[pypy-commit] pypy stmgc-c4: Disable use of immutable read barriers in most cases. Since there can be a

[Raemi]

Author: Remi Meier <remi.meier at gmail.com>
Branch: stmgc-c4
Changeset: r67873:5f1727595de0
Date: 2013-11-07 12:07 +0100
http://bitbucket.org/pypy/pypy/changeset/5f1727595de0/

Log:	Disable use of immutable read barriers in most cases. Since there
	can be a transaction break between allocation and initialization of
	the immutable field...

diff --git a/rpython/jit/backend/llsupport/stmrewrite.py b/rpython/jit/backend/llsupport/stmrewrite.py
--- a/rpython/jit/backend/llsupport/stmrewrite.py
+++ b/rpython/jit/backend/llsupport/stmrewrite.py
@@ -271,18 +271,19 @@
         opnum = op.getopnum()
         descr = op.getdescr()
         target_category = 'R'
-        if opnum == rop.GETFIELD_GC:
-            assert isinstance(descr, FieldDescr)
-            if descr.is_immutable():
-                target_category = 'I'
-        elif opnum == rop.GETINTERIORFIELD_GC:
-            assert isinstance(descr, InteriorFieldDescr)
-            if descr.is_immutable():
-                target_category = 'I'
-        elif opnum == rop.GETARRAYITEM_GC:
-            assert isinstance(descr, ArrayDescr)
-            if descr.is_immutable():
-                target_category = 'I'
+        # XXX: review:
+        # if opnum == rop.GETFIELD_GC:
+        #     assert isinstance(descr, FieldDescr)
+        #     if descr.is_immutable():
+        #         target_category = 'I'
+        # elif opnum == rop.GETINTERIORFIELD_GC:
+        #     assert isinstance(descr, InteriorFieldDescr)
+        #     if descr.is_immutable():
+        #         target_category = 'I'
+        # elif opnum == rop.GETARRAYITEM_GC:
+        #     assert isinstance(descr, ArrayDescr)
+        #     if descr.is_immutable():
+        #         target_category = 'I'
                 
         self.handle_category_operations(op, target_category)
 
diff --git a/rpython/translator/stm/writebarrier.py b/rpython/translator/stm/writebarrier.py
--- a/rpython/translator/stm/writebarrier.py
+++ b/rpython/translator/stm/writebarrier.py
@@ -85,8 +85,8 @@
                 # field even on a stub
                 pass
 
-            elif (op.opname in ('getarraysize', 'getinteriorarraysize')
-                or (is_getter and is_immutable(op))):
+            elif op.opname in ('getarraysize', 'getinteriorarraysize'):
+                # XXX: or (is_getter and is_immutable(op))):
                 # we can't leave getarraysize or the immutable getfields
                 # fully unmodified: we need at least immut_read_barrier
                 # to detect stubs.