diff -r e488bff4ed0e Modules/audioop.c
--- a/Modules/audioop.c	Wed Aug 15 17:10:43 2012 +0200
+++ b/Modules/audioop.c	Thu Aug 16 10:19:29 2012 +0200
@@ -293,15 +293,42 @@
 #define SHORTP(cp, i) ((short *)(cp+i))
 #define LONGP(cp, i) ((Py_Int32 *)(cp+i))
 
+typedef struct {
+  PyObject *AudioopError;
+} audioopstate;
 
+#define audioop_state(o) ((audioopstate *)PyModule_GetState(o))
 
-static PyObject *AudioopError;
+static int
+audioop_clear(PyObject *m)
+{
+   Py_CLEAR(audioop_state(m)->AudioopError);
+   return 0;
+}
+
+static int
+audioop_traverse(PyObject *m, visitproc visit, void *arg)
+{
+    Py_VISIT(audioop_state(m)->AudioopError);
+    return 0;
+}
+
+static void
+audioop_free(void *m)
+{
+    audioop_clear((PyObject *)m);
+}
+
+static PyModuleDef audioopmodule;
+
+#define audioopstate_global ((audioopstate *)PyModule_GetState(PyState_FindModule(&audioopmodule)))
+
 
 static int
 audioop_check_size(int size)
 {
     if (size != 1 && size != 2 && size != 4) {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
+        PyErr_SetString(audioopstate_global->AudioopError, "Size should be 1, 2 or 4");
         return 0;
     }
     else
@@ -314,7 +341,7 @@
     if (!audioop_check_size(size))
         return 0;
     if (len % size != 0) {
-        PyErr_SetString(AudioopError, "not a whole number of frames");
+        PyErr_SetString(audioopstate_global->AudioopError, "not a whole number of frames");
         return 0;
     }
     return 1;
@@ -332,7 +359,7 @@
     if (!audioop_check_parameters(len, size))
         return NULL;
     if ( i < 0 || i >= len/size ) {
-        PyErr_SetString(AudioopError, "Index out of range");
+        PyErr_SetString(audioopstate_global->AudioopError, "Index out of range");
         return 0;
     }
     if ( size == 1 )      val = (int)*CHARP(cp, i);
@@ -495,14 +522,14 @@
                            (char**)&cp1, &len1, (char**)&cp2, &len2) )
         return 0;
     if ( len1 & 1 || len2 & 1 ) {
-        PyErr_SetString(AudioopError, "Strings should be even-sized");
+        PyErr_SetString(audioopstate_global->AudioopError, "Strings should be even-sized");
         return 0;
     }
     len1 >>= 1;
     len2 >>= 1;
 
     if ( len1 < len2 ) {
-        PyErr_SetString(AudioopError, "First sample should be longer");
+        PyErr_SetString(audioopstate_global->AudioopError, "First sample should be longer");
         return 0;
     }
     sum_ri_2 = _sum2(cp2, cp2, len2);
@@ -551,11 +578,11 @@
                            (char**)&cp1, &len1, (char**)&cp2, &len2) )
         return 0;
     if ( len1 & 1 || len2 & 1 ) {
-        PyErr_SetString(AudioopError, "Strings should be even-sized");
+        PyErr_SetString(audioopstate_global->AudioopError, "Strings should be even-sized");
         return 0;
     }
     if ( len1 != len2 ) {
-        PyErr_SetString(AudioopError, "Samples should be same size");
+        PyErr_SetString(audioopstate_global->AudioopError, "Samples should be same size");
         return 0;
     }
     len2 >>= 1;
@@ -584,13 +611,13 @@
                            (char**)&cp1, &len1, &len2) )
         return 0;
     if ( len1 & 1 ) {
-        PyErr_SetString(AudioopError, "Strings should be even-sized");
+        PyErr_SetString(audioopstate_global->AudioopError, "Strings should be even-sized");
         return 0;
     }
     len1 >>= 1;
 
     if ( len2 < 0 || len1 < len2 ) {
-        PyErr_SetString(AudioopError, "Input sample should be longer");
+        PyErr_SetString(audioopstate_global->AudioopError, "Input sample should be longer");
         return 0;
     }
 
@@ -765,7 +792,7 @@
     else if ( size == 2 ) maxval = (double) 0x7fff;
     else if ( size == 4 ) maxval = (double) 0x7fffffff;
     else {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
+        PyErr_SetString(audioopstate_global->AudioopError, "Size should be 1, 2 or 4");
         return 0;
     }
 
@@ -810,7 +837,7 @@
         return NULL;
     }
     if (((len / size) & 1) != 0) {
-        PyErr_SetString(AudioopError, "not a whole number of frames");
+        PyErr_SetString(audioopstate_global->AudioopError, "not a whole number of frames");
         PyBuffer_Release(&pcp);
         return NULL;
     }
@@ -820,7 +847,7 @@
     else if ( size == 4 ) maxval = (double) 0x7fffffff;
     else {
         PyBuffer_Release(&pcp);
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
+        PyErr_SetString(audioopstate_global->AudioopError, "Size should be 1, 2 or 4");
         return 0;
     }
 
@@ -870,7 +897,7 @@
     else if ( size == 2 ) maxval = (double) 0x7fff;
     else if ( size == 4 ) maxval = (double) 0x7fffffff;
     else {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
+        PyErr_SetString(audioopstate_global->AudioopError, "Size should be 1, 2 or 4");
         return 0;
     }
 
@@ -926,7 +953,7 @@
     if (!audioop_check_parameters(len1, size))
         return NULL;
     if ( len1 != len2 ) {
-        PyErr_SetString(AudioopError, "Lengths should be the same");
+        PyErr_SetString(audioopstate_global->AudioopError, "Lengths should be the same");
         return 0;
     }
 
@@ -934,7 +961,7 @@
     else if ( size == 2 ) maxval = 0x7fff;
     else if ( size == 4 ) maxval = 0x7fffffff;
     else {
-        PyErr_SetString(AudioopError, "Size should be 1, 2 or 4");
+        PyErr_SetString(audioopstate_global->AudioopError, "Size should be 1, 2 or 4");
         return 0;
     }
 
@@ -1105,7 +1132,7 @@
     if (!audioop_check_size(size))
         return NULL;
     if (nchannels < 1) {
-        PyErr_SetString(AudioopError, "# of channels should be >= 1");
+        PyErr_SetString(audioopstate_global->AudioopError, "# of channels should be >= 1");
         return NULL;
     }
     bytes_per_frame = size * nchannels;
@@ -1118,16 +1145,16 @@
         return NULL;
     }
     if (weightA < 1 || weightB < 0) {
-        PyErr_SetString(AudioopError,
+        PyErr_SetString(audioopstate_global->AudioopError,
             "weightA should be >= 1, weightB should be >= 0");
         return NULL;
     }
     if (len % bytes_per_frame != 0) {
-        PyErr_SetString(AudioopError, "not a whole number of frames");
+        PyErr_SetString(audioopstate_global->AudioopError, "not a whole number of frames");
         return NULL;
     }
     if (inrate <= 0 || outrate <= 0) {
-        PyErr_SetString(AudioopError, "sampling rate not > 0");
+        PyErr_SetString(audioopstate_global->AudioopError, "sampling rate not > 0");
         return NULL;
     }
     /* divide inrate and outrate by their greatest common divisor */
@@ -1160,7 +1187,7 @@
                         &d, &PyTuple_Type, &samps))
             goto exit;
         if (PyTuple_Size(samps) != nchannels) {
-            PyErr_SetString(AudioopError,
+            PyErr_SetString(audioopstate_global->AudioopError,
                             "illegal state argument");
             goto exit;
         }
@@ -1637,12 +1664,12 @@
     PyModuleDef_HEAD_INIT,
     "audioop",
     NULL,
-    -1,
+    sizeof(audioopstate),
     audioop_methods,
     NULL,
-    NULL,
-    NULL,
-    NULL
+    audioop_traverse,
+    audioop_clear,
+    audioop_free
 };
 
 PyMODINIT_FUNC
@@ -1655,8 +1682,8 @@
     d = PyModule_GetDict(m);
     if (d == NULL)
         return NULL;
-    AudioopError = PyErr_NewException("audioop.error", NULL, NULL);
-    if (AudioopError != NULL)
-         PyDict_SetItemString(d,"error",AudioopError);
+    audioop_state(m)->AudioopError = PyErr_NewException("audioop.error", NULL, NULL);
+    if (audioop_state(m)->AudioopError != NULL)
+         PyDict_SetItemString(d,"error", audioop_state(m)->AudioopError);
     return m;
 }