DisplayQue.c revision 6c321187 
1/* $Xorg: DisplayQue.c,v 1.4 2001/02/09 02:03:52 xorgcvs Exp $ */
2
3/*
4
5Copyright 1989, 1998  The Open Group
6
7Permission to use, copy, modify, distribute, and sell this software and its
8documentation for any purpose is hereby granted without fee, provided that
9the above copyright notice appear in all copies and that both that
10copyright notice and this permission notice appear in supporting
11documentation.
12
13The above copyright notice and this permission notice shall be included in
14all copies or substantial portions of the Software.
15
16THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
19OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
20AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22
23Except as contained in this notice, the name of The Open Group shall not be
24used in advertising or otherwise to promote the sale, use or other dealings
25in this Software without prior written authorization from The Open Group.
26
27*/
28/* $XFree86: xc/lib/Xmu/DisplayQue.c,v 3.4 2001/07/25 15:04:50 dawes Exp $ */
29
30/*
31 * Author:  Jim Fulton, MIT X Consortium
32 */
33
34#ifdef HAVE_CONFIG_H
35#include <config.h>
36#endif
37#include <stdio.h>
38#include <X11/Xlib.h>
39#include <stdlib.h>
40#include <X11/Xmu/DisplayQue.h>
41
42/*
43 * Prototypes
44 */
45static int _DQCloseDisplay(Display*, XPointer);
46
47#define CallCloseCallback(q,e) (void) (*((q)->closefunc)) ((q), (e))
48#define CallFreeCallback(q) (void) (*((q)->freefunc)) ((q))
49
50/*
51 * XmuDQCreate - create a display queue
52 */
53XmuDisplayQueue *
54XmuDQCreate(XmuCloseDisplayQueueProc closefunc,
55	    XmuFreeDisplayQueueProc freefunc,
56	    XPointer data)
57{
58    XmuDisplayQueue *q = (XmuDisplayQueue *) malloc (sizeof (XmuDisplayQueue));
59    if (q) {
60	q->nentries = 0;
61	q->head = q->tail = NULL;
62	q->closefunc = closefunc;
63	q->freefunc = freefunc;
64	q->data = data;
65    }
66    return q;
67}
68
69
70/*
71 * XmuDQDestroy - free all storage associated with this display queue,
72 * optionally invoking the close callbacks.
73 */
74
75Bool
76XmuDQDestroy(XmuDisplayQueue *q, Bool docallbacks)
77{
78    XmuDisplayQueueEntry *e = q->head;
79
80    while (e) {
81	XmuDisplayQueueEntry *nexte = e->next;
82	if (docallbacks && q->closefunc) CallCloseCallback (q, e);
83	free ((char *) e);
84	e = nexte;
85    }
86    free ((char *) q);
87    return True;
88}
89
90
91/*
92 * XmuDQLookupDisplay - finds the indicated display on the given queue
93 */
94XmuDisplayQueueEntry *
95XmuDQLookupDisplay(XmuDisplayQueue *q, Display *dpy)
96{
97    XmuDisplayQueueEntry *e;
98
99    for (e = q->head; e; e = e->next) {
100	if (e->display == dpy) return e;
101    }
102    return NULL;
103}
104
105
106/*
107 * XmuDQAddDisplay - add the specified display to the queue; set data as a
108 * convenience.  Does not ensure that dpy hasn't already been added.
109 */
110XmuDisplayQueueEntry *
111XmuDQAddDisplay(XmuDisplayQueue *q, Display *dpy, XPointer data)
112{
113    XmuDisplayQueueEntry *e;
114
115    if (!(e = (XmuDisplayQueueEntry *) malloc (sizeof (XmuDisplayQueueEntry)))) {
116	return NULL;
117    }
118    if (!(e->closehook = XmuAddCloseDisplayHook (dpy, _DQCloseDisplay,
119						 (XPointer) q))) {
120	free ((char *) e);
121	return NULL;
122    }
123
124    e->display = dpy;
125    e->next = NULL;
126    e->data = data;
127
128    if (q->tail) {
129	q->tail->next = e;
130	e->prev = q->tail;
131    } else {
132	q->head = e;
133	e->prev = NULL;
134    }
135    q->tail = e;
136    q->nentries++;
137    return e;
138}
139
140
141/*
142 * XmuDQRemoveDisplay - remove the specified display from the queue
143 */
144Bool
145XmuDQRemoveDisplay(XmuDisplayQueue *q, Display *dpy)
146{
147    XmuDisplayQueueEntry *e;
148
149    for (e = q->head; e; e = e->next) {
150	if (e->display == dpy) {
151	    if (q->head == e)
152	      q->head = e->next;	/* if at head, then bump head */
153	    else
154	      e->prev->next = e->next;	/* else splice out */
155	    if (q->tail == e)
156	      q->tail = e->prev;	/* if at tail, then bump tail */
157	    else
158	      e->next->prev = e->prev;	/* else splice out */
159	    (void) XmuRemoveCloseDisplayHook (dpy, e->closehook,
160					      _DQCloseDisplay, (XPointer) q);
161	    free ((char *) e);
162	    q->nentries--;
163	    return True;
164	}
165    }
166    return False;
167}
168
169
170/*****************************************************************************
171 *			       private functions                             *
172 *****************************************************************************/
173
174/*
175 * _DQCloseDisplay - upcalled from CloseHook to notify this queue; remove the
176 * display when finished
177 */
178static int
179_DQCloseDisplay(Display *dpy, XPointer arg)
180{
181    XmuDisplayQueue *q = (XmuDisplayQueue *) arg;
182    XmuDisplayQueueEntry *e;
183
184    for (e = q->head; e; e = e->next) {
185	if (e->display == dpy) {
186	    if (q->closefunc) CallCloseCallback (q, e);
187	    (void) XmuDQRemoveDisplay (q, dpy);
188	    if (q->nentries == 0 && q->freefunc) CallFreeCallback (q);
189	    return 1;
190	}
191    }
192
193    return 0;
194}
195