1 /* Copyright (C) 1999 artofcode LLC. All rights reserved.
2
3 This program is free software; you can redistribute it and/or modify it
4 under the terms of the GNU General Public License as published by the
5 Free Software Foundation; either version 2 of the License, or (at your
6 option) any later version.
7
8 This program is distributed in the hope that it will be useful, but
9 WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 General Public License for more details.
12
13 You should have received a copy of the GNU General Public License along
14 with this program; if not, write to the Free Software Foundation, Inc.,
15 59 Temple Place, Suite 330, Boston, MA, 02111-1307.
16
17 */
18
19 /*$Id: gsnotify.c,v 1.2.6.1.2.1 2003/01/17 00:49:03 giles Exp $ */
20 /* Notification machinery implementation */
21 #include "gx.h"
22 #include "gserrors.h"
23 #include "gsstruct.h"
24 #include "gsnotify.h"
25
26 /* GC descriptors */
27 private_st_gs_notify_registration();
28 public_st_gs_notify_list();
29
30 /* Initialize a notification list. */
31 void
gs_notify_init(gs_notify_list_t * nlist,gs_memory_t * mem)32 gs_notify_init(gs_notify_list_t *nlist, gs_memory_t *mem)
33 {
34 nlist->first = 0;
35 nlist->memory = mem;
36 }
37
38 /* Register a client. */
39 int
gs_notify_register(gs_notify_list_t * nlist,gs_notify_proc_t proc,void * proc_data)40 gs_notify_register(gs_notify_list_t *nlist, gs_notify_proc_t proc,
41 void *proc_data)
42 {
43 gs_notify_registration_t *nreg =
44 gs_alloc_struct(nlist->memory, gs_notify_registration_t,
45 &st_gs_notify_registration, "gs_notify_register");
46
47 if (nreg == 0)
48 return_error(gs_error_VMerror);
49 nreg->proc = proc;
50 nreg->proc_data = proc_data;
51 nreg->next = nlist->first;
52 nlist->first = nreg;
53 return 0;
54 }
55
56 /*
57 * Unregister a client. Return 1 if the client was registered, 0 if not.
58 * If proc_data is 0, unregister all registrations of that proc; otherwise,
59 * unregister only the registration of that procedure with that proc_data.
60 */
61 private void
no_unreg_proc(void * pdata)62 no_unreg_proc(void *pdata)
63 {
64 }
65 int
gs_notify_unregister_calling(gs_notify_list_t * nlist,gs_notify_proc_t proc,void * proc_data,void (* unreg_proc)(P1 (void * pdata)))66 gs_notify_unregister_calling(gs_notify_list_t *nlist, gs_notify_proc_t proc,
67 void *proc_data,
68 void (*unreg_proc)(P1(void *pdata)))
69 {
70 gs_notify_registration_t **prev = &nlist->first;
71 gs_notify_registration_t *cur;
72 bool found = 0;
73
74 while ((cur = *prev) != 0)
75 if (cur->proc == proc &&
76 (proc_data == 0 || cur->proc_data == proc_data)
77 ) {
78 *prev = cur->next;
79 unreg_proc(cur->proc_data);
80 gs_free_object(nlist->memory, cur, "gs_notify_unregister");
81 found = 1;
82 } else
83 prev = &cur->next;
84 return found;
85 }
86 int
gs_notify_unregister(gs_notify_list_t * nlist,gs_notify_proc_t proc,void * proc_data)87 gs_notify_unregister(gs_notify_list_t *nlist, gs_notify_proc_t proc,
88 void *proc_data)
89 {
90 return gs_notify_unregister_calling(nlist, proc, proc_data, no_unreg_proc);
91 }
92
93 /*
94 * Notify the clients on a list. If an error occurs, return the first
95 * error code, but notify all clients regardless.
96 */
97 int
gs_notify_all(gs_notify_list_t * nlist,void * event_data)98 gs_notify_all(gs_notify_list_t *nlist, void *event_data)
99 {
100 gs_notify_registration_t *cur;
101 gs_notify_registration_t *next;
102 int ecode = 0;
103
104 for (next = nlist->first; (cur = next) != 0;) {
105 int code;
106
107 next = cur->next;
108 code = cur->proc(cur->proc_data, event_data);
109 if (code < 0 && ecode == 0)
110 ecode = code;
111 }
112 return ecode;
113 }
114
115 /* Release a notification list. */
116 void
gs_notify_release(gs_notify_list_t * nlist)117 gs_notify_release(gs_notify_list_t *nlist)
118 {
119 gs_memory_t *mem = nlist->memory;
120
121 while (nlist->first) {
122 gs_notify_registration_t *next = nlist->first->next;
123
124 gs_free_object(mem, nlist->first, "gs_notify_release");
125 nlist->first = next;
126 }
127 }
128