diff options
| -rw-r--r-- | src/xcb.h | 16 | ||||
| -rw-r--r-- | src/xcb_in.c | 110 |
2 files changed, 126 insertions, 0 deletions
@@ -285,6 +285,22 @@ xcb_generic_event_t *xcb_poll_for_event(xcb_connection_t *c); */ xcb_generic_error_t *xcb_request_check(xcb_connection_t *c, xcb_void_cookie_t cookie); +/** + * @brief Discards the reply for a request. + * @param c: The connection to the X server. + * @param sequence: The request sequence number from a cookie. + * + * Discards the reply for a request. Additionally, any error generated + * by the request is also discarded (unless it was an _unchecked request + * and the error has already arrived). + * + * This function will not block even if the reply is not yet available. + * + * Note that the sequence really does have to come from an xcb cookie; + * this function is not designed to operate on socket-handoff replies. + */ +void xcb_discard_reply(xcb_connection_t *c, unsigned int sequence); + /* xcb_ext.c */ diff --git a/src/xcb_in.c b/src/xcb_in.c index 26ab358..80f5523 100644 --- a/src/xcb_in.c +++ b/src/xcb_in.c @@ -409,6 +409,116 @@ void *xcb_wait_for_reply(xcb_connection_t *c, unsigned int request, xcb_generic_ return ret; } +static void insert_pending_discard(xcb_connection_t *c, pending_reply **prev_next, uint64_t seq) +{ + pending_reply *pend; + pend = malloc(sizeof(*pend)); + if(!pend) + { + _xcb_conn_shutdown(c); + return; + } + + pend->first_request = seq; + pend->last_request = seq; + pend->workaround = 0; + pend->flags = XCB_REQUEST_DISCARD_REPLY; + pend->next = *prev_next; + *prev_next = pend; + + if(!pend->next) + c->in.pending_replies_tail = &pend->next; +} + +static void discard_reply(xcb_connection_t *c, unsigned int request) +{ + pending_reply *pend = 0; + pending_reply **prev_pend; + uint64_t widened_request; + + /* We've read requests past the one we want, so if it has replies we have + * them all and they're in the replies map. */ + if(XCB_SEQUENCE_COMPARE_32(request, <, c->in.request_read)) + { + struct reply_list *head; + head = _xcb_map_remove(c->in.replies, request); + while (head) + { + struct reply_list *next = head->next; + free(head->reply); + free(head); + head = next; + } + return; + } + + /* We're currently processing the responses to the request we want, and we + * have a reply ready to return. Free it, and mark the pend to free any further + * replies. */ + if(XCB_SEQUENCE_COMPARE_32(request, ==, c->in.request_read) && c->in.current_reply) + { + struct reply_list *head; + head = c->in.current_reply; + c->in.current_reply = NULL; + c->in.current_reply_tail = &c->in.current_reply; + while (head) + { + struct reply_list *next = head->next; + free(head->reply); + free(head); + head = next; + } + + pend = c->in.pending_replies; + if(pend && + !(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; + if(pend) + pend->flags |= XCB_REQUEST_DISCARD_REPLY; + else + insert_pending_discard(c, &c->in.pending_replies, c->in.request_read); + + return; + } + + /* Walk the list of pending requests. Mark the first match for deletion. */ + for(prev_pend = &c->in.pending_replies; *prev_pend; prev_pend = &(*prev_pend)->next) + { + if(XCB_SEQUENCE_COMPARE_32((*prev_pend)->first_request, >, request)) + break; + + if(XCB_SEQUENCE_COMPARE_32((*prev_pend)->first_request, ==, request)) + { + /* Pending reply found. Mark for discard: */ + (*prev_pend)->flags |= XCB_REQUEST_DISCARD_REPLY; + return; + } + } + + /* Pending reply not found (likely due to _unchecked request). Create one: */ + widened_request = (c->out.request & UINT64_C(0xffffffff00000000)) | request; + if(widened_request > c->out.request) + widened_request -= UINT64_C(1) << 32; + + insert_pending_discard(c, prev_pend, widened_request); +} + +void xcb_discard_reply(xcb_connection_t *c, unsigned int sequence) +{ + if(c->has_error) + return; + + /* If an error occurred when issuing the request, fail immediately. */ + if(!sequence) + return; + + pthread_mutex_lock(&c->iolock); + discard_reply(c, sequence); + pthread_mutex_unlock(&c->iolock); +} + int xcb_poll_for_reply(xcb_connection_t *c, unsigned int request, void **reply, xcb_generic_error_t **error) { int ret; |