diff -r 5f90ef1df157 Modules/ossaudiodev.c
--- a/Modules/ossaudiodev.c	Wed Mar 18 16:05:32 2015 +0100
+++ b/Modules/ossaudiodev.c	Thu Mar 19 14:29:23 2015 +0100
@@ -48,12 +48,12 @@ typedef unsigned long uint32_t;
 
 typedef struct {
     PyObject_HEAD
-    char    *devicename;              /* name of the device file */
-    int      fd;                      /* file descriptor */
-    int      mode;                    /* file mode (O_RDONLY, etc.) */
-    int      icount;                  /* input count */
-    int      ocount;                  /* output count */
-    uint32_t afmts;                   /* audio formats supported by hardware */
+    char      *devicename;            /* name of the device file */
+    int        fd;                    /* file descriptor */
+    int        mode;                  /* file mode (O_RDONLY, etc.) */
+    Py_ssize_t icount;                /* input count */
+    Py_ssize_t ocount;                /* output count */
+    uint32_t   afmts;                 /* audio formats supported by hardware */
 } oss_audio_t;
 
 typedef struct {
@@ -399,29 +399,24 @@ oss_post(oss_audio_t *self, PyObject *ar
 static PyObject *
 oss_read(oss_audio_t *self, PyObject *args)
 {
-    int size, count;
-    char *cp;
+    Py_ssize_t size, count;
     PyObject *rv;
 
     if (!_is_fd_valid(self->fd))
         return NULL;
 
-    if (!PyArg_ParseTuple(args, "i:read", &size))
+    if (!PyArg_ParseTuple(args, "n:read", &size))
         return NULL;
     rv = PyBytes_FromStringAndSize(NULL, size);
     if (rv == NULL)
         return NULL;
-    cp = PyBytes_AS_STRING(rv);
 
-    Py_BEGIN_ALLOW_THREADS
-    count = read(self->fd, cp, size);
-    Py_END_ALLOW_THREADS
-
-    if (count < 0) {
-        PyErr_SetFromErrno(PyExc_IOError);
+    count = _Py_read(self->fd, PyBytes_AS_STRING(rv), size);
+    if (count == -1) {
         Py_DECREF(rv);
         return NULL;
     }
+
     self->icount += count;
     _PyBytes_Resize(&rv, count);
     return rv;
@@ -430,35 +425,33 @@ oss_read(oss_audio_t *self, PyObject *ar
 static PyObject *
 oss_write(oss_audio_t *self, PyObject *args)
 {
-    char *cp;
-    int rv, size;
+    Py_buffer buf;
+    Py_ssize_t rv;
 
     if (!_is_fd_valid(self->fd))
         return NULL;
 
-    if (!PyArg_ParseTuple(args, "y#:write", &cp, &size)) {
+    if (!PyArg_ParseTuple(args, "y*:write", &buf))
         return NULL;
-    }
 
-    Py_BEGIN_ALLOW_THREADS
-    rv = write(self->fd, cp, size);
-    Py_END_ALLOW_THREADS
+    rv = _Py_write(self->fd, buf.buf, buf.len);
+    PyBuffer_Release(&buf);
+    if (rv == -1)
+        return NULL;
 
-    if (rv == -1) {
-        return PyErr_SetFromErrno(PyExc_IOError);
-    } else {
-        self->ocount += rv;
-    }
+    self->ocount += rv;
     return PyLong_FromLong(rv);
 }
 
 static PyObject *
 oss_writeall(oss_audio_t *self, PyObject *args)
 {
+    Py_buffer buf;
     char *cp;
-    int rv, size;
+    Py_ssize_t size, rv;
     fd_set write_set_fds;
     int select_rv;
+    PyObject *res = NULL;
 
     /* NB. writeall() is only useful in non-blocking mode: according to
        Guenter Geiger <geiger@xdv.org> on the linux-audio-dev list
@@ -470,13 +463,15 @@ oss_writeall(oss_audio_t *self, PyObject
     if (!_is_fd_valid(self->fd))
         return NULL;
 
-    if (!PyArg_ParseTuple(args, "y#:write", &cp, &size))
+    if (!PyArg_ParseTuple(args, "y*:write", &buf))
         return NULL;
+    cp = buf.buf;
+    size = buf.len;
 
     if (!_PyIsSelectable_fd(self->fd)) {
         PyErr_SetString(PyExc_ValueError,
                         "file descriptor out of range for select");
-        return NULL;
+        goto finally;
     }
     /* use select to wait for audio device to be available */
     FD_ZERO(&write_set_fds);
@@ -487,26 +482,35 @@ oss_writeall(oss_audio_t *self, PyObject
         select_rv = select(self->fd+1, NULL, &write_set_fds, NULL, NULL);
         Py_END_ALLOW_THREADS
         assert(select_rv != 0);         /* no timeout, can't expire */
-        if (select_rv == -1)
-            return PyErr_SetFromErrno(PyExc_IOError);
+        if (select_rv == -1) {
+            PyErr_SetFromErrno(PyExc_IOError);
+            goto finally;
+        }
 
-        Py_BEGIN_ALLOW_THREADS
-        rv = write(self->fd, cp, size);
-        Py_END_ALLOW_THREADS
+        rv = _Py_write(self->fd, cp, size);
         if (rv == -1) {
-            if (errno == EAGAIN) {      /* buffer is full, try again */
-                errno = 0;
+            /* buffer is full, try again */
+            if (errno == EAGAIN) {
+                PyErr_Clear();
                 continue;
-            } else                      /* it's a real error */
-                return PyErr_SetFromErrno(PyExc_IOError);
-        } else {                        /* wrote rv bytes */
-            self->ocount += rv;
-            size -= rv;
-            cp += rv;
+            }
+            /* it's a real error */
+            goto finally;
         }
+
+        /* wrote rv bytes */
+        self->ocount += rv;
+        size -= rv;
+        cp += rv;
     }
+    PyBuffer_Release(&buf);
+
     Py_INCREF(Py_None);
-    return Py_None;
+    res = Py_None;
+
+finally:
+    PyBuffer_Release(&buf);
+    return res;
 }
 
 static PyObject *