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1 | /* |
1 | /* |
2 | * Copyright (C) 2001-2004 Jakub Jermar |
2 | * Copyright (C) 2001-2004 Jakub Jermar |
3 | * All rights reserved. |
3 | * All rights reserved. |
4 | * |
4 | * |
5 | * Redistribution and use in source and binary forms, with or without |
5 | * Redistribution and use in source and binary forms, with or without |
6 | * modification, are permitted provided that the following conditions |
6 | * modification, are permitted provided that the following conditions |
7 | * are met: |
7 | * are met: |
8 | * |
8 | * |
9 | * - Redistributions of source code must retain the above copyright |
9 | * - Redistributions of source code must retain the above copyright |
10 | * notice, this list of conditions and the following disclaimer. |
10 | * notice, this list of conditions and the following disclaimer. |
11 | * - Redistributions in binary form must reproduce the above copyright |
11 | * - Redistributions in binary form must reproduce the above copyright |
12 | * notice, this list of conditions and the following disclaimer in the |
12 | * notice, this list of conditions and the following disclaimer in the |
13 | * documentation and/or other materials provided with the distribution. |
13 | * documentation and/or other materials provided with the distribution. |
14 | * - The name of the author may not be used to endorse or promote products |
14 | * - The name of the author may not be used to endorse or promote products |
15 | * derived from this software without specific prior written permission. |
15 | * derived from this software without specific prior written permission. |
16 | * |
16 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
27 | */ |
27 | */ |
28 | 28 | ||
29 | /** |
29 | /** |
30 | * @file waitq.c |
30 | * @file waitq.c |
31 | * @brief Wait queue. |
31 | * @brief Wait queue. |
32 | * |
32 | * |
33 | * Wait queue is the basic synchronization primitive upon which all |
33 | * Wait queue is the basic synchronization primitive upon which all |
34 | * other synchronization primitives build. |
34 | * other synchronization primitives build. |
35 | * |
35 | * |
36 | * It allows threads to wait for an event in first-come, first-served |
36 | * It allows threads to wait for an event in first-come, first-served |
37 | * fashion. Conditional operation as well as timeouts and interruptions |
37 | * fashion. Conditional operation as well as timeouts and interruptions |
38 | * are supported. |
38 | * are supported. |
39 | */ |
39 | */ |
40 | 40 | ||
41 | #include <synch/waitq.h> |
41 | #include <synch/waitq.h> |
42 | #include <synch/synch.h> |
42 | #include <synch/synch.h> |
43 | #include <synch/spinlock.h> |
43 | #include <synch/spinlock.h> |
44 | #include <proc/thread.h> |
44 | #include <proc/thread.h> |
45 | #include <proc/scheduler.h> |
45 | #include <proc/scheduler.h> |
46 | #include <arch/asm.h> |
46 | #include <arch/asm.h> |
47 | #include <arch/types.h> |
47 | #include <arch/types.h> |
48 | #include <typedefs.h> |
48 | #include <typedefs.h> |
49 | #include <time/timeout.h> |
49 | #include <time/timeout.h> |
50 | #include <arch.h> |
50 | #include <arch.h> |
51 | #include <context.h> |
51 | #include <context.h> |
52 | #include <adt/list.h> |
52 | #include <adt/list.h> |
53 | 53 | ||
54 | static void waitq_timeouted_sleep(void *data); |
54 | static void waitq_timeouted_sleep(void *data); |
55 | 55 | ||
56 | /** Initialize wait queue |
56 | /** Initialize wait queue |
57 | * |
57 | * |
58 | * Initialize wait queue. |
58 | * Initialize wait queue. |
59 | * |
59 | * |
60 | * @param wq Pointer to wait queue to be initialized. |
60 | * @param wq Pointer to wait queue to be initialized. |
61 | */ |
61 | */ |
62 | void waitq_initialize(waitq_t *wq) |
62 | void waitq_initialize(waitq_t *wq) |
63 | { |
63 | { |
64 | spinlock_initialize(&wq->lock, "waitq_lock"); |
64 | spinlock_initialize(&wq->lock, "waitq_lock"); |
65 | list_initialize(&wq->head); |
65 | list_initialize(&wq->head); |
66 | wq->missed_wakeups = 0; |
66 | wq->missed_wakeups = 0; |
67 | } |
67 | } |
68 | 68 | ||
69 | /** Handle timeout during waitq_sleep_timeout() call |
69 | /** Handle timeout during waitq_sleep_timeout() call |
70 | * |
70 | * |
71 | * This routine is called when waitq_sleep_timeout() timeouts. |
71 | * This routine is called when waitq_sleep_timeout() timeouts. |
72 | * Interrupts are disabled. |
72 | * Interrupts are disabled. |
73 | * |
73 | * |
74 | * It is supposed to try to remove 'its' thread from the wait queue; |
74 | * It is supposed to try to remove 'its' thread from the wait queue; |
75 | * it can eventually fail to achieve this goal when these two events |
75 | * it can eventually fail to achieve this goal when these two events |
76 | * overlap. In that case it behaves just as though there was no |
76 | * overlap. In that case it behaves just as though there was no |
77 | * timeout at all. |
77 | * timeout at all. |
78 | * |
78 | * |
79 | * @param data Pointer to the thread that called waitq_sleep_timeout(). |
79 | * @param data Pointer to the thread that called waitq_sleep_timeout(). |
80 | */ |
80 | */ |
81 | void waitq_timeouted_sleep(void *data) |
81 | void waitq_timeouted_sleep(void *data) |
82 | { |
82 | { |
83 | thread_t *t = (thread_t *) data; |
83 | thread_t *t = (thread_t *) data; |
84 | waitq_t *wq; |
84 | waitq_t *wq; |
85 | bool do_wakeup = false; |
85 | bool do_wakeup = false; |
86 | 86 | ||
87 | spinlock_lock(&threads_lock); |
87 | spinlock_lock(&threads_lock); |
88 | if (!thread_exists(t)) |
88 | if (!thread_exists(t)) |
89 | goto out; |
89 | goto out; |
90 | 90 | ||
91 | grab_locks: |
91 | grab_locks: |
92 | spinlock_lock(&t->lock); |
92 | spinlock_lock(&t->lock); |
93 | if ((wq = t->sleep_queue)) { /* assignment */ |
93 | if ((wq = t->sleep_queue)) { /* assignment */ |
94 | if (!spinlock_trylock(&wq->lock)) { |
94 | if (!spinlock_trylock(&wq->lock)) { |
95 | spinlock_unlock(&t->lock); |
95 | spinlock_unlock(&t->lock); |
96 | goto grab_locks; /* avoid deadlock */ |
96 | goto grab_locks; /* avoid deadlock */ |
97 | } |
97 | } |
98 | 98 | ||
99 | list_remove(&t->wq_link); |
99 | list_remove(&t->wq_link); |
100 | t->saved_context = t->sleep_timeout_context; |
100 | t->saved_context = t->sleep_timeout_context; |
101 | do_wakeup = true; |
101 | do_wakeup = true; |
102 | 102 | ||
103 | spinlock_unlock(&wq->lock); |
103 | spinlock_unlock(&wq->lock); |
104 | t->sleep_queue = NULL; |
104 | t->sleep_queue = NULL; |
105 | } |
105 | } |
106 | 106 | ||
107 | t->timeout_pending = false; |
107 | t->timeout_pending = false; |
108 | spinlock_unlock(&t->lock); |
108 | spinlock_unlock(&t->lock); |
109 | 109 | ||
110 | if (do_wakeup) |
110 | if (do_wakeup) |
111 | thread_ready(t); |
111 | thread_ready(t); |
112 | 112 | ||
113 | out: |
113 | out: |
114 | spinlock_unlock(&threads_lock); |
114 | spinlock_unlock(&threads_lock); |
115 | } |
115 | } |
116 | 116 | ||
117 | /** Interrupt sleeping thread. |
117 | /** Interrupt sleeping thread. |
118 | * |
118 | * |
119 | * This routine attempts to interrupt a thread from its sleep in a waitqueue. |
119 | * This routine attempts to interrupt a thread from its sleep in a waitqueue. |
120 | * If the thread is not found sleeping, no action is taken. |
120 | * If the thread is not found sleeping, no action is taken. |
121 | * |
121 | * |
122 | * @param t Thread to be interrupted. |
122 | * @param t Thread to be interrupted. |
123 | */ |
123 | */ |
124 | void waitq_interrupt_sleep(thread_t *t) |
124 | void waitq_interrupt_sleep(thread_t *t) |
125 | { |
125 | { |
126 | waitq_t *wq; |
126 | waitq_t *wq; |
127 | bool do_wakeup = false; |
127 | bool do_wakeup = false; |
128 | ipl_t ipl; |
128 | ipl_t ipl; |
129 | 129 | ||
130 | ipl = interrupts_disable(); |
130 | ipl = interrupts_disable(); |
131 | spinlock_lock(&threads_lock); |
131 | spinlock_lock(&threads_lock); |
132 | if (!thread_exists(t)) |
132 | if (!thread_exists(t)) |
133 | goto out; |
133 | goto out; |
134 | 134 | ||
135 | grab_locks: |
135 | grab_locks: |
136 | spinlock_lock(&t->lock); |
136 | spinlock_lock(&t->lock); |
137 | if ((wq = t->sleep_queue)) { /* assignment */ |
137 | if ((wq = t->sleep_queue)) { /* assignment */ |
138 | if (!spinlock_trylock(&wq->lock)) { |
138 | if (!spinlock_trylock(&wq->lock)) { |
139 | spinlock_unlock(&t->lock); |
139 | spinlock_unlock(&t->lock); |
140 | goto grab_locks; /* avoid deadlock */ |
140 | goto grab_locks; /* avoid deadlock */ |
141 | } |
141 | } |
142 | 142 | ||
143 | list_remove(&t->wq_link); |
143 | list_remove(&t->wq_link); |
144 | t->saved_context = t->sleep_interruption_context; |
144 | t->saved_context = t->sleep_interruption_context; |
145 | do_wakeup = true; |
145 | do_wakeup = true; |
146 | 146 | ||
147 | spinlock_unlock(&wq->lock); |
147 | spinlock_unlock(&wq->lock); |
148 | t->sleep_queue = NULL; |
148 | t->sleep_queue = NULL; |
149 | } |
149 | } |
150 | spinlock_unlock(&t->lock); |
150 | spinlock_unlock(&t->lock); |
151 | 151 | ||
152 | if (do_wakeup) |
152 | if (do_wakeup) |
153 | thread_ready(t); |
153 | thread_ready(t); |
154 | 154 | ||
155 | out: |
155 | out: |
156 | spinlock_unlock(&threads_lock); |
156 | spinlock_unlock(&threads_lock); |
157 | interrupts_restore(ipl); |
157 | interrupts_restore(ipl); |
158 | } |
158 | } |
159 | 159 | ||
160 | /** Sleep until either wakeup, timeout or interruption occurs |
160 | /** Sleep until either wakeup, timeout or interruption occurs |
161 | * |
161 | * |
162 | * This is a sleep implementation which allows itself to be |
162 | * This is a sleep implementation which allows itself to be |
163 | * interrupted from the sleep, restoring a failover context. |
163 | * interrupted from the sleep, restoring a failover context. |
164 | * |
164 | * |
165 | * Sleepers are organised in a FIFO fashion in a structure called wait queue. |
165 | * Sleepers are organised in a FIFO fashion in a structure called wait queue. |
166 | * |
166 | * |
167 | * This function is really basic in that other functions as waitq_sleep() |
167 | * This function is really basic in that other functions as waitq_sleep() |
168 | * and all the *_timeout() functions use it. |
168 | * and all the *_timeout() functions use it. |
169 | * |
169 | * |
170 | * @param wq Pointer to wait queue. |
170 | * @param wq Pointer to wait queue. |
171 | * @param usec Timeout in microseconds. |
171 | * @param usec Timeout in microseconds. |
172 | * @param nonblocking Blocking vs. non-blocking operation mode switch. |
172 | * @param nonblocking Blocking vs. non-blocking operation mode switch. |
173 | * |
173 | * |
174 | * If usec is greater than zero, regardless of the value of nonblocking, |
174 | * If usec is greater than zero, regardless of the value of nonblocking, |
175 | * the call will not return until either timeout or wakeup comes. |
175 | * the call will not return until either timeout or wakeup comes. |
176 | * |
176 | * |
177 | * If usec is zero and @nonblocking is zero (false), the call |
177 | * If usec is zero and @nonblocking is zero (false), the call |
178 | * will not return until wakeup comes. |
178 | * will not return until wakeup comes. |
179 | * |
179 | * |
180 | * If usec is zero and nonblocking is non-zero (true), the call will |
180 | * If usec is zero and nonblocking is non-zero (true), the call will |
181 | * immediately return, reporting either success or failure. |
181 | * immediately return, reporting either success or failure. |
182 | * |
182 | * |
183 | * @return Returns one of: ESYNCH_WOULD_BLOCK, ESYNCH_TIMEOUT, |
183 | * @return Returns one of: ESYNCH_WOULD_BLOCK, ESYNCH_TIMEOUT, |
184 | * ESYNCH_OK_ATOMIC, ESYNCH_OK_BLOCKED. |
184 | * ESYNCH_OK_ATOMIC, ESYNCH_OK_BLOCKED. |
185 | * |
185 | * |
186 | * @li ESYNCH_WOULD_BLOCK means that the sleep failed because at the time |
186 | * @li ESYNCH_WOULD_BLOCK means that the sleep failed because at the time |
187 | * of the call there was no pending wakeup. |
187 | * of the call there was no pending wakeup. |
188 | * |
188 | * |
189 | * @li ESYNCH_TIMEOUT means that the sleep timed out. |
189 | * @li ESYNCH_TIMEOUT means that the sleep timed out. |
190 | * |
190 | * |
191 | * @li ESYNCH_INTERRUPTED means that somebody interrupted the sleeping thread. |
191 | * @li ESYNCH_INTERRUPTED means that somebody interrupted the sleeping thread. |
192 | * |
192 | * |
193 | * @li ESYNCH_OK_ATOMIC means that the sleep succeeded and that there was |
193 | * @li ESYNCH_OK_ATOMIC means that the sleep succeeded and that there was |
194 | * a pending wakeup at the time of the call. The caller was not put |
194 | * a pending wakeup at the time of the call. The caller was not put |
195 | * asleep at all. |
195 | * asleep at all. |
196 | * |
196 | * |
197 | * @li ESYNCH_OK_BLOCKED means that the sleep succeeded; the full sleep was |
197 | * @li ESYNCH_OK_BLOCKED means that the sleep succeeded; the full sleep was |
198 | * attempted. |
198 | * attempted. |
199 | */ |
199 | */ |
200 | int waitq_sleep_timeout(waitq_t *wq, __u32 usec, int nonblocking) |
200 | int waitq_sleep_timeout(waitq_t *wq, __u32 usec, int nonblocking) |
201 | { |
201 | { |
202 | ipl_t ipl; |
202 | ipl_t ipl; |
203 | int rc; |
203 | int rc; |
204 | 204 | ||
205 | ipl = waitq_sleep_prepare(wq); |
205 | ipl = waitq_sleep_prepare(wq); |
206 | rc = waitq_sleep_timeout_unsafe(wq, usec, nonblocking); |
206 | rc = waitq_sleep_timeout_unsafe(wq, usec, nonblocking); |
207 | waitq_sleep_finish(wq, rc, ipl); |
207 | waitq_sleep_finish(wq, rc, ipl); |
208 | return rc; |
208 | return rc; |
209 | } |
209 | } |
210 | 210 | ||
211 | /** Prepare to sleep in a waitq. |
211 | /** Prepare to sleep in a waitq. |
212 | * |
212 | * |
213 | * This function will return holding the lock of the wait queue |
213 | * This function will return holding the lock of the wait queue |
214 | * and interrupts disabled. |
214 | * and interrupts disabled. |
215 | * |
215 | * |
216 | * @param wq Wait queue. |
216 | * @param wq Wait queue. |
217 | * |
217 | * |
218 | * @return Interrupt level as it existed on entry to this function. |
218 | * @return Interrupt level as it existed on entry to this function. |
219 | */ |
219 | */ |
220 | ipl_t waitq_sleep_prepare(waitq_t *wq) |
220 | ipl_t waitq_sleep_prepare(waitq_t *wq) |
221 | { |
221 | { |
222 | ipl_t ipl; |
222 | ipl_t ipl; |
223 | 223 | ||
224 | restart: |
224 | restart: |
225 | ipl = interrupts_disable(); |
225 | ipl = interrupts_disable(); |
226 | 226 | ||
- | 227 | if (THREAD) { /* needed during system initiailzation */ |
|
227 | /* |
228 | /* |
228 | * Busy waiting for a delayed timeout. |
229 | * Busy waiting for a delayed timeout. |
229 | * This is an important fix for the race condition between |
230 | * This is an important fix for the race condition between |
230 | * a delayed timeout and a next call to waitq_sleep_timeout(). |
231 | * a delayed timeout and a next call to waitq_sleep_timeout(). |
231 | * Simply, the thread is not allowed to go to sleep if |
232 | * Simply, the thread is not allowed to go to sleep if |
232 | * there are timeouts in progress. |
233 | * there are timeouts in progress. |
233 | */ |
234 | */ |
234 | spinlock_lock(&THREAD->lock); |
235 | spinlock_lock(&THREAD->lock); |
235 | if (THREAD->timeout_pending) { |
236 | if (THREAD->timeout_pending) { |
- | 237 | spinlock_unlock(&THREAD->lock); |
|
- | 238 | interrupts_restore(ipl); |
|
- | 239 | goto restart; |
|
- | 240 | } |
|
236 | spinlock_unlock(&THREAD->lock); |
241 | spinlock_unlock(&THREAD->lock); |
237 | interrupts_restore(ipl); |
- | |
238 | goto restart; |
- | |
239 | } |
242 | } |
240 | spinlock_unlock(&THREAD->lock); |
- | |
241 | 243 | ||
242 | spinlock_lock(&wq->lock); |
244 | spinlock_lock(&wq->lock); |
243 | return ipl; |
245 | return ipl; |
244 | } |
246 | } |
245 | 247 | ||
246 | /** Finish waiting in a wait queue. |
248 | /** Finish waiting in a wait queue. |
247 | * |
249 | * |
248 | * This function restores interrupts to the state that existed prior |
250 | * This function restores interrupts to the state that existed prior |
249 | * to the call to waitq_sleep_prepare(). If necessary, the wait queue |
251 | * to the call to waitq_sleep_prepare(). If necessary, the wait queue |
250 | * lock is released. |
252 | * lock is released. |
251 | * |
253 | * |
252 | * @param wq Wait queue. |
254 | * @param wq Wait queue. |
253 | * @param rc Return code of waitq_sleep_timeout_unsafe(). |
255 | * @param rc Return code of waitq_sleep_timeout_unsafe(). |
254 | * @param ipl Interrupt level returned by waitq_sleep_prepare(). |
256 | * @param ipl Interrupt level returned by waitq_sleep_prepare(). |
255 | */ |
257 | */ |
256 | void waitq_sleep_finish(waitq_t *wq, int rc, ipl_t ipl) |
258 | void waitq_sleep_finish(waitq_t *wq, int rc, ipl_t ipl) |
257 | { |
259 | { |
258 | switch (rc) { |
260 | switch (rc) { |
259 | case ESYNCH_WOULD_BLOCK: |
261 | case ESYNCH_WOULD_BLOCK: |
260 | case ESYNCH_OK_ATOMIC: |
262 | case ESYNCH_OK_ATOMIC: |
261 | spinlock_unlock(&wq->lock); |
263 | spinlock_unlock(&wq->lock); |
262 | break; |
264 | break; |
263 | default: |
265 | default: |
264 | break; |
266 | break; |
265 | } |
267 | } |
266 | interrupts_restore(ipl); |
268 | interrupts_restore(ipl); |
267 | } |
269 | } |
268 | 270 | ||
269 | /** Internal implementation of waitq_sleep_timeout(). |
271 | /** Internal implementation of waitq_sleep_timeout(). |
270 | * |
272 | * |
271 | * This function implements logic of sleeping in a wait queue. |
273 | * This function implements logic of sleeping in a wait queue. |
272 | * This call must be preceeded by a call to waitq_sleep_prepare() |
274 | * This call must be preceeded by a call to waitq_sleep_prepare() |
273 | * and followed by a call to waitq_slee_finish(). |
275 | * and followed by a call to waitq_slee_finish(). |
274 | * |
276 | * |
275 | * @param wq See waitq_sleep_timeout(). |
277 | * @param wq See waitq_sleep_timeout(). |
276 | * @param usec See waitq_sleep_timeout(). |
278 | * @param usec See waitq_sleep_timeout(). |
277 | * @param nonblocking See waitq_sleep_timeout(). |
279 | * @param nonblocking See waitq_sleep_timeout(). |
278 | * |
280 | * |
279 | * @return See waitq_sleep_timeout(). |
281 | * @return See waitq_sleep_timeout(). |
280 | */ |
282 | */ |
281 | int waitq_sleep_timeout_unsafe(waitq_t *wq, __u32 usec, int nonblocking) |
283 | int waitq_sleep_timeout_unsafe(waitq_t *wq, __u32 usec, int nonblocking) |
282 | { |
284 | { |
283 | /* checks whether to go to sleep at all */ |
285 | /* checks whether to go to sleep at all */ |
284 | if (wq->missed_wakeups) { |
286 | if (wq->missed_wakeups) { |
285 | wq->missed_wakeups--; |
287 | wq->missed_wakeups--; |
286 | return ESYNCH_OK_ATOMIC; |
288 | return ESYNCH_OK_ATOMIC; |
287 | } |
289 | } |
288 | else { |
290 | else { |
289 | if (nonblocking && (usec == 0)) { |
291 | if (nonblocking && (usec == 0)) { |
290 | /* return immediatelly instead of going to sleep */ |
292 | /* return immediatelly instead of going to sleep */ |
291 | return ESYNCH_WOULD_BLOCK; |
293 | return ESYNCH_WOULD_BLOCK; |
292 | } |
294 | } |
293 | } |
295 | } |
294 | 296 | ||
295 | /* |
297 | /* |
296 | * Now we are firmly decided to go to sleep. |
298 | * Now we are firmly decided to go to sleep. |
297 | */ |
299 | */ |
298 | spinlock_lock(&THREAD->lock); |
300 | spinlock_lock(&THREAD->lock); |
299 | 301 | ||
300 | /* |
302 | /* |
301 | * Set context that will be restored if the sleep |
303 | * Set context that will be restored if the sleep |
302 | * of this thread is ever interrupted. |
304 | * of this thread is ever interrupted. |
303 | */ |
305 | */ |
304 | if (!context_save(&THREAD->sleep_interruption_context)) { |
306 | if (!context_save(&THREAD->sleep_interruption_context)) { |
305 | /* Short emulation of scheduler() return code. */ |
307 | /* Short emulation of scheduler() return code. */ |
306 | spinlock_unlock(&THREAD->lock); |
308 | spinlock_unlock(&THREAD->lock); |
307 | return ESYNCH_INTERRUPTED; |
309 | return ESYNCH_INTERRUPTED; |
308 | } |
310 | } |
309 | 311 | ||
310 | if (usec) { |
312 | if (usec) { |
311 | /* We use the timeout variant. */ |
313 | /* We use the timeout variant. */ |
312 | if (!context_save(&THREAD->sleep_timeout_context)) { |
314 | if (!context_save(&THREAD->sleep_timeout_context)) { |
313 | /* Short emulation of scheduler() return code. */ |
315 | /* Short emulation of scheduler() return code. */ |
314 | spinlock_unlock(&THREAD->lock); |
316 | spinlock_unlock(&THREAD->lock); |
315 | return ESYNCH_TIMEOUT; |
317 | return ESYNCH_TIMEOUT; |
316 | } |
318 | } |
317 | THREAD->timeout_pending = true; |
319 | THREAD->timeout_pending = true; |
318 | timeout_register(&THREAD->sleep_timeout, (__u64) usec, waitq_timeouted_sleep, THREAD); |
320 | timeout_register(&THREAD->sleep_timeout, (__u64) usec, waitq_timeouted_sleep, THREAD); |
319 | } |
321 | } |
320 | 322 | ||
321 | list_append(&THREAD->wq_link, &wq->head); |
323 | list_append(&THREAD->wq_link, &wq->head); |
322 | 324 | ||
323 | /* |
325 | /* |
324 | * Suspend execution. |
326 | * Suspend execution. |
325 | */ |
327 | */ |
326 | THREAD->state = Sleeping; |
328 | THREAD->state = Sleeping; |
327 | THREAD->sleep_queue = wq; |
329 | THREAD->sleep_queue = wq; |
328 | 330 | ||
329 | spinlock_unlock(&THREAD->lock); |
331 | spinlock_unlock(&THREAD->lock); |
330 | 332 | ||
331 | scheduler(); /* wq->lock is released in scheduler_separated_stack() */ |
333 | scheduler(); /* wq->lock is released in scheduler_separated_stack() */ |
332 | 334 | ||
333 | return ESYNCH_OK_BLOCKED; |
335 | return ESYNCH_OK_BLOCKED; |
334 | } |
336 | } |
335 | 337 | ||
336 | 338 | ||
337 | /** Wake up first thread sleeping in a wait queue |
339 | /** Wake up first thread sleeping in a wait queue |
338 | * |
340 | * |
339 | * Wake up first thread sleeping in a wait queue. |
341 | * Wake up first thread sleeping in a wait queue. |
340 | * This is the SMP- and IRQ-safe wrapper meant for |
342 | * This is the SMP- and IRQ-safe wrapper meant for |
341 | * general use. |
343 | * general use. |
342 | * |
344 | * |
343 | * Besides its 'normal' wakeup operation, it attempts |
345 | * Besides its 'normal' wakeup operation, it attempts |
344 | * to unregister possible timeout. |
346 | * to unregister possible timeout. |
345 | * |
347 | * |
346 | * @param wq Pointer to wait queue. |
348 | * @param wq Pointer to wait queue. |
347 | * @param all If this is non-zero, all sleeping threads |
349 | * @param all If this is non-zero, all sleeping threads |
348 | * will be woken up and missed count will be zeroed. |
350 | * will be woken up and missed count will be zeroed. |
349 | */ |
351 | */ |
350 | void waitq_wakeup(waitq_t *wq, bool all) |
352 | void waitq_wakeup(waitq_t *wq, bool all) |
351 | { |
353 | { |
352 | ipl_t ipl; |
354 | ipl_t ipl; |
353 | 355 | ||
354 | ipl = interrupts_disable(); |
356 | ipl = interrupts_disable(); |
355 | spinlock_lock(&wq->lock); |
357 | spinlock_lock(&wq->lock); |
356 | 358 | ||
357 | _waitq_wakeup_unsafe(wq, all); |
359 | _waitq_wakeup_unsafe(wq, all); |
358 | 360 | ||
359 | spinlock_unlock(&wq->lock); |
361 | spinlock_unlock(&wq->lock); |
360 | interrupts_restore(ipl); |
362 | interrupts_restore(ipl); |
361 | } |
363 | } |
362 | 364 | ||
363 | /** Internal SMP- and IRQ-unsafe version of waitq_wakeup() |
365 | /** Internal SMP- and IRQ-unsafe version of waitq_wakeup() |
364 | * |
366 | * |
365 | * This is the internal SMP- and IRQ-unsafe version |
367 | * This is the internal SMP- and IRQ-unsafe version |
366 | * of waitq_wakeup(). It assumes wq->lock is already |
368 | * of waitq_wakeup(). It assumes wq->lock is already |
367 | * locked and interrupts are already disabled. |
369 | * locked and interrupts are already disabled. |
368 | * |
370 | * |
369 | * @param wq Pointer to wait queue. |
371 | * @param wq Pointer to wait queue. |
370 | * @param all If this is non-zero, all sleeping threads |
372 | * @param all If this is non-zero, all sleeping threads |
371 | * will be woken up and missed count will be zeroed. |
373 | * will be woken up and missed count will be zeroed. |
372 | */ |
374 | */ |
373 | void _waitq_wakeup_unsafe(waitq_t *wq, bool all) |
375 | void _waitq_wakeup_unsafe(waitq_t *wq, bool all) |
374 | { |
376 | { |
375 | thread_t *t; |
377 | thread_t *t; |
376 | 378 | ||
377 | loop: |
379 | loop: |
378 | if (list_empty(&wq->head)) { |
380 | if (list_empty(&wq->head)) { |
379 | wq->missed_wakeups++; |
381 | wq->missed_wakeups++; |
380 | if (all) |
382 | if (all) |
381 | wq->missed_wakeups = 0; |
383 | wq->missed_wakeups = 0; |
382 | return; |
384 | return; |
383 | } |
385 | } |
384 | 386 | ||
385 | t = list_get_instance(wq->head.next, thread_t, wq_link); |
387 | t = list_get_instance(wq->head.next, thread_t, wq_link); |
386 | 388 | ||
387 | list_remove(&t->wq_link); |
389 | list_remove(&t->wq_link); |
388 | spinlock_lock(&t->lock); |
390 | spinlock_lock(&t->lock); |
389 | if (t->timeout_pending && timeout_unregister(&t->sleep_timeout)) |
391 | if (t->timeout_pending && timeout_unregister(&t->sleep_timeout)) |
390 | t->timeout_pending = false; |
392 | t->timeout_pending = false; |
391 | t->sleep_queue = NULL; |
393 | t->sleep_queue = NULL; |
392 | spinlock_unlock(&t->lock); |
394 | spinlock_unlock(&t->lock); |
393 | 395 | ||
394 | thread_ready(t); |
396 | thread_ready(t); |
395 | 397 | ||
396 | if (all) |
398 | if (all) |
397 | goto loop; |
399 | goto loop; |
398 | } |
400 | } |
399 | 401 |