Bug Summary

File:src/usr.bin/dig/lib/isc/task.c
Warning:line 496, column 3
Use of memory after it is freed

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name task.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model pic -pic-level 1 -pic-is-pie -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/usr.bin/dig/obj -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/usr.bin/dig -I /usr/src/usr.bin/dig/obj -I /usr/src/usr.bin/dig/bin/dig/include -I /usr/src/usr.bin/dig/lib/dns/include -I /usr/src/usr.bin/dig/lib/isc/include -I /usr/src/usr.bin/dig/lib/isccfg/include -I /usr/src/usr.bin/dig/lib/lwres/include -D VERSION="9.10.8-P1" -internal-isystem /usr/local/lib/clang/13.0.0/include -internal-externc-isystem /usr/include -O2 -fdebug-compilation-dir=/usr/src/usr.bin/dig/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /home/ben/Projects/vmm/scan-build/2022-01-12-194120-40624-1 -x c /usr/src/usr.bin/dig/lib/isc/task.c
1/*
2 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
3 *
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
9 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
10 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
11 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
12 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
13 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
14 * PERFORMANCE OF THIS SOFTWARE.
15 */
16
17/*! \file
18 * \author Principal Author: Bob Halley
19 */
20
21/*
22 * XXXRTH Need to document the states a task can be in, and the rules
23 * for changing states.
24 */
25
26#include <stdlib.h>
27#include <string.h>
28#include <time.h>
29
30#include <isc/event.h>
31#include <isc/task.h>
32#include <isc/util.h>
33
34#include "task_p.h"
35
36/***
37 *** Types.
38 ***/
39
40typedef enum {
41 task_state_idle, task_state_ready, task_state_running,
42 task_state_done
43} task_state_t;
44
45struct isc_task {
46 /* Not locked. */
47 isc_taskmgr_t * manager;
48 /* Locked by task lock. */
49 task_state_t state;
50 unsigned int references;
51 isc_eventlist_t events;
52 isc_eventlist_t on_shutdown;
53 unsigned int nevents;
54 unsigned int quantum;
55 unsigned int flags;
56 time_t now;
57 char name[16];
58 void * tag;
59 /* Locked by task manager lock. */
60 LINK(isc_task_t)struct { isc_task_t *prev, *next; } link;
61 LINK(isc_task_t)struct { isc_task_t *prev, *next; } ready_link;
62 LINK(isc_task_t)struct { isc_task_t *prev, *next; } ready_priority_link;
63};
64
65#define TASK_F_SHUTTINGDOWN0x01 0x01
66#define TASK_F_PRIVILEGED0x02 0x02
67
68#define TASK_SHUTTINGDOWN(t)(((t)->flags & 0x01) != 0) (((t)->flags & TASK_F_SHUTTINGDOWN0x01) \
69 != 0)
70
71typedef ISC_LIST(isc_task_t)struct { isc_task_t *head, *tail; } isc_tasklist_t;
72
73struct isc_taskmgr {
74 /* Not locked. */
75 /* Locked by task manager lock. */
76 unsigned int default_quantum;
77 LIST(isc_task_t)struct { isc_task_t *head, *tail; } tasks;
78 isc_tasklist_t ready_tasks;
79 isc_tasklist_t ready_priority_tasks;
80 isc_taskmgrmode_t mode;
81 unsigned int tasks_running;
82 unsigned int tasks_ready;
83 int pause_requested;
84 int exclusive_requested;
85 int exiting;
86
87 /*
88 * Multiple threads can read/write 'excl' at the same time, so we need
89 * to protect the access. We can't use 'lock' since isc_task_detach()
90 * will try to acquire it.
91 */
92 isc_task_t *excl;
93 unsigned int refs;
94};
95
96#define DEFAULT_TASKMGR_QUANTUM10 10
97#define DEFAULT_DEFAULT_QUANTUM5 5
98#define FINISHED(m)((m)->exiting && (((m)->tasks).head == ((void *
)0))) ((m)->exiting && EMPTY((m)->tasks)(((m)->tasks).head == ((void *)0)))
99
100static isc_taskmgr_t *taskmgr = NULL((void *)0);
101
102static inline int
103empty_readyq(isc_taskmgr_t *manager);
104
105static inline isc_task_t *
106pop_readyq(isc_taskmgr_t *manager);
107
108static inline void
109push_readyq(isc_taskmgr_t *manager, isc_task_t *task);
110
111/***
112 *** Tasks.
113 ***/
114
115static void
116task_finished(isc_task_t *task) {
117 isc_taskmgr_t *manager = task->manager;
118
119 REQUIRE(EMPTY(task->events))((void) ((((task->events).head == ((void *)0))) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 119, isc_assertiontype_require
, "((task->events).head == ((void *)0))"), 0)));
120 REQUIRE(task->nevents == 0)((void) ((task->nevents == 0) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 120, isc_assertiontype_require, "task->nevents == 0"), 0
)));
32
←
Assuming field 'nevents' is equal to 0
→
121 REQUIRE(EMPTY(task->on_shutdown))((void) ((((task->on_shutdown).head == ((void *)0))) || ((
isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c", 121
, isc_assertiontype_require, "((task->on_shutdown).head == ((void *)0))"
), 0)));
33
←
Assuming field 'head' is equal to null
→
122 REQUIRE(task->references == 0)((void) ((task->references == 0) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 122, isc_assertiontype_require
, "task->references == 0"), 0)));
123 REQUIRE(task->state == task_state_done)((void) ((task->state == task_state_done) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 123, isc_assertiontype_require
, "task->state == task_state_done"), 0)));
124
125 UNLINK(manager->tasks, task, link)do { do { if ((task)->link.next != ((void *)0)) (task)->
link.next->link.prev = (task)->link.prev; else { ((void
) (((manager->tasks).tail == (task)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 125, isc_assertiontype_insist
, "(manager->tasks).tail == (task)"), 0))); (manager->tasks
).tail = (task)->link.prev; } if ((task)->link.prev != (
(void *)0)) (task)->link.prev->link.next = (task)->link
.next; else { ((void) (((manager->tasks).head == (task)) ||
((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 125, isc_assertiontype_insist, "(manager->tasks).head == (task)"
), 0))); (manager->tasks).head = (task)->link.next; } (
task)->link.prev = (void *)(-1); (task)->link.next = (void
*)(-1); ((void) (((manager->tasks).head != (task)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 125, isc_assertiontype_insist
, "(manager->tasks).head != (task)"), 0))); ((void) (((manager
->tasks).tail != (task)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 125, isc_assertiontype_insist, "(manager->tasks).tail != (task)"
), 0))); } while (0); } while (0);
34
←
Assuming field 'next' is not equal to null
→
35
←
Taking true branch
→
36
←
Assuming field 'prev' is not equal to null
→
37
←
Taking true branch
→
38
←
Assuming 'task' is not equal to field 'head'
→
39
←
Assuming 'task' is not equal to field 'tail'
→
40
←
Loop condition is false. Exiting loop
→
41
←
Loop condition is false. Exiting loop
→
126
127 free(task);
42
←
Memory is released
→
128}
129
130isc_result_t
131isc_task_create(isc_taskmgr_t *manager, unsigned int quantum,
132 isc_task_t **taskp)
133{
134 isc_task_t *task;
135 int exiting;
136
137 REQUIRE(taskp != NULL && *taskp == NULL)((void) ((taskp != ((void *)0) && *taskp == ((void *)
0)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 137, isc_assertiontype_require, "taskp != ((void *)0) && *taskp == ((void *)0)"
), 0)));
138
139 task = malloc(sizeof(*task));
140 if (task == NULL((void *)0))
141 return (ISC_R_NOMEMORY1);
142 task->manager = manager;
143 task->state = task_state_idle;
144 task->references = 1;
145 INIT_LIST(task->events)do { (task->events).head = ((void *)0); (task->events).
tail = ((void *)0); } while (0);
146 INIT_LIST(task->on_shutdown)do { (task->on_shutdown).head = ((void *)0); (task->on_shutdown
).tail = ((void *)0); } while (0);
147 task->nevents = 0;
148 task->quantum = quantum;
149 task->flags = 0;
150 task->now = 0;
151 memset(task->name, 0, sizeof(task->name));
152 task->tag = NULL((void *)0);
153 INIT_LINK(task, link)do { (task)->link.prev = (void *)(-1); (task)->link.next
= (void *)(-1); } while (0);
154 INIT_LINK(task, ready_link)do { (task)->ready_link.prev = (void *)(-1); (task)->ready_link
.next = (void *)(-1); } while (0);
155 INIT_LINK(task, ready_priority_link)do { (task)->ready_priority_link.prev = (void *)(-1); (task
)->ready_priority_link.next = (void *)(-1); } while (0);
156
157 exiting = 0;
158 if (!manager->exiting) {
159 if (task->quantum == 0)
160 task->quantum = manager->default_quantum;
161 APPEND(manager->tasks, task, link)do { do { if ((manager->tasks).tail != ((void *)0)) (manager
->tasks).tail->link.next = (task); else (manager->tasks
).head = (task); (task)->link.prev = (manager->tasks).tail
; (task)->link.next = ((void *)0); (manager->tasks).tail
= (task); } while (0); } while (0);
162 } else
163 exiting = 1;
164
165 if (exiting) {
166 free(task);
167 return (ISC_R_SHUTTINGDOWN22);
168 }
169
170 *taskp = (isc_task_t *)task;
171 return (ISC_R_SUCCESS0);
172}
173
174void
175isc_task_attach(isc_task_t *source0, isc_task_t **targetp) {
176 isc_task_t *source = (isc_task_t *)source0;
177
178 /*
179 * Attach *targetp to source.
180 */
181
182 REQUIRE(targetp != NULL && *targetp == NULL)((void) ((targetp != ((void *)0) && *targetp == ((void
*)0)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 182, isc_assertiontype_require, "targetp != ((void *)0) && *targetp == ((void *)0)"
), 0)));
183
184 source->references++;
185
186 *targetp = (isc_task_t *)source;
187}
188
189static inline int
190task_shutdown(isc_task_t *task) {
191 int was_idle = 0;
192 isc_event_t *event, *prev;
193
194 /*
195 * Caller must be holding the task's lock.
196 */
197
198 if (! TASK_SHUTTINGDOWN(task)(((task)->flags & 0x01) != 0)) {
199 task->flags |= TASK_F_SHUTTINGDOWN0x01;
200 if (task->state == task_state_idle) {
201 INSIST(EMPTY(task->events))((void) ((((task->events).head == ((void *)0))) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 201, isc_assertiontype_insist
, "((task->events).head == ((void *)0))"), 0)));
202 task->state = task_state_ready;
203 was_idle = 1;
204 }
205 INSIST(task->state == task_state_ready ||((void) ((task->state == task_state_ready || task->state
== task_state_running) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 206, isc_assertiontype_insist, "task->state == task_state_ready || task->state == task_state_running"
), 0)))
206 task->state == task_state_running)((void) ((task->state == task_state_ready || task->state
== task_state_running) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 206, isc_assertiontype_insist, "task->state == task_state_ready || task->state == task_state_running"
), 0)));
207
208 /*
209 * Note that we post shutdown events LIFO.
210 */
211 for (event = TAIL(task->on_shutdown)((task->on_shutdown).tail);
212 event != NULL((void *)0);
213 event = prev) {
214 prev = PREV(event, ev_link)((event)->ev_link.prev);
215 DEQUEUE(task->on_shutdown, event, ev_link)do { do { if ((event)->ev_link.next != ((void *)0)) (event
)->ev_link.next->ev_link.prev = (event)->ev_link.prev
; else { ((void) (((task->on_shutdown).tail == (event)) ||
((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 215, isc_assertiontype_insist, "(task->on_shutdown).tail == (event)"
), 0))); (task->on_shutdown).tail = (event)->ev_link.prev
; } if ((event)->ev_link.prev != ((void *)0)) (event)->
ev_link.prev->ev_link.next = (event)->ev_link.next; else
{ ((void) (((task->on_shutdown).head == (event)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 215, isc_assertiontype_insist
, "(task->on_shutdown).head == (event)"), 0))); (task->
on_shutdown).head = (event)->ev_link.next; } (event)->ev_link
.prev = (void *)(-1); (event)->ev_link.next = (void *)(-1)
; ((void) (((task->on_shutdown).head != (event)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 215, isc_assertiontype_insist
, "(task->on_shutdown).head != (event)"), 0))); ((void) ((
(task->on_shutdown).tail != (event)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 215, isc_assertiontype_insist
, "(task->on_shutdown).tail != (event)"), 0))); } while (0
); } while (0);
216 ENQUEUE(task->events, event, ev_link)do { do { if ((task->events).tail != ((void *)0)) (task->
events).tail->ev_link.next = (event); else (task->events
).head = (event); (event)->ev_link.prev = (task->events
).tail; (event)->ev_link.next = ((void *)0); (task->events
).tail = (event); } while (0); } while (0);
217 task->nevents++;
218 }
219 }
220
221 return (was_idle);
222}
223
224/*
225 * Moves a task onto the appropriate run queue.
226 *
227 * Caller must NOT hold manager lock.
228 */
229static inline void
230task_ready(isc_task_t *task) {
231 isc_taskmgr_t *manager = task->manager;
232
233 REQUIRE(task->state == task_state_ready)((void) ((task->state == task_state_ready) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 233, isc_assertiontype_require
, "task->state == task_state_ready"), 0)));
234
235 push_readyq(manager, task);
236}
237
238static inline int
239task_detach(isc_task_t *task) {
240
241 /*
242 * Caller must be holding the task lock.
243 */
244
245 REQUIRE(task->references > 0)((void) ((task->references > 0) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 245, isc_assertiontype_require
, "task->references > 0"), 0)));
246
247 task->references--;
248 if (task->references == 0 && task->state == task_state_idle) {
249 INSIST(EMPTY(task->events))((void) ((((task->events).head == ((void *)0))) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 249, isc_assertiontype_insist
, "((task->events).head == ((void *)0))"), 0)));
250 /*
251 * There are no references to this task, and no
252 * pending events. We could try to optimize and
253 * either initiate shutdown or clean up the task,
254 * depending on its state, but it's easier to just
255 * make the task ready and allow run() or the event
256 * loop to deal with shutting down and termination.
257 */
258 task->state = task_state_ready;
259 return (1);
260 }
261
262 return (0);
263}
264
265void
266isc_task_detach(isc_task_t **taskp) {
267 isc_task_t *task;
268 int was_idle;
269
270 /*
271 * Detach *taskp from its task.
272 */
273
274 REQUIRE(taskp != NULL)((void) ((taskp != ((void *)0)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 274, isc_assertiontype_require, "taskp != ((void *)0)"), 0)
));
275 task = (isc_task_t *)*taskp;
276
277 was_idle = task_detach(task);
278
279 if (was_idle)
280 task_ready(task);
281
282 *taskp = NULL((void *)0);
283}
284
285static inline int
286task_send(isc_task_t *task, isc_event_t **eventp) {
287 int was_idle = 0;
288 isc_event_t *event;
289
290 /*
291 * Caller must be holding the task lock.
292 */
293
294 REQUIRE(eventp != NULL)((void) ((eventp != ((void *)0)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 294, isc_assertiontype_require, "eventp != ((void *)0)"), 0
)));
295 event = *eventp;
296 REQUIRE(event != NULL)((void) ((event != ((void *)0)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 296, isc_assertiontype_require, "event != ((void *)0)"), 0)
));
297 REQUIRE(event->ev_type > 0)((void) ((event->ev_type > 0) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 297, isc_assertiontype_require
, "event->ev_type > 0"), 0)));
298 REQUIRE(task->state != task_state_done)((void) ((task->state != task_state_done) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 298, isc_assertiontype_require
, "task->state != task_state_done"), 0)));
299 REQUIRE(!ISC_LINK_LINKED(event, ev_ratelink))((void) ((!((void *)((event)->ev_ratelink.prev) != (void *
)(-1))) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 299, isc_assertiontype_require, "!((void *)((event)->ev_ratelink.prev) != (void *)(-1))"
), 0)));
300
301 if (task->state == task_state_idle) {
302 was_idle = 1;
303 INSIST(EMPTY(task->events))((void) ((((task->events).head == ((void *)0))) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 303, isc_assertiontype_insist
, "((task->events).head == ((void *)0))"), 0)));
304 task->state = task_state_ready;
305 }
306 INSIST(task->state == task_state_ready ||((void) ((task->state == task_state_ready || task->state
== task_state_running) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 307, isc_assertiontype_insist, "task->state == task_state_ready || task->state == task_state_running"
), 0)))
307 task->state == task_state_running)((void) ((task->state == task_state_ready || task->state
== task_state_running) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 307, isc_assertiontype_insist, "task->state == task_state_ready || task->state == task_state_running"
), 0)));
308 ENQUEUE(task->events, event, ev_link)do { do { if ((task->events).tail != ((void *)0)) (task->
events).tail->ev_link.next = (event); else (task->events
).head = (event); (event)->ev_link.prev = (task->events
).tail; (event)->ev_link.next = ((void *)0); (task->events
).tail = (event); } while (0); } while (0);
309 task->nevents++;
310 *eventp = NULL((void *)0);
311
312 return (was_idle);
313}
314
315void
316isc_task_send(isc_task_t *task, isc_event_t **eventp) {
317 int was_idle;
318
319 /*
320 * Send '*event' to 'task'.
321 */
322
323 /*
324 * We're trying hard to hold locks for as short a time as possible.
325 * We're also trying to hold as few locks as possible. This is why
326 * some processing is deferred until after the lock is released.
327 */
328 was_idle = task_send(task, eventp);
329
330 if (was_idle) {
331 /*
332 * We need to add this task to the ready queue.
333 *
334 * We've waited until now to do it because making a task
335 * ready requires locking the manager. If we tried to do
336 * this while holding the task lock, we could deadlock.
337 *
338 * We've changed the state to ready, so no one else will
339 * be trying to add this task to the ready queue. The
340 * only way to leave the ready state is by executing the
341 * task. It thus doesn't matter if events are added,
342 * removed, or a shutdown is started in the interval
343 * between the time we released the task lock, and the time
344 * we add the task to the ready queue.
345 */
346 task_ready(task);
347 }
348}
349
350void
351isc_task_sendanddetach(isc_task_t **taskp, isc_event_t **eventp) {
352 int idle1, idle2;
353 isc_task_t *task;
354
355 /*
356 * Send '*event' to '*taskp' and then detach '*taskp' from its
357 * task.
358 */
359
360 REQUIRE(taskp != NULL)((void) ((taskp != ((void *)0)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 360, isc_assertiontype_require, "taskp != ((void *)0)"), 0)
));
361 task = (isc_task_t *)*taskp;
362
363 idle1 = task_send(task, eventp);
364 idle2 = task_detach(task);
365
366 /*
367 * If idle1, then idle2 shouldn't be true as well since we're holding
368 * the task lock, and thus the task cannot switch from ready back to
369 * idle.
370 */
371 INSIST(!(idle1 && idle2))((void) ((!(idle1 && idle2)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 371, isc_assertiontype_insist
, "!(idle1 && idle2)"), 0)));
372
373 if (idle1 || idle2)
374 task_ready(task);
375
376 *taskp = NULL((void *)0);
377}
378
379#define PURGE_OK(event)(((event)->ev_attributes & 0x00000001) == 0) (((event)->ev_attributes & ISC_EVENTATTR_NOPURGE0x00000001) == 0)
380
381static unsigned int
382dequeue_events(isc_task_t *task, void *sender, isc_eventtype_t first,
383 isc_eventtype_t last, void *tag,
384 isc_eventlist_t *events, int purging)
385{
386 isc_event_t *event, *next_event;
387 unsigned int count = 0;
388
389 REQUIRE(last >= first)((void) ((last >= first) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 389, isc_assertiontype_require, "last >= first"), 0)));
390
391 /*
392 * Events matching 'sender', whose type is >= first and <= last, and
393 * whose tag is 'tag' will be dequeued. If 'purging', matching events
394 * which are marked as unpurgable will not be dequeued.
395 *
396 * sender == NULL means "any sender", and tag == NULL means "any tag".
397 */
398
399 for (event = HEAD(task->events)((task->events).head); event != NULL((void *)0); event = next_event) {
400 next_event = NEXT(event, ev_link)((event)->ev_link.next);
401 if (event->ev_type >= first && event->ev_type <= last &&
402 (sender == NULL((void *)0) || event->ev_sender == sender) &&
403 (tag == NULL((void *)0) || event->ev_tag == tag) &&
404 (!purging || PURGE_OK(event)(((event)->ev_attributes & 0x00000001) == 0))) {
405 DEQUEUE(task->events, event, ev_link)do { do { if ((event)->ev_link.next != ((void *)0)) (event
)->ev_link.next->ev_link.prev = (event)->ev_link.prev
; else { ((void) (((task->events).tail == (event)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 405, isc_assertiontype_insist
, "(task->events).tail == (event)"), 0))); (task->events
).tail = (event)->ev_link.prev; } if ((event)->ev_link.
prev != ((void *)0)) (event)->ev_link.prev->ev_link.next
= (event)->ev_link.next; else { ((void) (((task->events
).head == (event)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 405, isc_assertiontype_insist, "(task->events).head == (event)"
), 0))); (task->events).head = (event)->ev_link.next; }
(event)->ev_link.prev = (void *)(-1); (event)->ev_link
.next = (void *)(-1); ((void) (((task->events).head != (event
)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 405, isc_assertiontype_insist, "(task->events).head != (event)"
), 0))); ((void) (((task->events).tail != (event)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 405, isc_assertiontype_insist
, "(task->events).tail != (event)"), 0))); } while (0); } while
(0);
406 task->nevents--;
407 ENQUEUE(*events, event, ev_link)do { do { if ((*events).tail != ((void *)0)) (*events).tail->
ev_link.next = (event); else (*events).head = (event); (event
)->ev_link.prev = (*events).tail; (event)->ev_link.next
= ((void *)0); (*events).tail = (event); } while (0); } while
(0);
408 count++;
409 }
410 }
411
412 return (count);
413}
414
415unsigned int
416isc_task_purgerange(isc_task_t *task, void *sender, isc_eventtype_t first,
417 isc_eventtype_t last, void *tag)
418{
419 unsigned int count;
420 isc_eventlist_t events;
421 isc_event_t *event, *next_event;
422
423 /*
424 * Purge events from a task's event queue.
425 */
426
427 ISC_LIST_INIT(events)do { (events).head = ((void *)0); (events).tail = ((void *)0)
; } while (0);
428
429 count = dequeue_events(task, sender, first, last, tag, &events,
430 1);
431
432 for (event = HEAD(events)((events).head); event != NULL((void *)0); event = next_event) {
433 next_event = NEXT(event, ev_link)((event)->ev_link.next);
434 ISC_LIST_UNLINK(events, event, ev_link)do { do { if ((event)->ev_link.next != ((void *)0)) (event
)->ev_link.next->ev_link.prev = (event)->ev_link.prev
; else { ((void) (((events).tail == (event)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 434, isc_assertiontype_insist
, "(events).tail == (event)"), 0))); (events).tail = (event)->
ev_link.prev; } if ((event)->ev_link.prev != ((void *)0)) (
event)->ev_link.prev->ev_link.next = (event)->ev_link
.next; else { ((void) (((events).head == (event)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 434, isc_assertiontype_insist
, "(events).head == (event)"), 0))); (events).head = (event)->
ev_link.next; } (event)->ev_link.prev = (void *)(-1); (event
)->ev_link.next = (void *)(-1); ((void) (((events).head !=
(event)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 434, isc_assertiontype_insist, "(events).head != (event)"),
0))); ((void) (((events).tail != (event)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 434, isc_assertiontype_insist
, "(events).tail != (event)"), 0))); } while (0); } while (0);
435 isc_event_free(&event);
436 }
437
438 /*
439 * Note that purging never changes the state of the task.
440 */
441
442 return (count);
443}
444
445void
446isc_task_setname(isc_task_t *task, const char *name, void *tag) {
447 /*
448 * Name 'task'.
449 */
450
451 strlcpy(task->name, name, sizeof(task->name));
452 task->tag = tag;
453}
454
455/***
456 *** Task Manager.
457 ***/
458
459/*
460 * Return 1 if the current ready list for the manager, which is
461 * either ready_tasks or the ready_priority_tasks, depending on whether
462 * the manager is currently in normal or privileged execution mode.
463 *
464 * Caller must hold the task manager lock.
465 */
466static inline int
467empty_readyq(isc_taskmgr_t *manager) {
468 isc_tasklist_t queue;
469
470 if (manager->mode == isc_taskmgrmode_normal)
471 queue = manager->ready_tasks;
472 else
473 queue = manager->ready_priority_tasks;
474
475 return (EMPTY(queue)((queue).head == ((void *)0)));
476}
477
478/*
479 * Dequeue and return a pointer to the first task on the current ready
480 * list for the manager.
481 * If the task is privileged, dequeue it from the other ready list
482 * as well.
483 *
484 * Caller must hold the task manager lock.
485 */
486static inline isc_task_t *
487pop_readyq(isc_taskmgr_t *manager) {
488 isc_task_t *task;
489
490 if (manager->mode
6.1
Field 'mode' is not equal to isc_taskmgrmode_normal
47.1
Field 'mode' is not equal to isc_taskmgrmode_normal
 == isc_taskmgrmode_normal)
7
←
Taking false branch
→
48
←
Taking false branch
→
491 task = HEAD(manager->ready_tasks)((manager->ready_tasks).head);
492 else
493 task = HEAD(manager->ready_priority_tasks)((manager->ready_priority_tasks).head);
494
495 if (task
7.1
'task' is not equal to NULL
48.1
'task' is not equal to NULL
 != NULL((void *)0)) {
8
←
Taking true branch
→
49
←
Taking true branch
→
496 DEQUEUE(manager->ready_tasks, task, ready_link)do { do { if ((task)->ready_link.next != ((void *)0)) (task
)->ready_link.next->ready_link.prev = (task)->ready_link
.prev; else { ((void) (((manager->ready_tasks).tail == (task
)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 496, isc_assertiontype_insist, "(manager->ready_tasks).tail == (task)"
), 0))); (manager->ready_tasks).tail = (task)->ready_link
.prev; } if ((task)->ready_link.prev != ((void *)0)) (task
)->ready_link.prev->ready_link.next = (task)->ready_link
.next; else { ((void) (((manager->ready_tasks).head == (task
)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 496, isc_assertiontype_insist, "(manager->ready_tasks).head == (task)"
), 0))); (manager->ready_tasks).head = (task)->ready_link
.next; } (task)->ready_link.prev = (void *)(-1); (task)->
ready_link.next = (void *)(-1); ((void) (((manager->ready_tasks
).head != (task)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 496, isc_assertiontype_insist, "(manager->ready_tasks).head != (task)"
), 0))); ((void) (((manager->ready_tasks).tail != (task)) ||
((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 496, isc_assertiontype_insist, "(manager->ready_tasks).tail != (task)"
), 0))); } while (0); } while (0);
9
←
Assuming field 'next' is equal to null
→
10
←
Taking false branch
→
11
←
Assuming 'task' is equal to field 'tail'
→
12
←
Assuming field 'prev' is equal to null
→
13
←
Taking false branch
→
14
←
Assuming 'task' is equal to field 'head'
→
15
←
Loop condition is false. Exiting loop
→
16
←
Loop condition is false. Exiting loop
→
50
←
Use of memory after it is freed
497 if (ISC_LINK_LINKED(task, ready_priority_link)((void *)((task)->ready_priority_link.prev) != (void *)(-1
)))
17
←
Assuming the condition is false
→
18
←
Taking false branch
→
498 DEQUEUE(manager->ready_priority_tasks, task,do { do { if ((task)->ready_priority_link.next != ((void *
)0)) (task)->ready_priority_link.next->ready_priority_link
.prev = (task)->ready_priority_link.prev; else { ((void) (
((manager->ready_priority_tasks).tail == (task)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 499, isc_assertiontype_insist
, "(manager->ready_priority_tasks).tail == (task)"), 0)));
(manager->ready_priority_tasks).tail = (task)->ready_priority_link
.prev; } if ((task)->ready_priority_link.prev != ((void *)
0)) (task)->ready_priority_link.prev->ready_priority_link
.next = (task)->ready_priority_link.next; else { ((void) (
((manager->ready_priority_tasks).head == (task)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 499, isc_assertiontype_insist
, "(manager->ready_priority_tasks).head == (task)"), 0)));
(manager->ready_priority_tasks).head = (task)->ready_priority_link
.next; } (task)->ready_priority_link.prev = (void *)(-1); (
task)->ready_priority_link.next = (void *)(-1); ((void) ((
(manager->ready_priority_tasks).head != (task)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 499, isc_assertiontype_insist
, "(manager->ready_priority_tasks).head != (task)"), 0)));
((void) (((manager->ready_priority_tasks).tail != (task))
|| ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 499, isc_assertiontype_insist, "(manager->ready_priority_tasks).tail != (task)"
), 0))); } while (0); } while (0)
499 ready_priority_link)do { do { if ((task)->ready_priority_link.next != ((void *
)0)) (task)->ready_priority_link.next->ready_priority_link
.prev = (task)->ready_priority_link.prev; else { ((void) (
((manager->ready_priority_tasks).tail == (task)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 499, isc_assertiontype_insist
, "(manager->ready_priority_tasks).tail == (task)"), 0)));
(manager->ready_priority_tasks).tail = (task)->ready_priority_link
.prev; } if ((task)->ready_priority_link.prev != ((void *)
0)) (task)->ready_priority_link.prev->ready_priority_link
.next = (task)->ready_priority_link.next; else { ((void) (
((manager->ready_priority_tasks).head == (task)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 499, isc_assertiontype_insist
, "(manager->ready_priority_tasks).head == (task)"), 0)));
(manager->ready_priority_tasks).head = (task)->ready_priority_link
.next; } (task)->ready_priority_link.prev = (void *)(-1); (
task)->ready_priority_link.next = (void *)(-1); ((void) ((
(manager->ready_priority_tasks).head != (task)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 499, isc_assertiontype_insist
, "(manager->ready_priority_tasks).head != (task)"), 0)));
((void) (((manager->ready_priority_tasks).tail != (task))
|| ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 499, isc_assertiontype_insist, "(manager->ready_priority_tasks).tail != (task)"
), 0))); } while (0); } while (0);
500 }
501
502 return (task);
503}
504
505/*
506 * Push 'task' onto the ready_tasks queue. If 'task' has the privilege
507 * flag set, then also push it onto the ready_priority_tasks queue.
508 *
509 * Caller must hold the task manager lock.
510 */
511static inline void
512push_readyq(isc_taskmgr_t *manager, isc_task_t *task) {
513 ENQUEUE(manager->ready_tasks, task, ready_link)do { do { if ((manager->ready_tasks).tail != ((void *)0)) (
manager->ready_tasks).tail->ready_link.next = (task); else
(manager->ready_tasks).head = (task); (task)->ready_link
.prev = (manager->ready_tasks).tail; (task)->ready_link
.next = ((void *)0); (manager->ready_tasks).tail = (task);
} while (0); } while (0);
514 if ((task->flags & TASK_F_PRIVILEGED0x02) != 0)
515 ENQUEUE(manager->ready_priority_tasks, task,do { do { if ((manager->ready_priority_tasks).tail != ((void
*)0)) (manager->ready_priority_tasks).tail->ready_priority_link
.next = (task); else (manager->ready_priority_tasks).head =
(task); (task)->ready_priority_link.prev = (manager->ready_priority_tasks
).tail; (task)->ready_priority_link.next = ((void *)0); (manager
->ready_priority_tasks).tail = (task); } while (0); } while
(0)
516 ready_priority_link)do { do { if ((manager->ready_priority_tasks).tail != ((void
*)0)) (manager->ready_priority_tasks).tail->ready_priority_link
.next = (task); else (manager->ready_priority_tasks).head =
(task); (task)->ready_priority_link.prev = (manager->ready_priority_tasks
).tail; (task)->ready_priority_link.next = ((void *)0); (manager
->ready_priority_tasks).tail = (task); } while (0); } while
(0);
517 manager->tasks_ready++;
518}
519
520static void
521dispatch(isc_taskmgr_t *manager) {
522 isc_task_t *task;
523 unsigned int total_dispatch_count = 0;
524 isc_tasklist_t new_ready_tasks;
525 isc_tasklist_t new_priority_tasks;
526 unsigned int tasks_ready = 0;
527
528 ISC_LIST_INIT(new_ready_tasks)do { (new_ready_tasks).head = ((void *)0); (new_ready_tasks).
tail = ((void *)0); } while (0);
1
Loop condition is false. Exiting loop
→
529 ISC_LIST_INIT(new_priority_tasks)do { (new_priority_tasks).head = ((void *)0); (new_priority_tasks
).tail = ((void *)0); } while (0);
2
←
Loop condition is false. Exiting loop
→
530
531 while (!FINISHED(manager)((manager)->exiting && (((manager)->tasks).head
== ((void *)0)))) {
3
←
Assuming field 'exiting' is 0
→
4
←
Loop condition is true. Entering loop body
→
45
←
Loop condition is true. Entering loop body
→
532 if (total_dispatch_count
4.1
'total_dispatch_count' is < DEFAULT_TASKMGR_QUANTUM
45.1
'total_dispatch_count' is < DEFAULT_TASKMGR_QUANTUM
 >= DEFAULT_TASKMGR_QUANTUM10 ||
5
←
Taking false branch
→
46
←
Taking false branch
→
533 empty_readyq(manager))
534 break;
535
536 task = pop_readyq(manager);
6
←
Calling 'pop_readyq'
→
19
←
Returning from 'pop_readyq'
→
47
←
Calling 'pop_readyq'
→
537 if (task
19.1
'task' is not equal to NULL
 != NULL((void *)0)) {
20
←
Taking true branch
→
538 unsigned int dispatch_count = 0;
539 int done = 0;
540 int requeue = 0;
541 int finished = 0;
542 isc_event_t *event;
543
544 /*
545 * Note we only unlock the manager lock if we actually
546 * have a task to do. We must reacquire the manager
547 * lock before exiting the 'if (task != NULL)' block.
548 */
549 manager->tasks_ready--;
550 manager->tasks_running++;
551
552 INSIST(task->state == task_state_ready)((void) ((task->state == task_state_ready) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 552, isc_assertiontype_insist
, "task->state == task_state_ready"), 0)));
21
←
Assuming field 'state' is equal to task_state_ready
→
553 task->state = task_state_running;
554 time(&task->now);
555 do {
29
←
Loop condition is false. Exiting loop
→
556 if (!EMPTY(task->events)((task->events).head == ((void *)0))) {
22
←
Assuming field 'head' is equal to null
→
23
←
Taking false branch
→
557 event = HEAD(task->events)((task->events).head);
558 DEQUEUE(task->events, event, ev_link)do { do { if ((event)->ev_link.next != ((void *)0)) (event
)->ev_link.next->ev_link.prev = (event)->ev_link.prev
; else { ((void) (((task->events).tail == (event)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 558, isc_assertiontype_insist
, "(task->events).tail == (event)"), 0))); (task->events
).tail = (event)->ev_link.prev; } if ((event)->ev_link.
prev != ((void *)0)) (event)->ev_link.prev->ev_link.next
= (event)->ev_link.next; else { ((void) (((task->events
).head == (event)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 558, isc_assertiontype_insist, "(task->events).head == (event)"
), 0))); (task->events).head = (event)->ev_link.next; }
(event)->ev_link.prev = (void *)(-1); (event)->ev_link
.next = (void *)(-1); ((void) (((task->events).head != (event
)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 558, isc_assertiontype_insist, "(task->events).head != (event)"
), 0))); ((void) (((task->events).tail != (event)) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 558, isc_assertiontype_insist
, "(task->events).tail != (event)"), 0))); } while (0); } while
(0);
559 task->nevents--;
560
561 /*
562 * Execute the event action.
563 */
564 if (event->ev_action != NULL((void *)0)) {
565 (event->ev_action)(
566 (isc_task_t *)task,
567 event);
568 }
569 dispatch_count++;
570 total_dispatch_count++;
571 }
572
573 if (task->references == 0 &&
24
←
Assuming field 'references' is equal to 0
→
26
←
Taking false branch
→
574 EMPTY(task->events)((task->events).head == ((void *)0)) &&
575 !TASK_SHUTTINGDOWN(task)(((task)->flags & 0x01) != 0)) {
25
←
Assuming the condition is true
→
576 int was_idle;
577
578 /*
579 * There are no references and no
580 * pending events for this task,
581 * which means it will not become
582 * runnable again via an external
583 * action (such as sending an event
584 * or detaching).
585 *
586 * We initiate shutdown to prevent
587 * it from becoming a zombie.
588 *
589 * We do this here instead of in
590 * the "if EMPTY(task->events)" block
591 * below because:
592 *
593 * If we post no shutdown events,
594 * we want the task to finish.
595 *
596 * If we did post shutdown events,
597 * will still want the task's
598 * quantum to be applied.
599 */
600 was_idle = task_shutdown(task);
601 INSIST(!was_idle)((void) ((!was_idle) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 601, isc_assertiontype_insist, "!was_idle"), 0)));
602 }
603
604 if (EMPTY(task->events)((task->events).head == ((void *)0))) {
27
←
Taking true branch
→
605 /*
606 * Nothing else to do for this task
607 * right now.
608 */
609 if (task->references
27.1
Field 'references' is equal to 0
 == 0 &&
28
←
Taking true branch
→
610 TASK_SHUTTINGDOWN(task)(((task)->flags & 0x01) != 0)) {
611 /*
612 * The task is done.
613 */
614 finished = 1;
615 task->state = task_state_done;
616 } else
617 task->state = task_state_idle;
618 done = 1;
619 } else if (dispatch_count >= task->quantum) {
620 /*
621 * Our quantum has expired, but
622 * there is more work to be done.
623 * We'll requeue it to the ready
624 * queue later.
625 *
626 * We don't check quantum until
627 * dispatching at least one event,
628 * so the minimum quantum is one.
629 */
630 task->state = task_state_ready;
631 requeue = 1;
632 done = 1;
633 }
634 } while (!done);
635
636 if (finished
29.1
'finished' is 1
)
30
←
Taking true branch
→
637 task_finished(task);
31
←
Calling 'task_finished'
→
43
←
Returning; memory was released via 1st parameter
→
638
639 manager->tasks_running--;
640 if (requeue
43.1
'requeue' is 0
) {
44
←
Taking false branch
→
641 /*
642 * We know we're awake, so we don't have
643 * to wakeup any sleeping threads if the
644 * ready queue is empty before we requeue.
645 *
646 * A possible optimization if the queue is
647 * empty is to 'goto' the 'if (task != NULL)'
648 * block, avoiding the ENQUEUE of the task
649 * and the subsequent immediate DEQUEUE
650 * (since it is the only executable task).
651 * We don't do this because then we'd be
652 * skipping the exit_requested check. The
653 * cost of ENQUEUE is low anyway, especially
654 * when you consider that we'd have to do
655 * an extra EMPTY check to see if we could
656 * do the optimization. If the ready queue
657 * were usually nonempty, the 'optimization'
658 * might even hurt rather than help.
659 */
660 ENQUEUE(new_ready_tasks, task, ready_link)do { do { if ((new_ready_tasks).tail != ((void *)0)) (new_ready_tasks
).tail->ready_link.next = (task); else (new_ready_tasks).head
= (task); (task)->ready_link.prev = (new_ready_tasks).tail
; (task)->ready_link.next = ((void *)0); (new_ready_tasks)
.tail = (task); } while (0); } while (0);
661 if ((task->flags & TASK_F_PRIVILEGED0x02) != 0)
662 ENQUEUE(new_priority_tasks, task,do { do { if ((new_priority_tasks).tail != ((void *)0)) (new_priority_tasks
).tail->ready_priority_link.next = (task); else (new_priority_tasks
).head = (task); (task)->ready_priority_link.prev = (new_priority_tasks
).tail; (task)->ready_priority_link.next = ((void *)0); (new_priority_tasks
).tail = (task); } while (0); } while (0)
663 ready_priority_link)do { do { if ((new_priority_tasks).tail != ((void *)0)) (new_priority_tasks
).tail->ready_priority_link.next = (task); else (new_priority_tasks
).head = (task); (task)->ready_priority_link.prev = (new_priority_tasks
).tail; (task)->ready_priority_link.next = ((void *)0); (new_priority_tasks
).tail = (task); } while (0); } while (0);
664 tasks_ready++;
665 }
666 }
667
668 }
669
670 ISC_LIST_APPENDLIST(manager->ready_tasks, new_ready_tasks, ready_link)do { if (((manager->ready_tasks).head == ((void *)0))) (manager
->ready_tasks) = (new_ready_tasks); else if (!((new_ready_tasks
).head == ((void *)0))) { (manager->ready_tasks).tail->
ready_link.next = (new_ready_tasks).head; (new_ready_tasks).head
->ready_link.prev = (manager->ready_tasks).tail; (manager
->ready_tasks).tail = (new_ready_tasks).tail; } (new_ready_tasks
).head = ((void *)0); (new_ready_tasks).tail = ((void *)0); }
while (0);
671 ISC_LIST_APPENDLIST(manager->ready_priority_tasks, new_priority_tasks,do { if (((manager->ready_priority_tasks).head == ((void *
)0))) (manager->ready_priority_tasks) = (new_priority_tasks
); else if (!((new_priority_tasks).head == ((void *)0))) { (manager
->ready_priority_tasks).tail->ready_priority_link.next =
(new_priority_tasks).head; (new_priority_tasks).head->ready_priority_link
.prev = (manager->ready_priority_tasks).tail; (manager->
ready_priority_tasks).tail = (new_priority_tasks).tail; } (new_priority_tasks
).head = ((void *)0); (new_priority_tasks).tail = ((void *)0)
; } while (0)
672 ready_priority_link)do { if (((manager->ready_priority_tasks).head == ((void *
)0))) (manager->ready_priority_tasks) = (new_priority_tasks
); else if (!((new_priority_tasks).head == ((void *)0))) { (manager
->ready_priority_tasks).tail->ready_priority_link.next =
(new_priority_tasks).head; (new_priority_tasks).head->ready_priority_link
.prev = (manager->ready_priority_tasks).tail; (manager->
ready_priority_tasks).tail = (new_priority_tasks).tail; } (new_priority_tasks
).head = ((void *)0); (new_priority_tasks).tail = ((void *)0)
; } while (0);
673 manager->tasks_ready += tasks_ready;
674 if (empty_readyq(manager))
675 manager->mode = isc_taskmgrmode_normal;
676
677}
678
679static void
680manager_free(isc_taskmgr_t *manager) {
681 free(manager);
682 taskmgr = NULL((void *)0);
683}
684
685isc_result_t
686isc_taskmgr_create(unsigned int workers,
687 unsigned int default_quantum, isc_taskmgr_t **managerp)
688{
689 unsigned int i, started = 0;
690 isc_taskmgr_t *manager;
691
692 /*
693 * Create a new task manager.
694 */
695
696 REQUIRE(workers > 0)((void) ((workers > 0) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 696, isc_assertiontype_require, "workers > 0"), 0)));
697 REQUIRE(managerp != NULL && *managerp == NULL)((void) ((managerp != ((void *)0) && *managerp == ((void
*)0)) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 697, isc_assertiontype_require, "managerp != ((void *)0) && *managerp == ((void *)0)"
), 0)));
698
699 UNUSED(i)(void)(i);
700 UNUSED(started)(void)(started);
701
702 if (taskmgr != NULL((void *)0)) {
703 if (taskmgr->refs == 0)
704 return (ISC_R_SHUTTINGDOWN22);
705 taskmgr->refs++;
706 *managerp = (isc_taskmgr_t *)taskmgr;
707 return (ISC_R_SUCCESS0);
708 }
709
710 manager = malloc(sizeof(*manager));
711 if (manager == NULL((void *)0))
712 return (ISC_R_NOMEMORY1);
713 manager->mode = isc_taskmgrmode_normal;
714
715 if (default_quantum == 0)
716 default_quantum = DEFAULT_DEFAULT_QUANTUM5;
717 manager->default_quantum = default_quantum;
718 INIT_LIST(manager->tasks)do { (manager->tasks).head = ((void *)0); (manager->tasks
).tail = ((void *)0); } while (0);
719 INIT_LIST(manager->ready_tasks)do { (manager->ready_tasks).head = ((void *)0); (manager->
ready_tasks).tail = ((void *)0); } while (0);
720 INIT_LIST(manager->ready_priority_tasks)do { (manager->ready_priority_tasks).head = ((void *)0); (
manager->ready_priority_tasks).tail = ((void *)0); } while
(0);
721 manager->tasks_running = 0;
722 manager->tasks_ready = 0;
723 manager->exclusive_requested = 0;
724 manager->pause_requested = 0;
725 manager->exiting = 0;
726 manager->excl = NULL((void *)0);
727
728 manager->refs = 1;
729 taskmgr = manager;
730
731 *managerp = (isc_taskmgr_t *)manager;
732
733 return (ISC_R_SUCCESS0);
734}
735
736void
737isc_taskmgr_destroy(isc_taskmgr_t **managerp) {
738 isc_taskmgr_t *manager;
739 isc_task_t *task;
740 unsigned int i;
741
742 /*
743 * Destroy '*managerp'.
744 */
745
746 REQUIRE(managerp != NULL)((void) ((managerp != ((void *)0)) || ((isc_assertion_failed)
("/usr/src/usr.bin/dig/lib/isc/task.c", 746, isc_assertiontype_require
, "managerp != ((void *)0)"), 0)));
747 manager = (isc_taskmgr_t *)*managerp;
748
749 UNUSED(i)(void)(i);
750
751 manager->refs--;
752 if (manager->refs > 0) {
753 *managerp = NULL((void *)0);
754 return;
755 }
756
757 /*
758 * Only one non-worker thread may ever call this routine.
759 * If a worker thread wants to initiate shutdown of the
760 * task manager, it should ask some non-worker thread to call
761 * isc_taskmgr_destroy(), e.g. by signalling a condition variable
762 * that the startup thread is sleeping on.
763 */
764
765 /*
766 * Detach the exclusive task before acquiring the manager lock
767 */
768 if (manager->excl != NULL((void *)0))
769 isc_task_detach((isc_task_t **) &manager->excl);
770
771 /*
772 * Make sure we only get called once.
773 */
774 INSIST(!manager->exiting)((void) ((!manager->exiting) || ((isc_assertion_failed)("/usr/src/usr.bin/dig/lib/isc/task.c"
, 774, isc_assertiontype_insist, "!manager->exiting"), 0))
);
775 manager->exiting = 1;
776
777 /*
778 * If privileged mode was on, turn it off.
779 */
780 manager->mode = isc_taskmgrmode_normal;
781
782 /*
783 * Post shutdown event(s) to every task (if they haven't already been
784 * posted).
785 */
786 for (task = HEAD(manager->tasks)((manager->tasks).head);
787 task != NULL((void *)0);
788 task = NEXT(task, link)((task)->link.next)) {
789 if (task_shutdown(task))
790 push_readyq(manager, task);
791 }
792 /*
793 * Dispatch the shutdown events.
794 */
795 while (isc_taskmgr_ready((isc_taskmgr_t *)manager))
796 (void)isc_taskmgr_dispatch((isc_taskmgr_t *)manager);
797 INSIST(ISC_LIST_EMPTY(manager->tasks))((void) ((((manager->tasks).head == ((void *)0))) || ((isc_assertion_failed
)("/usr/src/usr.bin/dig/lib/isc/task.c", 797, isc_assertiontype_insist
, "((manager->tasks).head == ((void *)0))"), 0)));
798 taskmgr = NULL((void *)0);
799
800 manager_free(manager);
801
802 *managerp = NULL((void *)0);
803}
804
805int
806isc_taskmgr_ready(isc_taskmgr_t *manager) {
807 int is_ready;
808
809 if (manager == NULL((void *)0))
810 manager = taskmgr;
811 if (manager == NULL((void *)0))
812 return (0);
813
814 is_ready = !empty_readyq(manager);
815
816 return (is_ready);
817}
818
819isc_result_t
820isc_taskmgr_dispatch(isc_taskmgr_t *manager) {
821 if (manager == NULL((void *)0))
822 manager = taskmgr;
823 if (manager == NULL((void *)0))
824 return (ISC_R_NOTFOUND23);
825
826 dispatch(manager);
827
828 return (ISC_R_SUCCESS0);
829}