From cb621341a62e6d2233db3e337611f6fdd4f675a6 Mon Sep 17 00:00:00 2001 From: Christian Linhart Date: Wed, 29 Apr 2015 09:11:37 +0200 Subject: [PATCH 1/3] expose 64-bit sequence numbers for XLib While XCB uses 64-bit sequence number internally, it only exposes "unsigned int" so that, on 32-bit architecture, Xlib based applications may see their sequence number wrap which causes the connection to the X server to be lost. Expose 64-bit sequence number from XCB API so that Xlib and others can use it even on 32-bit environment. This implies the following API addition: xcb_send_request64() xcb_discard_reply64() xcb_wait_for_reply64() xcb_poll_for_reply64() Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=71338 Reviewed-by: Uli Schlachter Signed-off-by: Christian Linhart Signed-off-by: Olivier Fourdan --- src/xcb.h | 20 ++++++++++++++++++++ src/xcb_in.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ src/xcb_out.c | 8 +++++++- src/xcbext.h | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 126 insertions(+), 1 deletion(-) diff --git a/src/xcb.h b/src/xcb.h index 23fe74e..86eb1bc 100644 --- a/src/xcb.h +++ b/src/xcb.h @@ -378,6 +378,26 @@ xcb_generic_error_t *xcb_request_check(xcb_connection_t *c, xcb_void_cookie_t co */ void xcb_discard_reply(xcb_connection_t *c, unsigned int sequence); +/** + * @brief Discards the reply for a request, given by a 64bit sequence number + * @param c: The connection to the X server. + * @param sequence: 64-bit sequence number as returned by xcb_send_request64(). + * + * 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 xcb_send_request64(); + * the cookie sequence number is defined as "unsigned" int and therefore + * not 64-bit on all platforms. + * This function is not designed to operate on socket-handoff replies. + * + * Unlike its xcb_discard_reply() counterpart, the given sequence number is not + * automatically "widened" to 64-bit. + */ +void xcb_discard_reply64(xcb_connection_t *c, uint64_t sequence); /* xcb_ext.c */ diff --git a/src/xcb_in.c b/src/xcb_in.c index ad870c1..623a0a8 100644 --- a/src/xcb_in.c +++ b/src/xcb_in.c @@ -523,6 +523,20 @@ void *xcb_wait_for_reply(xcb_connection_t *c, unsigned int request, xcb_generic_ return ret; } +void *xcb_wait_for_reply64(xcb_connection_t *c, uint64_t request, xcb_generic_error_t **e) +{ + void *ret; + if(e) + *e = 0; + if(c->has_error) + return 0; + + pthread_mutex_lock(&c->iolock); + ret = wait_for_reply(c, request, e); + pthread_mutex_unlock(&c->iolock); + return ret; +} + int *xcb_get_reply_fds(xcb_connection_t *c, void *reply, size_t reply_size) { return (int *) (&((char *) reply)[reply_size]); @@ -595,6 +609,20 @@ void xcb_discard_reply(xcb_connection_t *c, unsigned int sequence) pthread_mutex_unlock(&c->iolock); } +void xcb_discard_reply64(xcb_connection_t *c, uint64_t 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; @@ -612,6 +640,23 @@ int xcb_poll_for_reply(xcb_connection_t *c, unsigned int request, void **reply, return ret; } +int xcb_poll_for_reply64(xcb_connection_t *c, uint64_t request, void **reply, xcb_generic_error_t **error) +{ + int ret; + if(c->has_error) + { + *reply = 0; + if(error) + *error = 0; + return 1; /* would not block */ + } + assert(reply != 0); + pthread_mutex_lock(&c->iolock); + ret = poll_for_reply(c, request, reply, error); + pthread_mutex_unlock(&c->iolock); + return ret; +} + xcb_generic_event_t *xcb_wait_for_event(xcb_connection_t *c) { xcb_generic_event_t *ret; diff --git a/src/xcb_out.c b/src/xcb_out.c index dc42954..8cc5be8 100644 --- a/src/xcb_out.c +++ b/src/xcb_out.c @@ -177,7 +177,7 @@ uint32_t xcb_get_maximum_request_length(xcb_connection_t *c) return c->out.maximum_request_length.value; } -unsigned int xcb_send_request(xcb_connection_t *c, int flags, struct iovec *vector, const xcb_protocol_request_t *req) +uint64_t xcb_send_request64(xcb_connection_t *c, int flags, struct iovec *vector, const xcb_protocol_request_t *req) { uint64_t request; uint32_t prefix[2]; @@ -286,6 +286,12 @@ unsigned int xcb_send_request(xcb_connection_t *c, int flags, struct iovec *vect return request; } +/* request number are actually uint64_t internally but keep API compat with unsigned int */ +unsigned int xcb_send_request(xcb_connection_t *c, int flags, struct iovec *vector, const xcb_protocol_request_t *req) +{ + return xcb_send_request64(c, flags, vector, req); +} + void xcb_send_fd(xcb_connection_t *c, int fd) { diff --git a/src/xcbext.h b/src/xcbext.h index 7587513..b2575f7 100644 --- a/src/xcbext.h +++ b/src/xcbext.h @@ -83,6 +83,30 @@ 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); /** + * @brief Send a request to the server, with 64-bit sequence number returned. + * @param c: The connection to the X server. + * @param flags: A combination of flags from the xcb_send_request_flags_t enumeration. + * @param vector: Data to send; must have two iovecs before start for internal use. + * @param request: Information about the request to be sent. + * @return The request's sequence number on success, 0 otherwise. + * + * This function sends a new request to the X server. The data of the request is + * given as an array of @c iovecs in the @p vector argument. The length of that + * array and the neccessary management information are given in the @p request + * argument. + * + * When this function returns, the request might or might not be sent already. + * Use xcb_flush() to make sure that it really was sent. + * + * Please note that this function is not the prefered way for sending requests. + * It's better to use the generated wrapper functions. + * + * Please note that xcb might use index -1 and -2 of the @p vector array internally, + * so they must be valid! + */ +uint64_t xcb_send_request64(xcb_connection_t *c, int flags, struct iovec *vector, const xcb_protocol_request_t *request); + +/** * @brief Send a file descriptor to the server in the next call to xcb_send_request. * @param c: The connection to the X server. * @param fd: The file descriptor to send. @@ -162,6 +186,21 @@ int xcb_writev(xcb_connection_t *c, struct iovec *vector, int count, uint64_t re void *xcb_wait_for_reply(xcb_connection_t *c, unsigned int request, xcb_generic_error_t **e); /** + * @brief Wait for the reply of a given request, with 64-bit sequence number + * @param c: The connection to the X server. + * @param request: 64-bit sequence number of the request as returned by xcb_send_request64(). + * @param e: Location to store errors in, or NULL. Ignored for unchecked requests. + * + * Returns the reply to the given request or returns null in the event of + * errors. Blocks until the reply or error for the request arrives, or an I/O + * error occurs. + * + * Unlike its xcb_wait_for_reply() counterpart, the given sequence number is not + * automatically "widened" to 64-bit. + */ +void *xcb_wait_for_reply64(xcb_connection_t *c, uint64_t request, xcb_generic_error_t **e); + +/** * @brief Poll for the reply of a given request. * @param c: The connection to the X server. * @param request: Sequence number of the request as returned by xcb_send_request(). @@ -174,6 +213,21 @@ void *xcb_wait_for_reply(xcb_connection_t *c, unsigned int request, xcb_generic_ int xcb_poll_for_reply(xcb_connection_t *c, unsigned int request, void **reply, xcb_generic_error_t **error); /** + * @brief Poll for the reply of a given request, with 64-bit sequence number. + * @param c: The connection to the X server. + * @param request: 64-bit sequence number of the request as returned by xcb_send_request(). + * @param reply: Location to store the reply in, must not be NULL. + * @param e: Location to store errors in, or NULL. Ignored for unchecked requests. + * @return 1 when the reply to the request was returned, else 0. + * + * Checks if the reply to the given request already received. Does not block. + * + * Unlike its xcb_poll_for_reply() counterpart, the given sequence number is not + * automatically "widened" to 64-bit. + */ +int xcb_poll_for_reply64(xcb_connection_t *c, uint64_t request, void **reply, xcb_generic_error_t **error); + +/** * @brief Don't use this, only needed by the generated code. * @param c: The connection to the X server. * @param reply: A reply that was received from the server -- 2.4.2