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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 (!(t->sleep_interruptible)) { |
138 | if (!(t->sleep_interruptible)) { |
139 | /* |
139 | /* |
140 | * The sleep cannot be interrupted. |
140 | * The sleep cannot be interrupted. |
141 | */ |
141 | */ |
142 | spinlock_unlock(&t->lock); |
142 | spinlock_unlock(&t->lock); |
143 | goto out; |
143 | goto out; |
144 | } |
144 | } |
145 | 145 | ||
146 | if (!spinlock_trylock(&wq->lock)) { |
146 | if (!spinlock_trylock(&wq->lock)) { |
147 | spinlock_unlock(&t->lock); |
147 | spinlock_unlock(&t->lock); |
148 | goto grab_locks; /* avoid deadlock */ |
148 | goto grab_locks; /* avoid deadlock */ |
149 | } |
149 | } |
150 | 150 | ||
- | 151 | if (t->timeout_pending && timeout_unregister(&t->sleep_timeout)) |
|
- | 152 | t->timeout_pending = false; |
|
- | 153 | ||
151 | list_remove(&t->wq_link); |
154 | list_remove(&t->wq_link); |
152 | t->saved_context = t->sleep_interruption_context; |
155 | t->saved_context = t->sleep_interruption_context; |
153 | do_wakeup = true; |
156 | do_wakeup = true; |
154 | 157 | ||
155 | spinlock_unlock(&wq->lock); |
158 | spinlock_unlock(&wq->lock); |
156 | t->sleep_queue = NULL; |
159 | t->sleep_queue = NULL; |
157 | } |
160 | } |
158 | spinlock_unlock(&t->lock); |
161 | spinlock_unlock(&t->lock); |
159 | 162 | ||
160 | if (do_wakeup) |
163 | if (do_wakeup) |
161 | thread_ready(t); |
164 | thread_ready(t); |
162 | 165 | ||
163 | out: |
166 | out: |
164 | spinlock_unlock(&threads_lock); |
167 | spinlock_unlock(&threads_lock); |
165 | interrupts_restore(ipl); |
168 | interrupts_restore(ipl); |
166 | } |
169 | } |
167 | 170 | ||
168 | /** Sleep until either wakeup, timeout or interruption occurs |
171 | /** Sleep until either wakeup, timeout or interruption occurs |
169 | * |
172 | * |
170 | * This is a sleep implementation which allows itself to time out or to be |
173 | * This is a sleep implementation which allows itself to time out or to be |
171 | * interrupted from the sleep, restoring a failover context. |
174 | * interrupted from the sleep, restoring a failover context. |
172 | * |
175 | * |
173 | * Sleepers are organised in a FIFO fashion in a structure called wait queue. |
176 | * Sleepers are organised in a FIFO fashion in a structure called wait queue. |
174 | * |
177 | * |
175 | * This function is really basic in that other functions as waitq_sleep() |
178 | * This function is really basic in that other functions as waitq_sleep() |
176 | * and all the *_timeout() functions use it. |
179 | * and all the *_timeout() functions use it. |
177 | * |
180 | * |
178 | * @param wq Pointer to wait queue. |
181 | * @param wq Pointer to wait queue. |
179 | * @param usec Timeout in microseconds. |
182 | * @param usec Timeout in microseconds. |
180 | * @param flags Specify mode of the sleep. |
183 | * @param flags Specify mode of the sleep. |
181 | * |
184 | * |
182 | * The sleep can be interrupted only if the |
185 | * The sleep can be interrupted only if the |
183 | * SYNCH_FLAGS_INTERRUPTIBLE bit is specified in flags. |
186 | * SYNCH_FLAGS_INTERRUPTIBLE bit is specified in flags. |
184 | |
187 | |
185 | * If usec is greater than zero, regardless of the value of the |
188 | * If usec is greater than zero, regardless of the value of the |
186 | * SYNCH_FLAGS_NON_BLOCKING bit in flags, the call will not return until either timeout, |
189 | * SYNCH_FLAGS_NON_BLOCKING bit in flags, the call will not return until either timeout, |
187 | * interruption or wakeup comes. |
190 | * interruption or wakeup comes. |
188 | * |
191 | * |
189 | * If usec is zero and the SYNCH_FLAGS_NON_BLOCKING bit is not set in flags, the call |
192 | * If usec is zero and the SYNCH_FLAGS_NON_BLOCKING bit is not set in flags, the call |
190 | * will not return until wakeup or interruption comes. |
193 | * will not return until wakeup or interruption comes. |
191 | * |
194 | * |
192 | * If usec is zero and the SYNCH_FLAGS_NON_BLOCKING bit is set in flags, the call will |
195 | * If usec is zero and the SYNCH_FLAGS_NON_BLOCKING bit is set in flags, the call will |
193 | * immediately return, reporting either success or failure. |
196 | * immediately return, reporting either success or failure. |
194 | * |
197 | * |
195 | * @return Returns one of: ESYNCH_WOULD_BLOCK, ESYNCH_TIMEOUT, ESYNCH_INTERRUPTED, |
198 | * @return Returns one of: ESYNCH_WOULD_BLOCK, ESYNCH_TIMEOUT, ESYNCH_INTERRUPTED, |
196 | * ESYNCH_OK_ATOMIC, ESYNCH_OK_BLOCKED. |
199 | * ESYNCH_OK_ATOMIC, ESYNCH_OK_BLOCKED. |
197 | * |
200 | * |
198 | * @li ESYNCH_WOULD_BLOCK means that the sleep failed because at the time |
201 | * @li ESYNCH_WOULD_BLOCK means that the sleep failed because at the time |
199 | * of the call there was no pending wakeup. |
202 | * of the call there was no pending wakeup. |
200 | * |
203 | * |
201 | * @li ESYNCH_TIMEOUT means that the sleep timed out. |
204 | * @li ESYNCH_TIMEOUT means that the sleep timed out. |
202 | * |
205 | * |
203 | * @li ESYNCH_INTERRUPTED means that somebody interrupted the sleeping thread. |
206 | * @li ESYNCH_INTERRUPTED means that somebody interrupted the sleeping thread. |
204 | * |
207 | * |
205 | * @li ESYNCH_OK_ATOMIC means that the sleep succeeded and that there was |
208 | * @li ESYNCH_OK_ATOMIC means that the sleep succeeded and that there was |
206 | * a pending wakeup at the time of the call. The caller was not put |
209 | * a pending wakeup at the time of the call. The caller was not put |
207 | * asleep at all. |
210 | * asleep at all. |
208 | * |
211 | * |
209 | * @li ESYNCH_OK_BLOCKED means that the sleep succeeded; the full sleep was |
212 | * @li ESYNCH_OK_BLOCKED means that the sleep succeeded; the full sleep was |
210 | * attempted. |
213 | * attempted. |
211 | */ |
214 | */ |
212 | int waitq_sleep_timeout(waitq_t *wq, __u32 usec, int flags) |
215 | int waitq_sleep_timeout(waitq_t *wq, __u32 usec, int flags) |
213 | { |
216 | { |
214 | ipl_t ipl; |
217 | ipl_t ipl; |
215 | int rc; |
218 | int rc; |
216 | 219 | ||
217 | ipl = waitq_sleep_prepare(wq); |
220 | ipl = waitq_sleep_prepare(wq); |
218 | rc = waitq_sleep_timeout_unsafe(wq, usec, flags); |
221 | rc = waitq_sleep_timeout_unsafe(wq, usec, flags); |
219 | waitq_sleep_finish(wq, rc, ipl); |
222 | waitq_sleep_finish(wq, rc, ipl); |
220 | return rc; |
223 | return rc; |
221 | } |
224 | } |
222 | 225 | ||
223 | /** Prepare to sleep in a waitq. |
226 | /** Prepare to sleep in a waitq. |
224 | * |
227 | * |
225 | * This function will return holding the lock of the wait queue |
228 | * This function will return holding the lock of the wait queue |
226 | * and interrupts disabled. |
229 | * and interrupts disabled. |
227 | * |
230 | * |
228 | * @param wq Wait queue. |
231 | * @param wq Wait queue. |
229 | * |
232 | * |
230 | * @return Interrupt level as it existed on entry to this function. |
233 | * @return Interrupt level as it existed on entry to this function. |
231 | */ |
234 | */ |
232 | ipl_t waitq_sleep_prepare(waitq_t *wq) |
235 | ipl_t waitq_sleep_prepare(waitq_t *wq) |
233 | { |
236 | { |
234 | ipl_t ipl; |
237 | ipl_t ipl; |
235 | 238 | ||
236 | restart: |
239 | restart: |
237 | ipl = interrupts_disable(); |
240 | ipl = interrupts_disable(); |
238 | 241 | ||
239 | if (THREAD) { /* needed during system initiailzation */ |
242 | if (THREAD) { /* needed during system initiailzation */ |
240 | /* |
243 | /* |
241 | * Busy waiting for a delayed timeout. |
244 | * Busy waiting for a delayed timeout. |
242 | * This is an important fix for the race condition between |
245 | * This is an important fix for the race condition between |
243 | * a delayed timeout and a next call to waitq_sleep_timeout(). |
246 | * a delayed timeout and a next call to waitq_sleep_timeout(). |
244 | * Simply, the thread is not allowed to go to sleep if |
247 | * Simply, the thread is not allowed to go to sleep if |
245 | * there are timeouts in progress. |
248 | * there are timeouts in progress. |
246 | */ |
249 | */ |
247 | spinlock_lock(&THREAD->lock); |
250 | spinlock_lock(&THREAD->lock); |
248 | if (THREAD->timeout_pending) { |
251 | if (THREAD->timeout_pending) { |
249 | spinlock_unlock(&THREAD->lock); |
252 | spinlock_unlock(&THREAD->lock); |
250 | interrupts_restore(ipl); |
253 | interrupts_restore(ipl); |
251 | goto restart; |
254 | goto restart; |
252 | } |
255 | } |
253 | spinlock_unlock(&THREAD->lock); |
256 | spinlock_unlock(&THREAD->lock); |
254 | } |
257 | } |
255 | 258 | ||
256 | spinlock_lock(&wq->lock); |
259 | spinlock_lock(&wq->lock); |
257 | return ipl; |
260 | return ipl; |
258 | } |
261 | } |
259 | 262 | ||
260 | /** Finish waiting in a wait queue. |
263 | /** Finish waiting in a wait queue. |
261 | * |
264 | * |
262 | * This function restores interrupts to the state that existed prior |
265 | * This function restores interrupts to the state that existed prior |
263 | * to the call to waitq_sleep_prepare(). If necessary, the wait queue |
266 | * to the call to waitq_sleep_prepare(). If necessary, the wait queue |
264 | * lock is released. |
267 | * lock is released. |
265 | * |
268 | * |
266 | * @param wq Wait queue. |
269 | * @param wq Wait queue. |
267 | * @param rc Return code of waitq_sleep_timeout_unsafe(). |
270 | * @param rc Return code of waitq_sleep_timeout_unsafe(). |
268 | * @param ipl Interrupt level returned by waitq_sleep_prepare(). |
271 | * @param ipl Interrupt level returned by waitq_sleep_prepare(). |
269 | */ |
272 | */ |
270 | void waitq_sleep_finish(waitq_t *wq, int rc, ipl_t ipl) |
273 | void waitq_sleep_finish(waitq_t *wq, int rc, ipl_t ipl) |
271 | { |
274 | { |
272 | switch (rc) { |
275 | switch (rc) { |
273 | case ESYNCH_WOULD_BLOCK: |
276 | case ESYNCH_WOULD_BLOCK: |
274 | case ESYNCH_OK_ATOMIC: |
277 | case ESYNCH_OK_ATOMIC: |
275 | spinlock_unlock(&wq->lock); |
278 | spinlock_unlock(&wq->lock); |
276 | break; |
279 | break; |
277 | default: |
280 | default: |
278 | break; |
281 | break; |
279 | } |
282 | } |
280 | interrupts_restore(ipl); |
283 | interrupts_restore(ipl); |
281 | } |
284 | } |
282 | 285 | ||
283 | /** Internal implementation of waitq_sleep_timeout(). |
286 | /** Internal implementation of waitq_sleep_timeout(). |
284 | * |
287 | * |
285 | * This function implements logic of sleeping in a wait queue. |
288 | * This function implements logic of sleeping in a wait queue. |
286 | * This call must be preceeded by a call to waitq_sleep_prepare() |
289 | * This call must be preceeded by a call to waitq_sleep_prepare() |
287 | * and followed by a call to waitq_slee_finish(). |
290 | * and followed by a call to waitq_slee_finish(). |
288 | * |
291 | * |
289 | * @param wq See waitq_sleep_timeout(). |
292 | * @param wq See waitq_sleep_timeout(). |
290 | * @param usec See waitq_sleep_timeout(). |
293 | * @param usec See waitq_sleep_timeout(). |
291 | * @param flags See waitq_sleep_timeout(). |
294 | * @param flags See waitq_sleep_timeout(). |
292 | * |
295 | * |
293 | * @return See waitq_sleep_timeout(). |
296 | * @return See waitq_sleep_timeout(). |
294 | */ |
297 | */ |
295 | int waitq_sleep_timeout_unsafe(waitq_t *wq, __u32 usec, int flags) |
298 | int waitq_sleep_timeout_unsafe(waitq_t *wq, __u32 usec, int flags) |
296 | { |
299 | { |
297 | /* checks whether to go to sleep at all */ |
300 | /* checks whether to go to sleep at all */ |
298 | if (wq->missed_wakeups) { |
301 | if (wq->missed_wakeups) { |
299 | wq->missed_wakeups--; |
302 | wq->missed_wakeups--; |
300 | return ESYNCH_OK_ATOMIC; |
303 | return ESYNCH_OK_ATOMIC; |
301 | } |
304 | } |
302 | else { |
305 | else { |
303 | if ((flags & SYNCH_FLAGS_NON_BLOCKING) && (usec == 0)) { |
306 | if ((flags & SYNCH_FLAGS_NON_BLOCKING) && (usec == 0)) { |
304 | /* return immediatelly instead of going to sleep */ |
307 | /* return immediatelly instead of going to sleep */ |
305 | return ESYNCH_WOULD_BLOCK; |
308 | return ESYNCH_WOULD_BLOCK; |
306 | } |
309 | } |
307 | } |
310 | } |
308 | 311 | ||
309 | /* |
312 | /* |
310 | * Now we are firmly decided to go to sleep. |
313 | * Now we are firmly decided to go to sleep. |
311 | */ |
314 | */ |
312 | spinlock_lock(&THREAD->lock); |
315 | spinlock_lock(&THREAD->lock); |
313 | 316 | ||
314 | if (flags & SYNCH_FLAGS_INTERRUPTIBLE) { |
317 | if (flags & SYNCH_FLAGS_INTERRUPTIBLE) { |
315 | 318 | ||
316 | /* |
319 | /* |
317 | * If the thread was already interrupted, |
320 | * If the thread was already interrupted, |
318 | * don't go to sleep at all. |
321 | * don't go to sleep at all. |
319 | */ |
322 | */ |
320 | if (THREAD->interrupted) { |
323 | if (THREAD->interrupted) { |
321 | spinlock_unlock(&THREAD->lock); |
324 | spinlock_unlock(&THREAD->lock); |
322 | spinlock_unlock(&wq->lock); |
325 | spinlock_unlock(&wq->lock); |
323 | return ESYNCH_INTERRUPTED; |
326 | return ESYNCH_INTERRUPTED; |
324 | } |
327 | } |
325 | 328 | ||
326 | /* |
329 | /* |
327 | * Set context that will be restored if the sleep |
330 | * Set context that will be restored if the sleep |
328 | * of this thread is ever interrupted. |
331 | * of this thread is ever interrupted. |
329 | */ |
332 | */ |
330 | THREAD->sleep_interruptible = true; |
333 | THREAD->sleep_interruptible = true; |
331 | if (!context_save(&THREAD->sleep_interruption_context)) { |
334 | if (!context_save(&THREAD->sleep_interruption_context)) { |
332 | /* Short emulation of scheduler() return code. */ |
335 | /* Short emulation of scheduler() return code. */ |
333 | spinlock_unlock(&THREAD->lock); |
336 | spinlock_unlock(&THREAD->lock); |
334 | return ESYNCH_INTERRUPTED; |
337 | return ESYNCH_INTERRUPTED; |
335 | } |
338 | } |
336 | 339 | ||
337 | } else { |
340 | } else { |
338 | THREAD->sleep_interruptible = false; |
341 | THREAD->sleep_interruptible = false; |
339 | } |
342 | } |
340 | 343 | ||
341 | if (usec) { |
344 | if (usec) { |
342 | /* We use the timeout variant. */ |
345 | /* We use the timeout variant. */ |
343 | if (!context_save(&THREAD->sleep_timeout_context)) { |
346 | if (!context_save(&THREAD->sleep_timeout_context)) { |
344 | /* Short emulation of scheduler() return code. */ |
347 | /* Short emulation of scheduler() return code. */ |
345 | spinlock_unlock(&THREAD->lock); |
348 | spinlock_unlock(&THREAD->lock); |
346 | return ESYNCH_TIMEOUT; |
349 | return ESYNCH_TIMEOUT; |
347 | } |
350 | } |
348 | THREAD->timeout_pending = true; |
351 | THREAD->timeout_pending = true; |
349 | timeout_register(&THREAD->sleep_timeout, (__u64) usec, waitq_timeouted_sleep, THREAD); |
352 | timeout_register(&THREAD->sleep_timeout, (__u64) usec, waitq_timeouted_sleep, THREAD); |
350 | } |
353 | } |
351 | 354 | ||
352 | list_append(&THREAD->wq_link, &wq->head); |
355 | list_append(&THREAD->wq_link, &wq->head); |
353 | 356 | ||
354 | /* |
357 | /* |
355 | * Suspend execution. |
358 | * Suspend execution. |
356 | */ |
359 | */ |
357 | THREAD->state = Sleeping; |
360 | THREAD->state = Sleeping; |
358 | THREAD->sleep_queue = wq; |
361 | THREAD->sleep_queue = wq; |
359 | 362 | ||
360 | spinlock_unlock(&THREAD->lock); |
363 | spinlock_unlock(&THREAD->lock); |
361 | 364 | ||
362 | scheduler(); /* wq->lock is released in scheduler_separated_stack() */ |
365 | scheduler(); /* wq->lock is released in scheduler_separated_stack() */ |
363 | 366 | ||
364 | return ESYNCH_OK_BLOCKED; |
367 | return ESYNCH_OK_BLOCKED; |
365 | } |
368 | } |
366 | 369 | ||
367 | 370 | ||
368 | /** Wake up first thread sleeping in a wait queue |
371 | /** Wake up first thread sleeping in a wait queue |
369 | * |
372 | * |
370 | * Wake up first thread sleeping in a wait queue. |
373 | * Wake up first thread sleeping in a wait queue. |
371 | * This is the SMP- and IRQ-safe wrapper meant for |
374 | * This is the SMP- and IRQ-safe wrapper meant for |
372 | * general use. |
375 | * general use. |
373 | * |
376 | * |
374 | * Besides its 'normal' wakeup operation, it attempts |
377 | * Besides its 'normal' wakeup operation, it attempts |
375 | * to unregister possible timeout. |
378 | * to unregister possible timeout. |
376 | * |
379 | * |
377 | * @param wq Pointer to wait queue. |
380 | * @param wq Pointer to wait queue. |
378 | * @param all If this is non-zero, all sleeping threads |
381 | * @param all If this is non-zero, all sleeping threads |
379 | * will be woken up and missed count will be zeroed. |
382 | * will be woken up and missed count will be zeroed. |
380 | */ |
383 | */ |
381 | void waitq_wakeup(waitq_t *wq, bool all) |
384 | void waitq_wakeup(waitq_t *wq, bool all) |
382 | { |
385 | { |
383 | ipl_t ipl; |
386 | ipl_t ipl; |
384 | 387 | ||
385 | ipl = interrupts_disable(); |
388 | ipl = interrupts_disable(); |
386 | spinlock_lock(&wq->lock); |
389 | spinlock_lock(&wq->lock); |
387 | 390 | ||
388 | _waitq_wakeup_unsafe(wq, all); |
391 | _waitq_wakeup_unsafe(wq, all); |
389 | 392 | ||
390 | spinlock_unlock(&wq->lock); |
393 | spinlock_unlock(&wq->lock); |
391 | interrupts_restore(ipl); |
394 | interrupts_restore(ipl); |
392 | } |
395 | } |
393 | 396 | ||
394 | /** Internal SMP- and IRQ-unsafe version of waitq_wakeup() |
397 | /** Internal SMP- and IRQ-unsafe version of waitq_wakeup() |
395 | * |
398 | * |
396 | * This is the internal SMP- and IRQ-unsafe version |
399 | * This is the internal SMP- and IRQ-unsafe version |
397 | * of waitq_wakeup(). It assumes wq->lock is already |
400 | * of waitq_wakeup(). It assumes wq->lock is already |
398 | * locked and interrupts are already disabled. |
401 | * locked and interrupts are already disabled. |
399 | * |
402 | * |
400 | * @param wq Pointer to wait queue. |
403 | * @param wq Pointer to wait queue. |
401 | * @param all If this is non-zero, all sleeping threads |
404 | * @param all If this is non-zero, all sleeping threads |
402 | * will be woken up and missed count will be zeroed. |
405 | * will be woken up and missed count will be zeroed. |
403 | */ |
406 | */ |
404 | void _waitq_wakeup_unsafe(waitq_t *wq, bool all) |
407 | void _waitq_wakeup_unsafe(waitq_t *wq, bool all) |
405 | { |
408 | { |
406 | thread_t *t; |
409 | thread_t *t; |
407 | 410 | ||
408 | loop: |
411 | loop: |
409 | if (list_empty(&wq->head)) { |
412 | if (list_empty(&wq->head)) { |
410 | wq->missed_wakeups++; |
413 | wq->missed_wakeups++; |
411 | if (all) |
414 | if (all) |
412 | wq->missed_wakeups = 0; |
415 | wq->missed_wakeups = 0; |
413 | return; |
416 | return; |
414 | } |
417 | } |
415 | 418 | ||
416 | t = list_get_instance(wq->head.next, thread_t, wq_link); |
419 | t = list_get_instance(wq->head.next, thread_t, wq_link); |
417 | 420 | ||
418 | list_remove(&t->wq_link); |
421 | list_remove(&t->wq_link); |
419 | spinlock_lock(&t->lock); |
422 | spinlock_lock(&t->lock); |
420 | if (t->timeout_pending && timeout_unregister(&t->sleep_timeout)) |
423 | if (t->timeout_pending && timeout_unregister(&t->sleep_timeout)) |
421 | t->timeout_pending = false; |
424 | t->timeout_pending = false; |
422 | t->sleep_queue = NULL; |
425 | t->sleep_queue = NULL; |
423 | spinlock_unlock(&t->lock); |
426 | spinlock_unlock(&t->lock); |
424 | 427 | ||
425 | thread_ready(t); |
428 | thread_ready(t); |
426 | 429 | ||
427 | if (all) |
430 | if (all) |
428 | goto loop; |
431 | goto loop; |
429 | } |
432 | } |
430 | 433 |