+/* precondition: there must be something for us to write. */
+static int write_vec(xcb_connection_t *c, struct iovec **vector, int *count)
+{
+ int n;
+ assert(!c->out.queue_len);
+
+#ifdef _WIN32
+ int i = 0;
+ int ret = 0,err = 0;
+ struct iovec *vec;
+ n = 0;
+
+ /* Could use the WSASend win32 function for scatter/gather i/o but setting up the WSABUF struct from
+ an iovec would require more work and I'm not sure of the benefit....works for now */
+ vec = *vector;
+ while(i < *count)
+ {
+ ret = send(c->fd,vec->iov_base,vec->iov_len,0);
+ if(ret == SOCKET_ERROR)
+ {
+ err = WSAGetLastError();
+ if(err == WSAEWOULDBLOCK)
+ {
+ return 1;
+ }
+ }
+ n += ret;
+ *vec++;
+ i++;
+ }
+#else
+ n = writev(c->fd, *vector, *count);
+ if(n < 0 && errno == EAGAIN)
+ return 1;
+#endif /* _WIN32 */
+
+ if(n <= 0)
+ {
+ _xcb_conn_shutdown(c, XCB_CONN_ERROR);
+ return 0;
+ }
+
+ for(; *count; --*count, ++*vector)
+ {
+ int cur = (*vector)->iov_len;
+ if(cur > n)
+ cur = n;
+ (*vector)->iov_len -= cur;
+ (*vector)->iov_base = (char *) (*vector)->iov_base + cur;
+ n -= cur;
+ if((*vector)->iov_len)
+ break;
+ }
+ if(!*count)
+ *vector = 0;
+ assert(n == 0);
+ return 1;
+}
+