1 /**************************************************************************/
2 /* */
3 /* Copyright (c) Microsoft Corporation. All rights reserved. */
4 /* */
5 /* This software is licensed under the Microsoft Software License */
6 /* Terms for Microsoft Azure RTOS. Full text of the license can be */
7 /* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
8 /* and in the root directory of this software. */
9 /* */
10 /**************************************************************************/
11
12
13 /**************************************************************************/
14 /**************************************************************************/
15 /** */
16 /** ThreadX Component */
17 /** */
18 /** Thread */
19 /** */
20 /**************************************************************************/
21 /**************************************************************************/
22
23 #define TX_SOURCE_CODE
24 #define TX_THREAD_SMP_SOURCE_CODE
25
26
27 /* Include necessary system files. */
28
29 #include "tx_api.h"
30 #include "tx_trace.h"
31 #include "tx_thread.h"
32
33
34 /**************************************************************************/
35 /* */
36 /* FUNCTION RELEASE */
37 /* */
38 /* _tx_thread_priority_change PORTABLE SMP */
39 /* 6.1 */
40 /* AUTHOR */
41 /* */
42 /* William E. Lamie, Microsoft Corporation */
43 /* */
44 /* DESCRIPTION */
45 /* */
46 /* This function changes the priority of the specified thread. It */
47 /* also returns the old priority and handles preemption if the calling */
48 /* thread is currently executing and the priority change results in a */
49 /* higher priority thread ready for execution. */
50 /* */
51 /* Note: the preemption-threshold is automatically changed to the new */
52 /* priority. */
53 /* */
54 /* INPUT */
55 /* */
56 /* thread_ptr Pointer to thread to suspend */
57 /* new_priority New thread priority */
58 /* old_priority Old thread priority */
59 /* */
60 /* OUTPUT */
61 /* */
62 /* status Completion status */
63 /* */
64 /* CALLS */
65 /* */
66 /* _tx_thread_smp_rebalance_execute_list Rebalance the execution list */
67 /* _tx_thread_smp_simple_priority_change Change priority */
68 /* _tx_thread_system_resume Resume thread */
69 /* _tx_thread_system_ni_resume Non-interruptable resume */
70 /* _tx_thread_system_suspend Suspend thread */
71 /* _tx_thread_system_ni_suspend Non-interruptable suspend */
72 /* _tx_thread_system_preempt_check Check for preemption */
73 /* */
74 /* CALLED BY */
75 /* */
76 /* Application Code */
77 /* */
78 /* RELEASE HISTORY */
79 /* */
80 /* DATE NAME DESCRIPTION */
81 /* */
82 /* 09-30-2020 William E. Lamie Initial Version 6.1 */
83 /* */
84 /**************************************************************************/
_tx_thread_priority_change(TX_THREAD * thread_ptr,UINT new_priority,UINT * old_priority)85 UINT _tx_thread_priority_change(TX_THREAD *thread_ptr, UINT new_priority, UINT *old_priority)
86 {
87
88 TX_INTERRUPT_SAVE_AREA
89
90 TX_THREAD *execute_ptr;
91 UINT core_index;
92 UINT original_priority;
93 UINT lowest_priority;
94 TX_THREAD *original_pt_thread;
95 #ifndef TX_DISABLE_PREEMPTION_THRESHOLD
96 TX_THREAD *new_pt_thread;
97 UINT priority;
98 ULONG priority_bit;
99 #if TX_MAX_PRIORITIES > 32
100 UINT map_index;
101 #endif
102 #endif
103 UINT status;
104
105
106 /* Default status to not done. */
107 status = TX_NOT_DONE;
108
109 /* Lockout interrupts while the thread is being suspended. */
110 TX_DISABLE
111
112 /* If trace is enabled, insert this event into the trace buffer. */
113 TX_TRACE_IN_LINE_INSERT(TX_TRACE_THREAD_PRIORITY_CHANGE, thread_ptr, new_priority, thread_ptr -> tx_thread_priority, thread_ptr -> tx_thread_state, TX_TRACE_THREAD_EVENTS)
114
115 /* Log this kernel call. */
116 TX_EL_THREAD_PRIORITY_CHANGE_INSERT
117
118 /* Save the previous priority. */
119 *old_priority = thread_ptr -> tx_thread_user_priority;
120
121 /* Determine if the new priority is the same as the last requested priority. */
122 if ((thread_ptr -> tx_thread_user_priority == new_priority) &&
123 (thread_ptr -> tx_thread_user_preempt_threshold == new_priority))
124 {
125
126 /* Nothing to do at this point, simply return. */
127
128 /* Restore interrupts. */
129 TX_RESTORE
130
131 /* Done, return success. */
132 status = TX_SUCCESS;
133 }
134
135 /* Determine if the inherit priority is in effect and there is no preemption-threshold in force. */
136 else if ((thread_ptr -> tx_thread_inherit_priority < new_priority) &&
137 (thread_ptr -> tx_thread_user_preempt_threshold == thread_ptr -> tx_thread_user_priority))
138 {
139
140 /* In this case, simply setup the user priority and preemption-threshold and return. */
141
142 /* Setup the new priority for this thread. */
143 thread_ptr -> tx_thread_user_priority = new_priority;
144 thread_ptr -> tx_thread_user_preempt_threshold = new_priority;
145
146 /* Restore interrupts. */
147 TX_RESTORE
148
149 /* Done, return success. */
150 status = TX_SUCCESS;
151 }
152 else
153 {
154
155 /* Default the execute pointer to NULL. */
156 execute_ptr = TX_NULL;
157
158 /* Determine if this thread is currently ready. */
159 if (thread_ptr -> tx_thread_state != TX_READY)
160 {
161
162 /* Setup the user priority and threshold in the thread's control
163 block. */
164 thread_ptr -> tx_thread_user_priority = new_priority;
165 thread_ptr -> tx_thread_user_preempt_threshold = new_priority;
166
167 /* Determine if the actual thread priority should be setup, which is the
168 case if the new priority is higher than the priority inheritance. */
169 if (new_priority < thread_ptr -> tx_thread_inherit_priority)
170 {
171
172 /* Change thread priority to the new user's priority. */
173 thread_ptr -> tx_thread_priority = new_priority;
174 thread_ptr -> tx_thread_preempt_threshold = new_priority;
175 }
176 else
177 {
178
179 /* Change thread priority to the priority inheritance. */
180 thread_ptr -> tx_thread_priority = thread_ptr -> tx_thread_inherit_priority;
181 thread_ptr -> tx_thread_preempt_threshold = thread_ptr -> tx_thread_inherit_priority;
182 }
183
184 /* Restore interrupts. */
185 TX_RESTORE
186
187 /* Done, return success. */
188 status = TX_SUCCESS;
189 }
190 else
191 {
192
193 /* Pickup the core index. */
194 core_index = thread_ptr -> tx_thread_smp_core_mapped;
195
196 /* Save the original priority. */
197 original_priority = thread_ptr -> tx_thread_priority;
198
199 /* Determine if this thread is the currently scheduled thread. */
200 if (thread_ptr == _tx_thread_execute_ptr[core_index])
201 {
202
203 /* Yes, this thread is scheduled. */
204
205 /* Remember this thread as the currently executing thread. */
206 execute_ptr = thread_ptr;
207
208 /* Determine if the thread is being set to a higher-priority and it does't have
209 preemption-threshold set. */
210 if ((new_priority < thread_ptr -> tx_thread_priority) &&
211 (thread_ptr -> tx_thread_user_priority == thread_ptr -> tx_thread_user_preempt_threshold))
212 {
213
214 /* Simple case, remove the thread from the current priority list and place in
215 the higher priority list. */
216 _tx_thread_smp_simple_priority_change(thread_ptr, new_priority);
217
218 /* Setup the new priority for this thread. */
219 thread_ptr -> tx_thread_user_priority = new_priority;
220 thread_ptr -> tx_thread_user_preempt_threshold = new_priority;
221
222 /* Restore interrupts. */
223 TX_RESTORE
224
225 /* Return a successful completion. */
226 status = TX_SUCCESS;
227 }
228 }
229 else
230 {
231
232 /* Thread is not currently executing, so it can just be moved to the lower priority in the list. */
233
234 /* Determine if the thread is being set to a lower-priority and it does't have
235 preemption-threshold set. */
236 if ((new_priority > thread_ptr -> tx_thread_priority) &&
237 (thread_ptr -> tx_thread_user_priority == thread_ptr -> tx_thread_user_preempt_threshold))
238 {
239
240 /* Simple case, remove the thread from the current priority list and place in
241 the lower priority list. */
242 _tx_thread_smp_simple_priority_change(thread_ptr, new_priority);
243
244 /* Setup the new priority for this thread. */
245 thread_ptr -> tx_thread_user_priority = new_priority;
246 thread_ptr -> tx_thread_user_preempt_threshold = new_priority;
247
248 /* Restore interrupts. */
249 TX_RESTORE
250
251 /* Return a successful completion. */
252 status = TX_SUCCESS;
253 }
254 }
255
256 /* Determine if we are done. */
257 if (status == TX_NOT_DONE)
258 {
259
260 /* Yes, more to do. */
261
262 /* Default the status to success. */
263 status = TX_SUCCESS;
264
265 /* Save the original preemption-threshold thread. */
266 original_pt_thread = _tx_thread_preemption__threshold_scheduled;
267
268 #ifdef TX_NOT_INTERRUPTABLE
269
270 /* Increment the preempt disable flag. */
271 _tx_thread_preempt_disable++;
272
273 /* Set the state to priority change. */
274 thread_ptr -> tx_thread_state = TX_PRIORITY_CHANGE;
275
276 /* Call actual non-interruptable thread suspension routine. */
277 _tx_thread_system_ni_suspend(thread_ptr, ((ULONG) 0));
278
279 /* At this point, the preempt disable flag is still set, so we still have
280 protection against all preemption. */
281
282 /* Setup the new priority for this thread. */
283 thread_ptr -> tx_thread_user_priority = new_priority;
284 thread_ptr -> tx_thread_user_preempt_threshold = new_priority;
285
286 /* Determine if the actual thread priority should be setup, which is the
287 case if the new priority is higher than the priority inheritance. */
288 if (new_priority < thread_ptr -> tx_thread_inherit_priority)
289 {
290
291 /* Change thread priority to the new user's priority. */
292 thread_ptr -> tx_thread_priority = new_priority;
293 thread_ptr -> tx_thread_preempt_threshold = new_priority;
294 }
295 else
296 {
297
298 /* Change thread priority to the priority inheritance. */
299 thread_ptr -> tx_thread_priority = thread_ptr -> tx_thread_inherit_priority;
300 thread_ptr -> tx_thread_preempt_threshold = thread_ptr -> tx_thread_inherit_priority;
301 }
302
303 /* Resume the thread with the new priority. */
304 _tx_thread_system_ni_resume(thread_ptr);
305
306 /* Decrement the preempt disable flag. */
307 _tx_thread_preempt_disable--;
308 #else
309
310 /* Increment the preempt disable flag. */
311 _tx_thread_preempt_disable = _tx_thread_preempt_disable + ((UINT) 3);
312
313 /* Set the state to priority change. */
314 thread_ptr -> tx_thread_state = TX_PRIORITY_CHANGE;
315
316 /* Set the suspending flag. */
317 thread_ptr -> tx_thread_suspending = TX_TRUE;
318
319 /* Setup the timeout period. */
320 thread_ptr -> tx_thread_timer.tx_timer_internal_remaining_ticks = ((ULONG) 0);
321
322 /* Restore interrupts. */
323 TX_RESTORE
324
325 /* The thread is ready and must first be removed from the list. Call the
326 system suspend function to accomplish this. */
327 _tx_thread_system_suspend(thread_ptr);
328
329 /* Lockout interrupts again. */
330 TX_DISABLE
331
332 /* At this point, the preempt disable flag is still set, so we still have
333 protection against all preemption. */
334
335 /* Setup the new priority for this thread. */
336 thread_ptr -> tx_thread_user_priority = new_priority;
337 thread_ptr -> tx_thread_user_preempt_threshold = new_priority;
338
339 /* Determine if the actual thread priority should be setup, which is the
340 case if the new priority is higher than the priority inheritance. */
341 if (new_priority < thread_ptr -> tx_thread_inherit_priority)
342 {
343
344 /* Change thread priority to the new user's priority. */
345 thread_ptr -> tx_thread_priority = new_priority;
346 thread_ptr -> tx_thread_preempt_threshold = new_priority;
347 }
348 else
349 {
350
351 /* Change thread priority to the priority inheritance. */
352 thread_ptr -> tx_thread_priority = thread_ptr -> tx_thread_inherit_priority;
353 thread_ptr -> tx_thread_preempt_threshold = thread_ptr -> tx_thread_inherit_priority;
354 }
355
356 /* Restore interrupts. */
357 TX_RESTORE
358
359 /* Resume the thread with the new priority. */
360 _tx_thread_system_resume(thread_ptr);
361 #endif
362
363 /* Optional processing extension. */
364 TX_THREAD_PRIORITY_CHANGE_EXTENSION
365
366 #ifndef TX_NOT_INTERRUPTABLE
367
368 /* Disable interrupts. */
369 TX_DISABLE
370
371 /* Decrement the preemption-threshold flag. */
372 _tx_thread_preempt_disable--;
373 #endif
374
375 /* Determine if the thread was previously executing. */
376 if (thread_ptr == execute_ptr)
377 {
378
379 /* Make sure the thread is still ready. */
380 if (thread_ptr -> tx_thread_state == TX_READY)
381 {
382
383 #ifndef TX_DISABLE_PREEMPTION_THRESHOLD
384 /* Determine if preemption-threshold is in force at the new priority level. */
385 if (_tx_thread_preemption_threshold_list[thread_ptr -> tx_thread_priority] == TX_NULL)
386 {
387
388 /* Ensure that this thread is placed at the front of the priority list. */
389 _tx_thread_priority_list[thread_ptr -> tx_thread_priority] = thread_ptr;
390 }
391 #else
392
393 /* Ensure that this thread is placed at the front of the priority list. */
394 _tx_thread_priority_list[thread_ptr -> tx_thread_priority] = thread_ptr;
395 #endif
396 }
397 }
398
399 /* Pickup the core index. */
400 core_index = thread_ptr -> tx_thread_smp_core_mapped;
401
402 #ifndef TX_THREAD_SMP_DYNAMIC_CORE_MAX
403
404 /* Pickup the next thread to execute. */
405 if (core_index < ((UINT) TX_THREAD_SMP_MAX_CORES))
406 #else
407
408 /* Pickup the next thread to execute. */
409 if (core_index < _tx_thread_smp_max_cores)
410 #endif
411 {
412
413 /* Determine if this thread is not the next thread to execute. */
414 if (thread_ptr != _tx_thread_execute_ptr[core_index])
415 {
416
417 /* Now determine if this thread was previously executing thread. */
418 if (thread_ptr == execute_ptr)
419 {
420
421 /* Determine if we moved to a lower priority. If so, move the thread to the front of the priority list. */
422 if (original_priority < new_priority)
423 {
424
425 /* Make sure the thread is still ready. */
426 if (thread_ptr -> tx_thread_state == TX_READY)
427 {
428
429 /* Determine the lowest priority scheduled thread. */
430 lowest_priority = _tx_thread_smp_lowest_priority_get();
431
432 /* Determine if this thread has a higher or same priority as the lowest priority
433 in the list. */
434 if (thread_ptr -> tx_thread_priority <= lowest_priority)
435 {
436
437 /* Yes, we need to rebalance to make it possible for this thread to execute. */
438
439 /* Determine if the thread with preemption-threshold thread has changed... and is
440 not the scheduled thread. */
441 if ((original_pt_thread != _tx_thread_preemption__threshold_scheduled) &&
442 (original_pt_thread != thread_ptr))
443 {
444
445 /* Yes, preemption-threshold has changed. Determine if it can or should
446 be reversed. */
447
448 #ifndef TX_DISABLE_PREEMPTION_THRESHOLD
449
450 /* Pickup the preemption-threshold thread. */
451 new_pt_thread = _tx_thread_preemption__threshold_scheduled;
452 #endif
453
454 /* Restore the original preemption-threshold thread. */
455 _tx_thread_preemption__threshold_scheduled = original_pt_thread;
456
457
458 #ifndef TX_DISABLE_PREEMPTION_THRESHOLD
459
460 /* Determine if there is a new preemption-threshold thread to reverse. */
461 if (new_pt_thread != TX_NULL)
462 {
463
464 /* Clear the information associated with the new preemption-threshold thread. */
465
466 /* Pickup the priority. */
467 priority = new_pt_thread -> tx_thread_priority;
468
469 /* Clear the preempted list entry. */
470 _tx_thread_preemption_threshold_list[priority] = TX_NULL;
471
472 #if TX_MAX_PRIORITIES > 32
473 /* Calculate the bit map array index. */
474 map_index = new_priority/((UINT) 32);
475 #endif
476
477 /* Ensure that this thread's priority is clear in the preempt map. */
478 TX_MOD32_BIT_SET(priority, priority_bit)
479 _tx_thread_preempted_maps[MAP_INDEX] = _tx_thread_preempted_maps[MAP_INDEX] & (~(priority_bit));
480 #if TX_MAX_PRIORITIES > 32
481
482 /* Determine if there are any other bits set in this preempt map. */
483 if (_tx_thread_preempted_maps[MAP_INDEX] == ((ULONG) 0))
484 {
485
486 /* No, clear the active bit to signify this preempted map has nothing set. */
487 TX_DIV32_BIT_SET(priority, priority_bit)
488 _tx_thread_preempted_map_active = _tx_thread_preempted_map_active & (~(priority_bit));
489 }
490 #endif
491 }
492 #endif
493 }
494
495 /* Pickup the index. */
496 core_index = TX_SMP_CORE_ID;
497
498 /* Call the rebalance routine. This routine maps cores and ready threads. */
499 _tx_thread_smp_rebalance_execute_list(core_index);
500 }
501 }
502 }
503 }
504 }
505 }
506
507 /* Restore interrupts. */
508 TX_RESTORE
509
510 /* Check for preemption. */
511 _tx_thread_system_preempt_check();
512 }
513 }
514 }
515
516 /* Return completion status. */
517 return(status);
518 }
519
520
