Uploaded image for project: 'JDK'
  1. JDK
  2. JDK-8251397

NPE on ClassValue.ClassValueMap.cacheArray

    XMLWordPrintable

    Details

    • Subcomponent:
    • Resolved In Build:
      b17

      Backports

        Description

        When GraalVM is building its points-to analysis graph using jdk11u-dev, we see the JVM process fail with the following NPE:

        Caused by: java.lang.NullPointerException
                at java.base/java.lang.ClassValue$ClassValueMap.loadFromCache(ClassValue.java:535)
                at java.base/java.lang.ClassValue$ClassValueMap.probeHomeLocation(ClassValue.java:541)
                at java.base/java.lang.ClassValue.get(ClassValue.java:101)
                at jdk.internal.vm.ci/jdk.vm.ci.hotspot.HotSpotJVMCIMetaAccessContext.fromClass(HotSpotJVMCIMetaAccessContext.java:163)
                at jdk.internal.vm.ci/jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.fromClass(HotSpotJVMCIRuntime.java:339)
                at jdk.internal.vm.ci/jdk.vm.ci.hotspot.HotSpotResolvedObjectTypeImpl.fromObjectClass(HotSpotResolvedObjectTypeImpl.java:83)
                at jdk.internal.vm.ci/jdk.vm.ci.hotspot.HotSpotResolvedObjectTypeImpl.fromMetaspace(HotSpotResolvedObjectTypeImpl.java:97)
                at jdk.internal.vm.ci/jdk.vm.ci.hotspot.CompilerToVM.resolveTypeInPool(Native Method)
                at jdk.internal.vm.ci/jdk.vm.ci.hotspot.HotSpotConstantPool.loadReferencedType(HotSpotConstantPool.java:727)
                at java.base/jdk.internal.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)

        The issue is with ClassValue.ClassValueMap.cacheArray field, which can sometimes be seen as null.

        A discussion was started in core-lib-devs (see https://mail.openjdk.java.net/pipermail/core-libs-dev/2020-August/068086.html ) which confirmed the possibility of such issue and ideas were provided for potential fixes.

        As a side note: an Oracle GraalVM distribution uses a special Oracle Labs JDK as base that has a more modern JVMCI stack compared to JDK 11, hence this issue is unlikely to be seen in that environment.

        A fix will be sent for RFR shortly.

          Attachments

            Issue Links

              Activity

                People

                Assignee:
                sgehwolf Severin Gehwolf
                Reporter:
                sgehwolf Severin Gehwolf
                Votes:
                0 Vote for this issue
                Watchers:
                6 Start watching this issue

                  Dates

                  Created:
                  Updated:
                  Resolved: