--- a/Python/import.c	Wed Feb 12 19:09:45 2003 +0000
+++ b/Python/import.c	Thu Feb 13 17:06:02 2003 +0000
@@ -161,7 +161,8 @@
 		import_lock_level++;
 		return;
 	}
-	if (import_lock_thread != -1 || !PyThread_acquire_lock(import_lock, 0)) {
+	if (import_lock_thread != -1 || !PyThread_acquire_lock(import_lock, 0))
+	{
 		PyThreadState *tstate = PyEval_SaveThread();
 		PyThread_acquire_lock(import_lock, 1);
 		PyEval_RestoreThread(tstate);
@@ -170,25 +171,26 @@
 	import_lock_level = 1;
 }
 
-static void
+static int
 unlock_import(void)
 {
 	long me = PyThread_get_thread_ident();
 	if (me == -1)
-		return; /* Too bad */
+		return 0; /* Too bad */
 	if (import_lock_thread != me)
-		Py_FatalError("unlock_import: not holding the import lock");
+		return -1;
 	import_lock_level--;
 	if (import_lock_level == 0) {
 		import_lock_thread = -1;
 		PyThread_release_lock(import_lock);
 	}
+	return 1;
 }
 
 #else
 
 #define lock_import()
-#define unlock_import()
+#define unlock_import() 0
 
 #endif
 
@@ -204,6 +206,34 @@
 #endif
 }
 
+static PyObject *
+imp_acquire_lock(PyObject *self, PyObject *args)
+{
+	if (!PyArg_ParseTuple(args, ":acquire_lock"))
+		return NULL;
+#ifdef WITH_THREAD
+	lock_import();
+#endif
+	Py_INCREF(Py_None);
+	return Py_None;
+}
+
+static PyObject *
+imp_release_lock(PyObject *self, PyObject *args)
+{
+	if (!PyArg_ParseTuple(args, ":release_lock"))
+		return NULL;
+#ifdef WITH_THREAD
+	if (unlock_import() < 0) {
+		PyErr_SetString(PyExc_RuntimeError,
+				"not holding the import lock");
+		return NULL;
+	}
+#endif
+	Py_INCREF(Py_None);
+	return Py_None;
+}
+
 /* Helper for sys */
 
 PyObject *
@@ -1656,7 +1686,12 @@
 	PyObject *result;
 	lock_import();
 	result = import_module_ex(name, globals, locals, fromlist);
-	unlock_import();
+	if (unlock_import() < 0) {
+		Py_XDECREF(result);
+		PyErr_SetString(PyExc_RuntimeError,
+				"not holding the import lock");
+		return NULL;
+	}
 	return result;
 }
 
@@ -2426,6 +2461,18 @@
 On platforms without threads, return 0.\
 ";
 
+static char doc_acquire_lock[] = "\
+acquire_lock() -> None\n\
+Acquires the interpreter's import lock for the current thread.\n\
+This lock should be used by import hooks to ensure thread-safety\n\
+when importing modules.\n\
+On platforms without threads, this function does nothing.";
+
+static char doc_release_lock[] = "\
+release_lock() -> None\n\
+Release the interpreter's import lock.\n\
+On platforms without threads, this function does nothing.";
+
 static PyMethodDef imp_methods[] = {
 	{"find_module",		imp_find_module,	1, doc_find_module},
 	{"get_magic",		imp_get_magic,		1, doc_get_magic},
@@ -2433,6 +2480,8 @@
 	{"load_module",		imp_load_module,	1, doc_load_module},
 	{"new_module",		imp_new_module,		1, doc_new_module},
 	{"lock_held",		imp_lock_held,		1, doc_lock_held},
+	{"acquire_lock",	imp_acquire_lock,	1, doc_acquire_lock},
+	{"release_lock",	imp_release_lock,	1, doc_release_lock},
 	/* The rest are obsolete */
 	{"get_frozen_object",	imp_get_frozen_object,	1},
 	{"init_builtin",	imp_init_builtin,	1},