diff --git a/src/Makefile.am b/src/Makefile.am
index bf6e991..756337a 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -24,7 +24,7 @@ libxcb_la_SOURCES = \
 # * If you add an interface, increment current and age and set revision to 0.
 # * If you change or remove an interface, increment current and set revision
 #   and age to 0.
-libxcb_la_LDFLAGS = -version-info 1:0:0
+libxcb_la_LDFLAGS = -version-info 2:0:1
 
 XCB_LIBS = libxcb.la
 
diff --git a/src/xcb_in.c b/src/xcb_in.c
index 6bf6648..212dc9a 100644
--- a/src/xcb_in.c
+++ b/src/xcb_in.c
@@ -113,6 +113,7 @@ static int read_packet(xcb_connection_t *c)
         }
 
         while(c->in.pending_replies && 
+              c->in.pending_replies->workaround != WORKAROUND_EXTERNAL_SOCKET_OWNER &&
 	      XCB_SEQUENCE_COMPARE (c->in.pending_replies->last_request, <=, c->in.request_completed))
         {
             pending_reply *oldpend = c->in.pending_replies;
@@ -130,8 +131,9 @@ static int read_packet(xcb_connection_t *c)
     {
         pend = c->in.pending_replies;
         if(pend &&
-           (XCB_SEQUENCE_COMPARE(c->in.request_read, <, pend->first_request) ||
-            XCB_SEQUENCE_COMPARE(c->in.request_read, >, pend->last_request)))
+           !(XCB_SEQUENCE_COMPARE(pend->first_request, <=, c->in.request_read) &&
+             (pend->workaround == WORKAROUND_EXTERNAL_SOCKET_OWNER ||
+              XCB_SEQUENCE_COMPARE(c->in.request_read, <=, pend->last_request))))
             pend = 0;
     }
 
@@ -352,7 +354,7 @@ void *xcb_wait_for_reply(xcb_connection_t *c, unsigned int request, xcb_generic_
         widened_request -= UINT64_C(1) << 32;
 
     /* If this request has not been written yet, write it. */
-    if(_xcb_out_flush_to(c, widened_request))
+    if(c->out.return_socket || _xcb_out_flush_to(c, widened_request))
     {
         pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
         reader_list reader;
@@ -523,6 +525,20 @@ int _xcb_in_expect_reply(xcb_connection_t *c, uint64_t request, enum workarounds
     return 1;
 }
 
+void _xcb_in_replies_done(xcb_connection_t *c)
+{
+    struct pending_reply *pend;
+    if (c->in.pending_replies_tail != &c->in.pending_replies)
+    {
+        pend = container_of(c->in.pending_replies_tail, struct pending_reply, next);
+        if(pend->workaround == WORKAROUND_EXTERNAL_SOCKET_OWNER)
+        {
+            pend->last_request = c->out.request;
+            pend->workaround = WORKAROUND_NONE;
+        }
+    }
+}
+
 int _xcb_in_read(xcb_connection_t *c)
 {
     int n = read(c->fd, c->in.queue + c->in.queue_len, sizeof(c->in.queue) - c->in.queue_len);
diff --git a/src/xcb_out.c b/src/xcb_out.c
index 1094ceb..4c6ab13 100644
--- a/src/xcb_out.c
+++ b/src/xcb_out.c
@@ -55,6 +55,25 @@ static int write_block(xcb_connection_t *c, struct iovec *vector, int count)
     return _xcb_out_send(c, &vector, &count);
 }
 
+static void get_socket_back(xcb_connection_t *c)
+{
+    while(c->out.return_socket && c->out.socket_moving)
+        pthread_cond_wait(&c->out.socket_cond, &c->iolock);
+    if(!c->out.return_socket)
+        return;
+
+    c->out.socket_moving = 1;
+    pthread_mutex_unlock(&c->iolock);
+    c->out.return_socket(c->out.socket_closure);
+    pthread_mutex_lock(&c->iolock);
+    c->out.socket_moving = 0;
+
+    pthread_cond_broadcast(&c->out.socket_cond);
+    c->out.return_socket = 0;
+    c->out.socket_closure = 0;
+    _xcb_in_replies_done(c);
+}
+
 /* Public interface */
 
 void xcb_prefetch_maximum_request_length(xcb_connection_t *c)
@@ -191,6 +210,7 @@ unsigned int xcb_send_request(xcb_connection_t *c, int flags, struct iovec *vect
     /* wait for other writing threads to get out of my way. */
     while(c->out.writing)
         pthread_cond_wait(&c->out.cond, &c->iolock);
+    get_socket_back(c);
 
     request = ++c->out.request;
     /* send GetInputFocus (sync_req) when 64k-2 requests have been sent without
@@ -235,6 +255,39 @@ unsigned int xcb_send_request(xcb_connection_t *c, int flags, struct iovec *vect
     return request;
 }
 
+int xcb_take_socket(xcb_connection_t *c, void (*return_socket)(void *closure), void *closure, int flags, uint64_t *sent)
+{
+    int ret;
+    if(c->has_error)
+        return 0;
+    pthread_mutex_lock(&c->iolock);
+    get_socket_back(c);
+    ret = _xcb_out_flush_to(c, c->out.request);
+    if(ret)
+    {
+        c->out.return_socket = return_socket;
+        c->out.socket_closure = closure;
+        if(flags)
+            _xcb_in_expect_reply(c, c->out.request, WORKAROUND_EXTERNAL_SOCKET_OWNER, flags);
+        assert(c->out.request == c->out.request_written);
+        *sent = c->out.request;
+    }
+    pthread_mutex_unlock(&c->iolock);
+    return ret;
+}
+
+int xcb_writev(xcb_connection_t *c, struct iovec *vector, int count, uint64_t requests)
+{
+    int ret;
+    if(c->has_error)
+        return 0;
+    pthread_mutex_lock(&c->iolock);
+    c->out.request += requests;
+    ret = _xcb_out_send(c, &vector, &count);
+    pthread_mutex_unlock(&c->iolock);
+    return ret;
+}
+
 int xcb_flush(xcb_connection_t *c)
 {
     int ret;
@@ -250,6 +303,12 @@ int xcb_flush(xcb_connection_t *c)
 
 int _xcb_out_init(_xcb_out *out)
 {
+    if(pthread_cond_init(&out->socket_cond, 0))
+        return 0;
+    out->return_socket = 0;
+    out->socket_closure = 0;
+    out->socket_moving = 0;
+
     if(pthread_cond_init(&out->cond, 0))
         return 0;
     out->writing = 0;
diff --git a/src/xcbext.h b/src/xcbext.h
index 01dd590..2e10ba2 100644
--- a/src/xcbext.h
+++ b/src/xcbext.h
@@ -59,6 +59,23 @@ enum xcb_send_request_flags_t {
 
 unsigned int xcb_send_request(xcb_connection_t *c, int flags, struct iovec *vector, const xcb_protocol_request_t *request);
 
+/* xcb_take_socket allows external code to ask XCB for permission to
+ * take over the write side of the socket and send raw data with
+ * xcb_writev. xcb_take_socket provides the sequence number of the last
+ * request XCB sent. The caller of xcb_take_socket must supply a
+ * callback which XCB can call when it wants the write side of the
+ * socket back to make a request. This callback synchronizes with the
+ * external socket owner, flushes any output queues if appropriate, and
+ * then returns the sequence number of the last request sent over the
+ * socket. */
+int xcb_take_socket(xcb_connection_t *c, void (*return_socket)(void *closure), void *closure, int flags, uint64_t *sent);
+
+/* You must own the write-side of the socket (you've called
+ * xcb_take_socket, and haven't returned from return_socket yet) to call
+ * xcb_writev. Also, the iovec must have at least 1 byte of data in it.
+ * */
+int xcb_writev(xcb_connection_t *c, struct iovec *vector, int count, uint64_t requests);
+
 
 /* xcb_in.c */
 
diff --git a/src/xcbint.h b/src/xcbint.h
index cd351de..2c9f7cd 100644
--- a/src/xcbint.h
+++ b/src/xcbint.h
@@ -40,7 +40,8 @@
 
 enum workarounds {
     WORKAROUND_NONE,
-    WORKAROUND_GLX_GET_FB_CONFIGS_BUG
+    WORKAROUND_GLX_GET_FB_CONFIGS_BUG,
+    WORKAROUND_EXTERNAL_SOCKET_OWNER
 };
 
 enum lazy_reply_tag
@@ -55,6 +56,12 @@ enum lazy_reply_tag
 #define XCB_SEQUENCE_COMPARE(a,op,b)	((int64_t) ((a) - (b)) op 0)
 #define XCB_SEQUENCE_COMPARE_32(a,op,b)	(((int) (a) - (int) (b)) op 0)
 
+#ifndef offsetof
+#define offsetof(type,member) ((size_t) &((type *)0)->member)
+#endif
+
+#define container_of(pointer,type,member) ((type *)(((char *)(pointer)) - offsetof(type, member)))
+
 /* xcb_list.c */
 
 typedef void (*xcb_list_free_func_t)(void *);
@@ -73,6 +80,11 @@ typedef struct _xcb_out {
     pthread_cond_t cond;
     int writing;
 
+    pthread_cond_t socket_cond;
+    void (*return_socket)(void *closure);
+    void *socket_closure;
+    int socket_moving;
+
     char queue[4096];
     int queue_len;
 
@@ -122,6 +134,7 @@ int _xcb_in_init(_xcb_in *in);
 void _xcb_in_destroy(_xcb_in *in);
 
 int _xcb_in_expect_reply(xcb_connection_t *c, uint64_t request, enum workarounds workaround, int flags);
+void _xcb_in_replies_done(xcb_connection_t *c);
 
 int _xcb_in_read(xcb_connection_t *c);
 int _xcb_in_read_block(xcb_connection_t *c, void *buf, int nread);