1 /* $NetBSD: ev_waits.c,v 1.1.1.2 2012/09/09 16:08:02 christos Exp $ */
2
3 /*
4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
5 * Copyright (c) 1996-1999 by Internet Software Consortium
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20 /* ev_waits.c - implement deferred function calls for the eventlib
21 * vix 05dec95 [initial]
22 */
23
24 #if !defined(LINT) && !defined(CODECENTER)
25 static const char rcsid[] = "Id: ev_waits.c,v 1.4 2005/04/27 04:56:36 sra Exp ";
26 #endif
27
28 #include "port_before.h"
29 #include "fd_setsize.h"
30
31 #include <errno.h>
32
33 #include <isc/eventlib.h>
34 #include <isc/assertions.h>
35 #include "eventlib_p.h"
36
37 #include "port_after.h"
38
39 /* Forward. */
40
41 static void print_waits(evContext_p *ctx);
42 static evWaitList * evNewWaitList(evContext_p *);
43 static void evFreeWaitList(evContext_p *, evWaitList *);
44 static evWaitList * evGetWaitList(evContext_p *, const void *, int);
45
46
47 /* Public. */
48
49 /*%
50 * Enter a new wait function on the queue.
51 */
52 int
evWaitFor(evContext opaqueCtx,const void * tag,evWaitFunc func,void * uap,evWaitID * id)53 evWaitFor(evContext opaqueCtx, const void *tag,
54 evWaitFunc func, void *uap, evWaitID *id)
55 {
56 evContext_p *ctx = opaqueCtx.opaque;
57 evWait *new;
58 evWaitList *wl = evGetWaitList(ctx, tag, 1);
59
60 OKNEW(new);
61 new->func = func;
62 new->uap = uap;
63 new->tag = tag;
64 new->next = NULL;
65 if (wl->last != NULL)
66 wl->last->next = new;
67 else
68 wl->first = new;
69 wl->last = new;
70 if (id != NULL)
71 id->opaque = new;
72 if (ctx->debug >= 9)
73 print_waits(ctx);
74 return (0);
75 }
76
77 /*%
78 * Mark runnable all waiting functions having a certain tag.
79 */
80 int
evDo(evContext opaqueCtx,const void * tag)81 evDo(evContext opaqueCtx, const void *tag) {
82 evContext_p *ctx = opaqueCtx.opaque;
83 evWaitList *wl = evGetWaitList(ctx, tag, 0);
84 evWait *first;
85
86 if (!wl) {
87 errno = ENOENT;
88 return (-1);
89 }
90
91 first = wl->first;
92 INSIST(first != NULL);
93
94 if (ctx->waitDone.last != NULL)
95 ctx->waitDone.last->next = first;
96 else
97 ctx->waitDone.first = first;
98 ctx->waitDone.last = wl->last;
99 evFreeWaitList(ctx, wl);
100
101 return (0);
102 }
103
104 /*%
105 * Remove a waiting (or ready to run) function from the queue.
106 */
107 int
evUnwait(evContext opaqueCtx,evWaitID id)108 evUnwait(evContext opaqueCtx, evWaitID id) {
109 evContext_p *ctx = opaqueCtx.opaque;
110 evWait *this, *prev;
111 evWaitList *wl;
112 int found = 0;
113
114 this = id.opaque;
115 INSIST(this != NULL);
116 wl = evGetWaitList(ctx, this->tag, 0);
117 if (wl != NULL) {
118 for (prev = NULL, this = wl->first;
119 this != NULL;
120 prev = this, this = this->next)
121 if (this == (evWait *)id.opaque) {
122 found = 1;
123 if (prev != NULL)
124 prev->next = this->next;
125 else
126 wl->first = this->next;
127 if (wl->last == this)
128 wl->last = prev;
129 if (wl->first == NULL)
130 evFreeWaitList(ctx, wl);
131 break;
132 }
133 }
134
135 if (!found) {
136 /* Maybe it's done */
137 for (prev = NULL, this = ctx->waitDone.first;
138 this != NULL;
139 prev = this, this = this->next)
140 if (this == (evWait *)id.opaque) {
141 found = 1;
142 if (prev != NULL)
143 prev->next = this->next;
144 else
145 ctx->waitDone.first = this->next;
146 if (ctx->waitDone.last == this)
147 ctx->waitDone.last = prev;
148 break;
149 }
150 }
151
152 if (!found) {
153 errno = ENOENT;
154 return (-1);
155 }
156
157 FREE(this);
158
159 if (ctx->debug >= 9)
160 print_waits(ctx);
161
162 return (0);
163 }
164
165 int
evDefer(evContext opaqueCtx,evWaitFunc func,void * uap)166 evDefer(evContext opaqueCtx, evWaitFunc func, void *uap) {
167 evContext_p *ctx = opaqueCtx.opaque;
168 evWait *new;
169
170 OKNEW(new);
171 new->func = func;
172 new->uap = uap;
173 new->tag = NULL;
174 new->next = NULL;
175 if (ctx->waitDone.last != NULL)
176 ctx->waitDone.last->next = new;
177 else
178 ctx->waitDone.first = new;
179 ctx->waitDone.last = new;
180 if (ctx->debug >= 9)
181 print_waits(ctx);
182 return (0);
183 }
184
185 /* Private. */
186
187 static void
print_waits(evContext_p * ctx)188 print_waits(evContext_p *ctx) {
189 evWaitList *wl;
190 evWait *this;
191
192 evPrintf(ctx, 9, "wait waiting:\n");
193 for (wl = ctx->waitLists; wl != NULL; wl = wl->next) {
194 INSIST(wl->first != NULL);
195 evPrintf(ctx, 9, " tag %p:", wl->first->tag);
196 for (this = wl->first; this != NULL; this = this->next)
197 evPrintf(ctx, 9, " %p", this);
198 evPrintf(ctx, 9, "\n");
199 }
200 evPrintf(ctx, 9, "wait done:");
201 for (this = ctx->waitDone.first; this != NULL; this = this->next)
202 evPrintf(ctx, 9, " %p", this);
203 evPrintf(ctx, 9, "\n");
204 }
205
206 static evWaitList *
evNewWaitList(evContext_p * ctx)207 evNewWaitList(evContext_p *ctx) {
208 evWaitList *new;
209
210 NEW(new);
211 if (new == NULL)
212 return (NULL);
213 new->first = new->last = NULL;
214 new->prev = NULL;
215 new->next = ctx->waitLists;
216 if (new->next != NULL)
217 new->next->prev = new;
218 ctx->waitLists = new;
219 return (new);
220 }
221
222 static void
evFreeWaitList(evContext_p * ctx,evWaitList * this)223 evFreeWaitList(evContext_p *ctx, evWaitList *this) {
224
225 INSIST(this != NULL);
226
227 if (this->prev != NULL)
228 this->prev->next = this->next;
229 else
230 ctx->waitLists = this->next;
231 if (this->next != NULL)
232 this->next->prev = this->prev;
233 FREE(this);
234 }
235
236 static evWaitList *
evGetWaitList(evContext_p * ctx,const void * tag,int should_create)237 evGetWaitList(evContext_p *ctx, const void *tag, int should_create) {
238 evWaitList *this;
239
240 for (this = ctx->waitLists; this != NULL; this = this->next) {
241 if (this->first != NULL && this->first->tag == tag)
242 break;
243 }
244 if (this == NULL && should_create)
245 this = evNewWaitList(ctx);
246 return (this);
247 }
248
249 /*! \file */
250