8277216: Examine InstanceKlass::_misc_flags for concurrency issues

Reviewed-by: hseigel, dholmes

src/hotspot/share/oops/instanceKlass.hpp

@@ -253,8 +253,7 @@ class InstanceKlass: public Klass {
     _misc_is_shared_boot_class                = 1 << 10, // defining class loader is boot class loader
     _misc_is_shared_platform_class            = 1 << 11, // defining class loader is platform class loader
     _misc_is_shared_app_class                 = 1 << 12, // defining class loader is app class loader
-    _misc_has_resolved_methods                = 1 << 13, // resolved methods table entries added for this class
-    _misc_has_contended_annotations           = 1 << 14  // has @Contended annotation
+    _misc_has_contended_annotations           = 1 << 13  // has @Contended annotation
   };
   u2 shared_loader_type_bits() const {
     return _misc_is_shared_boot_class|_misc_is_shared_platform_class|_misc_is_shared_app_class;
@@ -366,10 +365,6 @@ class InstanceKlass: public Klass {
     _misc_flags |= _misc_shared_loading_failed;
   }
 
-  void clear_shared_loading_failed() {
-    _misc_flags &= ~_misc_shared_loading_failed;
-  }
-
   void set_shared_class_loader_type(s2 loader_type);
 
   void assign_class_loader_type();
@@ -378,10 +373,9 @@ class InstanceKlass: public Klass {
     return (_misc_flags & _misc_has_nonstatic_fields) != 0;
   }
   void set_has_nonstatic_fields(bool b)    {
+    assert(!has_nonstatic_fields(), "set once");
     if (b) {
       _misc_flags |= _misc_has_nonstatic_fields;
-    } else {
-      _misc_flags &= ~_misc_has_nonstatic_fields;
     }
   }
 
@@ -563,10 +557,9 @@ class InstanceKlass: public Klass {
     return (_misc_flags & _misc_should_verify_class) != 0;
   }
   void set_should_verify_class(bool value) {
+    assert(!should_verify_class(), "set once");
     if (value) {
       _misc_flags |= _misc_should_verify_class;
-    } else {
-      _misc_flags &= ~_misc_should_verify_class;
     }
   }
 
@@ -695,10 +688,9 @@ class InstanceKlass: public Klass {
     return (_misc_flags & _misc_is_contended) != 0;
   }
   void set_is_contended(bool value)        {
+    assert(!is_contended(), "set once");
     if (value) {
       _misc_flags |= _misc_is_contended;
-    } else {
-      _misc_flags &= ~_misc_is_contended;
     }
   }
 
@@ -733,10 +725,9 @@ class InstanceKlass: public Klass {
     return ((_misc_flags & _misc_has_contended_annotations) != 0);
   }
   void set_has_contended_annotations(bool value)  {
+    assert(!has_contended_annotations(), "set once");
     if (value) {
       _misc_flags |= _misc_has_contended_annotations;
-    } else {
-      _misc_flags &= ~_misc_has_contended_annotations;
     }
   }
 
@@ -789,11 +780,11 @@ class InstanceKlass: public Klass {
   }
 
   bool has_resolved_methods() const {
-    return (_misc_flags & _misc_has_resolved_methods) != 0;
+    return _access_flags.has_resolved_methods();
   }
 
   void set_has_resolved_methods() {
-    _misc_flags |= _misc_has_resolved_methods;
+    _access_flags.set_has_resolved_methods();
   }
 private:
 
@@ -862,21 +853,19 @@ class InstanceKlass: public Klass {
     return (_misc_flags & _misc_has_nonstatic_concrete_methods) != 0;
   }
   void set_has_nonstatic_concrete_methods(bool b) {
+    assert(!has_nonstatic_concrete_methods(), "set once");
     if (b) {
       _misc_flags |= _misc_has_nonstatic_concrete_methods;
-    } else {
-      _misc_flags &= ~_misc_has_nonstatic_concrete_methods;
     }
   }
 
   bool declares_nonstatic_concrete_methods() const {
     return (_misc_flags & _misc_declares_nonstatic_concrete_methods) != 0;
   }
   void set_declares_nonstatic_concrete_methods(bool b) {
+    assert(!declares_nonstatic_concrete_methods(), "set once");
     if (b) {
       _misc_flags |= _misc_declares_nonstatic_concrete_methods;
-    } else {
-      _misc_flags &= ~_misc_declares_nonstatic_concrete_methods;
     }
   }
 

src/hotspot/share/utilities/accessFlags.hpp

@@ -70,11 +70,12 @@ enum {
   JVM_ACC_IS_HIDDEN_CLASS         = 0x04000000,     // True if klass is hidden
   JVM_ACC_IS_VALUE_BASED_CLASS    = 0x08000000,     // True if klass is marked as a ValueBased class
   JVM_ACC_IS_BEING_REDEFINED      = 0x00100000,     // True if the klass is being redefined.
+  JVM_ACC_HAS_RESOLVED_METHODS    = 0x00200000,     // True if the klass has resolved methods
 
   // Klass* and Method* flags
-  JVM_ACC_HAS_LOCAL_VARIABLE_TABLE= 0x00200000,
+  JVM_ACC_HAS_LOCAL_VARIABLE_TABLE= 0x00400000,
 
-  JVM_ACC_PROMOTED_FLAGS          = 0x00200000,     // flags promoted from methods to the holding klass
+  JVM_ACC_PROMOTED_FLAGS          = 0x00400000,     // flags promoted from methods to the holding klass
 
   // field flags
   // Note: these flags must be defined in the low order 16 bits because
@@ -164,6 +165,9 @@ class AccessFlags {
   void set_is_being_redefined()         { atomic_set_bits(JVM_ACC_IS_BEING_REDEFINED); }
   void clear_is_being_redefined()       { atomic_clear_bits(JVM_ACC_IS_BEING_REDEFINED); }
 
+  bool has_resolved_methods() const     { return (_flags & JVM_ACC_HAS_RESOLVED_METHODS) != 0; }
+  void set_has_resolved_methods()       { atomic_set_bits(JVM_ACC_HAS_RESOLVED_METHODS); }
+
   // field flags
   bool is_field_access_watched() const  { return (_flags & JVM_ACC_FIELD_ACCESS_WATCHED) != 0; }
   bool is_field_modification_watched() const