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[GR-63772] Fix serial GC write barrier verification. #10971

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Merged
merged 1 commit into from
Apr 3, 2025
Merged

[GR-63772] Fix serial GC write barrier verification. #10971

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17 changes: 6 additions & 11 deletions ...racle.svm.core.genscavenge/src/com/oracle/svm/core/genscavenge/graal/BarrierSnippets.java
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Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,8 @@
import jdk.graal.compiler.core.common.GraalOptions;
import jdk.graal.compiler.core.common.spi.ForeignCallDescriptor;
import jdk.graal.compiler.graph.Node;
import jdk.graal.compiler.graph.Node.ConstantNodeParameter;
import jdk.graal.compiler.graph.Node.NodeIntrinsic;
import jdk.graal.compiler.nodes.BreakpointNode;
import jdk.graal.compiler.nodes.NamedLocationIdentity;
import jdk.graal.compiler.nodes.extended.BranchProbabilityNode;
Expand All @@ -74,8 +76,7 @@ public class BarrierSnippets extends SubstrateTemplates implements Snippets {
public static final LocationIdentity CARD_REMEMBERED_SET_LOCATION = NamedLocationIdentity.mutable("CardRememberedSet");

private static final SnippetRuntime.SubstrateForeignCallDescriptor POST_WRITE_BARRIER = SnippetRuntime.findForeignCall(BarrierSnippets.class, "postWriteBarrierStub",
NO_SIDE_EFFECT,
CARD_REMEMBERED_SET_LOCATION);
NO_SIDE_EFFECT, CARD_REMEMBERED_SET_LOCATION);

private final SnippetInfo postWriteBarrierSnippet;

Expand Down Expand Up @@ -108,8 +109,8 @@ public static void postWriteBarrierStub(Object object) {
}
}

@Node.NodeIntrinsic(ForeignCallNode.class)
private static native void callPostWriteBarrierStub(@Node.ConstantNodeParameter ForeignCallDescriptor descriptor, Object object);
@NodeIntrinsic(ForeignCallNode.class)
private static native void callPostWriteBarrierStub(@ConstantNodeParameter ForeignCallDescriptor descriptor, Object object);

@Snippet
public static void postWriteBarrierSnippet(Object object, @ConstantParameter boolean shouldOutline, @ConstantParameter boolean alwaysAlignedChunk, @ConstantParameter boolean verifyOnly) {
Expand All @@ -120,20 +121,14 @@ public static void postWriteBarrierSnippet(Object object, @ConstantParameter boo
if (SerialGCOptions.VerifyWriteBarriers.getValue() && alwaysAlignedChunk) {
/*
* To increase verification coverage, we do the verification before checking if a
* barrier is needed at all. And in addition to verifying that the object is in an
* aligned chunk, we also verify that it is not an array at all because most arrays are
* small and therefore in an aligned chunk.
* barrier is needed at all.
*/

if (BranchProbabilityNode.probability(BranchProbabilityNode.SLOW_PATH_PROBABILITY, ObjectHeaderImpl.isUnalignedHeader(objectHeader))) {
BreakpointNode.breakpoint();
}
if (BranchProbabilityNode.probability(BranchProbabilityNode.SLOW_PATH_PROBABILITY, fixedObject == null)) {
BreakpointNode.breakpoint();
}
if (BranchProbabilityNode.probability(BranchProbabilityNode.SLOW_PATH_PROBABILITY, fixedObject.getClass().isArray())) {
BreakpointNode.breakpoint();
}
}

boolean needsBarrier = RememberedSet.get().hasRememberedSet(objectHeader);
Expand Down
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