[pypy-svn] r69951 - in pypy/branch/virtual-forcing/pypy/rlib: . test

[arigo at codespeak.net]

Author: arigo
Date: Mon Dec  7 16:22:58 2009
New Revision: 69951

Modified:
   pypy/branch/virtual-forcing/pypy/rlib/jit.py
   pypy/branch/virtual-forcing/pypy/rlib/test/test__jit_vref.py
Log:
Write docstrings for the functions virtual_ref and virtual_ref_finish.
Fix the tests according to the docstrings.  Note that this behavior
would be more relaxed than what 'metainterp' currently implements,
but I think it's possible and a good idea for the pypy interpreter.


Modified: pypy/branch/virtual-forcing/pypy/rlib/jit.py
==============================================================================
--- pypy/branch/virtual-forcing/pypy/rlib/jit.py	(original)
+++ pypy/branch/virtual-forcing/pypy/rlib/jit.py	Mon Dec  7 16:22:58 2009
@@ -1,7 +1,7 @@
 import py
 import sys
 from pypy.rpython.extregistry import ExtRegistryEntry
-from pypy.rlib.objectmodel import CDefinedIntSymbolic, we_are_translated
+from pypy.rlib.objectmodel import CDefinedIntSymbolic
 from pypy.rlib.objectmodel import keepalive_until_here
 from pypy.rlib.unroll import unrolling_iterable
 
@@ -103,22 +103,30 @@
 # VRefs
 
 def virtual_ref(x):
+    """Creates a 'vref' object that contains a reference to 'x'.  Calls
+    to virtual_ref/virtual_ref_finish must be properly nested.  The idea
+    is that the object 'x' is supposed to be JITted as a virtual (the
+    JIT will abort if it is not), at least between the calls to
+    virtual_ref and virtual_ref_finish.  The point is that the 'vref'
+    returned by virtual_ref may escape early.  If at runtime it is
+    dereferenced (by calling it, as in 'vref()') before the
+    virtual_ref_finish, then we get out of the assembler.  If it is not
+    dereferenced at all, or only after the virtual_ref_finish, then
+    nothing special occurs.
+    """
     return DirectVRef(x)
 virtual_ref.oopspec = 'virtual_ref(x)'
 
 def virtual_ref_finish(x):
-    if not we_are_translated():
-        x._forced = x._forced or -1
+    """See docstring in virtual_ref(x).  Note that virtual_ref_finish
+    takes as argument the real object, not the vref."""
     keepalive_until_here(x)   # otherwise the whole function call is removed
 virtual_ref_finish.oopspec = 'virtual_ref_finish(x)'
 
 class DirectVRef(object):
-    _forced = 0
     def __init__(self, x):
         self._x = x
     def __call__(self):
-        assert self._forced >= 0, "too late to force the virtual_ref!"
-        self._forced = 1
         return self._x
     def _freeze_(self):
         raise Exception("should not see a prebuilt virtual_ref")

Modified: pypy/branch/virtual-forcing/pypy/rlib/test/test__jit_vref.py
==============================================================================
--- pypy/branch/virtual-forcing/pypy/rlib/test/test__jit_vref.py	(original)
+++ pypy/branch/virtual-forcing/pypy/rlib/test/test__jit_vref.py	Mon Dec  7 16:22:58 2009
@@ -18,20 +18,17 @@
     pass
 
 
-def test_direct():
+def test_direct_1():
     x1 = X()
     vref = virtual_ref(x1)
     assert vref() is x1
+    virtual_ref_finish(x1)
+    assert vref() is x1
 
-def test_finish():
-    vref = virtual_ref(X())
-    virtual_ref_finish(vref)
-    py.test.raises(AssertionError, "vref()")
-    #
+def test_direct_2():
     x1 = X()
     vref = virtual_ref(x1)
-    assert vref() is x1
-    virtual_ref_finish(vref)
+    virtual_ref_finish(x1)
     assert vref() is x1
 
 def test_annotate_1():
@@ -45,8 +42,11 @@
 
 def test_annotate_2():
     def f():
-        vref = virtual_ref(X())
-        return vref()
+        x1 = X()
+        vref = virtual_ref(x1)
+        x2 = vref()
+        virtual_ref_finish(x1)
+        return x2
     a = RPythonAnnotator()
     s = a.build_types(f, [])
     assert isinstance(s, annmodel.SomeInstance)
@@ -84,8 +84,11 @@
 
 def test_rtype_2():
     def f():
-        vref = virtual_ref(X())
-        return vref()
+        x1 = X()
+        vref = virtual_ref(x1)
+        x2 = vref()
+        virtual_ref_finish(x2)
+        return x2
     x = interpret(f, [])
     assert lltype.castable(OBJECTPTR, lltype.typeOf(x)) > 0
 
@@ -107,5 +110,3 @@
     x = interpret(f, [-5])
     assert lltype.typeOf(x) == OBJECTPTR
     assert not x
-
-# the path "we_are_jitted()" is tested in jit/metainterp/test/test_codewriter.