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/* Copyright (C) 2001-2004 Bart Massey and Jamey Sharp.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* Except as contained in this notice, the names of the authors or their
* institutions shall not be used in advertising or otherwise to promote the
* sale, use or other dealings in this Software without prior written
* authorization from the authors.
*/
/* A cache for QueryExtension results. */
#include <stdlib.h>
#include <string.h>
#include "xcb.h"
#include "xcbext.h"
#include "xcbint.h"
typedef struct {
enum { LAZY_COOKIE, LAZY_FORCED } tag;
union {
XCBQueryExtensionCookie cookie;
XCBQueryExtensionRep *reply;
} value;
} lazyreply;
static lazyreply *get_lazyreply(XCBConnection *c, XCBExtension *ext)
{
static pthread_mutex_t global_lock = PTHREAD_MUTEX_INITIALIZER;
static int next_global_id;
lazyreply *data;
pthread_mutex_lock(&global_lock);
if(!ext->global_id)
ext->global_id = ++next_global_id;
pthread_mutex_unlock(&global_lock);
data = _xcb_map_get(c->ext.extensions, ext->global_id);
if(!data)
{
/* cache miss: query the server */
data = malloc(sizeof(lazyreply));
if(!data)
return 0;
data->tag = LAZY_COOKIE;
data->value.cookie = XCBQueryExtension(c, strlen(ext->name), ext->name);
_xcb_map_put(c->ext.extensions, ext->global_id, data);
}
return data;
}
static void free_lazyreply(void *p)
{
lazyreply *data = p;
if(data->tag == LAZY_FORCED)
free(data->value.reply);
free(data);
}
/* Public interface */
/* Do not free the returned XCBQueryExtensionRep - on return, it's aliased
* from the cache. */
const XCBQueryExtensionRep *XCBGetExtensionData(XCBConnection *c, XCBExtension *ext)
{
lazyreply *data;
pthread_mutex_lock(&c->ext.lock);
data = get_lazyreply(c, ext);
if(data && data->tag == LAZY_COOKIE)
{
data->tag = LAZY_FORCED;
data->value.reply = XCBQueryExtensionReply(c, data->value.cookie, 0);
}
pthread_mutex_unlock(&c->ext.lock);
return data ? data->value.reply : 0;
}
void XCBPrefetchExtensionData(XCBConnection *c, XCBExtension *ext)
{
pthread_mutex_lock(&c->ext.lock);
get_lazyreply(c, ext);
pthread_mutex_unlock(&c->ext.lock);
}
/* Private interface */
int _xcb_ext_init(XCBConnection *c)
{
if(pthread_mutex_init(&c->ext.lock, 0))
return 0;
c->ext.extensions = _xcb_map_new();
if(!c->ext.extensions)
return 0;
return 1;
}
void _xcb_ext_destroy(XCBConnection *c)
{
pthread_mutex_destroy(&c->ext.lock);
_xcb_map_delete(c->ext.extensions, free_lazyreply);
}
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