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554f755e55
Generic events require more bytes than Xlib provides in the standard XEvent.
Memory allocated by the extension and stored as pointers inside the event is
prone to leak by simple 'while (1) { XNextEvent(...); }' loops.
This patch adds cookie handling for generic events. Extensions may register
a cookie handler in addition to the normal event vectors. If an extension
has registered a cookie handler, _all_ generic events for this extensions
must be handled through cookies. Otherwise, the default event handler is
used.
The cookie handler must return an XGenericEventCookie with a pointer to the
data.The rest of the event (type, serialNumber, etc.) are to be filled as
normal. When a client retrieves such a cookie event, the data is stored in
an internal queue (the 'cookiejar'). This data is freed on the next call to
XNextEvent().
New extension interfaces:
XESetWireToEventCookie(display, extension_number, cookie_handler)
Where cookie_handler must set cookie->data. The data pointer is of arbitray
size and type but must be a single memory block. This memory block
represents the actual extension's event.
New client interfaces:
XGetEventData(display, *cookie);
XFreeEventData(display, *cookie);
If the client needs the actual event data, it must call XGetEventData() with
the cookie. This returns the data pointer (and removes it from the cookie
jar) and the client is then responsible for freeing the event with
XFreeEventData(). It is safe to call either function with a non-cookie
event. Events unclaimed or not handled by the XGetEventData() are cleaned up
automatically.
Example client code:
XEvent event;
XGenericEventCookie *cookie = &ev;
XNextEvent(display, &event);
if (XGetEventData(display, cookie)) {
XIEvent *xievent = cookie->data;
...
} else if (cookie->type == GenericEvent) {
/* handle generic event */
} else {
/* handle extension/core event */
}
XFreeEventData(display, cookie);
Cookies are not multi-threading safe. Clients that use XGetEventData() must
lock between XNextEvent and XGetEventData to avoid other threads freeing
cookies.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
116 lines
5.7 KiB
C
116 lines
5.7 KiB
C
/*
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Copyright (c) 2007-2009, Troy D. Hanson
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
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PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
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OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef UTLIST_H
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#define UTLIST_H
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#define UTLIST_VERSION 1.7
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/* From: http://uthash.sourceforge.net/utlist.html */
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/*
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* This file contains macros to manipulate singly and doubly-linked lists.
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*
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* 1. LL_ macros: singly-linked lists.
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* 2. DL_ macros: doubly-linked lists.
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* 3. CDL_ macros: circular doubly-linked lists.
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*
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* To use singly-linked lists, your structure must have a "next" pointer.
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* To use doubly-linked lists, your structure must "prev" and "next" pointers.
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* Either way, the pointer to the head of the list must be initialized to NULL.
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*
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* ----------------.EXAMPLE -------------------------
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* struct item {
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* int id;
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* struct item *prev, *next;
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* }
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*
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* struct item *list = NULL:
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*
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* int main() {
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* struct item *item;
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* ... allocate and populate item ...
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* DL_APPEND(list, item);
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* }
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* --------------------------------------------------
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*
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* For doubly-linked lists, the append and delete macros are O(1)
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* For singly-linked lists, append and delete are O(n) but prepend is O(1)
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* The sort macro is O(n log(n)) for all types of single/double/circular lists.
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*/
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/******************************************************************************
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* doubly linked list macros (non-circular) *
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*****************************************************************************/
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#define DL_PREPEND(head,add) \
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do { \
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(add)->next = head; \
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if (head) { \
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(add)->prev = (head)->prev; \
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(head)->prev = (add); \
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} else { \
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(add)->prev = (add); \
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} \
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(head) = (add); \
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} while (0)
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#define DL_APPEND(head,add) \
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do { \
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if (head) { \
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(add)->prev = (head)->prev; \
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(head)->prev->next = (add); \
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(head)->prev = (add); \
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(add)->next = NULL; \
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} else { \
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(head)=(add); \
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(head)->prev = (head); \
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(head)->next = NULL; \
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} \
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} while (0);
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#define DL_DELETE(head,del) \
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do { \
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if ((del)->prev == (del)) { \
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(head)=NULL; \
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} else if ((del)==(head)) { \
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(del)->next->prev = (del)->prev; \
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(head) = (del)->next; \
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} else { \
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(del)->prev->next = (del)->next; \
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if ((del)->next) { \
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(del)->next->prev = (del)->prev; \
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} else { \
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(head)->prev = (del)->prev; \
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} \
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} \
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} while (0);
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#define DL_FOREACH(head,el) \
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for(el=head;el;el=el->next)
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#define DL_FOREACH_SAFE(head,el,tmp) \
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for(el=head,tmp=el->next;el;el=tmp,tmp=(el) ? (el->next) : NULL)
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#endif /* UTLIST_H */
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