8232071: Avoid shared dictionary lookup when the class name is not sh…

…ared Reviewed-by: jiangli, ccheung
openjdk · Oct 10, 2019 · 5a120f0 · 5a120f0
1 parent dc66194
commit 5a120f0
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Showing 2 changed files with 26 additions and 24 deletions.
diff --git a/src/hotspot/share/classfile/systemDictionaryShared.cpp b/src/hotspot/share/classfile/systemDictionaryShared.cpp
@@ -905,14 +905,9 @@ InstanceKlass* SystemDictionaryShared::lookup_from_stream(Symbol* class_name,
     return NULL;
   }
 
-  const RunTimeSharedClassInfo* record = find_record(&_unregistered_dictionary, class_name);
+  const RunTimeSharedClassInfo* record = find_record(&_unregistered_dictionary, &_dynamic_unregistered_dictionary, class_name);
   if (record == NULL) {
-    if (DynamicArchive::is_mapped()) {
-      record = find_record(&_dynamic_unregistered_dictionary, class_name);
-    }
-    if (record == NULL) {
-      return NULL;
-    }
+    return NULL;
   }
 
   int clsfile_size  = cfs->length();
@@ -1412,29 +1407,34 @@ void SystemDictionaryShared::serialize_dictionary_headers(SerializeClosure* soc,
 }
 
 const RunTimeSharedClassInfo*
-SystemDictionaryShared::find_record(RunTimeSharedDictionary* dict, Symbol* name) {
-  if (UseSharedSpaces) {
-    unsigned int hash = primitive_hash<Symbol*>(name);
-    return dict->lookup(name, hash, 0);
-  } else {
+SystemDictionaryShared::find_record(RunTimeSharedDictionary* static_dict, RunTimeSharedDictionary* dynamic_dict, Symbol* name) {
+  if (!UseSharedSpaces || !name->is_shared()) {
+    // The names of all shared classes must also be a shared Symbol.
     return NULL;
   }
-}
 
-InstanceKlass* SystemDictionaryShared::find_builtin_class(Symbol* name) {
-  const RunTimeSharedClassInfo* record = find_record(&_builtin_dictionary, name);
-  if (record) {
-    return record->_klass;
+  unsigned int hash = primitive_hash<Symbol*>(name);
+  const RunTimeSharedClassInfo* record = NULL;
+  if (!MetaspaceShared::is_shared_dynamic(name)) {
+    // The names of all shared classes in the static dict must also be in the
+    // static archive
+    record = static_dict->lookup(name, hash, 0);
   }
 
-  if (DynamicArchive::is_mapped()) {
-    record = find_record(&_dynamic_builtin_dictionary, name);
-    if (record) {
-      return record->_klass;
-    }
+  if (record == NULL && DynamicArchive::is_mapped()) {
+    record = dynamic_dict->lookup(name, hash, 0);
   }
 
-  return NULL;
+  return record;
+}
+
+InstanceKlass* SystemDictionaryShared::find_builtin_class(Symbol* name) {
+  const RunTimeSharedClassInfo* record = find_record(&_builtin_dictionary, &_dynamic_builtin_dictionary, name);
+  if (record != NULL) {
+    return record->_klass;
+  } else {
+    return NULL;
+  }
 }
 
 void SystemDictionaryShared::update_shared_entry(InstanceKlass* k, int id) {

diff --git a/src/hotspot/share/classfile/systemDictionaryShared.hpp b/src/hotspot/share/classfile/systemDictionaryShared.hpp
@@ -223,7 +223,9 @@ class SystemDictionaryShared: public SystemDictionary {
 public:
   static InstanceKlass* find_builtin_class(Symbol* class_name);
 
-  static const RunTimeSharedClassInfo* find_record(RunTimeSharedDictionary* dict, Symbol* name);
+  static const RunTimeSharedClassInfo* find_record(RunTimeSharedDictionary* static_dict,
+                                                   RunTimeSharedDictionary* dynamic_dict,
+                                                   Symbol* name);
 
   static bool has_platform_or_app_classes();