diff options
| -rw-r--r-- | src/xcbext.h | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/src/xcbext.h b/src/xcbext.h index 2e10ba2..d6366cb 100644 --- a/src/xcbext.h +++ b/src/xcbext.h @@ -65,15 +65,22 @@ unsigned int xcb_send_request(xcb_connection_t *c, int flags, struct iovec *vect * 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. */ + * external socket owner and flushes any output queues if appropriate. + * If you are sending requests which won't cause a reply, please note the + * comment for xcb_writev which explains some sequence number wrap issues. + * */ 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. - * */ + * You have to make sure that xcb can detect sequence number wraps correctly. + * This means that the first request you send after xcb_take_socket must cause a + * reply (e.g. just insert a GetInputFocus request). After every (1 << 16) - 1 + * requests without a reply, you have to insert a request which will cause a + * reply. You can again use GetInputFocus for this. You do not have to wait for + * any of the GetInputFocus replies, but can instead handle them via + * xcb_discard_reply(). */ int xcb_writev(xcb_connection_t *c, struct iovec *vector, int count, uint64_t requests); |