src/hotspot/share/memory/filemap.cpp

@@ -912,10 +912,24 @@
     log_info(cds)("CDS heap data is being ignored. UseG1GC, "
                   "UseCompressedOops and UseCompressedClassPointers are required.");
     return;
   }
 
+  if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::early_class_hook_env()) {
+    ShouldNotReachHere(); // CDS should have been disabled.
+    // The archived objects are mapped at JVM start-up, but we don't know if
+    // j.l.String or j.l.Class might be replaced by the ClassFileLoadHook,
+    // which would make the archived String or mirror objects invalid. Let's be safe and not
+    // use the archived objects. These 2 classes are loaded during the JVMTI "early" stage
+    // (aka JVMTI_PHASE_PRIMORDIAL).
+    //
+    // If JvmtiExport::early_class_hook_env() is false, the classes of some objects
+    // in the archived subgraphs may be replaced by the ClassFileLoadHook. But that's OK
+    // because we won't install an archived object subgraph if the klass of any of the
+    // referenced objects are replaced. See HeapShared::initialize_from_archived_subgraph().
+  }
+
   MemRegion heap_reserved = Universe::heap()->reserved_region();
 
   log_info(cds)("CDS archive was created with max heap size = " SIZE_FORMAT "M, and the following configuration:",
                 max_heap_size()/M);
   log_info(cds)("    narrow_klass_base = " PTR_FORMAT ", narrow_klass_shift = %d",

@@ -1222,10 +1236,19 @@
 // [2] validate_shared_path_table - this is done later, because the table is in the RW
 //     region of the archive, which is not mapped yet.
 bool FileMapInfo::initialize() {
   assert(UseSharedSpaces, "UseSharedSpaces expected.");
 
+  if (JvmtiExport::should_post_class_file_load_hook() && JvmtiExport::early_class_hook_env()) {
+    // CDS assumes that no classes resolved in SystemDictionary::resolve_well_known_classes
+    // are replaced at runtime by JVMTI ClassFileLoadHook. All of those classes are resolved
+    // during the JVMTI "early" stage (JVMTI_PHASE_PRIMORDIAL), so we're OK if
+    // JvmtiExport::early_class_hook_env() is not requested by native agent(s).
+    FileMapInfo::fail_continue("CDS is disabled because early JVMTI ClassFileLoadHook is in use.");
+    return false;
+  }
+
   if (!open_for_read()) {
     return false;
   }
 
   init_from_file(_fd);