Merged revisions 60143-60149 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r60143 | georg.brandl | 2008-01-20 15:50:05 +0100 (Sun, 20 Jan 2008) | 3 lines Switch mmap from old Py_FindMethod to new PyObject_GenericGetAttr attribute access. Fixes #1087735. ........ r60145 | georg.brandl | 2008-01-20 20:40:58 +0100 (Sun, 20 Jan 2008) | 2 lines Add blurb about executable scripts on Windows. #760657. ........ r60146 | georg.brandl | 2008-01-20 20:48:40 +0100 (Sun, 20 Jan 2008) | 2 lines #1219903: fix tp_richcompare docs. ........ r60147 | georg.brandl | 2008-01-20 22:10:08 +0100 (Sun, 20 Jan 2008) | 2 lines Fix markup. ........ r60148 | gregory.p.smith | 2008-01-21 08:11:11 +0100 (Mon, 21 Jan 2008) | 14 lines Provide a sanity check during PyThreadState_DeleteCurrent() and PyThreadState_Delete() to avoid an infinite loop when the tstate list is messed up and has somehow becomes circular and does not contain the current thread. I don't know how this happens but it does, *very* rarely. On more than one hardware platform. I have not been able to reproduce it manually. Attaching to a process where its happening: it has always been in an infinite loop over a single element tstate list that is not the tstate we're looking to delete. It has been in t_bootstrap()'s call to PyThreadState_DeleteCurrent() as a pthread is exiting. ........ r60149 | georg.brandl | 2008-01-21 11:24:59 +0100 (Mon, 21 Jan 2008) | 2 lines #1269: fix a bug in pstats.add_callers() and add a unit test file for pstats. ........

--- a/Python/pystate.c	Sun Jan 20 15:14:11 2008 +0000
+++ b/Python/pystate.c	Mon Jan 21 11:20:28 2008 +0000
@@ -242,6 +242,7 @@
 {
 	PyInterpreterState *interp;
 	PyThreadState **p;
+	PyThreadState *prev_p = NULL;
 	if (tstate == NULL)
 		Py_FatalError("PyThreadState_Delete: NULL tstate");
 	interp = tstate->interp;
@@ -254,6 +255,15 @@
 				"PyThreadState_Delete: invalid tstate");
 		if (*p == tstate)
 			break;
+		if (*p == prev_p)
+			Py_FatalError(
+				"PyThreadState_Delete: small circular list(!)"
+                                " and tstate not found.");
+		prev_p = *p;
+		if ((*p)->next == interp->tstate_head)
+			Py_FatalError(
+				"PyThreadState_Delete: circular list(!) and"
+                                " tstate not found.");
 	}
 	*p = tstate->next;
 	HEAD_UNLOCK();