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src/java.base/share/classes/java/lang/invoke/BootstrapMethodInvoker.java
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rev 48895 : 8195850: Improve startup of code to pull arguments from BootstrapMethodInvoker
Reviewed-by: psandoz, jrose
@@ -65,16 +65,16 @@
// match the VM with the BSM
if (vmIsPushing) {
// VM is pushing arguments at us
pullModeBSM = null;
if (pullMode) {
- bootstrapMethod = Adapters.pushMePullYou(bootstrapMethod, true);
+ bootstrapMethod = pushMePullYou(bootstrapMethod, true);
}
} else {
// VM wants us to pull args from it
pullModeBSM = pullMode ? bootstrapMethod :
- Adapters.pushMePullYou(bootstrapMethod, false);
+ pushMePullYou(bootstrapMethod, false);
bootstrapMethod = null;
}
try {
info = maybeReBox(info);
if (info == null) {
@@ -235,13 +235,14 @@
i++;
}
// give up at first null and grab the rest in one big block
if (i >= end) return i;
Object[] temp = new Object[end - i];
- if (TRACE_METHOD_LINKAGE)
- System.out.println("resolving more BSM arguments: "+
+ if (TRACE_METHOD_LINKAGE) {
+ System.out.println("resolving more BSM arguments: " +
Arrays.asList(caller.getSimpleName(), Arrays.toString(indexInfo), i, end));
+ }
copyOutBootstrapArguments(caller, indexInfo,
i, end, temp, 0,
true, null);
for (Object x : temp) {
x = maybeReBox(x);
@@ -283,13 +284,14 @@
}
private void prefetchIntoCache(int i, int pfLimit) {
if (pfLimit <= i) return; // corner case
Object[] temp = new Object[pfLimit - i];
- if (TRACE_METHOD_LINKAGE)
- System.out.println("prefetching BSM arguments: "+
+ if (TRACE_METHOD_LINKAGE) {
+ System.out.println("prefetching BSM arguments: " +
Arrays.asList(caller.getSimpleName(), Arrays.toString(indexInfo), i, pfLimit));
+ }
copyOutBootstrapArguments(caller, indexInfo,
i, pfLimit, temp, 0,
false, NOT_PRESENT);
for (Object x : temp) {
if (x != NOT_PRESENT && cache[i] == null) {
@@ -299,11 +301,11 @@
}
}
}
/*non-public*/ static final
- class Adapters {
+ class PushAdapter {
// skeleton for push-mode BSM which wraps a pull-mode BSM:
static Object pushToBootstrapMethod(MethodHandle pullModeBSM,
MethodHandles.Lookup lookup, String name, Object type,
Object... arguments) throws Throwable {
ConstantGroup cons = makeConstantGroup(Arrays.asList(arguments));
@@ -311,56 +313,104 @@
if (TRACE_METHOD_LINKAGE)
System.out.println("pull-mode BSM gets pushed arguments from fake BSCI");
return pullModeBSM.invoke(lookup, bsci);
}
+ static final MethodHandle MH_pushToBootstrapMethod;
+ static {
+ final Class<?> THIS_CLASS = PushAdapter.class;
+ try {
+ MH_pushToBootstrapMethod = IMPL_LOOKUP
+ .findStatic(THIS_CLASS, "pushToBootstrapMethod",
+ MethodType.methodType(Object.class, MethodHandle.class,
+ Lookup.class, String.class, Object.class, Object[].class));
+ } catch (Throwable ex) {
+ throw new InternalError(ex);
+ }
+ }
+ }
+
+ /*non-public*/ static final
+ class PullAdapter {
// skeleton for pull-mode BSM which wraps a push-mode BSM:
static Object pullFromBootstrapMethod(MethodHandle pushModeBSM,
- MethodHandles.Lookup lookup, BootstrapCallInfo<?> bsci)
+ MethodHandles.Lookup lookup,
+ BootstrapCallInfo<?> bsci)
throws Throwable {
int argc = bsci.size();
- Object arguments[] = new Object[3 + argc];
- arguments[0] = lookup;
- arguments[1] = bsci.invocationName();
- arguments[2] = bsci.invocationType();
- bsci.copyConstants(0, argc, arguments, 3);
- if (TRACE_METHOD_LINKAGE)
- System.out.println("pulled arguments from VM for push-mode BSM");
- return pushModeBSM.invokeWithArguments(arguments);
+ switch (argc) {
+ case 0:
+ return pushModeBSM.invoke(lookup, bsci.invocationName(), bsci.invocationType());
+ case 1:
+ return pushModeBSM.invoke(lookup, bsci.invocationName(), bsci.invocationType(),
+ bsci.get(0));
+ case 2:
+ return pushModeBSM.invoke(lookup, bsci.invocationName(), bsci.invocationType(),
+ bsci.get(0), bsci.get(1));
+ case 3:
+ return pushModeBSM.invoke(lookup, bsci.invocationName(), bsci.invocationType(),
+ bsci.get(0), bsci.get(1), bsci.get(2));
+ case 4:
+ return pushModeBSM.invoke(lookup, bsci.invocationName(), bsci.invocationType(),
+ bsci.get(0), bsci.get(1), bsci.get(2), bsci.get(3));
+ case 5:
+ return pushModeBSM.invoke(lookup, bsci.invocationName(), bsci.invocationType(),
+ bsci.get(0), bsci.get(1), bsci.get(2), bsci.get(3), bsci.get(4));
+ case 6:
+ return pushModeBSM.invoke(lookup, bsci.invocationName(), bsci.invocationType(),
+ bsci.get(0), bsci.get(1), bsci.get(2), bsci.get(3), bsci.get(4), bsci.get(5));
+ default:
+ final int NON_SPREAD_ARG_COUNT = 3; // (lookup, name, type)
+ final int MAX_SAFE_SIZE = MethodType.MAX_MH_ARITY / 2 - NON_SPREAD_ARG_COUNT;
+ if (argc >= MAX_SAFE_SIZE) {
+ // to be on the safe side, use invokeWithArguments which handles jumbo lists
+ Object[] newargv = new Object[NON_SPREAD_ARG_COUNT + argc];
+ newargv[0] = lookup;
+ newargv[1] = bsci.invocationName();
+ newargv[2] = bsci.invocationType();
+ bsci.copyConstants(0, argc, newargv, NON_SPREAD_ARG_COUNT);
+ return pushModeBSM.invokeWithArguments(newargv);
}
- static final MethodHandle MH_pushToBootstrapMethod;
+ MethodType invocationType = MethodType.genericMethodType(NON_SPREAD_ARG_COUNT + argc);
+ MethodHandle typedBSM = pushModeBSM.asType(invocationType);
+ MethodHandle spreader = invocationType.invokers().spreadInvoker(NON_SPREAD_ARG_COUNT);
+ Object[] argv = new Object[argc];
+ bsci.copyConstants(0, argc, argv, 0);
+ return spreader.invokeExact(typedBSM, (Object) lookup, (Object) bsci.invocationName(), bsci.invocationType(), argv);
+ }
+ }
+
static final MethodHandle MH_pullFromBootstrapMethod;
+
static {
- final Class<?> THIS_CLASS = Adapters.class;
+ final Class<?> THIS_CLASS = PullAdapter.class;
try {
- MH_pushToBootstrapMethod = IMPL_LOOKUP
- .findStatic(THIS_CLASS, "pushToBootstrapMethod",
- MethodType.methodType(Object.class, MethodHandle.class,
- Lookup.class, String.class, Object.class, Object[].class));
MH_pullFromBootstrapMethod = IMPL_LOOKUP
.findStatic(THIS_CLASS, "pullFromBootstrapMethod",
MethodType.methodType(Object.class, MethodHandle.class,
Lookup.class, BootstrapCallInfo.class));
} catch (Throwable ex) {
throw new InternalError(ex);
}
}
+ }
/** Given a push-mode BSM (taking one argument) convert it to a
* pull-mode BSM (taking N pre-resolved arguments).
* This method is used when, in fact, the JVM is passing up
* pre-resolved arguments, but the BSM is expecting lazy stuff.
* Or, when goToPushMode is true, do the reverse transform.
* (The two transforms are exactly inverse.)
*/
static MethodHandle pushMePullYou(MethodHandle bsm, boolean goToPushMode) {
- if (TRACE_METHOD_LINKAGE)
- System.out.println("converting BSM to "+(goToPushMode ? "push mode" : "pull mode"));
- assert(isPullModeBSM(bsm) == goToPushMode); //there must be a change
+ if (TRACE_METHOD_LINKAGE) {
+ System.out.println("converting BSM of type " + bsm.type() + " to "
+ + (goToPushMode ? "push mode" : "pull mode"));
+ }
+ assert(isPullModeBSM(bsm) == goToPushMode); // there must be a change
if (goToPushMode) {
- return Adapters.MH_pushToBootstrapMethod.bindTo(bsm).withVarargs(true);
+ return PushAdapter.MH_pushToBootstrapMethod.bindTo(bsm).withVarargs(true);
} else {
- return Adapters.MH_pullFromBootstrapMethod.bindTo(bsm).withVarargs(false);
- }
+ return PullAdapter.MH_pullFromBootstrapMethod.bindTo(bsm).withVarargs(false);
}
}
}
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