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* particular file as subject to the "Classpath" exception as provided
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* 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).
*
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package com.oracle.svm.core.genscavenge;
import org.graalvm.nativeimage.Platform;
import org.graalvm.nativeimage.Platforms;
import org.graalvm.word.Pointer;
import org.graalvm.word.UnsignedWord;
import com.oracle.svm.core.annotate.DuplicatedInNativeCode;
import com.oracle.svm.core.heap.ObjectReferenceVisitor;
import com.oracle.svm.core.heap.ReferenceAccess;
import com.oracle.svm.core.heap.RuntimeCodeCacheCleaner;
import com.oracle.svm.core.hub.DynamicHub;
@DuplicatedInNativeCode
final class RuntimeCodeCacheReachabilityAnalyzer implements ObjectReferenceVisitor {
private boolean unreachableObjects;
@Platforms(Platform.HOSTED_ONLY.class)
RuntimeCodeCacheReachabilityAnalyzer() {
}
public void initialize() {
this.unreachableObjects = false;
}
public boolean hasUnreachableObjects() {
return unreachableObjects;
}
@Override
public boolean visitObjectReference(Pointer ptrPtrToObject, boolean compressed) {
assert !unreachableObjects;
Pointer ptrToObj = ReferenceAccess.singleton().readObjectAsUntrackedPointer(ptrPtrToObject, compressed);
if (ptrToObj.isNonNull() && !isReachable(ptrToObj)) {
unreachableObjects = true;
return false;
}
return true;
}
public static boolean isReachable(Pointer ptrToObj) {
assert ptrToObj.isNonNull();
if (HeapImpl.getHeapImpl().isInImageHeap(ptrToObj)) {
return true;
}
UnsignedWord header = ObjectHeaderImpl.readHeaderFromPointer(ptrToObj);
if (ObjectHeaderImpl.isForwardedHeader(header)) {
return true;
}
Space space = HeapChunk.getSpace(HeapChunk.getEnclosingHeapChunk(ptrToObj, header));
if (!space.isFromSpace()) {
return true;
}
ObjectHeaderImpl ohi = ObjectHeaderImpl.getObjectHeaderImpl();
Class<?> clazz = DynamicHub.toClass(ohi.dynamicHubFromObjectHeader(header));
return isAssumedReachable(clazz);
}
private static boolean isAssumedReachable(Class<?> clazz) {
Class<?>[] classesAssumedReachable = RuntimeCodeCacheCleaner.CLASSES_ASSUMED_REACHABLE;
for (int i = 0; i < classesAssumedReachable.length; i++) {
if (classesAssumedReachable[i].isAssignableFrom(clazz)) {
return true;
}
}
return false;
}
}