1 /*
2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1996-1999 by Internet Software Consortium
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 /* ev_waits.c - implement deferred function calls for the eventlib
19 * vix 05dec95 [initial]
20 */
21
22 #if !defined(LINT) && !defined(CODECENTER)
23 static const char rcsid[] = "$Id: ev_waits.c,v 1.4 2005/04/27 04:56:36 sra Exp $";
24 #endif
25
26 #include "port_before.h"
27 #include "fd_setsize.h"
28
29 #include <errno.h>
30
31 #include <isc/eventlib.h>
32 #include <isc/assertions.h>
33 #include "eventlib_p.h"
34
35 #include "port_after.h"
36
37 /* Forward. */
38
39 static void print_waits(evContext_p *ctx);
40 static evWaitList * evNewWaitList(evContext_p *);
41 static void evFreeWaitList(evContext_p *, evWaitList *);
42 static evWaitList * evGetWaitList(evContext_p *, const void *, int);
43
44
45 /* Public. */
46
47 /*%
48 * Enter a new wait function on the queue.
49 */
50 int
evWaitFor(evContext opaqueCtx,const void * tag,evWaitFunc func,void * uap,evWaitID * id)51 evWaitFor(evContext opaqueCtx, const void *tag,
52 evWaitFunc func, void *uap, evWaitID *id)
53 {
54 evContext_p *ctx = opaqueCtx.opaque;
55 evWait *new;
56 evWaitList *wl = evGetWaitList(ctx, tag, 1);
57
58 OKNEW(new);
59 new->func = func;
60 new->uap = uap;
61 new->tag = tag;
62 new->next = NULL;
63 if (wl->last != NULL)
64 wl->last->next = new;
65 else
66 wl->first = new;
67 wl->last = new;
68 if (id != NULL)
69 id->opaque = new;
70 if (ctx->debug >= 9)
71 print_waits(ctx);
72 return (0);
73 }
74
75 /*%
76 * Mark runnable all waiting functions having a certain tag.
77 */
78 int
evDo(evContext opaqueCtx,const void * tag)79 evDo(evContext opaqueCtx, const void *tag) {
80 evContext_p *ctx = opaqueCtx.opaque;
81 evWaitList *wl = evGetWaitList(ctx, tag, 0);
82 evWait *first;
83
84 if (!wl) {
85 errno = ENOENT;
86 return (-1);
87 }
88
89 first = wl->first;
90 INSIST(first != NULL);
91
92 if (ctx->waitDone.last != NULL)
93 ctx->waitDone.last->next = first;
94 else
95 ctx->waitDone.first = first;
96 ctx->waitDone.last = wl->last;
97 evFreeWaitList(ctx, wl);
98
99 return (0);
100 }
101
102 /*%
103 * Remove a waiting (or ready to run) function from the queue.
104 */
105 int
evUnwait(evContext opaqueCtx,evWaitID id)106 evUnwait(evContext opaqueCtx, evWaitID id) {
107 evContext_p *ctx = opaqueCtx.opaque;
108 evWait *this, *prev;
109 evWaitList *wl;
110 int found = 0;
111
112 this = id.opaque;
113 INSIST(this != NULL);
114 wl = evGetWaitList(ctx, this->tag, 0);
115 if (wl != NULL) {
116 for (prev = NULL, this = wl->first;
117 this != NULL;
118 prev = this, this = this->next)
119 if (this == (evWait *)id.opaque) {
120 found = 1;
121 if (prev != NULL)
122 prev->next = this->next;
123 else
124 wl->first = this->next;
125 if (wl->last == this)
126 wl->last = prev;
127 if (wl->first == NULL)
128 evFreeWaitList(ctx, wl);
129 break;
130 }
131 }
132
133 if (!found) {
134 /* Maybe it's done */
135 for (prev = NULL, this = ctx->waitDone.first;
136 this != NULL;
137 prev = this, this = this->next)
138 if (this == (evWait *)id.opaque) {
139 found = 1;
140 if (prev != NULL)
141 prev->next = this->next;
142 else
143 ctx->waitDone.first = this->next;
144 if (ctx->waitDone.last == this)
145 ctx->waitDone.last = prev;
146 break;
147 }
148 }
149
150 if (!found) {
151 errno = ENOENT;
152 return (-1);
153 }
154
155 FREE(this);
156
157 if (ctx->debug >= 9)
158 print_waits(ctx);
159
160 return (0);
161 }
162
163 int
evDefer(evContext opaqueCtx,evWaitFunc func,void * uap)164 evDefer(evContext opaqueCtx, evWaitFunc func, void *uap) {
165 evContext_p *ctx = opaqueCtx.opaque;
166 evWait *new;
167
168 OKNEW(new);
169 new->func = func;
170 new->uap = uap;
171 new->tag = NULL;
172 new->next = NULL;
173 if (ctx->waitDone.last != NULL)
174 ctx->waitDone.last->next = new;
175 else
176 ctx->waitDone.first = new;
177 ctx->waitDone.last = new;
178 if (ctx->debug >= 9)
179 print_waits(ctx);
180 return (0);
181 }
182
183 /* Private. */
184
185 static void
print_waits(evContext_p * ctx)186 print_waits(evContext_p *ctx) {
187 evWaitList *wl;
188 evWait *this;
189
190 evPrintf(ctx, 9, "wait waiting:\n");
191 for (wl = ctx->waitLists; wl != NULL; wl = wl->next) {
192 INSIST(wl->first != NULL);
193 evPrintf(ctx, 9, " tag %p:", wl->first->tag);
194 for (this = wl->first; this != NULL; this = this->next)
195 evPrintf(ctx, 9, " %p", this);
196 evPrintf(ctx, 9, "\n");
197 }
198 evPrintf(ctx, 9, "wait done:");
199 for (this = ctx->waitDone.first; this != NULL; this = this->next)
200 evPrintf(ctx, 9, " %p", this);
201 evPrintf(ctx, 9, "\n");
202 }
203
204 static evWaitList *
evNewWaitList(evContext_p * ctx)205 evNewWaitList(evContext_p *ctx) {
206 evWaitList *new;
207
208 NEW(new);
209 if (new == NULL)
210 return (NULL);
211 new->first = new->last = NULL;
212 new->prev = NULL;
213 new->next = ctx->waitLists;
214 if (new->next != NULL)
215 new->next->prev = new;
216 ctx->waitLists = new;
217 return (new);
218 }
219
220 static void
evFreeWaitList(evContext_p * ctx,evWaitList * this)221 evFreeWaitList(evContext_p *ctx, evWaitList *this) {
222
223 INSIST(this != NULL);
224
225 if (this->prev != NULL)
226 this->prev->next = this->next;
227 else
228 ctx->waitLists = this->next;
229 if (this->next != NULL)
230 this->next->prev = this->prev;
231 FREE(this);
232 }
233
234 static evWaitList *
evGetWaitList(evContext_p * ctx,const void * tag,int should_create)235 evGetWaitList(evContext_p *ctx, const void *tag, int should_create) {
236 evWaitList *this;
237
238 for (this = ctx->waitLists; this != NULL; this = this->next) {
239 if (this->first != NULL && this->first->tag == tag)
240 break;
241 }
242 if (this == NULL && should_create)
243 this = evNewWaitList(ctx);
244 return (this);
245 }
246
247 /*! \file */
248