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8172905: Minor startup cleanup of CallSite and MethodType

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Reviewed-by: psandoz, jrose
This commit is contained in:
Claes Redestad 2017-01-19 13:37:05 +01:00
parent 95a45889e9
commit ced9c19693
2 changed files with 41 additions and 18 deletions
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55
jdk/src/java.base/share/classes/java/lang/invoke/CallSite.java
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@ -28,6 +28,8 @@ package java.lang.invoke;
import static java.lang.invoke.MethodHandleStatics.*;
import static java.lang.invoke.MethodHandles.Lookup.IMPL_LOOKUP;
import jdk.internal.vm.annotation.Stable;
/**
* A {@code CallSite} is a holder for a variable {@link MethodHandle},
* which is called its {@code target}.
@ -215,19 +217,36 @@ public class CallSite {
public abstract MethodHandle dynamicInvoker();
/*non-public*/ MethodHandle makeDynamicInvoker() {
MethodHandle getTarget = GET_TARGET.bindArgumentL(0, this);
MethodHandle getTarget = getTargetHandle().bindArgumentL(0, this);
MethodHandle invoker = MethodHandles.exactInvoker(this.type());
return MethodHandles.foldArguments(invoker, getTarget);
}
private static final MethodHandle GET_TARGET;
private static final MethodHandle THROW_UCS;
static {
private static @Stable MethodHandle GET_TARGET;
private static MethodHandle getTargetHandle() {
MethodHandle handle = GET_TARGET;
if (handle != null) {
return handle;
}
try {
GET_TARGET = IMPL_LOOKUP.
findVirtual(CallSite.class, "getTarget", MethodType.methodType(MethodHandle.class));
THROW_UCS = IMPL_LOOKUP.
findStatic(CallSite.class, "uninitializedCallSite", MethodType.methodType(Object.class, Object[].class));
return GET_TARGET = IMPL_LOOKUP.
findVirtual(CallSite.class, "getTarget",
MethodType.methodType(MethodHandle.class));
} catch (ReflectiveOperationException e) {
throw newInternalError(e);
}
}
private static @Stable MethodHandle THROW_UCS;
private static MethodHandle uninitializedCallSiteHandle() {
MethodHandle handle = THROW_UCS;
if (handle != null) {
return handle;
}
try {
return THROW_UCS = IMPL_LOOKUP.
findStatic(CallSite.class, "uninitializedCallSite",
MethodType.methodType(Object.class, Object[].class));
} catch (ReflectiveOperationException e) {
throw newInternalError(e);
}
@ -242,7 +261,7 @@ public class CallSite {
MethodType basicType = targetType.basicType();
MethodHandle invoker = basicType.form().cachedMethodHandle(MethodTypeForm.MH_UNINIT_CS);
if (invoker == null) {
invoker = THROW_UCS.asType(basicType);
invoker = uninitializedCallSiteHandle().asType(basicType);
invoker = basicType.form().setCachedMethodHandle(MethodTypeForm.MH_UNINIT_CS, invoker);
}
// unchecked view is OK since no values will be received or returned
@ -250,12 +269,16 @@ public class CallSite {
}
// unsafe stuff:
private static final long TARGET_OFFSET;
private static final long CONTEXT_OFFSET;
static {
private static @Stable long TARGET_OFFSET;
private static long getTargetOffset() {
long offset = TARGET_OFFSET;
if (offset > 0) {
return offset;
}
try {
TARGET_OFFSET = UNSAFE.objectFieldOffset(CallSite.class.getDeclaredField("target"));
CONTEXT_OFFSET = UNSAFE.objectFieldOffset(CallSite.class.getDeclaredField("context"));
offset = TARGET_OFFSET = UNSAFE.objectFieldOffset(CallSite.class.getDeclaredField("target"));
assert(offset > 0);
return offset;
} catch (Exception ex) { throw newInternalError(ex); }
}
@ -265,7 +288,7 @@ public class CallSite {
}
/*package-private*/
MethodHandle getTargetVolatile() {
return (MethodHandle) UNSAFE.getObjectVolatile(this, TARGET_OFFSET);
return (MethodHandle) UNSAFE.getObjectVolatile(this, getTargetOffset());
}
/*package-private*/
void setTargetVolatile(MethodHandle newTarget) {
@ -324,7 +347,7 @@ public class CallSite {
final int NON_SPREAD_ARG_COUNT = 3; // (caller, name, type)
if (NON_SPREAD_ARG_COUNT + argv.length > MethodType.MAX_MH_ARITY)
throw new BootstrapMethodError("too many bootstrap method arguments");
MethodType bsmType = bootstrapMethod.type();
MethodType invocationType = MethodType.genericMethodType(NON_SPREAD_ARG_COUNT + argv.length);
MethodHandle typedBSM = bootstrapMethod.asType(invocationType);
MethodHandle spreader = invocationType.invokers().spreadInvoker(NON_SPREAD_ARG_COUNT);