| /* |
| * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package jdk.nashorn.internal.runtime; |
| |
| import static jdk.nashorn.internal.lookup.Lookup.MH; |
| import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT; |
| import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.isValid; |
| |
| import java.lang.invoke.CallSite; |
| import java.lang.invoke.MethodHandle; |
| import java.lang.invoke.MethodHandles; |
| import java.lang.invoke.MethodType; |
| import java.lang.invoke.MutableCallSite; |
| import java.lang.invoke.SwitchPoint; |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.TreeMap; |
| import java.util.function.Supplier; |
| import java.util.logging.Level; |
| import jdk.internal.dynalink.linker.GuardedInvocation; |
| import jdk.nashorn.internal.codegen.Compiler; |
| import jdk.nashorn.internal.codegen.Compiler.CompilationPhases; |
| import jdk.nashorn.internal.codegen.TypeMap; |
| import jdk.nashorn.internal.codegen.types.ArrayType; |
| import jdk.nashorn.internal.codegen.types.Type; |
| import jdk.nashorn.internal.ir.FunctionNode; |
| import jdk.nashorn.internal.objects.annotations.SpecializedFunction.LinkLogic; |
| import jdk.nashorn.internal.runtime.events.RecompilationEvent; |
| import jdk.nashorn.internal.runtime.linker.Bootstrap; |
| import jdk.nashorn.internal.runtime.logging.DebugLogger; |
| |
| /** |
| * An version of a JavaScript function, native or JavaScript. |
| * Supports lazily generating a constructor version of the invocation. |
| */ |
| final class CompiledFunction { |
| |
| private static final MethodHandle NEWFILTER = findOwnMH("newFilter", Object.class, Object.class, Object.class); |
| private static final MethodHandle RELINK_COMPOSABLE_INVOKER = findOwnMH("relinkComposableInvoker", void.class, CallSite.class, CompiledFunction.class, boolean.class); |
| private static final MethodHandle HANDLE_REWRITE_EXCEPTION = findOwnMH("handleRewriteException", MethodHandle.class, CompiledFunction.class, OptimismInfo.class, RewriteException.class); |
| private static final MethodHandle RESTOF_INVOKER = MethodHandles.exactInvoker(MethodType.methodType(Object.class, RewriteException.class)); |
| |
| private final DebugLogger log; |
| |
| static final Collection<CompiledFunction> NO_FUNCTIONS = Collections.emptySet(); |
| |
| /** |
| * The method type may be more specific than the invoker, if. e.g. |
| * the invoker is guarded, and a guard with a generic object only |
| * fallback, while the target is more specific, we still need the |
| * more specific type for sorting |
| */ |
| private MethodHandle invoker; |
| private MethodHandle constructor; |
| private OptimismInfo optimismInfo; |
| private final int flags; // from FunctionNode |
| private final MethodType callSiteType; |
| |
| private final Specialization specialization; |
| |
| CompiledFunction(final MethodHandle invoker) { |
| this(invoker, null, null); |
| } |
| |
| static CompiledFunction createBuiltInConstructor(final MethodHandle invoker, final Specialization specialization) { |
| return new CompiledFunction(MH.insertArguments(invoker, 0, false), createConstructorFromInvoker(MH.insertArguments(invoker, 0, true)), specialization); |
| } |
| |
| CompiledFunction(final MethodHandle invoker, final MethodHandle constructor, final Specialization specialization) { |
| this(invoker, constructor, 0, null, specialization, DebugLogger.DISABLED_LOGGER); |
| } |
| |
| CompiledFunction(final MethodHandle invoker, final MethodHandle constructor, final int flags, final MethodType callSiteType, final Specialization specialization, final DebugLogger log) { |
| this.specialization = specialization; |
| if (specialization != null && specialization.isOptimistic()) { |
| /* |
| * An optimistic builtin with isOptimistic=true works like any optimistic generated function, i.e. it |
| * can throw unwarranted optimism exceptions. As native functions trivially can't have parts of them |
| * regenerated as "restOf" methods, this only works if the methods are atomic/functional in their behavior |
| * and doesn't modify state before an UOE can be thrown. If they aren't, we can reexecute a wider version |
| * of the same builtin in a recompilation handler for FinalScriptFunctionData. There are several |
| * candidate methods in Native* that would benefit from this, but I haven't had time to implement any |
| * of them currently. In order to fit in with the relinking framework, the current thinking is |
| * that the methods still take a program point to fit in with other optimistic functions, but |
| * it is set to "first", which is the beginning of the method. The relinker can tell the difference |
| * between builtin and JavaScript functions. This might change. TODO |
| */ |
| this.invoker = MH.insertArguments(invoker, invoker.type().parameterCount() - 1, UnwarrantedOptimismException.FIRST_PROGRAM_POINT); |
| throw new AssertionError("Optimistic (UnwarrantedOptimismException throwing) builtin functions are currently not in use"); |
| } |
| this.invoker = invoker; |
| this.constructor = constructor; |
| this.flags = flags; |
| this.callSiteType = callSiteType; |
| this.log = log; |
| } |
| |
| CompiledFunction(final MethodHandle invoker, final RecompilableScriptFunctionData functionData, |
| final Map<Integer, Type> invalidatedProgramPoints, final MethodType callSiteType, final int flags) { |
| this(invoker, null, flags, callSiteType, null, functionData.getLogger()); |
| if ((flags & FunctionNode.IS_DEOPTIMIZABLE) != 0) { |
| optimismInfo = new OptimismInfo(functionData, invalidatedProgramPoints); |
| } else { |
| optimismInfo = null; |
| } |
| } |
| |
| static CompiledFunction createBuiltInConstructor(final MethodHandle invoker) { |
| return new CompiledFunction(MH.insertArguments(invoker, 0, false), createConstructorFromInvoker(MH.insertArguments(invoker, 0, true)), null); |
| } |
| |
| boolean isSpecialization() { |
| return specialization != null; |
| } |
| |
| boolean hasLinkLogic() { |
| return getLinkLogicClass() != null; |
| } |
| |
| Class<? extends LinkLogic> getLinkLogicClass() { |
| if (isSpecialization()) { |
| final Class<? extends LinkLogic> linkLogicClass = specialization.getLinkLogicClass(); |
| assert !LinkLogic.isEmpty(linkLogicClass) : "empty link logic classes should have been removed by nasgen"; |
| return linkLogicClass; |
| } |
| return null; |
| } |
| |
| int getFlags() { |
| return flags; |
| } |
| |
| /** |
| * An optimistic specialization is one that can throw UnwarrantedOptimismException. |
| * This is allowed for native methods, as long as they are functional, i.e. don't change |
| * any state between entering and throwing the UOE. Then we can re-execute a wider version |
| * of the method in the continuation. Rest-of method generation for optimistic builtins is |
| * of course not possible, but this approach works and fits into the same relinking |
| * framework |
| * |
| * @return true if optimistic builtin |
| */ |
| boolean isOptimistic() { |
| return isSpecialization() ? specialization.isOptimistic() : false; |
| } |
| |
| boolean isApplyToCall() { |
| return (flags & FunctionNode.HAS_APPLY_TO_CALL_SPECIALIZATION) != 0; |
| } |
| |
| boolean isVarArg() { |
| return isVarArgsType(invoker.type()); |
| } |
| |
| @Override |
| public String toString() { |
| final StringBuilder sb = new StringBuilder(); |
| final Class<? extends LinkLogic> linkLogicClass = getLinkLogicClass(); |
| |
| sb.append("[invokerType="). |
| append(invoker.type()). |
| append(" ctor="). |
| append(constructor). |
| append(" weight="). |
| append(weight()). |
| append(" linkLogic="). |
| append(linkLogicClass != null ? linkLogicClass.getSimpleName() : "none"); |
| |
| return sb.toString(); |
| } |
| |
| boolean needsCallee() { |
| return ScriptFunctionData.needsCallee(invoker); |
| } |
| |
| /** |
| * Returns an invoker method handle for this function. Note that the handle is safely composable in |
| * the sense that you can compose it with other handles using any combinators even if you can't affect call site |
| * invalidation. If this compiled function is non-optimistic, then it returns the same value as |
| * {@link #getInvokerOrConstructor(boolean)}. However, if the function is optimistic, then this handle will |
| * incur an overhead as it will add an intermediate internal call site that can relink itself when the function |
| * needs to regenerate its code to always point at the latest generated code version. |
| * @return a guaranteed composable invoker method handle for this function. |
| */ |
| MethodHandle createComposableInvoker() { |
| return createComposableInvoker(false); |
| } |
| |
| /** |
| * Returns an invoker method handle for this function when invoked as a constructor. Note that the handle should be |
| * considered non-composable in the sense that you can only compose it with other handles using any combinators if |
| * you can ensure that the composition is guarded by {@link #getOptimisticAssumptionsSwitchPoint()} if it's |
| * non-null, and that you can relink the call site it is set into as a target if the switch point is invalidated. In |
| * all other cases, use {@link #createComposableConstructor()}. |
| * @return a direct constructor method handle for this function. |
| */ |
| private MethodHandle getConstructor() { |
| if (constructor == null) { |
| constructor = createConstructorFromInvoker(createInvokerForPessimisticCaller()); |
| } |
| |
| return constructor; |
| } |
| |
| /** |
| * Creates a version of the invoker intended for a pessimistic caller (return type is Object, no caller optimistic |
| * program point available). |
| * @return a version of the invoker intended for a pessimistic caller. |
| */ |
| private MethodHandle createInvokerForPessimisticCaller() { |
| return createInvoker(Object.class, INVALID_PROGRAM_POINT); |
| } |
| |
| /** |
| * Compose a constructor from an invoker. |
| * |
| * @param invoker invoker |
| * @return the composed constructor |
| */ |
| private static MethodHandle createConstructorFromInvoker(final MethodHandle invoker) { |
| final boolean needsCallee = ScriptFunctionData.needsCallee(invoker); |
| // If it was (callee, this, args...), permute it to (this, callee, args...). We're doing this because having |
| // "this" in the first argument position is what allows the elegant folded composition of |
| // (newFilter x constructor x allocator) further down below in the code. Also, ensure the composite constructor |
| // always returns Object. |
| final MethodHandle swapped = needsCallee ? swapCalleeAndThis(invoker) : invoker; |
| |
| final MethodHandle returnsObject = MH.asType(swapped, swapped.type().changeReturnType(Object.class)); |
| |
| final MethodType ctorType = returnsObject.type(); |
| |
| // Construct a dropping type list for NEWFILTER, but don't include constructor "this" into it, so it's actually |
| // captured as "allocation" parameter of NEWFILTER after we fold the constructor into it. |
| // (this, [callee, ]args...) => ([callee, ]args...) |
| final Class<?>[] ctorArgs = ctorType.dropParameterTypes(0, 1).parameterArray(); |
| |
| // Fold constructor into newFilter that replaces the return value from the constructor with the originally |
| // allocated value when the originally allocated value is a JS primitive (String, Boolean, Number). |
| // (result, this, [callee, ]args...) x (this, [callee, ]args...) => (this, [callee, ]args...) |
| final MethodHandle filtered = MH.foldArguments(MH.dropArguments(NEWFILTER, 2, ctorArgs), returnsObject); |
| |
| // allocate() takes a ScriptFunction and returns a newly allocated ScriptObject... |
| if (needsCallee) { |
| // ...we either fold it into the previous composition, if we need both the ScriptFunction callee object and |
| // the newly allocated object in the arguments, so (this, callee, args...) x (callee) => (callee, args...), |
| // or... |
| return MH.foldArguments(filtered, ScriptFunction.ALLOCATE); |
| } |
| |
| // ...replace the ScriptFunction argument with the newly allocated object, if it doesn't need the callee |
| // (this, args...) filter (callee) => (callee, args...) |
| return MH.filterArguments(filtered, 0, ScriptFunction.ALLOCATE); |
| } |
| |
| /** |
| * Permutes the parameters in the method handle from {@code (callee, this, ...)} to {@code (this, callee, ...)}. |
| * Used when creating a constructor handle. |
| * @param mh a method handle with order of arguments {@code (callee, this, ...)} |
| * @return a method handle with order of arguments {@code (this, callee, ...)} |
| */ |
| private static MethodHandle swapCalleeAndThis(final MethodHandle mh) { |
| final MethodType type = mh.type(); |
| assert type.parameterType(0) == ScriptFunction.class : type; |
| assert type.parameterType(1) == Object.class : type; |
| final MethodType newType = type.changeParameterType(0, Object.class).changeParameterType(1, ScriptFunction.class); |
| final int[] reorder = new int[type.parameterCount()]; |
| reorder[0] = 1; |
| assert reorder[1] == 0; |
| for (int i = 2; i < reorder.length; ++i) { |
| reorder[i] = i; |
| } |
| return MethodHandles.permuteArguments(mh, newType, reorder); |
| } |
| |
| /** |
| * Returns an invoker method handle for this function when invoked as a constructor. Note that the handle is safely |
| * composable in the sense that you can compose it with other handles using any combinators even if you can't affect |
| * call site invalidation. If this compiled function is non-optimistic, then it returns the same value as |
| * {@link #getConstructor()}. However, if the function is optimistic, then this handle will incur an overhead as it |
| * will add an intermediate internal call site that can relink itself when the function needs to regenerate its code |
| * to always point at the latest generated code version. |
| * @return a guaranteed composable constructor method handle for this function. |
| */ |
| MethodHandle createComposableConstructor() { |
| return createComposableInvoker(true); |
| } |
| |
| boolean hasConstructor() { |
| return constructor != null; |
| } |
| |
| MethodType type() { |
| return invoker.type(); |
| } |
| |
| int weight() { |
| return weight(type()); |
| } |
| |
| private static int weight(final MethodType type) { |
| if (isVarArgsType(type)) { |
| return Integer.MAX_VALUE; //if there is a varargs it should be the heavist and last fallback |
| } |
| |
| int weight = Type.typeFor(type.returnType()).getWeight(); |
| for (int i = 0 ; i < type.parameterCount() ; i++) { |
| final Class<?> paramType = type.parameterType(i); |
| final int pweight = Type.typeFor(paramType).getWeight() * 2; //params are more important than call types as return values are always specialized |
| weight += pweight; |
| } |
| |
| weight += type.parameterCount(); //more params outweigh few parameters |
| |
| return weight; |
| } |
| |
| static boolean isVarArgsType(final MethodType type) { |
| assert type.parameterCount() >= 1 : type; |
| return type.parameterType(type.parameterCount() - 1) == Object[].class; |
| } |
| |
| static boolean moreGenericThan(final MethodType mt0, final MethodType mt1) { |
| return weight(mt0) > weight(mt1); |
| } |
| |
| boolean betterThanFinal(final CompiledFunction other, final MethodType callSiteMethodType) { |
| // Prefer anything over nothing, as we can't compile new versions. |
| if (other == null) { |
| return true; |
| } |
| return betterThanFinal(this, other, callSiteMethodType); |
| } |
| |
| private static boolean betterThanFinal(final CompiledFunction cf, final CompiledFunction other, final MethodType callSiteMethodType) { |
| final MethodType thisMethodType = cf.type(); |
| final MethodType otherMethodType = other.type(); |
| final int thisParamCount = getParamCount(thisMethodType); |
| final int otherParamCount = getParamCount(otherMethodType); |
| final int callSiteRawParamCount = getParamCount(callSiteMethodType); |
| final boolean csVarArg = callSiteRawParamCount == Integer.MAX_VALUE; |
| // Subtract 1 for callee for non-vararg call sites |
| final int callSiteParamCount = csVarArg ? callSiteRawParamCount : callSiteRawParamCount - 1; |
| |
| // Prefer the function that discards less parameters |
| final int thisDiscardsParams = Math.max(callSiteParamCount - thisParamCount, 0); |
| final int otherDiscardsParams = Math.max(callSiteParamCount - otherParamCount, 0); |
| if(thisDiscardsParams < otherDiscardsParams) { |
| return true; |
| } |
| if(thisDiscardsParams > otherDiscardsParams) { |
| return false; |
| } |
| |
| final boolean thisVarArg = thisParamCount == Integer.MAX_VALUE; |
| final boolean otherVarArg = otherParamCount == Integer.MAX_VALUE; |
| if(!(thisVarArg && otherVarArg && csVarArg)) { |
| // At least one of them isn't vararg |
| final Type[] thisType = toTypeWithoutCallee(thisMethodType, 0); // Never has callee |
| final Type[] otherType = toTypeWithoutCallee(otherMethodType, 0); // Never has callee |
| final Type[] callSiteType = toTypeWithoutCallee(callSiteMethodType, 1); // Always has callee |
| |
| int narrowWeightDelta = 0; |
| int widenWeightDelta = 0; |
| final int minParamsCount = Math.min(Math.min(thisParamCount, otherParamCount), callSiteParamCount); |
| for(int i = 0; i < minParamsCount; ++i) { |
| final int callSiteParamWeight = getParamType(i, callSiteType, csVarArg).getWeight(); |
| // Delta is negative for narrowing, positive for widening |
| final int thisParamWeightDelta = getParamType(i, thisType, thisVarArg).getWeight() - callSiteParamWeight; |
| final int otherParamWeightDelta = getParamType(i, otherType, otherVarArg).getWeight() - callSiteParamWeight; |
| // Only count absolute values of narrowings |
| narrowWeightDelta += Math.max(-thisParamWeightDelta, 0) - Math.max(-otherParamWeightDelta, 0); |
| // Only count absolute values of widenings |
| widenWeightDelta += Math.max(thisParamWeightDelta, 0) - Math.max(otherParamWeightDelta, 0); |
| } |
| |
| // If both functions accept more arguments than what is passed at the call site, account for ability |
| // to receive Undefined un-narrowed in the remaining arguments. |
| if(!thisVarArg) { |
| for(int i = callSiteParamCount; i < thisParamCount; ++i) { |
| narrowWeightDelta += Math.max(Type.OBJECT.getWeight() - thisType[i].getWeight(), 0); |
| } |
| } |
| if(!otherVarArg) { |
| for(int i = callSiteParamCount; i < otherParamCount; ++i) { |
| narrowWeightDelta -= Math.max(Type.OBJECT.getWeight() - otherType[i].getWeight(), 0); |
| } |
| } |
| |
| // Prefer function that narrows less |
| if(narrowWeightDelta < 0) { |
| return true; |
| } |
| if(narrowWeightDelta > 0) { |
| return false; |
| } |
| |
| // Prefer function that widens less |
| if(widenWeightDelta < 0) { |
| return true; |
| } |
| if(widenWeightDelta > 0) { |
| return false; |
| } |
| } |
| |
| // Prefer the function that exactly matches the arity of the call site. |
| if(thisParamCount == callSiteParamCount && otherParamCount != callSiteParamCount) { |
| return true; |
| } |
| if(thisParamCount != callSiteParamCount && otherParamCount == callSiteParamCount) { |
| return false; |
| } |
| |
| // Otherwise, neither function matches arity exactly. We also know that at this point, they both can receive |
| // more arguments than call site, otherwise we would've already chosen the one that discards less parameters. |
| // Note that variable arity methods are preferred, as they actually match the call site arity better, since they |
| // really have arbitrary arity. |
| if(thisVarArg) { |
| if(!otherVarArg) { |
| return true; // |
| } |
| } else if(otherVarArg) { |
| return false; |
| } |
| |
| // Neither is variable arity; chose the one that has less extra parameters. |
| final int fnParamDelta = thisParamCount - otherParamCount; |
| if(fnParamDelta < 0) { |
| return true; |
| } |
| if(fnParamDelta > 0) { |
| return false; |
| } |
| |
| final int callSiteRetWeight = Type.typeFor(callSiteMethodType.returnType()).getWeight(); |
| // Delta is negative for narrower return type, positive for wider return type |
| final int thisRetWeightDelta = Type.typeFor(thisMethodType.returnType()).getWeight() - callSiteRetWeight; |
| final int otherRetWeightDelta = Type.typeFor(otherMethodType.returnType()).getWeight() - callSiteRetWeight; |
| |
| // Prefer function that returns a less wide return type |
| final int widenRetDelta = Math.max(thisRetWeightDelta, 0) - Math.max(otherRetWeightDelta, 0); |
| if(widenRetDelta < 0) { |
| return true; |
| } |
| if(widenRetDelta > 0) { |
| return false; |
| } |
| |
| // Prefer function that returns a less narrow return type |
| final int narrowRetDelta = Math.max(-thisRetWeightDelta, 0) - Math.max(-otherRetWeightDelta, 0); |
| if(narrowRetDelta < 0) { |
| return true; |
| } |
| if(narrowRetDelta > 0) { |
| return false; |
| } |
| |
| //if they are equal, pick the specialized one first |
| if (cf.isSpecialization() != other.isSpecialization()) { |
| return cf.isSpecialization(); //always pick the specialized version if we can |
| } |
| |
| if (cf.isSpecialization() && other.isSpecialization()) { |
| return cf.getLinkLogicClass() != null; //pick link logic specialization above generic specializations |
| } |
| |
| // Signatures are identical |
| throw new AssertionError(thisMethodType + " identically applicable to " + otherMethodType + " for " + callSiteMethodType); |
| } |
| |
| private static Type[] toTypeWithoutCallee(final MethodType type, final int thisIndex) { |
| final int paramCount = type.parameterCount(); |
| final Type[] t = new Type[paramCount - thisIndex]; |
| for(int i = thisIndex; i < paramCount; ++i) { |
| t[i - thisIndex] = Type.typeFor(type.parameterType(i)); |
| } |
| return t; |
| } |
| |
| private static Type getParamType(final int i, final Type[] paramTypes, final boolean isVarArg) { |
| final int fixParamCount = paramTypes.length - (isVarArg ? 1 : 0); |
| if(i < fixParamCount) { |
| return paramTypes[i]; |
| } |
| assert isVarArg; |
| return ((ArrayType)paramTypes[paramTypes.length - 1]).getElementType(); |
| } |
| |
| boolean matchesCallSite(final MethodType other, final boolean pickVarArg) { |
| if (other.equals(this.callSiteType)) { |
| return true; |
| } |
| final MethodType type = type(); |
| final int fnParamCount = getParamCount(type); |
| final boolean isVarArg = fnParamCount == Integer.MAX_VALUE; |
| if (isVarArg) { |
| return pickVarArg; |
| } |
| |
| final int csParamCount = getParamCount(other); |
| final boolean csIsVarArg = csParamCount == Integer.MAX_VALUE; |
| final int thisThisIndex = needsCallee() ? 1 : 0; // Index of "this" parameter in this function's type |
| |
| final int fnParamCountNoCallee = fnParamCount - thisThisIndex; |
| final int minParams = Math.min(csParamCount - 1, fnParamCountNoCallee); // callSiteType always has callee, so subtract 1 |
| // We must match all incoming parameters, including "this". "this" will usually be Object, but there |
| // are exceptions, e.g. when calling functions with primitive "this" in strict mode or through call/apply. |
| for(int i = 0; i < minParams; ++i) { |
| final Type fnType = Type.typeFor(type.parameterType(i + thisThisIndex)); |
| final Type csType = csIsVarArg ? Type.OBJECT : Type.typeFor(other.parameterType(i + 1)); |
| if(!fnType.isEquivalentTo(csType)) { |
| return false; |
| } |
| } |
| |
| // Must match any undefined parameters to Object type. |
| for(int i = minParams; i < fnParamCountNoCallee; ++i) { |
| if(!Type.typeFor(type.parameterType(i + thisThisIndex)).isEquivalentTo(Type.OBJECT)) { |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| private static int getParamCount(final MethodType type) { |
| final int paramCount = type.parameterCount(); |
| return type.parameterType(paramCount - 1).isArray() ? Integer.MAX_VALUE : paramCount; |
| } |
| |
| private boolean canBeDeoptimized() { |
| return optimismInfo != null; |
| } |
| |
| private MethodHandle createComposableInvoker(final boolean isConstructor) { |
| final MethodHandle handle = getInvokerOrConstructor(isConstructor); |
| |
| // If compiled function is not optimistic, it can't ever change its invoker/constructor, so just return them |
| // directly. |
| if(!canBeDeoptimized()) { |
| return handle; |
| } |
| |
| // Otherwise, we need a new level of indirection; need to introduce a mutable call site that can relink itself |
| // to the compiled function's changed target whenever the optimistic assumptions are invalidated. |
| final CallSite cs = new MutableCallSite(handle.type()); |
| relinkComposableInvoker(cs, this, isConstructor); |
| return cs.dynamicInvoker(); |
| } |
| |
| private static class HandleAndAssumptions { |
| final MethodHandle handle; |
| final SwitchPoint assumptions; |
| |
| HandleAndAssumptions(final MethodHandle handle, final SwitchPoint assumptions) { |
| this.handle = handle; |
| this.assumptions = assumptions; |
| } |
| |
| GuardedInvocation createInvocation() { |
| return new GuardedInvocation(handle, assumptions); |
| } |
| } |
| |
| /** |
| * Returns a pair of an invocation created with a passed-in supplier and a non-invalidated switch point for |
| * optimistic assumptions (or null for the switch point if the function can not be deoptimized). While the method |
| * makes a best effort to return a non-invalidated switch point (compensating for possible deoptimizing |
| * recompilation happening on another thread) it is still possible that by the time this method returns the |
| * switchpoint has been invalidated by a {@code RewriteException} triggered on another thread for this function. |
| * This is not a problem, though, as these switch points are always used to produce call sites that fall back to |
| * relinking when they are invalidated, and in this case the execution will end up here again. What this method |
| * basically does is minimize such busy-loop relinking while the function is being recompiled on a different thread. |
| * @param invocationSupplier the supplier that constructs the actual invocation method handle; should use the |
| * {@code CompiledFunction} method itself in some capacity. |
| * @return a tuple object containing the method handle as created by the supplier and an optimistic assumptions |
| * switch point that is guaranteed to not have been invalidated before the call to this method (or null if the |
| * function can't be further deoptimized). |
| */ |
| private synchronized HandleAndAssumptions getValidOptimisticInvocation(final Supplier<MethodHandle> invocationSupplier) { |
| for(;;) { |
| final MethodHandle handle = invocationSupplier.get(); |
| final SwitchPoint assumptions = canBeDeoptimized() ? optimismInfo.optimisticAssumptions : null; |
| if(assumptions != null && assumptions.hasBeenInvalidated()) { |
| // We can be in a situation where one thread is in the middle of a deoptimizing compilation when we hit |
| // this and thus, it has invalidated the old switch point, but hasn't created the new one yet. Note that |
| // the behavior of invalidating the old switch point before recompilation, and only creating the new one |
| // after recompilation is by design. If we didn't wait here for the recompilation to complete, we would |
| // be busy looping through the fallback path of the invalidated switch point, relinking the call site |
| // again with the same invalidated switch point, invoking the fallback, etc. stealing CPU cycles from |
| // the recompilation task we're dependent on. This can still happen if the switch point gets invalidated |
| // after we grabbed it here, in which case we'll indeed do one busy relink immediately. |
| try { |
| wait(); |
| } catch (final InterruptedException e) { |
| // Intentionally ignored. There's nothing meaningful we can do if we're interrupted |
| } |
| } else { |
| return new HandleAndAssumptions(handle, assumptions); |
| } |
| } |
| } |
| |
| private static void relinkComposableInvoker(final CallSite cs, final CompiledFunction inv, final boolean constructor) { |
| final HandleAndAssumptions handleAndAssumptions = inv.getValidOptimisticInvocation(new Supplier<MethodHandle>() { |
| @Override |
| public MethodHandle get() { |
| return inv.getInvokerOrConstructor(constructor); |
| } |
| }); |
| final MethodHandle handle = handleAndAssumptions.handle; |
| final SwitchPoint assumptions = handleAndAssumptions.assumptions; |
| final MethodHandle target; |
| if(assumptions == null) { |
| target = handle; |
| } else { |
| final MethodHandle relink = MethodHandles.insertArguments(RELINK_COMPOSABLE_INVOKER, 0, cs, inv, constructor); |
| target = assumptions.guardWithTest(handle, MethodHandles.foldArguments(cs.dynamicInvoker(), relink)); |
| } |
| cs.setTarget(target.asType(cs.type())); |
| } |
| |
| private MethodHandle getInvokerOrConstructor(final boolean selectCtor) { |
| return selectCtor ? getConstructor() : createInvokerForPessimisticCaller(); |
| } |
| |
| /** |
| * Returns a guarded invocation for this function when not invoked as a constructor. The guarded invocation has no |
| * guard but it potentially has an optimistic assumptions switch point. As such, it will probably not be used as a |
| * final guarded invocation, but rather as a holder for an invocation handle and switch point to be decomposed and |
| * reassembled into a different final invocation by the user of this method. Any recompositions should take care to |
| * continue to use the switch point. If that is not possible, use {@link #createComposableInvoker()} instead. |
| * @return a guarded invocation for an ordinary (non-constructor) invocation of this function. |
| */ |
| GuardedInvocation createFunctionInvocation(final Class<?> callSiteReturnType, final int callerProgramPoint) { |
| return getValidOptimisticInvocation(new Supplier<MethodHandle>() { |
| @Override |
| public MethodHandle get() { |
| return createInvoker(callSiteReturnType, callerProgramPoint); |
| } |
| }).createInvocation(); |
| } |
| |
| /** |
| * Returns a guarded invocation for this function when invoked as a constructor. The guarded invocation has no guard |
| * but it potentially has an optimistic assumptions switch point. As such, it will probably not be used as a final |
| * guarded invocation, but rather as a holder for an invocation handle and switch point to be decomposed and |
| * reassembled into a different final invocation by the user of this method. Any recompositions should take care to |
| * continue to use the switch point. If that is not possible, use {@link #createComposableConstructor()} instead. |
| * @return a guarded invocation for invocation of this function as a constructor. |
| */ |
| GuardedInvocation createConstructorInvocation() { |
| return getValidOptimisticInvocation(new Supplier<MethodHandle>() { |
| @Override |
| public MethodHandle get() { |
| return getConstructor(); |
| } |
| }).createInvocation(); |
| } |
| |
| private MethodHandle createInvoker(final Class<?> callSiteReturnType, final int callerProgramPoint) { |
| final boolean isOptimistic = canBeDeoptimized(); |
| MethodHandle handleRewriteException = isOptimistic ? createRewriteExceptionHandler() : null; |
| |
| MethodHandle inv = invoker; |
| if(isValid(callerProgramPoint)) { |
| inv = OptimisticReturnFilters.filterOptimisticReturnValue(inv, callSiteReturnType, callerProgramPoint); |
| inv = changeReturnType(inv, callSiteReturnType); |
| if(callSiteReturnType.isPrimitive() && handleRewriteException != null) { |
| // because handleRewriteException always returns Object |
| handleRewriteException = OptimisticReturnFilters.filterOptimisticReturnValue(handleRewriteException, |
| callSiteReturnType, callerProgramPoint); |
| } |
| } else if(isOptimistic) { |
| // Required so that rewrite exception has the same return type. It'd be okay to do it even if we weren't |
| // optimistic, but it isn't necessary as the linker upstream will eventually convert the return type. |
| inv = changeReturnType(inv, callSiteReturnType); |
| } |
| |
| if(isOptimistic) { |
| assert handleRewriteException != null; |
| final MethodHandle typedHandleRewriteException = changeReturnType(handleRewriteException, inv.type().returnType()); |
| return MH.catchException(inv, RewriteException.class, typedHandleRewriteException); |
| } |
| return inv; |
| } |
| |
| private MethodHandle createRewriteExceptionHandler() { |
| return MH.foldArguments(RESTOF_INVOKER, MH.insertArguments(HANDLE_REWRITE_EXCEPTION, 0, this, optimismInfo)); |
| } |
| |
| private static MethodHandle changeReturnType(final MethodHandle mh, final Class<?> newReturnType) { |
| return Bootstrap.getLinkerServices().asType(mh, mh.type().changeReturnType(newReturnType)); |
| } |
| |
| @SuppressWarnings("unused") |
| private static MethodHandle handleRewriteException(final CompiledFunction function, final OptimismInfo oldOptimismInfo, final RewriteException re) { |
| return function.handleRewriteException(oldOptimismInfo, re); |
| } |
| |
| /** |
| * Debug function for printing out all invalidated program points and their |
| * invalidation mapping to next type |
| * @param ipp |
| * @return string describing the ipp map |
| */ |
| private static List<String> toStringInvalidations(final Map<Integer, Type> ipp) { |
| if (ipp == null) { |
| return Collections.emptyList(); |
| } |
| |
| final List<String> list = new ArrayList<>(); |
| |
| for (final Iterator<Map.Entry<Integer, Type>> iter = ipp.entrySet().iterator(); iter.hasNext(); ) { |
| final Map.Entry<Integer, Type> entry = iter.next(); |
| final char bct = entry.getValue().getBytecodeStackType(); |
| final String type; |
| |
| switch (entry.getValue().getBytecodeStackType()) { |
| case 'A': |
| type = "object"; |
| break; |
| case 'I': |
| type = "int"; |
| break; |
| case 'J': |
| type = "long"; |
| break; |
| case 'D': |
| type = "double"; |
| break; |
| default: |
| type = String.valueOf(bct); |
| break; |
| } |
| |
| final StringBuilder sb = new StringBuilder(); |
| sb.append('['). |
| append("program point: "). |
| append(entry.getKey()). |
| append(" -> "). |
| append(type). |
| append(']'); |
| |
| list.add(sb.toString()); |
| } |
| |
| return list; |
| } |
| |
| private void logRecompile(final String reason, final FunctionNode fn, final MethodType type, final Map<Integer, Type> ipp) { |
| if (log.isEnabled()) { |
| log.info(reason, DebugLogger.quote(fn.getName()), " signature: ", type); |
| log.indent(); |
| for (final String str : toStringInvalidations(ipp)) { |
| log.fine(str); |
| } |
| log.unindent(); |
| } |
| } |
| |
| /** |
| * Handles a {@link RewriteException} raised during the execution of this function by recompiling (if needed) the |
| * function with an optimistic assumption invalidated at the program point indicated by the exception, and then |
| * executing a rest-of method to complete the execution with the deoptimized version. |
| * @param oldOptInfo the optimism info of this function. We must store it explicitly as a bound argument in the |
| * method handle, otherwise it could be null for handling a rewrite exception in an outer invocation of a recursive |
| * function when recursive invocations of the function have completely deoptimized it. |
| * @param re the rewrite exception that was raised |
| * @return the method handle for the rest-of method, for folding composition. |
| */ |
| private synchronized MethodHandle handleRewriteException(final OptimismInfo oldOptInfo, final RewriteException re) { |
| if (log.isEnabled()) { |
| log.info( |
| new RecompilationEvent( |
| Level.INFO, |
| re, |
| re.getReturnValueNonDestructive()), |
| "caught RewriteException ", |
| re.getMessageShort()); |
| log.indent(); |
| } |
| |
| final MethodType type = type(); |
| |
| // Compiler needs a call site type as its input, which always has a callee parameter, so we must add it if |
| // this function doesn't have a callee parameter. |
| final MethodType ct = type.parameterType(0) == ScriptFunction.class ? |
| type : |
| type.insertParameterTypes(0, ScriptFunction.class); |
| final OptimismInfo currentOptInfo = optimismInfo; |
| final boolean shouldRecompile = currentOptInfo != null && currentOptInfo.requestRecompile(re); |
| |
| // Effective optimism info, for subsequent use. We'll normally try to use the current (latest) one, but if it |
| // isn't available, we'll use the old one bound into the call site. |
| final OptimismInfo effectiveOptInfo = currentOptInfo != null ? currentOptInfo : oldOptInfo; |
| FunctionNode fn = effectiveOptInfo.reparse(); |
| final boolean cached = fn.isCached(); |
| final Compiler compiler = effectiveOptInfo.getCompiler(fn, ct, re); //set to non rest-of |
| |
| if (!shouldRecompile) { |
| // It didn't necessarily recompile, e.g. for an outer invocation of a recursive function if we already |
| // recompiled a deoptimized version for an inner invocation. |
| // We still need to do the rest of from the beginning |
| logRecompile("Rest-of compilation [STANDALONE] ", fn, ct, effectiveOptInfo.invalidatedProgramPoints); |
| return restOfHandle(effectiveOptInfo, compiler.compile(fn, cached ? CompilationPhases.COMPILE_CACHED_RESTOF : CompilationPhases.COMPILE_ALL_RESTOF), currentOptInfo != null); |
| } |
| |
| logRecompile("Deoptimizing recompilation (up to bytecode) ", fn, ct, effectiveOptInfo.invalidatedProgramPoints); |
| fn = compiler.compile(fn, cached ? CompilationPhases.RECOMPILE_CACHED_UPTO_BYTECODE : CompilationPhases.COMPILE_UPTO_BYTECODE); |
| log.fine("Reusable IR generated"); |
| |
| // compile the rest of the function, and install it |
| log.info("Generating and installing bytecode from reusable IR..."); |
| logRecompile("Rest-of compilation [CODE PIPELINE REUSE] ", fn, ct, effectiveOptInfo.invalidatedProgramPoints); |
| final FunctionNode normalFn = compiler.compile(fn, CompilationPhases.GENERATE_BYTECODE_AND_INSTALL); |
| |
| if (effectiveOptInfo.data.usePersistentCodeCache()) { |
| final RecompilableScriptFunctionData data = effectiveOptInfo.data; |
| final int functionNodeId = data.getFunctionNodeId(); |
| final TypeMap typeMap = data.typeMap(ct); |
| final Type[] paramTypes = typeMap == null ? null : typeMap.getParameterTypes(functionNodeId); |
| final String cacheKey = CodeStore.getCacheKey(functionNodeId, paramTypes); |
| compiler.persistClassInfo(cacheKey, normalFn); |
| } |
| |
| final boolean canBeDeoptimized = normalFn.canBeDeoptimized(); |
| |
| if (log.isEnabled()) { |
| log.unindent(); |
| log.info("Done."); |
| |
| log.info("Recompiled '", fn.getName(), "' (", Debug.id(this), ") ", canBeDeoptimized ? "can still be deoptimized." : " is completely deoptimized."); |
| log.finest("Looking up invoker..."); |
| } |
| |
| final MethodHandle newInvoker = effectiveOptInfo.data.lookup(fn); |
| invoker = newInvoker.asType(type.changeReturnType(newInvoker.type().returnType())); |
| constructor = null; // Will be regenerated when needed |
| |
| log.info("Done: ", invoker); |
| final MethodHandle restOf = restOfHandle(effectiveOptInfo, compiler.compile(fn, CompilationPhases.GENERATE_BYTECODE_AND_INSTALL_RESTOF), canBeDeoptimized); |
| |
| // Note that we only adjust the switch point after we set the invoker/constructor. This is important. |
| if (canBeDeoptimized) { |
| effectiveOptInfo.newOptimisticAssumptions(); // Otherwise, set a new switch point. |
| } else { |
| optimismInfo = null; // If we got to a point where we no longer have optimistic assumptions, let the optimism info go. |
| } |
| notifyAll(); |
| |
| return restOf; |
| } |
| |
| private MethodHandle restOfHandle(final OptimismInfo info, final FunctionNode restOfFunction, final boolean canBeDeoptimized) { |
| assert info != null; |
| assert restOfFunction.getCompileUnit().getUnitClassName().contains("restOf"); |
| final MethodHandle restOf = |
| changeReturnType( |
| info.data.lookupCodeMethod( |
| restOfFunction.getCompileUnit().getCode(), |
| MH.type(restOfFunction.getReturnType().getTypeClass(), |
| RewriteException.class)), |
| Object.class); |
| |
| if (!canBeDeoptimized) { |
| return restOf; |
| } |
| |
| // If rest-of is itself optimistic, we must make sure that we can repeat a deoptimization if it, too hits an exception. |
| return MH.catchException(restOf, RewriteException.class, createRewriteExceptionHandler()); |
| |
| } |
| |
| private static class OptimismInfo { |
| // TODO: this is pointing to its owning ScriptFunctionData. Re-evaluate if that's okay. |
| private final RecompilableScriptFunctionData data; |
| private final Map<Integer, Type> invalidatedProgramPoints; |
| private SwitchPoint optimisticAssumptions; |
| private final DebugLogger log; |
| |
| OptimismInfo(final RecompilableScriptFunctionData data, final Map<Integer, Type> invalidatedProgramPoints) { |
| this.data = data; |
| this.log = data.getLogger(); |
| this.invalidatedProgramPoints = invalidatedProgramPoints == null ? new TreeMap<Integer, Type>() : invalidatedProgramPoints; |
| newOptimisticAssumptions(); |
| } |
| |
| private void newOptimisticAssumptions() { |
| optimisticAssumptions = new SwitchPoint(); |
| } |
| |
| boolean requestRecompile(final RewriteException e) { |
| final Type retType = e.getReturnType(); |
| final Type previousFailedType = invalidatedProgramPoints.put(e.getProgramPoint(), retType); |
| |
| if (previousFailedType != null && !previousFailedType.narrowerThan(retType)) { |
| final StackTraceElement[] stack = e.getStackTrace(); |
| final String functionId = stack.length == 0 ? |
| data.getName() : |
| stack[0].getClassName() + "." + stack[0].getMethodName(); |
| |
| 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."); |
| |
| return false; |
| } |
| |
| SwitchPoint.invalidateAll(new SwitchPoint[] { optimisticAssumptions }); |
| |
| return true; |
| } |
| |
| Compiler getCompiler(final FunctionNode fn, final MethodType actualCallSiteType, final RewriteException e) { |
| return data.getCompiler(fn, actualCallSiteType, e.getRuntimeScope(), invalidatedProgramPoints, getEntryPoints(e)); |
| } |
| |
| private static int[] getEntryPoints(final RewriteException e) { |
| final int[] prevEntryPoints = e.getPreviousContinuationEntryPoints(); |
| final int[] entryPoints; |
| if (prevEntryPoints == null) { |
| entryPoints = new int[1]; |
| } else { |
| final int l = prevEntryPoints.length; |
| entryPoints = new int[l + 1]; |
| System.arraycopy(prevEntryPoints, 0, entryPoints, 1, l); |
| } |
| entryPoints[0] = e.getProgramPoint(); |
| return entryPoints; |
| } |
| |
| FunctionNode reparse() { |
| return data.reparse(); |
| } |
| } |
| |
| @SuppressWarnings("unused") |
| private static Object newFilter(final Object result, final Object allocation) { |
| return (result instanceof ScriptObject || !JSType.isPrimitive(result))? result : allocation; |
| } |
| |
| private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) { |
| return MH.findStatic(MethodHandles.lookup(), CompiledFunction.class, name, MH.type(rtype, types)); |
| } |
| } |
