=== modified file 'Include/ceval.h'
--- Include/ceval.h	2006-02-15 17:27:45 +0000
+++ Include/ceval.h	2008-05-07 16:34:26 +0000
@@ -129,6 +129,7 @@
 PyAPI_FUNC(void) PyEval_ReleaseLock(void);
 PyAPI_FUNC(void) PyEval_AcquireThread(PyThreadState *tstate);
 PyAPI_FUNC(void) PyEval_ReleaseThread(PyThreadState *tstate);
+PyAPI_FUNC(void) _PyEval_StayForever(void);
 PyAPI_FUNC(void) PyEval_ReInitThreads(void);
 
 #define Py_BEGIN_ALLOW_THREADS { \

=== modified file 'Include/import.h'
--- Include/import.h	2008-01-03 22:16:32 +0000
+++ Include/import.h	2008-05-07 16:43:13 +0000
@@ -30,6 +30,7 @@
 PyAPI_FUNC(struct filedescr *) _PyImport_FindModule(
 	const char *, PyObject *, char *, size_t, FILE **, PyObject **);
 PyAPI_FUNC(int) _PyImport_IsScript(struct filedescr *);
+PyAPI_FUNC(void) _PyImport_LockForever(void);
 PyAPI_FUNC(void) _PyImport_ReInitLock(void);
 
 PyAPI_FUNC(PyObject *)_PyImport_FindExtension(char *, char *);

=== modified file 'Python/ceval.c'
--- Python/ceval.c	2008-04-27 18:40:21 +0000
+++ Python/ceval.c	2008-05-07 17:45:27 +0000
@@ -214,6 +214,7 @@
 
 static PyThread_type_lock interpreter_lock = 0; /* This is the GIL */
 static long main_thread = 0;
+static int stay_forever = 0;
 
 int
 PyEval_ThreadsInitialized(void)
@@ -234,23 +235,34 @@
 void
 PyEval_AcquireLock(void)
 {
+	if (stay_forever && main_thread == PyThread_get_thread_ident())
+		return;
 	PyThread_acquire_lock(interpreter_lock, 1);
 }
 
 void
 PyEval_ReleaseLock(void)
 {
+	if (stay_forever && main_thread == PyThread_get_thread_ident())
+		return;
 	PyThread_release_lock(interpreter_lock);
 }
 
 void
+_PyEval_StayForever(void)
+{
+	assert(!interpreter_lock || main_thread == PyThread_get_thread_ident());
+	stay_forever = 1;
+}
+
+void
 PyEval_AcquireThread(PyThreadState *tstate)
 {
 	if (tstate == NULL)
 		Py_FatalError("PyEval_AcquireThread: NULL new thread state");
 	/* Check someone has called PyEval_InitThreads() to create the lock */
 	assert(interpreter_lock);
-	PyThread_acquire_lock(interpreter_lock, 1);
+	PyEval_AcquireLock();
 	if (PyThreadState_Swap(tstate) != NULL)
 		Py_FatalError(
 			"PyEval_AcquireThread: non-NULL old thread state");
@@ -263,7 +275,7 @@
 		Py_FatalError("PyEval_ReleaseThread: NULL thread state");
 	if (PyThreadState_Swap(NULL) != tstate)
 		Py_FatalError("PyEval_ReleaseThread: wrong thread state");
-	PyThread_release_lock(interpreter_lock);
+	PyEval_ReleaseLock();
 }
 
 /* This function is called from PyOS_AfterFork to ensure that newly
@@ -298,7 +310,7 @@
 		Py_FatalError("PyEval_SaveThread: NULL tstate");
 #ifdef WITH_THREAD
 	if (interpreter_lock)
-		PyThread_release_lock(interpreter_lock);
+		PyEval_ReleaseLock();
 #endif
 	return tstate;
 }
@@ -311,7 +323,7 @@
 #ifdef WITH_THREAD
 	if (interpreter_lock) {
 		int err = errno;
-		PyThread_acquire_lock(interpreter_lock, 1);
+		PyEval_AcquireLock();
 		errno = err;
 	}
 #endif
@@ -837,11 +849,11 @@
 
 				if (PyThreadState_Swap(NULL) != tstate)
 					Py_FatalError("ceval: tstate mix-up");
-				PyThread_release_lock(interpreter_lock);
+				PyEval_ReleaseLock();
 
 				/* Other threads may run now */
 
-				PyThread_acquire_lock(interpreter_lock, 1);
+				PyEval_AcquireLock();
 				if (PyThreadState_Swap(tstate) != NULL)
 					Py_FatalError("ceval: orphan tstate");
 

=== modified file 'Python/import.c'
--- Python/import.c	2008-03-27 10:35:52 +0000
+++ Python/import.c	2008-05-07 17:22:50 +0000
@@ -316,6 +316,13 @@
 
 #endif
 
+void
+_PyImport_LockForever(void)
+{
+    /* No matching unlock.  Should be sufficient. */
+    lock_import();
+}
+
 static PyObject *
 imp_lock_held(PyObject *self, PyObject *noargs)
 {

=== modified file 'Python/pythonrun.c'
--- Python/pythonrun.c	2008-04-12 23:44:07 +0000
+++ Python/pythonrun.c	2008-05-07 18:01:38 +0000
@@ -347,7 +347,10 @@
 	 * the threads created via Threading.
 	 */
 	call_sys_exitfunc();
+
+	_PyImport_LockForever();
 	initialized = 0;
+	_PyEval_StayForever();
 
 	/* Get current thread state and interpreter pointer */
 	tstate = PyThreadState_GET();