1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #include "iscsi_thread.h"
27
28 static void iscsi_threads_entry(void *arg);
29
30 /*
31 * iscsi_thread_create - Creates the needed resources to handle a thread
32 */
33 iscsi_thread_t *
iscsi_thread_create(dev_info_t * dip,char * name,iscsi_thread_ep_t entry_point,void * arg)34 iscsi_thread_create(dev_info_t *dip, char *name,
35 iscsi_thread_ep_t entry_point, void *arg)
36 {
37 iscsi_thread_t *thread;
38
39 thread = kmem_zalloc(sizeof (iscsi_thread_t), KM_SLEEP);
40
41 if (thread != NULL) {
42
43 thread->tq = ddi_taskq_create(dip, name, 1,
44 TASKQ_DEFAULTPRI, 0);
45
46 if (thread->tq != NULL) {
47 thread->signature = SIG_ISCSI_THREAD;
48 thread->dip = dip;
49 thread->entry_point = entry_point;
50 thread->arg = arg;
51 thread->state = ISCSI_THREAD_STATE_STOPPED;
52 thread->sign.bitmap = 0;
53 mutex_init(&thread->mgnt.mtx, NULL, MUTEX_DRIVER, NULL);
54 mutex_init(&thread->sign.mtx, NULL, MUTEX_DRIVER, NULL);
55 cv_init(&thread->sign.cdv, NULL, CV_DRIVER, NULL);
56 } else {
57 kmem_free(thread, sizeof (iscsi_thread_t));
58 thread = NULL;
59 }
60 }
61
62 return (thread);
63 }
64
65 /*
66 * iscsi_thread_destroy - Releases the needed resources to handle a thread
67 */
68 void
iscsi_thread_destroy(iscsi_thread_t * thread)69 iscsi_thread_destroy(
70 iscsi_thread_t *thread
71 )
72 {
73 ASSERT(thread != NULL);
74 ASSERT(thread->signature == SIG_ISCSI_THREAD);
75
76 mutex_enter(&thread->mgnt.mtx);
77
78 switch (thread->state) {
79
80 case ISCSI_THREAD_STATE_STARTED:
81
82 /* A kill signal is sent first. */
83 thread->state = ISCSI_THREAD_STATE_DESTROYING;
84 mutex_enter(&thread->sign.mtx);
85 if (!(thread->sign.bitmap & ISCSI_THREAD_SIGNAL_KILL)) {
86 thread->sign.bitmap |= ISCSI_THREAD_SIGNAL_KILL;
87 cv_signal(&thread->sign.cdv);
88 }
89 mutex_exit(&thread->sign.mtx);
90 ddi_taskq_wait(thread->tq);
91 break;
92
93 case ISCSI_THREAD_STATE_STOPPED:
94
95 /* Switch the state and wait for the thread to exit. */
96 thread->state = ISCSI_THREAD_STATE_DESTROYING;
97 break;
98
99 default:
100 ASSERT(0);
101 break;
102 }
103
104 mutex_exit(&thread->mgnt.mtx);
105 ddi_taskq_destroy(thread->tq);
106 cv_destroy(&thread->sign.cdv);
107 mutex_destroy(&thread->sign.mtx);
108 mutex_destroy(&thread->mgnt.mtx);
109 thread->signature = (uint32_t)~SIG_ISCSI_THREAD;
110 kmem_free(thread, sizeof (iscsi_thread_t));
111 }
112
113 /*
114 * iscsi_thread_start - Starts the thread given as an entry parameter
115 */
116 boolean_t
iscsi_thread_start(iscsi_thread_t * thread)117 iscsi_thread_start(
118 iscsi_thread_t *thread
119 )
120 {
121 boolean_t ret = B_FALSE;
122
123 ASSERT(thread != NULL);
124 ASSERT(thread->signature == SIG_ISCSI_THREAD);
125
126 mutex_enter(&thread->mgnt.mtx);
127
128 switch (thread->state) {
129
130 case ISCSI_THREAD_STATE_STARTED:
131
132 mutex_enter(&thread->sign.mtx);
133
134 thread->state = ISCSI_THREAD_STATE_STOPPING;
135
136 if (!(thread->sign.bitmap & ISCSI_THREAD_SIGNAL_KILL)) {
137 thread->sign.bitmap |= ISCSI_THREAD_SIGNAL_KILL;
138 cv_signal(&thread->sign.cdv);
139 }
140 mutex_exit(&thread->sign.mtx);
141 ddi_taskq_wait(thread->tq);
142 thread->state = ISCSI_THREAD_STATE_STOPPED;
143 /* FALLTHRU */
144
145 case ISCSI_THREAD_STATE_STOPPED:
146
147 thread->sign.bitmap = 0;
148 thread->state = ISCSI_THREAD_STATE_STARTING;
149
150 if (ddi_taskq_dispatch(thread->tq, iscsi_threads_entry,
151 thread, DDI_SLEEP) == DDI_SUCCESS) {
152 /*
153 * The dispatch succeeded.
154 */
155 thread->state = ISCSI_THREAD_STATE_STARTED;
156 ret = B_TRUE;
157 }
158 break;
159
160 default:
161 ASSERT(0);
162 break;
163 }
164 mutex_exit(&thread->mgnt.mtx);
165 return (ret);
166 }
167
168 /*
169 * iscsi_thread_stop -
170 */
171 boolean_t
iscsi_thread_stop(iscsi_thread_t * thread)172 iscsi_thread_stop(
173 iscsi_thread_t *thread
174 )
175 {
176 boolean_t ret = B_FALSE;
177
178 ASSERT(thread != NULL);
179 ASSERT(thread->signature == SIG_ISCSI_THREAD);
180
181 mutex_enter(&thread->mgnt.mtx);
182
183 switch (thread->state) {
184
185 case ISCSI_THREAD_STATE_STARTED:
186
187 mutex_enter(&thread->sign.mtx);
188
189 thread->state = ISCSI_THREAD_STATE_STOPPING;
190
191 if (!(thread->sign.bitmap & ISCSI_THREAD_SIGNAL_KILL)) {
192 thread->sign.bitmap |= ISCSI_THREAD_SIGNAL_KILL;
193 cv_signal(&thread->sign.cdv);
194 }
195 mutex_exit(&thread->sign.mtx);
196 ddi_taskq_wait(thread->tq);
197 thread->state = ISCSI_THREAD_STATE_STOPPED;
198 ret = B_TRUE;
199 break;
200
201 case ISCSI_THREAD_STATE_STOPPED:
202 ret = B_TRUE;
203 break;
204
205 default:
206 ASSERT(0);
207 break;
208 }
209 mutex_exit(&thread->mgnt.mtx);
210 return (ret);
211 }
212
213 /*
214 * iscsi_thread_send_kill -
215 */
216 void
iscsi_thread_send_kill(iscsi_thread_t * thread)217 iscsi_thread_send_kill(
218 iscsi_thread_t *thread
219 )
220 {
221 ASSERT(thread != NULL);
222 ASSERT(thread->signature == SIG_ISCSI_THREAD);
223
224 mutex_enter(&thread->mgnt.mtx);
225
226 switch (thread->state) {
227
228 case ISCSI_THREAD_STATE_STARTED:
229
230 mutex_enter(&thread->sign.mtx);
231 if (!(thread->sign.bitmap & ISCSI_THREAD_SIGNAL_KILL)) {
232 thread->sign.bitmap |= ISCSI_THREAD_SIGNAL_KILL;
233 cv_signal(&thread->sign.cdv);
234 }
235 mutex_exit(&thread->sign.mtx);
236 break;
237
238 default:
239 ASSERT(0);
240 break;
241 }
242 mutex_exit(&thread->mgnt.mtx);
243 }
244
245 /*
246 * iscsi_thread_send_wakeup -
247 */
248 boolean_t
iscsi_thread_send_wakeup(iscsi_thread_t * thread)249 iscsi_thread_send_wakeup(
250 iscsi_thread_t *thread
251 )
252 {
253 boolean_t ret = B_FALSE;
254
255 ASSERT(thread != NULL);
256 ASSERT(thread->signature == SIG_ISCSI_THREAD);
257
258 mutex_enter(&thread->mgnt.mtx);
259
260 switch (thread->state) {
261
262 case ISCSI_THREAD_STATE_STARTED:
263
264 mutex_enter(&thread->sign.mtx);
265 if (!(thread->sign.bitmap & ISCSI_THREAD_SIGNAL_WAKEUP)) {
266 thread->sign.bitmap |= ISCSI_THREAD_SIGNAL_WAKEUP;
267 cv_signal(&thread->sign.cdv);
268 }
269 mutex_exit(&thread->sign.mtx);
270 ret = B_TRUE;
271 break;
272
273 default:
274 break;
275 }
276 mutex_exit(&thread->mgnt.mtx);
277 return (ret);
278 }
279
280 /*
281 * iscsi_thread_check_signals -
282 */
283 uint32_t
iscsi_thread_check_signals(iscsi_thread_t * thread)284 iscsi_thread_check_signals(
285 iscsi_thread_t *thread
286 )
287 {
288 uint32_t bitmap;
289
290 ASSERT(thread != NULL);
291 ASSERT(thread->signature == SIG_ISCSI_THREAD);
292
293 /* Acquire the mutex before anychecking. */
294 mutex_enter(&thread->sign.mtx);
295 bitmap = thread->sign.bitmap;
296 mutex_exit(&thread->sign.mtx);
297 return (bitmap);
298 }
299 /*
300 * iscsi_thread_wait -
301 */
302 int
iscsi_thread_wait(iscsi_thread_t * thread,clock_t timeout)303 iscsi_thread_wait(
304 iscsi_thread_t *thread,
305 clock_t timeout
306 )
307 {
308 int rtn = 1;
309
310 ASSERT(thread != NULL);
311 ASSERT(thread->signature == SIG_ISCSI_THREAD);
312
313 /* Acquire the mutex before anychecking. */
314 mutex_enter(&thread->sign.mtx);
315
316 /* Check the signals. */
317 if (thread->sign.bitmap & ISCSI_THREAD_SIGNAL_KILL) {
318 goto signal_kill;
319 } else if (thread->sign.bitmap & ISCSI_THREAD_SIGNAL_WAKEUP) {
320 goto signal_wakeup;
321 } else if (timeout == 0) {
322 goto iscsi_thread_sleep_exit;
323 }
324
325 if (timeout == -1) {
326 cv_wait(&thread->sign.cdv, &thread->sign.mtx);
327 } else {
328 rtn = cv_reltimedwait(&thread->sign.cdv, &thread->sign.mtx,
329 timeout, TR_CLOCK_TICK);
330 }
331
332 /* Check the signals. */
333 if (thread->sign.bitmap & ISCSI_THREAD_SIGNAL_KILL) {
334 goto signal_kill;
335 } else if (thread->sign.bitmap & ISCSI_THREAD_SIGNAL_WAKEUP) {
336 goto signal_wakeup;
337 }
338
339 iscsi_thread_sleep_exit:
340 mutex_exit(&thread->sign.mtx);
341 return (rtn);
342
343 signal_kill:
344 mutex_exit(&thread->sign.mtx);
345 return (0);
346
347 signal_wakeup:
348 thread->sign.bitmap &= ~ISCSI_THREAD_SIGNAL_WAKEUP;
349 mutex_exit(&thread->sign.mtx);
350 return (1);
351 }
352
353 /*
354 * iscsi_threads_entry - Common entry point for all threads
355 */
356 static
357 void
iscsi_threads_entry(void * arg)358 iscsi_threads_entry(
359 void *arg
360 )
361 {
362 iscsi_thread_t *thread;
363
364 thread = (iscsi_thread_t *)arg;
365
366 ASSERT(thread != NULL);
367 ASSERT(thread->signature == SIG_ISCSI_THREAD);
368
369 (thread->entry_point)(thread, thread->arg);
370 }
371