Implement bitmap descriptor based marking for Boehm GC.

2000-09-30  Hans Boehm  <boehm@acm.org>
	    Bryce McKinlay  <bryce@albatross.co.nz>

	Implement bitmap descriptor based marking for Boehm GC.

	* configure.in: Define JC1GCSPEC. Set it if boehm-gc is used.
	* configure: Rebuilt.
	* libgcj.spec.in: Pass JC1GCSPEC to jc1.
	* include/jvm.h (struct _Jv_VTable): New field `gc_descr'. New inline
	method get_finalizer().
	(struct _Jv_ArrayVTable): Ditto. Declare method array with
	NUM_OBJECT_METHODS elements instead of NUM_OBJECT_METHODS + 1.
	(_Jv_AllocObj): Add new jclass parameter.
	(_Jv_AllocArray): Ditto.
	(_Jv_BuildGCDescr): New prototype.
	* prims.cc (_Jv_AllocObject): Rename parameter `c' to `klass'. Pass
	`klass' to _Jv_AllocObj. Don't set the new object's vtable. Use
	get_finalizer() instead of direct finalizer vtable offset.
	(_Jv_NewObjectArray): Rename parameter `clas' to `klass'. Pass
	`klass' to _Jv_AllocArray. Don't set the new array's vtable.
	(_Jv_NewPrimArray): Call _Jv_FindArrayClass before _Jv_AllocObj.
	Pass `klass' to _Jv_AllocObj. Don't set the new array's vtable.
	* resolve.cc (METHOD_NOT_THERE, METHOD_INACCESSIBLE): New #defines.
	(_Jv_ResolvePoolEntry): Use METHOD_NOT_THERE and METHOD_INACCESSIBLE.
	(_Jv_DetermineVTableIndex): Ditto.
	(_Jv_PrepareClass): Ditto. Remove offset-by-one adjustments from vtable
	calculations to account for new gc_descr field.
	* boehm.cc: #include gc_gcj.h.
	(obj_kind_x, obj_free_list): `#if 0'-ed away.
	(_Jv_MarkObj): Check that vtable doesn't point to a cleared object.
	New commentary from HB. Mark the classes vtable.
	(_Jv_MarkArray): Check that vtable doesn't point to a cleared object.
	(GC_DEFAULT_DESCR): New #define.
	(_Jv_BuildGCDescr): New function. Use GC_DEFAULT_DESCR, for now.
	(_Jv_AllocObj): New parameter `klass'. Use GC_GCJ_MALLOC ().
	(_Jv_AllocArray): New parameter `klass'. Allocate with GC_MALLOC and
	scan conservativly if size is less than min_heap_addr. Set vtable
	pointer of new object before returning.
	(_Jv_AllocBytes): Use GC_MALLOC_ATOMIC, not GC_GENERIC_MALLOC.
	(_Jv_InitGC): Call GC_init_gcj_malloc(). Don't set up marking and
	allocation for obj_kind_x.
	* nogc.cc (_Jv_BuildGCDescr): New function. Return 0.
	(_Jv_AllocObj): Set vtable on returned object.
	(_Jv_AllocArray): Ditto.
	* java/lang/Class.h (_Jv_NewObjectArray): No longer a friend.
	(_Jv_NewPrimArray): Ditto.
	(_Jv_AllocObj): Declare as a friend.
	(_Jv_AllocArray): Ditto.
	* java/lang/natClassLoader.cc (_Jv_FindArrayClass): Copy gc_descr
	from &ObjectClass into new array class. Remove offset-by-one
	adjustments from `method' size calculations to account for gc_descr
	field.

Co-Authored-By: Bryce McKinlay <bryce@albatross.co.nz>

From-SVN: r36679

2 files changed, 8 insertions, 6 deletions

diff --git a/libjava/java/lang/Class.h b/libjava/java/lang/Class.h
index 0f60274..0300a59 100644
--- a/libjava/java/lang/Class.h
+++ b/libjava/java/lang/Class.h
@@ -220,8 +220,8 @@ private:
   friend jint JvNumStaticFields (jclass);
 
   friend jobject _Jv_AllocObject (jclass, jint);
-  friend jobjectArray _Jv_NewObjectArray (jsize, jclass, jobject);
-  friend jobject _Jv_NewPrimArray (jclass, jint);
+  friend void *_Jv_AllocObj (jint, jclass);
+  friend void *_Jv_AllocArray (jint, jclass);
 
   friend jobject _Jv_JNI_ToReflectedField (_Jv_JNIEnv *, jclass, jfieldID,
 					   jboolean);
diff --git a/libjava/java/lang/natClassLoader.cc b/libjava/java/lang/natClassLoader.cc
index 54ffc42..b03b8c2 100644
--- a/libjava/java/lang/natClassLoader.cc
+++ b/libjava/java/lang/natClassLoader.cc
@@ -586,16 +586,15 @@ _Jv_FindArrayClass (jclass element, java::lang::ClassLoader *loader,
       array_class = _Jv_NewClass (array_name, &ObjectClass, element->loader);
 
       // Note that `vtable_method_count' doesn't include the initial
-      // NULL slot.
+      // gc_descr slot.
       JvAssert (ObjectClass.vtable_method_count == NUM_OBJECT_METHODS);
-      int dm_count = ObjectClass.vtable_method_count + 1;
+      int dm_count = ObjectClass.vtable_method_count;
 
       // Create a new vtable by copying Object's vtable (except the
       // class pointer, of course).  Note that we allocate this as
       // unscanned memory -- the vtables are handled specially by the
       // GC.
-      int size = (sizeof (_Jv_VTable) +
-		  ((dm_count - 1) * sizeof (void *)));
+      int size = (sizeof (_Jv_VTable) + ((dm_count - 1) * sizeof (void *)));
       _Jv_VTable *vtable;
       if (array_vtable)
 	vtable = array_vtable;
@@ -604,6 +603,7 @@ _Jv_FindArrayClass (jclass element, java::lang::ClassLoader *loader,
       vtable->clas = array_class;
       memcpy (vtable->method, ObjectClass.vtable->method,
 	      dm_count * sizeof (void *));
+      vtable->gc_descr = ObjectClass.vtable->gc_descr;
       array_class->vtable = vtable;
       array_class->vtable_method_count = ObjectClass.vtable_method_count;
 
@@ -615,6 +615,8 @@ _Jv_FindArrayClass (jclass element, java::lang::ClassLoader *loader,
       array_class->interfaces = interfaces;
       array_class->interface_count = sizeof interfaces / sizeof interfaces[0];
 
+      // FIXME: Shouldn't this be synchronized? _Jv_PrepareConstantTimeTables
+      // needs to be called with the mutex for array_class held.
       // Generate the interface dispatch table.
       _Jv_PrepareConstantTimeTables (array_class);