7903364: JOL: Fix support for modern SA

openjdk · Oct 18, 2022 · 2d958ff · 2d958ff
1 parent 247f12a
commit 2d958ff
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Showing 4 changed files with 42 additions and 43 deletions.
diff --git a/jol-core/src/main/java/org/openjdk/jol/vm/HotspotUnsafe.java b/jol-core/src/main/java/org/openjdk/jol/vm/HotspotUnsafe.java
@@ -111,7 +111,7 @@ very dirty moves to access. Since the magic field offset code pokes (*writes*)
         narrowKlassBase = saDetails.getNarrowKlassBase();
 
         sizes = new Sizes(this);
-        lilliputVM = guessLilliput(objectHeaderSize);
+        lilliputVM = guessLilliput(addressSize);
     }
 
     HotspotUnsafe(Unsafe u, Instrumentation inst) {

diff --git a/jol-core/src/main/java/org/openjdk/jol/vm/sa/Constants.java b/jol-core/src/main/java/org/openjdk/jol/vm/sa/Constants.java
@@ -28,6 +28,8 @@ class Constants {
 
     static final String HOTSPOT_AGENT_CLASSNAME = "sun.jvm.hotspot.HotSpotAgent";
     static final String VM_CLASSNAME = "sun.jvm.hotspot.runtime.VM";
+    static final String COMP_OOPS_CLASSNAME = "sun.jvm.hotspot.oops.CompressedOops";
+    static final String COMP_KLASS_CLASSNAME = "sun.jvm.hotspot.oops.CompressedKlassPointers";
     static final String UNIVERSE_CLASSNAME = "sun.jvm.hotspot.memory.Universe";
 
     static final String SKIP_HOTSPOT_SA_ATTACH_FLAG = "jol.skipHotspotSAAttach";

diff --git a/jol-core/src/main/java/org/openjdk/jol/vm/sa/ServiceabilityAgentSupport.java b/jol-core/src/main/java/org/openjdk/jol/vm/sa/ServiceabilityAgentSupport.java
@@ -271,6 +271,7 @@ private List<String> getArguments(boolean sudoRequired, AgentStyle style) {
                 args.add("--add-exports"); args.add("jdk.hotspot.agent/sun.jvm.hotspot=ALL-UNNAMED");
                 args.add("--add-exports"); args.add("jdk.hotspot.agent/sun.jvm.hotspot.runtime=ALL-UNNAMED");
                 args.add("--add-exports"); args.add("jdk.hotspot.agent/sun.jvm.hotspot.memory=ALL-UNNAMED");
+                args.add("--add-exports"); args.add("jdk.hotspot.agent/sun.jvm.hotspot.oops=ALL-UNNAMED");
                 break;
             default:
                 throw new IllegalStateException("Unhandled style: " + style);

diff --git a/jol-core/src/main/java/org/openjdk/jol/vm/sa/UniverseTask.java b/jol-core/src/main/java/org/openjdk/jol/vm/sa/UniverseTask.java
@@ -43,57 +43,53 @@ public UniverseData process() {
         try {
             Class<?> universeClass = ClassUtils.loadClass(UNIVERSE_CLASSNAME);
             Class<?> vmClass = ClassUtils.loadClass(VM_CLASSNAME);
-            Object vm = ClassUtils.loadClass(VM_CLASSNAME).getMethod("getVM").invoke(null);
 
-            Method getOopSizeMethod = vmClass.getMethod("getOopSize");
-            Method getObjectAlignmentInBytesMethod = vmClass.getMethod("getObjectAlignmentInBytes");
+            Method vmMethod = vmClass.getMethod("getVM");
 
-            Method getHeapOopSizeMethod = vmClass.getMethod("getHeapOopSize");
-            Method isCompressedOopsEnabledMethod = vmClass.getMethod("isCompressedOopsEnabled");
-            Method getNarrowOopBaseMethod = universeClass.getMethod("getNarrowOopBase");
-            Method getNarrowOopShiftMethod = universeClass.getMethod("getNarrowOopShift");
+            Method heapOopSizeMethod = vmClass.getMethod("getHeapOopSize");
+            Method oopSizeMethod = vmClass.getMethod("getOopSize");
+            Method objectAlignmentMethod = vmClass.getMethod("getObjectAlignmentInBytes");
 
-            Method isCompressedKlassPtrsEnabledMethod = null;
-            Method getNarrowKlassBaseMethod = null;
-            Method getNarrowKlassShiftMethod = null;
+            Method compOopsEnabledMethod = vmClass.getMethod("isCompressedOopsEnabled");
+            Method compKlassEnabledMethod = vmClass.getMethod("isCompressedKlassPointersEnabled");
 
+            Method narrowOopBaseMethod = null;
+            Method narrowOopShiftMethod = null;
             try {
-                isCompressedKlassPtrsEnabledMethod = vmClass.getMethod("isCompressedKlassPointersEnabled");
-                getNarrowKlassBaseMethod = universeClass.getMethod("getNarrowKlassBase");
-                getNarrowKlassShiftMethod = universeClass.getMethod("getNarrowKlassShift");
-            } catch (NoSuchMethodException e) {
-                // There is nothing to do, seems target JVM is not Java 8
+                // Past JDK 13, JDK-8223136, we have a special class for this data.
+                Class<?> coopClass = ClassUtils.loadClass(COMP_OOPS_CLASSNAME);
+                narrowOopBaseMethod = coopClass.getMethod("getBase");
+                narrowOopShiftMethod = coopClass.getMethod("getShift");
+            } catch (Exception e) {
+                narrowOopBaseMethod = universeClass.getMethod("getNarrowOopBase");
+                narrowOopShiftMethod = universeClass.getMethod("getNarrowOopShift");
             }
 
-            int addressSize = ((Long) getOopSizeMethod.invoke(vm)).intValue();
-            int objectAlignment = (Integer) getObjectAlignmentInBytesMethod.invoke(vm);
-
-            int oopSize = (Integer) getHeapOopSizeMethod.invoke(vm);
-            boolean compressedOopsEnabled = (Boolean) isCompressedOopsEnabledMethod.invoke(vm);
-            long narrowOopBase = (Long) getNarrowOopBaseMethod.invoke(null);
-            int narrowOopShift = (Integer) getNarrowOopShiftMethod.invoke(null);
-
-            /*
-             * If compressed klass references is not supported (before Java 8),
-             * use compressed oop references values instead of them.
-             */
+            Method narrowKlassBaseMethod = null;
+            Method narrowKlassShiftMethod = null;
+            try {
+                // Past JDK 13, JDK-8223136, we have a special class for this data.
+                Class<?> coopClass = ClassUtils.loadClass(COMP_KLASS_CLASSNAME);
+                narrowKlassBaseMethod = coopClass.getMethod("getBase");
+                narrowKlassShiftMethod = coopClass.getMethod("getShift");
+            } catch (Exception e) {
+                narrowKlassBaseMethod = universeClass.getMethod("getNarrowKlassBase");
+                narrowKlassShiftMethod = universeClass.getMethod("getNarrowKlassShift");
+            }
 
-            boolean compressedKlassPtrsEnabled = isCompressedKlassPtrsEnabledMethod != null ?
-                    (Boolean) isCompressedKlassPtrsEnabledMethod.invoke(vm) : compressedOopsEnabled;
-            long narrowKlassBase = getNarrowKlassBaseMethod != null ?
-                    (Long) getNarrowKlassBaseMethod.invoke(null) : narrowOopBase;
-            int narrowKlassShift = getNarrowKlassShiftMethod != null ?
-                    (Integer) getNarrowKlassShiftMethod.invoke(null) : narrowOopShift;
+            Object vm = vmMethod.invoke(null);
 
-            return new UniverseData(addressSize,
-                                                        objectAlignment,
-                                                        oopSize,
-                                                        compressedOopsEnabled,
-                                                        narrowOopBase,
-                                                        narrowOopShift,
-                                                        compressedKlassPtrsEnabled,
-                                                        narrowKlassBase,
-                                                        narrowKlassShift);
+            return new UniverseData(
+                    ((Long) oopSizeMethod.invoke(vm)).intValue(),
+                    (Integer) objectAlignmentMethod.invoke(vm),
+                    (Integer) heapOopSizeMethod.invoke(vm),
+                    (Boolean) compOopsEnabledMethod.invoke(vm),
+                    (Long) narrowOopBaseMethod.invoke(null),
+                    (Integer) narrowOopShiftMethod.invoke(null),
+                    (Boolean) compKlassEnabledMethod.invoke(vm),
+                    (Long) narrowKlassBaseMethod.invoke(null),
+                    (Integer) narrowKlassShiftMethod.invoke(null)
+            );
         } catch (Throwable t) {
             throw new RuntimeException(t.getMessage(), t);
         }