Fix writing of unnamed module (oracle#24)

* Fix writing of unnamed module * Ignore empty package; serialize null-class-loader as 'bootstrap' * Fix checkstyle complaint * Handle null string in JfrSymbolRepository as 0 ID/reference * Don't special-case 'null' module name, serialize it as 0
rkennke · Apr 30, 2021 · df7062a · df7062a
1 parent 864e7d2
commit df7062a
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Showing 2 changed files with 17 additions and 6 deletions.
diff --git a/substratevm/src/com.oracle.svm.jfr/src/com/oracle/svm/jfr/JfrSymbolRepository.java b/substratevm/src/com.oracle.svm.jfr/src/com/oracle/svm/jfr/JfrSymbolRepository.java
@@ -92,6 +92,11 @@ public long getSymbolId(String imageHeapString, boolean previousEpoch) {
 
     @Uninterruptible(reason = "Epoch must not change while in this method.")
     public long getSymbolId(String imageHeapString, boolean previousEpoch, boolean replaceDotWithSlash) {
+
+        if (imageHeapString == null) {
+            return 0;
+        }
+
         assert Heap.getHeap().isInImageHeap(imageHeapString);
 
         JfrSymbol symbol = StackValue.get(JfrSymbol.class);

diff --git a/substratevm/src/com.oracle.svm.jfr/src/com/oracle/svm/jfr/JfrTypeRepository.java b/substratevm/src/com.oracle.svm.jfr/src/com/oracle/svm/jfr/JfrTypeRepository.java
@@ -164,7 +164,7 @@ private void visitClass(TypeInfo typeInfo, Class<?> clazz) {
     }
 
     private void visitPackage(TypeInfo typeInfo, Package pkg, Module module) {
-        if (pkg != null && typeInfo.addPackage(pkg, module)) {
+        if (pkg != null && !"".equals(pkg.getName()) && typeInfo.addPackage(pkg, module)) {
             visitModule(typeInfo, module);
         }
     }
@@ -176,7 +176,8 @@ private void visitModule(TypeInfo typeInfo, Module module) {
     }
 
     private void visitClassLoader(TypeInfo typeInfo, ClassLoader classLoader) {
-        if (classLoader != null && typeInfo.addClassLoader(classLoader)) {
+        // Note: null class-loader is ok, we serialize it as "bootstrap" class-loader.
+        if (typeInfo.addClassLoader(classLoader) && classLoader != null) {
             visitClass(typeInfo, classLoader.getClass());
         }
     }
@@ -244,8 +245,8 @@ private void writeModule(JfrChunkWriter writer, TypeInfo typeInfo, Module module
         JfrSymbolRepository symbolRepo = SubstrateJVM.getSymbolRepository();
         writer.writeCompressedLong(id);
         writer.writeCompressedLong(symbolRepo.getSymbolId(module.getName(), true));
-        writer.writeCompressedLong(0); // Version?
-        writer.writeCompressedLong(0); // Location?
+        writer.writeCompressedLong(0); // Version? E.g. "11.0.10-internal"
+        writer.writeCompressedLong(0); // Location? E.g. "jrt:/java.base"
         writer.writeCompressedLong(typeInfo.getClassLoaderId(module.getClassLoader()));
     }
 
@@ -267,7 +268,12 @@ private int writeClassLoaders(JfrChunkWriter writer, TypeInfo typeInfo) throws I
     private void writeClassLoader(JfrChunkWriter writer, ClassLoader cl, long id) throws IOException {
         JfrSymbolRepository symbolRepo = SubstrateJVM.getSymbolRepository();
         writer.writeCompressedLong(id);
-        writer.writeCompressedLong(JfrTraceId.getTraceId(cl.getClass()));
-        writer.writeCompressedLong(symbolRepo.getSymbolId(cl.getName(), true));
+        if (cl == null) {
+            writer.writeCompressedLong(0);
+            writer.writeCompressedLong(symbolRepo.getSymbolId("bootstrap", true));
+        } else {
+            writer.writeCompressedLong(JfrTraceId.getTraceId(cl.getClass()));
+            writer.writeCompressedLong(symbolRepo.getSymbolId(cl.getName(), true));
+        }
     }
 }