1 /***************************************************************************
2 * Copyright (c) 2024 Microsoft Corporation
3 *
4 * This program and the accompanying materials are made available under the
5 * terms of the MIT License which is available at
6 * https://opensource.org/licenses/MIT.
7 *
8 * SPDX-License-Identifier: MIT
9 **************************************************************************/
10
11
12 /**************************************************************************/
13 /**************************************************************************/
14 /** */
15 /** ThreadX Component */
16 /** */
17 /** Mutex */
18 /** */
19 /**************************************************************************/
20 /**************************************************************************/
21
22 #define TX_SOURCE_CODE
23 #define TX_THREAD_SMP_SOURCE_CODE
24
25
26 /* Include necessary system files. */
27
28 #include "tx_api.h"
29 #include "tx_thread.h"
30 #include "tx_mutex.h"
31
32
33 /**************************************************************************/
34 /* */
35 /* FUNCTION RELEASE */
36 /* */
37 /* _tx_mutex_priority_change PORTABLE SMP */
38 /* 6.1 */
39 /* AUTHOR */
40 /* */
41 /* William E. Lamie, Microsoft Corporation */
42 /* */
43 /* DESCRIPTION */
44 /* */
45 /* This function changes the priority of the specified thread for the */
46 /* priority inheritance option of the mutex service. */
47 /* */
48 /* INPUT */
49 /* */
50 /* thread_ptr Pointer to thread to suspend */
51 /* new_priority New thread priority */
52 /* new_threshold New preemption-threshold */
53 /* */
54 /* OUTPUT */
55 /* */
56 /* None */
57 /* */
58 /* CALLS */
59 /* */
60 /* _tx_thread_smp_rebalance_execute_list */
61 /* Rebalance the execution list */
62 /* _tx_thread_smp_simple_priority_change */
63 /* Change priority */
64 /* _tx_thread_system_resume Resume thread */
65 /* _tx_thread_system_ni_resume Non-interruptable resume thread */
66 /* _tx_thread_system_suspend Suspend thread */
67 /* _tx_thread_system_ni_suspend Non-interruptable suspend thread */
68 /* */
69 /* CALLED BY */
70 /* */
71 /* _tx_mutex_get Inherit priority */
72 /* _tx_mutex_put Restore previous priority */
73 /* */
74 /* RELEASE HISTORY */
75 /* */
76 /* DATE NAME DESCRIPTION */
77 /* */
78 /* 09-30-2020 William E. Lamie Initial Version 6.1 */
79 /* */
80 /**************************************************************************/
_tx_mutex_priority_change(TX_THREAD * thread_ptr,UINT new_priority)81 VOID _tx_mutex_priority_change(TX_THREAD *thread_ptr, UINT new_priority)
82 {
83
84 #ifndef TX_NOT_INTERRUPTABLE
85
86 TX_INTERRUPT_SAVE_AREA
87 #endif
88
89 TX_THREAD *execute_ptr;
90 UINT core_index;
91 UINT original_priority;
92 UINT lowest_priority;
93 TX_THREAD *original_pt_thread;
94 #ifndef TX_DISABLE_PREEMPTION_THRESHOLD
95 TX_THREAD *new_pt_thread;
96 UINT priority;
97 ULONG priority_bit;
98 #if TX_MAX_PRIORITIES > 32
99 UINT map_index;
100 #endif
101 #endif
102 UINT finished;
103
104
105 /* Default finished to false. */
106 finished = TX_FALSE;
107
108 #ifndef TX_NOT_INTERRUPTABLE
109
110 /* Lockout interrupts while the thread is being suspended. */
111 TX_DISABLE
112 #endif
113
114 /* Determine if there is anything to do. */
115 if (thread_ptr -> tx_thread_priority == new_priority)
116 {
117
118 if (thread_ptr -> tx_thread_preempt_threshold == new_priority)
119 {
120
121 /* Set the finished flag to true. */
122 finished = TX_TRUE;
123 }
124 }
125
126 /* Determine if there is still more to do. */
127 if (finished == TX_FALSE)
128 {
129
130 /* Default the execute pointer to NULL. */
131 execute_ptr = TX_NULL;
132
133 /* Determine if this thread is currently ready. */
134 if (thread_ptr -> tx_thread_state != TX_READY)
135 {
136
137 /* Change thread priority to the new mutex priority-inheritance priority. */
138 thread_ptr -> tx_thread_priority = new_priority;
139
140 /* Determine how to setup the thread's preemption-threshold. */
141 if (thread_ptr -> tx_thread_user_preempt_threshold < new_priority)
142 {
143
144 /* Change thread preemption-threshold to the user's preemption-threshold. */
145 thread_ptr -> tx_thread_preempt_threshold = thread_ptr -> tx_thread_user_preempt_threshold;
146 }
147 else
148 {
149
150 /* Change the thread preemption-threshold to the new threshold. */
151 thread_ptr -> tx_thread_preempt_threshold = new_priority;
152 }
153
154 }
155 else
156 {
157
158 /* Pickup the core index. */
159 core_index = thread_ptr -> tx_thread_smp_core_mapped;
160
161 /* Save the original priority. */
162 original_priority = thread_ptr -> tx_thread_priority;
163
164 /* Determine if this thread is the currently executing thread. */
165 if (thread_ptr == _tx_thread_execute_ptr[core_index])
166 {
167
168 /* Yes, this thread is scheduled. */
169
170 /* Remember this thread as the currently executing thread. */
171 execute_ptr = thread_ptr;
172
173 /* Determine if the thread is being set to a higher-priority and it does't have
174 preemption-threshold set. */
175 if (new_priority < thread_ptr -> tx_thread_priority)
176 {
177
178 /* Check for preemption-threshold. */
179 if (thread_ptr -> tx_thread_user_priority == thread_ptr -> tx_thread_user_preempt_threshold)
180 {
181
182 /* Simple case, remove the thread from the current priority list and place in
183 the higher priority list. */
184 _tx_thread_smp_simple_priority_change(thread_ptr, new_priority);
185
186 /* Set the finished flag to true. */
187 finished = TX_TRUE;
188 }
189 }
190 }
191 else
192 {
193
194 /* Thread is not currently executing, so it can just be moved to the lower priority in the list. */
195
196 /* Determine if the thread is being set to a lower-priority and it does't have
197 preemption-threshold set. */
198 if (new_priority > thread_ptr -> tx_thread_priority)
199 {
200
201 /* Check for preemption-threshold. */
202 if (thread_ptr -> tx_thread_user_priority == thread_ptr -> tx_thread_user_preempt_threshold)
203 {
204
205 /* Simple case, remove the thread from the current priority list and place in
206 the lower priority list. */
207 if (new_priority < thread_ptr -> tx_thread_user_priority)
208 {
209
210 /* Use the new priority. */
211 _tx_thread_smp_simple_priority_change(thread_ptr, new_priority);
212 }
213 else
214 {
215
216 /* Use the user priority. */
217 _tx_thread_smp_simple_priority_change(thread_ptr, thread_ptr -> tx_thread_user_priority);
218 }
219
220 /* Set the finished flag to true. */
221 finished = TX_TRUE;
222 }
223 }
224 }
225
226 /* Now determine if we are finished. */
227 if (finished == TX_FALSE)
228 {
229
230 /* Save the original preemption-threshold thread. */
231 original_pt_thread = _tx_thread_preemption__threshold_scheduled;
232
233 #ifdef TX_NOT_INTERRUPTABLE
234
235 /* Increment the preempt disable flag. */
236 _tx_thread_preempt_disable++;
237
238 /* Set the state to priority change. */
239 thread_ptr -> tx_thread_state = TX_PRIORITY_CHANGE;
240
241 /* Call actual non-interruptable thread suspension routine. */
242 _tx_thread_system_ni_suspend(thread_ptr, ((ULONG) 0));
243
244 /* At this point, the preempt disable flag is still set, so we still have
245 protection against all preemption. */
246
247 /* Determine how to setup the thread's priority. */
248 if (thread_ptr -> tx_thread_user_priority < new_priority)
249 {
250
251 /* Change thread priority to the user's priority. */
252 thread_ptr -> tx_thread_priority = thread_ptr -> tx_thread_user_priority;
253 }
254 else
255 {
256
257 /* Change thread priority to the new mutex priority-inheritance priority. */
258 thread_ptr -> tx_thread_priority = new_priority;
259 }
260
261 /* Determine how to setup the thread's preemption-threshold. */
262 if (thread_ptr -> tx_thread_user_preempt_threshold < new_priority)
263 {
264
265 /* Change thread preemption-threshold to the user's preemption-threshold. */
266 thread_ptr -> tx_thread_preempt_threshold = thread_ptr -> tx_thread_user_preempt_threshold;
267 }
268 else
269 {
270
271 /* Change the thread preemption-threshold to the new threshold. */
272 thread_ptr -> tx_thread_preempt_threshold = new_priority;
273 }
274
275 /* Resume the thread with the new priority. */
276 _tx_thread_system_ni_resume(thread_ptr);
277
278 /* Decrement the preempt disable flag. */
279 _tx_thread_preempt_disable--;
280 #else
281
282 /* Increment the preempt disable flag. */
283 _tx_thread_preempt_disable = _tx_thread_preempt_disable + ((UINT) 2);
284
285 /* Set the state to priority change. */
286 thread_ptr -> tx_thread_state = TX_PRIORITY_CHANGE;
287
288 /* Set the suspending flag. */
289 thread_ptr -> tx_thread_suspending = TX_TRUE;
290
291 /* Setup the timeout period. */
292 thread_ptr -> tx_thread_timer.tx_timer_internal_remaining_ticks = ((UINT) 0);
293
294 /* Restore interrupts. */
295 TX_RESTORE
296
297 /* The thread is ready and must first be removed from the list. Call the
298 system suspend function to accomplish this. */
299 _tx_thread_system_suspend(thread_ptr);
300
301 /* Lockout interrupts again. */
302 TX_DISABLE
303
304 /* At this point, the preempt disable flag is still set, so we still have
305 protection against all preemption. */
306
307 /* Determine how to setup the thread's priority. */
308 if (thread_ptr -> tx_thread_user_priority < new_priority)
309 {
310
311 /* Change thread priority to the user's priority. */
312 thread_ptr -> tx_thread_priority = thread_ptr -> tx_thread_user_priority;
313 }
314 else
315 {
316
317 /* Change thread priority to the new mutex priority-inheritance priority. */
318 thread_ptr -> tx_thread_priority = new_priority;
319 }
320
321 /* Determine how to setup the thread's preemption-threshold. */
322 if (thread_ptr -> tx_thread_user_preempt_threshold < new_priority)
323 {
324
325 /* Change thread preemption-threshold to the user's preemption-threshold. */
326 thread_ptr -> tx_thread_preempt_threshold = thread_ptr -> tx_thread_user_preempt_threshold;
327 }
328 else
329 {
330
331 /* Change the thread preemption-threshold to the new threshold. */
332 thread_ptr -> tx_thread_preempt_threshold = new_priority;
333 }
334
335 /* Restore interrupts. */
336 TX_RESTORE
337
338 /* Resume the thread with the new priority. */
339 _tx_thread_system_resume(thread_ptr);
340 #endif
341
342 /* Optional processing extension. */
343 TX_MUTEX_PRIORITY_CHANGE_EXTENSION
344
345 #ifndef TX_NOT_INTERRUPTABLE
346
347 /* Disable interrupts. */
348 TX_DISABLE
349 #endif
350
351 /* Determine if the thread was previously executing. */
352 if (thread_ptr == execute_ptr)
353 {
354
355 /* Make sure the thread is still ready. */
356 if (thread_ptr -> tx_thread_state == TX_READY)
357 {
358
359 #ifndef TX_DISABLE_PREEMPTION_THRESHOLD
360 /* Determine if preemption-threshold is in force at the new priority level. */
361 if (_tx_thread_preemption_threshold_list[thread_ptr -> tx_thread_priority] == TX_NULL)
362 {
363
364 /* Ensure that this thread is placed at the front of the priority list. */
365 _tx_thread_priority_list[thread_ptr -> tx_thread_priority] = thread_ptr;
366 }
367 #else
368
369 /* Ensure that this thread is placed at the front of the priority list. */
370 _tx_thread_priority_list[thread_ptr -> tx_thread_priority] = thread_ptr;
371 #endif
372 }
373 }
374
375 /* Pickup the core index. */
376 core_index = thread_ptr -> tx_thread_smp_core_mapped;
377
378 #ifndef TX_THREAD_SMP_DYNAMIC_CORE_MAX
379
380 /* Pickup the next thread to execute. */
381 if (core_index < ((UINT) TX_THREAD_SMP_MAX_CORES))
382 #else
383
384 /* Pickup the next thread to execute. */
385 if (core_index < _tx_thread_smp_max_cores)
386 #endif
387 {
388
389 /* Determine if this thread is not the next thread to execute. */
390 if (thread_ptr != _tx_thread_execute_ptr[core_index])
391 {
392
393 /* Now determine if this thread was previously executing thread. */
394 if (thread_ptr == execute_ptr)
395 {
396
397 /* Determine if we moved to a lower priority. If so, move the thread to the front of the priority list. */
398 if (original_priority < new_priority)
399 {
400
401 /* Make sure the thread is still ready. */
402 if (thread_ptr -> tx_thread_state == TX_READY)
403 {
404
405 /* Determine the lowest priority scheduled thread. */
406 lowest_priority = _tx_thread_smp_lowest_priority_get();
407
408 /* Determine if this thread has a higher or same priority as the lowest priority
409 in the list. */
410 if (thread_ptr -> tx_thread_priority <= lowest_priority)
411 {
412
413 /* Yes, we need to rebalance to make it possible for this thread to execute. */
414
415 /* Determine if the thread with preemption-threshold thread has changed... and is
416 not the scheduled thread. */
417 if ((original_pt_thread != _tx_thread_preemption__threshold_scheduled) &&
418 (original_pt_thread != thread_ptr))
419 {
420
421 /* Yes, preemption-threshold has changed. Determine if it can or should
422 be reversed. */
423
424 #ifndef TX_DISABLE_PREEMPTION_THRESHOLD
425
426 /* Pickup the preemption-threshold thread. */
427 new_pt_thread = _tx_thread_preemption__threshold_scheduled;
428 #endif
429
430 /* Restore the original preemption-threshold thread. */
431 _tx_thread_preemption__threshold_scheduled = original_pt_thread;
432
433
434 #ifndef TX_DISABLE_PREEMPTION_THRESHOLD
435
436 /* Determine if there is a new preemption-threshold thread to reverse. */
437 if (new_pt_thread != TX_NULL)
438 {
439
440 /* Clear the information associated with the new preemption-threshold thread. */
441
442 /* Pickup the priority. */
443 priority = new_pt_thread -> tx_thread_priority;
444
445 /* Clear the preempted list entry. */
446 _tx_thread_preemption_threshold_list[priority] = TX_NULL;
447
448 #if TX_MAX_PRIORITIES > 32
449 /* Calculate the bit map array index. */
450 map_index = new_priority/((UINT) 32);
451 #endif
452 /* Ensure that this thread's priority is clear in the preempt map. */
453 TX_MOD32_BIT_SET(priority, priority_bit)
454 _tx_thread_preempted_maps[MAP_INDEX] = _tx_thread_preempted_maps[MAP_INDEX] & (~(priority_bit));
455 #if TX_MAX_PRIORITIES > 32
456
457 /* Determine if there are any other bits set in this preempt map. */
458 if (_tx_thread_preempted_maps[MAP_INDEX] == ((ULONG) 0))
459 {
460
461 /* No, clear the active bit to signify this preempted map has nothing set. */
462 TX_DIV32_BIT_SET(priority, priority_bit)
463 _tx_thread_preempted_map_active = _tx_thread_preempted_map_active & (~(priority_bit));
464 }
465 #endif
466 }
467 #endif
468 }
469
470 /* Pickup the index. */
471 core_index = TX_SMP_CORE_ID;
472
473 /* Call the rebalance routine. This routine maps cores and ready threads. */
474 _tx_thread_smp_rebalance_execute_list(core_index);
475 }
476 }
477 }
478 }
479 }
480 }
481 }
482 }
483 }
484
485 #ifndef TX_NOT_INTERRUPTABLE
486
487 /* Restore interrupts. */
488 TX_RESTORE
489 #endif
490 }
491
492
