8308464: Shared array class should not always be loaded in boot loader

Reviewed-by: dholmes, iklam

Author: calvinccheung

src/hotspot/share/oops/arrayKlass.cpp

@@ -175,7 +175,6 @@ void ArrayKlass::remove_java_mirror() {
 }
 
 void ArrayKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protection_domain, TRAPS) {
-  assert(loader_data == ClassLoaderData::the_null_class_loader_data(), "array classes belong to null loader");
   Klass::restore_unshareable_info(loader_data, protection_domain, CHECK);
   // Klass recreates the component mirror also
 

src/hotspot/share/oops/instanceKlass.cpp

@@ -2703,10 +2703,11 @@ void InstanceKlass::restore_unshareable_info(ClassLoaderData* loader_data, Handl
   if (array_klasses() != nullptr) {
     // To get a consistent list of classes we need MultiArray_lock to ensure
     // array classes aren't observed while they are being restored.
-     MutexLocker ml(MultiArray_lock);
+    MutexLocker ml(MultiArray_lock);
+    assert(this == array_klasses()->bottom_klass(), "sanity");
     // Array classes have null protection domain.
     // --> see ArrayKlass::complete_create_array_klass()
-    array_klasses()->restore_unshareable_info(ClassLoaderData::the_null_class_loader_data(), Handle(), CHECK);
+    array_klasses()->restore_unshareable_info(class_loader_data(), Handle(), CHECK);
   }
 
   // Initialize @ValueBased class annotation

src/hotspot/share/oops/klass.cpp

@@ -570,7 +570,9 @@ void Klass::restore_unshareable_info(ClassLoaderData* loader_data, Handle protec
   JFR_ONLY(RESTORE_ID(this);)
   if (log_is_enabled(Trace, cds, unshareable)) {
     ResourceMark rm(THREAD);
-    log_trace(cds, unshareable)("restore: %s", external_name());
+    oop class_loader = loader_data->class_loader();
+    log_trace(cds, unshareable)("restore: %s with class loader: %s", external_name(),
+      class_loader != nullptr ? class_loader->klass()->external_name() : "boot");
   }
 
   // If an exception happened during CDS restore, some of these fields may already be

test/hotspot/jtreg/runtime/cds/appcds/dynamicArchive/ArrayKlasses.java

@@ -44,8 +44,10 @@ public static void main(String[] args) throws Exception {
 
     static void test() throws Exception {
         String topArchiveName = getNewArchiveName();
-        String appJar = ClassFileInstaller.getJarPath("ArrayKlasses.jar");
-        String mainClass = "ArrayKlassesApp";
+        final String appJar = ClassFileInstaller.getJarPath("ArrayKlasses.jar");
+        final String mainClass = "ArrayKlassesApp";
+        final String runtimeLogOptions =
+            "-Xlog:class+load,class+load+array=debug,cds+dynamic=debug,cds=debug,cds+unshareable=trace";
 
         // Case 1
         // Create a dynamic archive with the ArrayKlassesApp app class and its
@@ -62,14 +64,17 @@ static void test() throws Exception {
         // Case 1
         // At runtime , the ArrayKlasesApp and its array class should be loaded
         // from the dynamic archive.
-        run2(null, topArchiveName,
-             "-Xlog:class+load,class+load+array=debug,cds+dynamic=debug,cds=debug",
+        run2(null, topArchiveName, runtimeLogOptions,
              "-cp", appJar, mainClass)
              .assertNormalExit(output -> {
                      output.shouldContain("ArrayKlassesApp source: shared objects file (top)")
+                           .shouldContain("restore: ArrayKlassesApp with class loader: jdk.internal.loader.ClassLoaders$AppClassLoader")
                            .shouldContain("[LArrayKlassesApp; source: shared objects file (top)")
+                           .shouldContain("restore: [LArrayKlassesApp; with class loader: jdk.internal.loader.ClassLoaders$AppClassLoader")
                            .shouldContain("[[LArrayKlassesApp; source: shared objects file (top)")
+                           .shouldContain("restore: [[LArrayKlassesApp; with class loader: jdk.internal.loader.ClassLoaders$AppClassLoader")
                            .shouldContain("[[[LArrayKlassesApp; source: shared objects file (top)")
+                           .shouldContain("restore: [[[LArrayKlassesApp; with class loader: jdk.internal.loader.ClassLoaders$AppClassLoader")
                            .shouldHaveExitValue(0);
                  });
 
@@ -90,14 +95,17 @@ static void test() throws Exception {
         // Case 2
         // At runtime, the java/util/Date class should be loaded from the default
         // CDS archive; its array class should be loaded from the dynamic archive.
-        run2(null, topArchiveName,
-             "-Xlog:class+load,class+load+array=debug,cds+dynamic=debug,cds=debug",
+        run2(null, topArchiveName, runtimeLogOptions,
              "-cp", appJar, mainClass, "system")
              .assertNormalExit(output -> {
                      output.shouldContain("java.util.Date source: shared objects file")
+                           .shouldContain("restore: java.util.Date with class loader: boot")
                            .shouldContain("[Ljava.util.Date; source: shared objects file (top)")
+                           .shouldContain("restore: [Ljava.util.Date; with class loader: boot")
                            .shouldContain("[[Ljava.util.Date; source: shared objects file (top)")
+                           .shouldContain("restore: [[Ljava.util.Date; with class loader: boot")
                            .shouldContain("[[[Ljava.util.Date; source: shared objects file (top)")
+                           .shouldContain("restore: [[[Ljava.util.Date; with class loader: boot")
                            .shouldHaveExitValue(0);
                  });
 
@@ -116,13 +124,15 @@ static void test() throws Exception {
         // Case 3
         // At runtime, the [J should be loaded from the default CDS archive;
         // the higher-dimension array should be loaded from the dynamic archive.
-        run2(null, topArchiveName,
-             "-Xlog:class+load,class+load+array=debug,cds+dynamic=debug,cds=debug",
+        run2(null, topArchiveName, runtimeLogOptions,
              "-cp", appJar, mainClass, "primitive")
              .assertNormalExit(output -> {
                      output.shouldContain("[J source: shared objects file")
+                           .shouldContain("restore: [J with class loader: boot")
                            .shouldContain("[[J source: shared objects file (top)")
+                           .shouldContain("restore: [[J with class loader: boot")
                            .shouldContain("[[[J source: shared objects file (top)")
+                           .shouldContain("restore: [[[J with class loader: boot")
                            .shouldHaveExitValue(0);
                  });
 
@@ -142,13 +152,18 @@ static void test() throws Exception {
         // Case 4
         // At runtime, the 4-dimension array of java/lang/Integer should be
         // loaded from the dynamic archive.
-        run2(null, topArchiveName,
-             "-Xlog:class+load,class+load+array=debug,cds+dynamic=debug,cds=debug",
+        run2(null, topArchiveName, runtimeLogOptions,
              "-cp", appJar, mainClass, "integer-array")
              .assertNormalExit(output -> {
-                     output.shouldContain("[[Ljava.lang.Integer; source: shared objects file (top)")
+                     output.shouldContain("java.lang.Integer source: shared objects file")
+                           .shouldContain("restore: java.lang.Integer with class loader: boot")
+                           .shouldContain("restore: [Ljava.lang.Integer; with class loader: boot")
+                           .shouldContain("[[Ljava.lang.Integer; source: shared objects file (top)")
+                           .shouldContain("restore: [[Ljava.lang.Integer; with class loader: boot")
                            .shouldContain("[[[Ljava.lang.Integer; source: shared objects file (top)")
+                           .shouldContain("restore: [[[Ljava.lang.Integer; with class loader: boot")
                            .shouldContain("[[[[Ljava.lang.Integer; source: shared objects file (top)")
+                           .shouldContain("restore: [[[[Ljava.lang.Integer; with class loader: boot")
                            .shouldHaveExitValue(0);
                  });
     }