, ensure the composite constructor 177 // always returns Object. 178 final MethodHandle swapped = needsCallee ? swapCalleeAndThis(invoker) : invoker; 179 180 final MethodHandle returnsObject = MH.asType(swapped, swapped.type().changeReturnType(Object.class)); 181 182 final MethodType ctorType = returnsObject.type(); 183 184 // Construct a dropping type list for NEWFILTER, but don't include constructor "this" into it, so it's actually 185 // captured as "allocation" parameter of NEWFILTER after we fold the constructor into it. 186 // (this, [callee, ]args...) => ([callee, ]args...) 187 final Class<?>[] ctorArgs = ctorType.dropParameterTypes(0, 1).parameterArray(); 188 189 // Fold constructor into newFilter that replaces the return value from the constructor with the originally 190 // allocated value when the originally allocated value is a JS primitive (String, Boolean, Number). 191 // (result, this, [callee, ]args...) x (this, [callee, ]args...) => (this, [callee, ]args...) 192 final MethodHandle filtered = MH.foldArguments(MH.dropArguments(NEWFILTER, 2, ctorArgs), returnsObject); 193 194 // allocate() takes a ScriptFunction and returns a newly allocated ScriptObject... 195 if (needsCallee) { 196 // ...we either fold it into the previous composition, if we need both the ScriptFunction callee object and 197 // the newly allocated object in the arguments, so (this, callee, args...) x (callee) => (callee, args...), 198 // or... 199 return MH.foldArguments(filtered, ScriptFunction.ALLOCATE); 200 } 201 202 // ...replace the ScriptFunction argument with the newly allocated object, if it doesn't need the callee 203 // (this, args...) filter (callee) => (callee, args...) 204 return MH.filterArguments(filtered, 0, ScriptFunction.ALLOCATE); 205 } 206 207 /** 208 * Permutes the parameters in the method handle from {@code (callee, this, ...)} to {@code (this, callee, ...)}. 209 * Used when creating a constructor handle. 210 * @param mh a method handle with order of arguments {@code (callee, this, ...)} 211 * @return a method handle with order of arguments {@code (this, callee, ...)} 212 */ 213 private static MethodHandle swapCalleeAndThis(final MethodHandle mh) { 214 final MethodType type = mh.type(); 215 assert type.parameterType(0) == ScriptFunction.class : type; 216 assert type.parameterType(1) == Object.class : type; 217 final MethodType newType = type.changeParameterType(0, Object.class).changeParameterType(1, ScriptFunction.class); 218 final int[] reorder = new int[type.parameterCount()]; 219 reorder[0] = 1; 220 assert reorder[1] == 0; 221 for (int i = 2; i < reorder.length; ++i) { 222 reorder[i] = i; 223 } 224 return MethodHandles.permuteArguments(mh, newType, reorder); 225 } 226 227 /** 228 * Returns an invoker method handle for this function when invoked as a constructor. Note that the handle is safely 229 * composable in the sense that you can compose it with other handles using any combinators even if you can't affect 230 * call site invalidation. If this compiled function is non-optimistic, then it returns the same value as 231 * {@link #getConstructor()}. However, if the function is optimistic, then this handle will incur an overhead as it 232 * will add an intermediate internal call site that can relink itself when the function needs to regenerate its code 233 * to always point at the latest generated code version. 234 * @return a guaranteed composable constructor method handle for this function. 235 */ 236 MethodHandle createComposableConstructor() { 237 return createComposableInvoker(true); 238 } 239 240 boolean hasConstructor() { 241 return constructor != null; 242 } 243 244 MethodType type() { 245 return invoker.type(); 246 } 247 248 int weight() { 249 return weight(type()); 250 } 251 252 private static int weight(final MethodType type) { 253 if (isVarArgsType(type)) { 254 return Integer.MAX_VALUE; //if there is a varargs it should be the heavist and last fallback 255 } 256 257 int weight = Type.typeFor(type.returnType()).getWeight(); 258 for (int i = 0 ; i < type.parameterCount() ; i++) { 259 final Class<?> paramType = type.parameterType(i); 260 final int pweight = Type.typeFor(paramType).getWeight() * 2; //params are more important than call types as return values are always specialized 261 weight += pweight; 262 } 263 264 weight += type.parameterCount(); //more params outweigh few parameters 265 266 return weight; 267 } 268 269 static boolean isVarArgsType(final MethodType type) { 270 assert type.parameterCount() >= 1 : type; 271 return type.parameterType(type.parameterCount() - 1) == Object[].class; 272 } 273 274 static boolean moreGenericThan(final MethodType mt0, final MethodType mt1) { 275 return weight(mt0) > weight(mt1); 276 } 277 278 boolean betterThanFinal(final CompiledFunction other, final MethodType callSiteMethodType) { 279 // Prefer anything over nothing, as we can't compile new versions. 280 if (other == null) { 281 return true; 282 } 283 return betterThanFinal(type(), other.type(), callSiteMethodType); 284 } 285 286 static boolean betterThanFinal(final MethodType thisMethodType, final MethodType otherMethodType, final MethodType callSiteMethodType) { 287 final int thisParamCount = getParamCount(thisMethodType); 288 final int otherParamCount = getParamCount(otherMethodType); 289 final int callSiteRawParamCount = getParamCount(callSiteMethodType); 290 final boolean csVarArg = callSiteRawParamCount == Integer.MAX_VALUE; 291 // Subtract 1 for callee for non-vararg call sites 292 final int callSiteParamCount = csVarArg ? callSiteRawParamCount : callSiteRawParamCount - 1; 293 294 // Prefer the function that discards less parameters 295 final int thisDiscardsParams = Math.max(callSiteParamCount - thisParamCount, 0); 296 final int otherDiscardsParams = Math.max(callSiteParamCount - otherParamCount, 0); 297 if(thisDiscardsParams < otherDiscardsParams) { 298 return true; 299 } 300 if(thisDiscardsParams > otherDiscardsParams) { 301 return false; 302 } 303 304 final boolean thisVarArg = thisParamCount == Integer.MAX_VALUE; 305 final boolean otherVarArg = otherParamCount == Integer.MAX_VALUE; 306 if(!(thisVarArg && otherVarArg && csVarArg)) { 307 // At least one of them isn't vararg 308 final Type[] thisType = toTypeWithoutCallee(thisMethodType, 0); // Never has callee 309 final Type[] otherType = toTypeWithoutCallee(otherMethodType, 0); // Never has callee 310 final Type[] callSiteType = toTypeWithoutCallee(callSiteMethodType, 1); // Always has callee 311 312 int narrowWeightDelta = 0; 313 int widenWeightDelta = 0; 314 final int minParamsCount = Math.min(Math.min(thisParamCount, otherParamCount), callSiteParamCount); 315 for(int i = 0; i < minParamsCount; ++i) { 316 final int callSiteParamWeight = getParamType(i, callSiteType, csVarArg).getWeight(); 317 // Delta is negative for narrowing, positive for widening 318 final int thisParamWeightDelta = getParamType(i, thisType, thisVarArg).getWeight() - callSiteParamWeight; 319 final int otherParamWeightDelta = getParamType(i, otherType, otherVarArg).getWeight() - callSiteParamWeight; 320 // Only count absolute values of narrowings 321 narrowWeightDelta += Math.max(-thisParamWeightDelta, 0) - Math.max(-otherParamWeightDelta, 0); 322 // Only count absolute values of widenings 323 widenWeightDelta += Math.max(thisParamWeightDelta, 0) - Math.max(otherParamWeightDelta, 0); 324 } 325 326 // If both functions accept more arguments than what is passed at the call site, account for ability 327 // to receive Undefined un-narrowed in the remaining arguments. 328 if(!thisVarArg) { 329 for(int i = callSiteParamCount; i < thisParamCount; ++i) { 330 narrowWeightDelta += Math.max(Type.OBJECT.getWeight() - thisType[i].getWeight(), 0); 331 } 332 } 333 if(!otherVarArg) { 334 for(int i = callSiteParamCount; i < otherParamCount; ++i) { 335 narrowWeightDelta -= Math.max(Type.OBJECT.getWeight() - otherType[i].getWeight(), 0); 336 } 337 } 338 339 // Prefer function that narrows less 340 if(narrowWeightDelta < 0) { 341 return true; 342 } 343 if(narrowWeightDelta > 0) { 344 return false; 345 } 346 347 // Prefer function that widens less 348 if(widenWeightDelta < 0) { 349 return true; 350 } 351 if(widenWeightDelta > 0) { 352 return false; 353 } 354 } 355 356 // Prefer the function that exactly matches the arity of the call site. 357 if(thisParamCount == callSiteParamCount && otherParamCount != callSiteParamCount) { 358 return true; 359 } 360 if(thisParamCount != callSiteParamCount && otherParamCount == callSiteParamCount) { 361 return false; 362 } 363 364 // Otherwise, neither function matches arity exactly. We also know that at this point, they both can receive 365 // more arguments than call site, otherwise we would've already chosen the one that discards less parameters. 366 // Note that variable arity methods are preferred, as they actually match the call site arity better, since they 367 // really have arbitrary arity. 368 if(thisVarArg) { 369 if(!otherVarArg) { 370 return true; // 371 } 372 } else if(otherVarArg) { 373 return false; 374 } 375 376 // Neither is variable arity; chose the one that has less extra parameters. 377 final int fnParamDelta = thisParamCount - otherParamCount; 378 if(fnParamDelta < 0) { 379 return true; 380 } 381 if(fnParamDelta > 0) { 382 return false; 383 } 384 385 final int callSiteRetWeight = Type.typeFor(callSiteMethodType.returnType()).getWeight(); 386 // Delta is negative for narrower return type, positive for wider return type 387 final int thisRetWeightDelta = Type.typeFor(thisMethodType.returnType()).getWeight() - callSiteRetWeight; 388 final int otherRetWeightDelta = Type.typeFor(otherMethodType.returnType()).getWeight() - callSiteRetWeight; 389 390 // Prefer function that returns a less wide return type 391 final int widenRetDelta = Math.max(thisRetWeightDelta, 0) - Math.max(otherRetWeightDelta, 0); 392 if(widenRetDelta < 0) { 393 return true; 394 } 395 if(widenRetDelta > 0) { 396 return false; 397 } 398 399 // Prefer function that returns a less narrow return type 400 final int narrowRetDelta = Math.max(-thisRetWeightDelta, 0) - Math.max(-otherRetWeightDelta, 0); 401 if(narrowRetDelta < 0) { 402 return true; 403 } 404 if(narrowRetDelta > 0) { 405 return false; 406 } 407 408 throw new AssertionError(thisMethodType + " identically applicable to " + otherMethodType + " for " + callSiteMethodType); // Signatures are identical 409 } 410 411 private static Type[] toTypeWithoutCallee(final MethodType type, final int thisIndex) { 412 final int paramCount = type.parameterCount(); 413 final Type[] t = new Type[paramCount - thisIndex]; 414 for(int i = thisIndex; i < paramCount; ++i) { 415 t[i - thisIndex] = Type.typeFor(type.parameterType(i)); 416 } 417 return t; 418 } 419 420 private static Type getParamType(final int i, final Type[] paramTypes, final boolean isVarArg) { 421 final int fixParamCount = paramTypes.length - (isVarArg ? 1 : 0); 422 if(i < fixParamCount) { 423 return paramTypes[i]; 424 } 425 assert isVarArg; 426 return ((ArrayType)paramTypes[paramTypes.length - 1]).getElementType(); 427 } 428 429 boolean matchesCallSite(final MethodType callSiteType, final boolean pickVarArg) { 430 if (callSiteType.equals(this.callSiteType)) { 431 return true; 432 } 433 final MethodType type = type(); 434 final int fnParamCount = getParamCount(type); 435 final boolean isVarArg = fnParamCount == Integer.MAX_VALUE; 436 if (isVarArg) { 437 return pickVarArg; 438 } 439 440 final int csParamCount = getParamCount(callSiteType); 441 final boolean csIsVarArg = csParamCount == Integer.MAX_VALUE; 442 final int thisThisIndex = needsCallee() ? 1 : 0; // Index of "this" parameter in this function's type 443 444 final int fnParamCountNoCallee = fnParamCount - thisThisIndex; 445 final int minParams = Math.min(csParamCount - 1, fnParamCountNoCallee); // callSiteType always has callee, so subtract 1 446 // We must match all incoming parameters, except "this". Starting from 1 to skip "this". 447 for(int i = 1; i < minParams; ++i) { 448 final Type fnType = Type.typeFor(type.parameterType(i + thisThisIndex)); 449 final Type csType = csIsVarArg ? Type.OBJECT : Type.typeFor(callSiteType.parameterType(i + 1)); 450 if(!fnType.isEquivalentTo(csType)) { 451 return false; 452 } 453 } 454 455 // Must match any undefined parameters to Object type. 456 for(int i = minParams; i < fnParamCountNoCallee; ++i) { 457 if(!Type.typeFor(type.parameterType(i + thisThisIndex)).isEquivalentTo(Type.OBJECT)) { 458 return false; 459 } 460 } 461 462 return true; 463 } 464 465 private static int getParamCount(final MethodType type) { 466 final int paramCount = type.parameterCount(); 467 return type.parameterType(paramCount - 1).isArray() ? Integer.MAX_VALUE : paramCount; 468 } 469 470 private boolean canBeDeoptimized() { 471 return optimismInfo != null; 472 } 473 474 private MethodHandle createComposableInvoker(final boolean isConstructor) { 475 final MethodHandle handle = getInvokerOrConstructor(isConstructor); 476 477 // If compiled function is not optimistic, it can't ever change its invoker/constructor, so just return them 478 // directly. 479 if(!canBeDeoptimized()) { 480 return handle; 481 } 482 483 // Otherwise, we need a new level of indirection; need to introduce a mutable call site that can relink itslef 484 // to the compiled function's changed target whenever the optimistic assumptions are invalidated. 485 final CallSite cs = new MutableCallSite(handle.type()); 486 relinkComposableInvoker(cs, this, isConstructor); 487 return cs.dynamicInvoker(); 488 } 489 490 private static class HandleAndAssumptions { 491 final MethodHandle handle; 492 final SwitchPoint assumptions; 493 494 HandleAndAssumptions(final MethodHandle handle, final SwitchPoint assumptions) { 495 this.handle = handle; 496 this.assumptions = assumptions; 497 } 498 499 GuardedInvocation createInvocation() { 500 return new GuardedInvocation(handle, assumptions); 501 } 502 } 503 504 /** 505 * Returns a pair of an invocation created with a passed-in supplier and a non-invalidated switch point for 506 * optimistic assumptions (or null for the switch point if the function can not be deoptimized). While the method 507 * makes a best effort to return a non-invalidated switch point (compensating for possible deoptimizing 508 * recompilation happening on another thread) it is still possible that by the time this method returns the 509 * switchpoint has been invalidated by a {@code RewriteException} triggered on another thread for this function. 510 * This is not a problem, though, as these switch points are always used to produce call sites that fall back to 511 * relinking when they are invalidated, and in this case the execution will end up here again. What this method 512 * basically does is minimize such busy-loop relinking while the function is being recompiled on a different thread. 513 * @param invocationSupplier the supplier that constructs the actual invocation method handle; should use the 514 * {@code CompiledFunction} method itself in some capacity. 515 * @return a tuple object containing the method handle as created by the supplier and an optimistic assumptions 516 * switch point that is guaranteed to not have been invalidated before the call to this method (or null if the 517 * function can't be further deoptimized). 518 */ 519 private synchronized HandleAndAssumptions getValidOptimisticInvocation(final Supplier<MethodHandle> invocationSupplier) { 520 for(;;) { 521 final MethodHandle handle = invocationSupplier.get(); 522 final SwitchPoint assumptions = canBeDeoptimized() ? optimismInfo.optimisticAssumptions : null; 523 if(assumptions != null && assumptions.hasBeenInvalidated()) { 524 // We can be in a situation where one thread is in the middle of a deoptimizing compilation when we hit 525 // this and thus, it has invalidated the old switch point, but hasn't created the new one yet. Note that 526 // the behavior of invalidating the old switch point before recompilation, and only creating the new one 527 // after recompilation is by design. If we didn't wait here for the recompilation to complete, we would 528 // be busy looping through the fallback path of the invalidated switch point, relinking the call site 529 // again with the same invalidated switch point, invoking the fallback, etc. stealing CPU cycles from 530 // the recompilation task we're dependent on. This can still happen if the switch point gets invalidated 531 // after we grabbed it here, in which case we'll indeed do one busy relink immediately. 532 try { 533 wait(); 534 } catch (final InterruptedException e) { 535 // Intentionally ignored. There's nothing meaningful we can do if we're interrupted 536 } 537 } else { 538 return new HandleAndAssumptions(handle, assumptions); 539 } 540 } 541 } 542 543 private static void relinkComposableInvoker(final CallSite cs, final CompiledFunction inv, final boolean constructor) { 544 final HandleAndAssumptions handleAndAssumptions = inv.getValidOptimisticInvocation(new Supplier<MethodHandle>() { 545 @Override 546 public MethodHandle get() { 547 return inv.getInvokerOrConstructor(constructor); 548 } 549 }); 550 final MethodHandle handle = handleAndAssumptions.handle; 551 final SwitchPoint assumptions = handleAndAssumptions.assumptions; 552 final MethodHandle target; 553 if(assumptions == null) { 554 target = handle; 555 } else { 556 final MethodHandle relink = MethodHandles.insertArguments(RELINK_COMPOSABLE_INVOKER, 0, cs, inv, constructor); 557 target = assumptions.guardWithTest(handle, MethodHandles.foldArguments(cs.dynamicInvoker(), relink)); 558 } 559 cs.setTarget(target.asType(cs.type())); 560 } 561 562 private MethodHandle getInvokerOrConstructor(final boolean selectCtor) { 563 return selectCtor ? getConstructor() : createInvokerForPessimisticCaller(); 564 } 565 566 /** 567 * Returns a guarded invocation for this function when not invoked as a constructor. The guarded invocation has no 568 * guard but it potentially has an optimistic assumptions switch point. As such, it will probably not be used as a 569 * final guarded invocation, but rather as a holder for an invocation handle and switch point to be decomposed and 570 * reassembled into a different final invocation by the user of this method. Any recompositions should take care to 571 * continue to use the switch point. If that is not possible, use {@link #createComposableInvoker()} instead. 572 * @return a guarded invocation for an ordinary (non-constructor) invocation of this function. 573 */ 574 GuardedInvocation createFunctionInvocation(final Class<?> callSiteReturnType, final int callerProgramPoint) { 575 return getValidOptimisticInvocation(new Supplier<MethodHandle>() { 576 @Override 577 public MethodHandle get() { 578 return createInvoker(callSiteReturnType, callerProgramPoint); 579 } 580 }).createInvocation(); 581 } 582 583 /** 584 * Returns a guarded invocation for this function when invoked as a constructor. The guarded invocation has no guard 585 * but it potentially has an optimistic assumptions switch point. As such, it will probably not be used as a final 586 * guarded invocation, but rather as a holder for an invocation handle and switch point to be decomposed and 587 * reassembled into a different final invocation by the user of this method. Any recompositions should take care to 588 * continue to use the switch point. If that is not possible, use {@link #createComposableConstructor()} instead. 589 * @return a guarded invocation for invocation of this function as a constructor. 590 */ 591 GuardedInvocation createConstructorInvocation() { 592 return getValidOptimisticInvocation(new Supplier<MethodHandle>() { 593 @Override 594 public MethodHandle get() { 595 return getConstructor(); 596 } 597 }).createInvocation(); 598 } 599 600 private MethodHandle createInvoker(final Class<?> callSiteReturnType, final int callerProgramPoint) { 601 final boolean isOptimistic = canBeDeoptimized(); 602 MethodHandle handleRewriteException = isOptimistic ? createRewriteExceptionHandler() : null; 603 604 MethodHandle inv = invoker; 605 if(isValid(callerProgramPoint)) { 606 inv = OptimisticReturnFilters.filterOptimisticReturnValue(inv, callSiteReturnType, callerProgramPoint); 607 inv = changeReturnType(inv, callSiteReturnType); 608 if(callSiteReturnType.isPrimitive() && handleRewriteException != null) { 609 // because handleRewriteException always returns Object 610 handleRewriteException = OptimisticReturnFilters.filterOptimisticReturnValue(handleRewriteException, 611 callSiteReturnType, callerProgramPoint); 612 } 613 } else if(isOptimistic) { 614 // Required so that rewrite exception has the same return type. It'd be okay to do it even if we weren't 615 // optimistic, but it isn't necessary as the linker upstream will eventually convert the return type. 616 inv = changeReturnType(inv, callSiteReturnType); 617 } 618 619 if(isOptimistic) { 620 assert handleRewriteException != null; 621 final MethodHandle typedHandleRewriteException = changeReturnType(handleRewriteException, inv.type().returnType()); 622 return MH.catchException(inv, RewriteException.class, typedHandleRewriteException); 623 } 624 return inv; 625 } 626 627 private MethodHandle createRewriteExceptionHandler() { 628 return MH.foldArguments(RESTOF_INVOKER, MH.insertArguments(HANDLE_REWRITE_EXCEPTION, 0, this, optimismInfo)); 629 } 630 631 private static MethodHandle changeReturnType(final MethodHandle mh, final Class<?> newReturnType) { 632 return Bootstrap.getLinkerServices().asType(mh, mh.type().changeReturnType(newReturnType)); 633 } 634 635 @SuppressWarnings("unused") 636 private static MethodHandle handleRewriteException(final CompiledFunction function, final OptimismInfo oldOptimismInfo, final RewriteException re) { 637 return function.handleRewriteException(oldOptimismInfo, re); 638 } 639 640 /** 641 * Debug function for printing out all invalidated program points and their 642 * invalidation mapping to next type 643 * @param ipp 644 * @return string describing the ipp map 645 */ 646 private static String toStringInvalidations(final Map<Integer, Type> ipp) { 647 if (ipp == null) { 648 return ""; 649 } 650 651 final StringBuilder sb = new StringBuilder(); 652 653 for (final Iterator<Map.Entry<Integer, Type>> iter = ipp.entrySet().iterator(); iter.hasNext(); ) { 654 final Map.Entry<Integer, Type> entry = iter.next(); 655 final char bct = entry.getValue().getBytecodeStackType(); 656 657 sb.append('['). 658 append(entry.getKey()). 659 append("->"). 660 append(bct == 'A' ? 'O' : bct). 661 append(']'); 662 663 if (iter.hasNext()) { 664 sb.append(' '); 665 } 666 } 667 668 return sb.toString(); 669 } 670 671 private void logRecompile(final String reason, final FunctionNode fn, final MethodType callSiteType, final Map<Integer, Type> ipp) { 672 if (log.isEnabled()) { 673 log.info(reason, DebugLogger.quote(fn.getName()), " signature: ", callSiteType, " ", toStringInvalidations(ipp)); 674 } 675 } 676 677 /** 678 * Handles a {@link RewriteException} raised during the execution of this function by recompiling (if needed) the 679 * function with an optimistic assumption invalidated at the program point indicated by the exception, and then 680 * executing a rest-of method to complete the execution with the deoptimized version. 681 * @param oldOptInfo the optimism info of this function. We must store it explicitly as a bound argument in the 682 * method handle, otherwise it could be null for handling a rewrite exception in an outer invocation of a recursive 683 * function when recursive invocations of the function have completely deoptimized it. 684 * @param re the rewrite exception that was raised 685 * @return the method handle for the rest-of method, for folding composition. 686 */ 687 private synchronized MethodHandle handleRewriteException(final OptimismInfo oldOptInfo, final RewriteException re) { 688 if (log.isEnabled()) { 689 log.info(new RecompilationEvent(Level.INFO, re, re.getReturnValueNonDestructive()), "RewriteException ", re.getMessageShort()); 690 } 691 692 final MethodType type = type(); 693 694 // Compiler needs a call site type as its input, which always has a callee parameter, so we must add it if 695 // this function doesn't have a callee parameter. 696 final MethodType callSiteType = type.parameterType(0) == ScriptFunction.class ? 697 type : 698 type.insertParameterTypes(0, ScriptFunction.class); 699 final OptimismInfo currentOptInfo = optimismInfo; 700 final boolean shouldRecompile = currentOptInfo != null && currentOptInfo.requestRecompile(re); 701 702 // Effective optimism info, for subsequent use. We'll normally try to use the current (latest) one, but if it 703 // isn't available, we'll use the old one bound into the call site. 704 final OptimismInfo effectiveOptInfo = currentOptInfo != null ? currentOptInfo : oldOptInfo; 705 FunctionNode fn = effectiveOptInfo.reparse(); 706 final Compiler compiler = effectiveOptInfo.getCompiler(fn, callSiteType, re); //set to non rest-of 707 708 if (!shouldRecompile) { 709 // It didn't necessarily recompile, e.g. for an outer invocation of a recursive function if we already 710 // recompiled a deoptimized version for an inner invocation. 711 // We still need to do the rest of from the beginning 712 logRecompile("Rest-of compilation [STANDALONE] ", fn, callSiteType, effectiveOptInfo.invalidatedProgramPoints); 713 return restOfHandle(effectiveOptInfo, compiler.compile(fn, CompilationPhases.COMPILE_ALL_RESTOF), currentOptInfo != null); 714 } 715 716 logRecompile("Deoptimizing recompilation (up to bytecode) ", fn, callSiteType, effectiveOptInfo.invalidatedProgramPoints); 717 fn = compiler.compile(fn, CompilationPhases.COMPILE_UPTO_BYTECODE); 718 log.info("Reusable IR generated"); 719 720 // compile the rest of the function, and install it 721 log.info("Generating and installing bytecode from reusable IR..."); 722 logRecompile("Rest-of compilation [CODE PIPELINE REUSE] ", fn, callSiteType, effectiveOptInfo.invalidatedProgramPoints); 723 final FunctionNode normalFn = compiler.compile(fn, CompilationPhases.COMPILE_FROM_BYTECODE); 724 725 if (effectiveOptInfo.data.usePersistentCodeCache()) { 726 final RecompilableScriptFunctionData data = effectiveOptInfo.data; 727 final int functionNodeId = data.getFunctionNodeId(); 728 final TypeMap typeMap = data.typeMap(callSiteType); 729 final Type[] paramTypes = typeMap == null ? null : typeMap.getParameterTypes(functionNodeId); 730 final String cacheKey = CodeStore.getCacheKey(functionNodeId, paramTypes); 731 compiler.persistClassInfo(cacheKey, normalFn); 732 } 733 734 FunctionNode fn2 = effectiveOptInfo.reparse(); 735 fn2 = compiler.compile(fn2, CompilationPhases.COMPILE_UPTO_BYTECODE); 736 log.info("Done."); 737 738 final boolean canBeDeoptimized = normalFn.canBeDeoptimized(); 739 740 if (log.isEnabled()) { 741 log.info("Recompiled '", fn.getName(), "' (", Debug.id(this), ") ", canBeDeoptimized ? " can still be deoptimized." : " is completely deoptimized."); 742 } 743 744 log.info("Looking up invoker..."); 745 746 final MethodHandle newInvoker = effectiveOptInfo.data.lookup(fn); 747 invoker = newInvoker.asType(type.changeReturnType(newInvoker.type().returnType())); 748 constructor = null; // Will be regenerated when needed 749 750 log.info("Done: ", invoker); 751 final MethodHandle restOf = restOfHandle(effectiveOptInfo, compiler.compile(fn, CompilationPhases.COMPILE_FROM_BYTECODE_RESTOF), canBeDeoptimized); 752 753 // Note that we only adjust the switch point after we set the invoker/constructor. This is important. 754 if (canBeDeoptimized) { 755 effectiveOptInfo.newOptimisticAssumptions(); // Otherwise, set a new switch point. 756 } else { 757 optimismInfo = null; // If we got to a point where we no longer have optimistic assumptions, let the optimism info go. 758 } 759 notifyAll(); 760 761 return restOf; 762 } 763 764 private MethodHandle restOfHandle(final OptimismInfo info, final FunctionNode restOfFunction, final boolean canBeDeoptimized) { 765 assert info != null; 766 assert restOfFunction.getCompileUnit().getUnitClassName().contains("restOf"); 767 final MethodHandle restOf = 768 changeReturnType( 769 info.data.lookupCodeMethod( 770 restOfFunction.getCompileUnit().getCode(), 771 MH.type(restOfFunction.getReturnType().getTypeClass(), 772 RewriteException.class)), 773 Object.class); 774 775 if (!canBeDeoptimized) { 776 return restOf; 777 } 778 779 // If rest-of is itself optimistic, we must make sure that we can repeat a deoptimization if it, too hits an exception. 780 return MH.catchException(restOf, RewriteException.class, createRewriteExceptionHandler()); 781 782 } 783 784 private static class OptimismInfo { 785 // TODO: this is pointing to its owning ScriptFunctionData. Re-evaluate if that's okay. 786 private final RecompilableScriptFunctionData data; 787 private final Map<Integer, Type> invalidatedProgramPoints; 788 private SwitchPoint optimisticAssumptions; 789 private final DebugLogger log; 790 791 OptimismInfo(final RecompilableScriptFunctionData data, final Map<Integer, Type> invalidatedProgramPoints) { 792 this.data = data; 793 this.log = data.getLogger(); 794 this.invalidatedProgramPoints = invalidatedProgramPoints == null ? new TreeMap<Integer, Type>() : invalidatedProgramPoints; 795 newOptimisticAssumptions(); 796 } 797 798 private void newOptimisticAssumptions() { 799 optimisticAssumptions = new SwitchPoint(); 800 } 801 802 boolean requestRecompile(final RewriteException e) { 803 final Type retType = e.getReturnType(); 804 final Type previousFailedType = invalidatedProgramPoints.put(e.getProgramPoint(), retType); 805 806 if (previousFailedType != null && !previousFailedType.narrowerThan(retType)) { 807 final StackTraceElement[] stack = e.getStackTrace(); 808 final String functionId = stack.length == 0 ? 809 data.getName() : 810 stack[0].getClassName() + "." + stack[0].getMethodName(); 811 812 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."); 813 814 return false; 815 } 816 817 SwitchPoint.invalidateAll(new SwitchPoint[] { optimisticAssumptions }); 818 819 return true; 820 } 821 822 Compiler getCompiler(final FunctionNode fn, final MethodType actualCallSiteType, final RewriteException e) { 823 return data.getCompiler(fn, actualCallSiteType, e.getRuntimeScope(), invalidatedProgramPoints, getEntryPoints(e)); 824 } 825 826 private static int[] getEntryPoints(final RewriteException e) { 827 final int[] prevEntryPoints = e.getPreviousContinuationEntryPoints(); 828 final int[] entryPoints; 829 if (prevEntryPoints == null) { 830 entryPoints = new int[1]; 831 } else { 832 final int l = prevEntryPoints.length; 833 entryPoints = new int[l + 1]; 834 System.arraycopy(prevEntryPoints, 0, entryPoints, 1, l); 835 } 836 entryPoints[0] = e.getProgramPoint(); 837 return entryPoints; 838 } 839 840 FunctionNode reparse() { 841 return data.reparse(); 842 } 843 } 844 845 @SuppressWarnings("unused") 846 private static Object newFilter(final Object result, final Object allocation) { 847 return (result instanceof ScriptObject || !JSType.isPrimitive(result))? result : allocation; 848 } 849 850 private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) { 851 return MH.findStatic(MethodHandles.lookup(), CompiledFunction.class, name, MH.type(rtype, types)); 852 } 853} 854