static void get_socket_back(xcb_connection_t *c)
{
- while (c->out.return_socket) {
- /* we are about to release the lock,
- so make a copy of the current status */
- xcb_return_socket_func_t return_socket = c->out.return_socket;
- void *socket_closure = c->out.socket_closure;
- int socket_seq = c->out.socket_seq;
-
- pthread_mutex_unlock(&c->iolock);
- return_socket(socket_closure);
- pthread_mutex_lock(&c->iolock);
-
- /* make sure nobody else has acquired the socket */
- if (socket_seq == c->out.socket_seq) {
- c->out.return_socket = 0;
- c->out.socket_closure = 0;
- _xcb_in_replies_done(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);
+}
+
+static void prepare_socket_request(xcb_connection_t *c)
+{
+ /* We're about to append data to out.queue, so we need to
+ * atomically test for an external socket owner *and* some other
+ * thread currently writing.
+ *
+ * If we have an external socket owner, we have to get the socket back
+ * before we can use it again.
+ *
+ * If some other thread is writing to the socket, we assume it's
+ * writing from out.queue, and so we can't stick data there.
+ *
+ * We satisfy this condition by first calling get_socket_back
+ * (which may drop the lock, but will return when XCB owns the
+ * socket again) and then checking for another writing thread and
+ * escaping the loop if we're ready to go.
+ */
+ for (;;) {
+ if(c->has_error)
+ return;
+ get_socket_back(c);
+ if (!c->out.writing)
+ break;
+ pthread_cond_wait(&c->out.cond, &c->iolock);
}
}
/* get a sequence number and arrange for delivery. */
pthread_mutex_lock(&c->iolock);
- /* 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);
+
+ prepare_socket_request(c);
/* send GetInputFocus (sync_req) when 64k-2 requests have been sent without
- * a reply. */
- if(req->isvoid && c->out.request == c->in.request_expected + (1 << 16) - 2)
- send_sync(c);
- /* Also send sync_req (could use NoOp) at 32-bit wrap to avoid having
+ * a reply.
+ * Also send sync_req (could use NoOp) at 32-bit wrap to avoid having
* applications see sequence 0 as that is used to indicate
- * an error in sending the request */
- if((unsigned int) (c->out.request + 1) == 0)
+ * an error in sending the request
+ */
+
+ while ((req->isvoid && c->out.request == c->in.request_expected + (1 << 16) - 2) ||
+ (unsigned int) (c->out.request + 1) == 0)
+ {
send_sync(c);
+ prepare_socket_request(c);
+ }
- /* The above send_sync calls could drop the I/O lock, but this
- * thread will still exclude any other thread that tries to write,
- * so the sequence number postconditions still hold. */
send_request(c, req->isvoid, workaround, flags, vector, veclen);
request = c->has_error ? 0 : c->out.request;
pthread_mutex_unlock(&c->iolock);
return request;
}
+void
+xcb_send_fd(xcb_connection_t *c, int fd)
+{
+#if HAVE_SENDMSG
+ if (c->has_error)
+ return;
+ pthread_mutex_lock(&c->iolock);
+ while (c->out.out_fd.nfd == XCB_MAX_PASS_FD) {
+ _xcb_out_flush_to(c, c->out.request);
+ if (c->has_error)
+ break;
+ }
+ if (!c->has_error)
+ c->out.out_fd.fd[c->out.out_fd.nfd++] = fd;
+ pthread_mutex_unlock(&c->iolock);
+#endif
+}
+
int xcb_take_socket(xcb_connection_t *c, void (*return_socket)(void *closure), void *closure, int flags, uint64_t *sent)
{
int ret;
{
c->out.return_socket = return_socket;
c->out.socket_closure = closure;
- ++c->out.socket_seq;
if(flags)
_xcb_in_expect_reply(c, c->out.request, WORKAROUND_EXTERNAL_SOCKET_OWNER, flags);
assert(c->out.request == c->out.request_written);
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_seq = 0;
+ out->socket_moving = 0;
if(pthread_cond_init(&out->cond, 0))
return 0;
void _xcb_out_send_sync(xcb_connection_t *c)
{
- /* 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);
+ prepare_socket_request(c);
send_sync(c);
}