[Python-checkins] python/dist/src/Include objimpl.h,2.53,2.54

tim_one@users.sourceforge.net tim_one@users.sourceforge.net
Mon, 01 Jul 2002 17:52:32 -0700


Update of /cvsroot/python/python/dist/src/Include
In directory usw-pr-cvs1:/tmp/cvs-serv8407/python/Include

Modified Files:
	objimpl.h 
Log Message:
Reserved another gc_refs value for untracked objects.  Every live gc
object should now have a well-defined gc_refs value, with clear transitions
among gc_refs states.  As a result, none of the visit_XYZ traversal
callbacks need to check IS_TRACKED() anymore, and those tests were removed.
(They were already looking for objects with specific gc_refs states, and
the gc_refs state of an untracked object can no longer match any other
gc_refs state by accident.)
Added more asserts.
I expect that the gc_next == NULL indicator for an untracked object is
now redundant and can also be removed, but I ran out of time for this.


Index: objimpl.h
===================================================================
RCS file: /cvsroot/python/python/dist/src/Include/objimpl.h,v
retrieving revision 2.53
retrieving revision 2.54
diff -C2 -d -r2.53 -r2.54
*** objimpl.h	4 May 2002 05:36:06 -0000	2.53
--- objimpl.h	2 Jul 2002 00:52:30 -0000	2.54
***************
*** 263,272 ****
  #define _Py_AS_GC(o) ((PyGC_Head *)(o)-1)
  
  /* Tell the GC to track this object.  NB: While the object is tracked the
   * collector it must be safe to call the ob_traverse method. */
  #define _PyObject_GC_TRACK(o) do { \
  	PyGC_Head *g = _Py_AS_GC(o); \
! 	if (g->gc.gc_next != NULL) \
! 		Py_FatalError("GC object already in linked list"); \
  	g->gc.gc_next = _PyGC_generation0; \
  	g->gc.gc_prev = _PyGC_generation0->gc.gc_prev; \
--- 263,278 ----
  #define _Py_AS_GC(o) ((PyGC_Head *)(o)-1)
  
+ #define _PyGC_REFS_UNTRACKED			(-2)
+ #define _PyGC_REFS_REACHABLE			(-3)
+ #define _PyGC_REFS_TENTATIVELY_UNREACHABLE	(-4)
+ 
  /* Tell the GC to track this object.  NB: While the object is tracked the
   * collector it must be safe to call the ob_traverse method. */
  #define _PyObject_GC_TRACK(o) do { \
  	PyGC_Head *g = _Py_AS_GC(o); \
! 	if (g->gc.gc_refs != _PyGC_REFS_UNTRACKED) \
! 		Py_FatalError("GC object already tracked"); \
! 	assert(g->gc.gc_refs == _PyGC_REFS_UNTRACKED); \
! 	g->gc.gc_refs = _PyGC_REFS_REACHABLE; \
  	g->gc.gc_next = _PyGC_generation0; \
  	g->gc.gc_prev = _PyGC_generation0->gc.gc_prev; \
***************
*** 278,281 ****
--- 284,289 ----
  #define _PyObject_GC_UNTRACK(o) do { \
  	PyGC_Head *g = _Py_AS_GC(o); \
+ 	assert(g->gc.gc_refs != _PyGC_REFS_UNTRACKED); \
+ 	g->gc.gc_refs = _PyGC_REFS_UNTRACKED; \
  	g->gc.gc_prev->gc.gc_next = g->gc.gc_next; \
  	g->gc.gc_next->gc.gc_prev = g->gc.gc_prev; \