[Xcb] [PATCH libxcb] expose 64-bit sequence numbers for XLib

[Christian Linhart]

This is ABI and API compatible because it only adds new functions.

I will post the corresponding patch for Xlib to the xorg-devel list.
---
 src/xcb.h    | 15 +++++++++++++++
 src/xcb_in.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
 src/xcbext.h | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 109 insertions(+)

diff --git a/src/xcb.h b/src/xcb.h
index 23fe74e..9a08fef 100644
--- a/src/xcb.h
+++ b/src/xcb.h
@@ -378,6 +378,21 @@ 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: 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_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/xcbext.h b/src/xcbext.h
index 7587513..25619aa 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 +186,19 @@ 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: Sequence number of the request as returned by xcb_send_request().
+ * @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.
+ */
+
+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 +211,18 @@ 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: 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.
+ */
+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
-- 
2.1.4