Mercurial > jdk8-mips64-public > nashorn / file comparison
comparison: src/jdk/nashorn/internal/objects/ScriptFunctionTrampolineImpl.java
src/jdk/nashorn/internal/objects/ScriptFunctionTrampolineImpl.java
- changeset 150
- 999cc1bf5520
- parent 133
- 5759f600fcf7
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| 135:fbbdef940138 | 150:999cc1bf5520 |
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| 1 package jdk.nashorn.internal.objects; | |
| 2 | |
| 3 import static jdk.nashorn.internal.lookup.Lookup.MH; | |
| 4 | |
| 5 import java.lang.invoke.MethodHandle; | |
| 6 import java.lang.invoke.MethodHandles; | |
| 7 import java.lang.invoke.MethodType; | |
| 8 import jdk.nashorn.internal.codegen.CompilationException; | |
| 9 import jdk.nashorn.internal.codegen.Compiler; | |
| 10 import jdk.nashorn.internal.codegen.FunctionSignature; | |
| 11 import jdk.nashorn.internal.codegen.types.Type; | |
| 12 import jdk.nashorn.internal.ir.FunctionNode; | |
| 13 import jdk.nashorn.internal.runtime.CodeInstaller; | |
| 14 import jdk.nashorn.internal.runtime.Context; | |
| 15 import jdk.nashorn.internal.runtime.ScriptEnvironment; | |
| 16 import jdk.nashorn.internal.runtime.ScriptFunction; | |
| 17 import jdk.nashorn.internal.runtime.ScriptFunctionData; | |
| 18 import jdk.nashorn.internal.runtime.ScriptObject; | |
| 19 | |
| 20 /** | |
| 21 * A trampoline is a promise to compile a {@link ScriptFunction} later. It just looks like | |
| 22 * the call to the script function, but when invoked it will compile the script function | |
| 23 * (in a new compile unit) and invoke it | |
| 24 */ | |
| 25 public final class ScriptFunctionTrampolineImpl extends ScriptFunctionImpl { | |
| 26 | |
| 27 private CodeInstaller<ScriptEnvironment> installer; | |
| 28 | |
| 29 /** Function node to lazily recompile when trampoline is hit */ | |
| 30 private FunctionNode functionNode; | |
| 31 | |
| 32 /** | |
| 33 * Constructor | |
| 34 * | |
| 35 * @param installer opaque code installer from context | |
| 36 * @param functionNode function node to lazily compile when trampoline is hit | |
| 37 * @param data {@link ScriptFunctionData} for function | |
| 38 * @param scope scope | |
| 39 * @param allocator allocator | |
| 40 */ | |
| 41 public ScriptFunctionTrampolineImpl(final CodeInstaller<ScriptEnvironment> installer, final FunctionNode functionNode, final ScriptFunctionData data, final ScriptObject scope, final MethodHandle allocator) { | |
| 42 super(null, data, scope, allocator); | |
| 43 | |
| 44 this.installer = installer; | |
| 45 this.functionNode = functionNode; | |
| 46 | |
| 47 data.setMethodHandles(makeTrampoline(), allocator); | |
| 48 } | |
| 49 | |
| 50 private final MethodHandle makeTrampoline() { | |
| 51 final MethodType mt = | |
| 52 new FunctionSignature( | |
| 53 true, | |
| 54 functionNode.needsCallee(), | |
| 55 Type.OBJECT, | |
| 56 functionNode.getParameters().size()). | |
| 57 getMethodType(); | |
| 58 | |
| 59 return | |
| 60 MH.bindTo( | |
| 61 MH.asCollector( | |
| 62 findOwnMH( | |
| 63 "trampoline", | |
| 64 Object.class, | |
| 65 Object[].class), | |
| 66 Object[].class, | |
| 67 mt.parameterCount()), | |
| 68 this); | |
| 69 } | |
| 70 | |
| 71 private static MethodHandle findOwnMH(final String name, final Class<?> rtype, final Class<?>... types) { | |
| 72 return MH.findVirtual(MethodHandles.lookup(), ScriptFunctionTrampolineImpl.class, name, MH.type(rtype, types)); | |
| 73 } | |
| 74 | |
| 75 @Override | |
| 76 protected ScriptFunction makeBoundFunction(final ScriptFunctionData data) { | |
| 77 //prevent trampoline recompilation cycle if a function is bound before use | |
| 78 compile(); | |
| 79 return super.makeBoundFunction(data); | |
| 80 } | |
| 81 | |
| 82 private MethodHandle compile() throws CompilationException { | |
| 83 final Compiler compiler = new Compiler(installer, functionNode); | |
| 84 | |
| 85 compiler.compile(); | |
| 86 | |
| 87 final Class<?> clazz = compiler.install(); | |
| 88 /* compute function signature for lazy method. this can be done first after compilation, as only then do we know | |
| 89 * the final state about callees, scopes and specialized parameter types */ | |
| 90 final FunctionSignature signature = new FunctionSignature(true, functionNode.needsCallee(), Type.OBJECT, functionNode.getParameters().size()); | |
| 91 final MethodType mt = signature.getMethodType(); | |
| 92 | |
| 93 MethodHandle mh = MH.findStatic(MethodHandles.publicLookup(), clazz, functionNode.getName(), mt); | |
| 94 if (functionNode.needsCallee()) { | |
| 95 mh = MH.bindTo(mh, this); | |
| 96 } | |
| 97 | |
| 98 // now the invoker method looks like the one our superclass is expecting | |
| 99 resetInvoker(mh); | |
| 100 | |
| 101 return mh; | |
| 102 } | |
| 103 | |
| 104 @SuppressWarnings("unused") | |
| 105 private Object trampoline(final Object... args) throws CompilationException { | |
| 106 Compiler.LOG.info(">>> TRAMPOLINE: Hitting trampoline for '" + functionNode.getName() + "'"); | |
| 107 MethodHandle mh = compile(); | |
| 108 | |
| 109 Compiler.LOG.info("<<< COMPILED TO: " + mh); | |
| 110 // spread the array to invididual args of the correct type | |
| 111 mh = MH.asSpreader(mh, Object[].class, mh.type().parameterCount()); | |
| 112 | |
| 113 try { | |
| 114 //invoke the real method the trampoline points to. this only happens once | |
| 115 return mh.invoke(args); | |
| 116 } catch (final RuntimeException | Error e) { | |
| 117 throw e; | |
| 118 } catch (final Throwable t) { | |
| 119 throw new RuntimeException(t); | |
| 120 } | |
| 121 } | |
| 122 } |
