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8202184: Reduce time blocking the ClassSpecializer cache creating SpeciesData

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Reviewed-by: psandoz, plevart
This commit is contained in:
Claes Redestad 2018-04-25 13:54:11 +02:00
parent 7904b56345
commit eed00fcf0a
1 changed files with 40 additions and 19 deletions
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59
src/java.base/share/classes/java/lang/invoke/ClassSpecializer.java
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@ -32,13 +32,17 @@ import jdk.internal.org.objectweb.asm.MethodVisitor;
import jdk.internal.vm.annotation.Stable;
import sun.invoke.util.BytecodeName;
import java.lang.reflect.*;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.ProtectionDomain;
import java.util.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.function.Function;
import static java.lang.invoke.LambdaForm.*;
@ -64,7 +68,7 @@ abstract class ClassSpecializer<T,K,S extends ClassSpecializer<T,K,S>.SpeciesDat
private final List<MemberName> transformMethods;
private final MethodType baseConstructorType;
private final S topSpecies;
private final ConcurrentMap<K, S> cache = new ConcurrentHashMap<>();
private final ConcurrentHashMap<K, S> cache = new ConcurrentHashMap<>();
private final Factory factory;
private @Stable boolean topClassIsSuper;
@ -113,8 +117,7 @@ abstract class ClassSpecializer<T,K,S extends ClassSpecializer<T,K,S>.SpeciesDat
this.keyType = keyType;
this.metaType = metaType;
this.sdAccessor = sdAccessor;
// FIXME: use List.copyOf once 8177290 is in
this.transformMethods = List.of(transformMethods.toArray(new MemberName[transformMethods.size()]));
this.transformMethods = List.copyOf(transformMethods);
this.sdFieldName = sdFieldName;
this.baseConstructorType = baseConstructorType.changeReturnType(void.class);
this.factory = makeFactory();
@ -149,12 +152,6 @@ abstract class ClassSpecializer<T,K,S extends ClassSpecializer<T,K,S>.SpeciesDat
}
public final S findSpecies(K key) {
S speciesData = cache.computeIfAbsent(key, new Function<>() {
@Override
public S apply(K key1) {
return factory.loadSpecies(newSpeciesData(key1));
}
});
// Note: Species instantiation may throw VirtualMachineError because of
// code cache overflow. If this happens the species bytecode may be
// loaded but not linked to its species metadata (with MH's etc).
@ -176,7 +173,33 @@ abstract class ClassSpecializer<T,K,S extends ClassSpecializer<T,K,S>.SpeciesDat
// successfully on a concrete class if ever.
// The concrete class is published via SpeciesData instance
// returned here only after the class and species data are linked together.
assert(speciesData != null);
S speciesData = cache.computeIfAbsent(key, new Function<>() {
@Override
public S apply(K key1) {
return newSpeciesData(key1);
}
});
// Separating the creation of a placeholder SpeciesData instance above
// from the loading and linking a real one below ensures we can never
// accidentally call computeIfAbsent recursively. Replacing rather than
// updating the placeholder is done to ensure safe publication.
if (!speciesData.isResolved()) {
synchronized (speciesData) {
S existingSpeciesData = cache.get(key);
if (existingSpeciesData == speciesData) { // won the race
// create a new SpeciesData...
speciesData = newSpeciesData(key);
// load and link it...
speciesData = factory.loadSpecies(speciesData);
if (!cache.replace(key, existingSpeciesData, speciesData)) {
throw newInternalError("Concurrent loadSpecies");
}
} else { // lost the race; the retrieved existingSpeciesData is the final
speciesData = existingSpeciesData;
}
}
}
assert(speciesData != null && speciesData.isResolved());
return speciesData;
}
@ -208,9 +231,7 @@ abstract class ClassSpecializer<T,K,S extends ClassSpecializer<T,K,S>.SpeciesDat
protected SpeciesData(K key) {
this.key = keyType.cast(Objects.requireNonNull(key));
List<Class<?>> types = deriveFieldTypes(key);
// TODO: List.copyOf
int arity = types.size();
this.fieldTypes = List.of(types.toArray(new Class<?>[arity]));
this.fieldTypes = List.copyOf(types);
}
public final K key() {
@ -458,8 +479,8 @@ abstract class ClassSpecializer<T,K,S extends ClassSpecializer<T,K,S>.SpeciesDat
final Class<? extends T> speciesCode;
if (salvage != null) {
speciesCode = salvage.asSubclass(topClass());
factory.linkSpeciesDataToCode(speciesData, speciesCode);
factory.linkCodeToSpeciesData(speciesCode, speciesData, true);
linkSpeciesDataToCode(speciesData, speciesCode);
linkCodeToSpeciesData(speciesCode, speciesData, true);
} else {
// Not pregenerated, generate the class
try {
@ -486,7 +507,7 @@ abstract class ClassSpecializer<T,K,S extends ClassSpecializer<T,K,S>.SpeciesDat
if (!speciesData.isResolved()) {
throw newInternalError("bad species class linkage for " + className + ": " + speciesData);
}
assert(speciesData == factory.loadSpeciesDataFromCode(speciesCode));
assert(speciesData == loadSpeciesDataFromCode(speciesCode));
return speciesData;
}