File : s-taprop-vxworks.adb
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
4 -- --
5 -- S Y S T E M . T A S K _ P R I M I T I V E S . O P E R A T I O N S --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2015, Free Software Foundation, Inc. --
10 -- --
11 -- GNARL is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
17 -- --
18 -- --
19 -- --
20 -- --
21 -- --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
26 -- --
27 -- GNARL was developed by the GNARL team at Florida State University. --
28 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
29 -- --
30 ------------------------------------------------------------------------------
31
32 -- This is the VxWorks version of this package
33
34 -- This package contains all the GNULL primitives that interface directly with
35 -- the underlying OS.
36
37 pragma Polling (Off);
38 -- Turn off polling, we do not want ATC polling to take place during tasking
39 -- operations. It causes infinite loops and other problems.
40
41 with Ada.Unchecked_Conversion;
42
43 with Interfaces.C;
44
45 with System.Multiprocessors;
46 with System.Tasking.Debug;
47 with System.Interrupt_Management;
48 with System.Float_Control;
49 with System.OS_Constants;
50
51 with System.Soft_Links;
52 -- We use System.Soft_Links instead of System.Tasking.Initialization
53 -- because the later is a higher level package that we shouldn't depend
54 -- on. For example when using the restricted run time, it is replaced by
55 -- System.Tasking.Restricted.Stages.
56
57 with System.Task_Info;
58 with System.VxWorks.Ext;
59
60 package body System.Task_Primitives.Operations is
61
62 package OSC renames System.OS_Constants;
63 package SSL renames System.Soft_Links;
64
65 use System.Tasking.Debug;
66 use System.Tasking;
67 use System.OS_Interface;
68 use System.Parameters;
69 use type System.VxWorks.Ext.t_id;
70 use type Interfaces.C.int;
71 use type System.OS_Interface.unsigned;
72
73 subtype int is System.OS_Interface.int;
74 subtype unsigned is System.OS_Interface.unsigned;
75
76 Relative : constant := 0;
77
78 ----------------
79 -- Local Data --
80 ----------------
81
82 -- The followings are logically constants, but need to be initialized at
83 -- run time.
84
85 Environment_Task_Id : Task_Id;
86 -- A variable to hold Task_Id for the environment task
87
88 -- The followings are internal configuration constants needed
89
90 Dispatching_Policy : Character;
91 pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
92
93 Foreign_Task_Elaborated : aliased Boolean := True;
94 -- Used to identified fake tasks (i.e., non-Ada Threads)
95
96 Locking_Policy : Character;
97 pragma Import (C, Locking_Policy, "__gl_locking_policy");
98
99 Mutex_Protocol : Priority_Type;
100
101 Single_RTS_Lock : aliased RTS_Lock;
102 -- This is a lock to allow only one thread of control in the RTS at a
103 -- time; it is used to execute in mutual exclusion from all other tasks.
104 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
105
106 Time_Slice_Val : Integer;
107 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
108
109 Null_Thread_Id : constant Thread_Id := 0;
110 -- Constant to indicate that the thread identifier has not yet been
111 -- initialized.
112
113 --------------------
114 -- Local Packages --
115 --------------------
116
117 package Specific is
118
119 procedure Initialize;
120 pragma Inline (Initialize);
121 -- Initialize task specific data
122
123 function Is_Valid_Task return Boolean;
124 pragma Inline (Is_Valid_Task);
125 -- Does executing thread have a TCB?
126
127 procedure Set (Self_Id : Task_Id);
128 pragma Inline (Set);
129 -- Set the self id for the current task, unless Self_Id is null, in
130 -- which case the task specific data is deleted.
131
132 function Self return Task_Id;
133 pragma Inline (Self);
134 -- Return a pointer to the Ada Task Control Block of the calling task
135
136 end Specific;
137
138 package body Specific is separate;
139 -- The body of this package is target specific
140
141 ----------------------------------
142 -- ATCB allocation/deallocation --
143 ----------------------------------
144
145 package body ATCB_Allocation is separate;
146 -- The body of this package is shared across several targets
147
148 ---------------------------------
149 -- Support for foreign threads --
150 ---------------------------------
151
152 function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
153 -- Allocate and Initialize a new ATCB for the current Thread
154
155 function Register_Foreign_Thread
156 (Thread : Thread_Id) return Task_Id is separate;
157
158 -----------------------
159 -- Local Subprograms --
160 -----------------------
161
162 procedure Abort_Handler (signo : Signal);
163 -- Handler for the abort (SIGABRT) signal to handle asynchronous abort
164
165 procedure Install_Signal_Handlers;
166 -- Install the default signal handlers for the current task
167
168 function Is_Task_Context return Boolean;
169 -- This function returns True if the current execution is in the context of
170 -- a task, and False if it is an interrupt context.
171
172 type Set_Stack_Limit_Proc_Acc is access procedure;
173 pragma Convention (C, Set_Stack_Limit_Proc_Acc);
174
175 Set_Stack_Limit_Hook : Set_Stack_Limit_Proc_Acc;
176 pragma Import (C, Set_Stack_Limit_Hook, "__gnat_set_stack_limit_hook");
177 -- Procedure to be called when a task is created to set stack limit. Used
178 -- only for VxWorks 5 and VxWorks MILS guest OS.
179
180 function To_Address is
181 new Ada.Unchecked_Conversion (Task_Id, System.Address);
182
183 -------------------
184 -- Abort_Handler --
185 -------------------
186
187 procedure Abort_Handler (signo : Signal) is
188 pragma Unreferenced (signo);
189
190 Self_ID : constant Task_Id := Self;
191 Old_Set : aliased sigset_t;
192 Unblocked_Mask : aliased sigset_t;
193 Result : int;
194 pragma Warnings (Off, Result);
195
196 use System.Interrupt_Management;
197
198 begin
199 -- It is not safe to raise an exception when using ZCX and the GCC
200 -- exception handling mechanism.
201
202 if ZCX_By_Default then
203 return;
204 end if;
205
206 if Self_ID.Deferral_Level = 0
207 and then Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
208 and then not Self_ID.Aborting
209 then
210 Self_ID.Aborting := True;
211
212 -- Make sure signals used for RTS internal purposes are unmasked
213
214 Result := sigemptyset (Unblocked_Mask'Access);
215 pragma Assert (Result = 0);
216 Result :=
217 sigaddset
218 (Unblocked_Mask'Access,
219 Signal (Abort_Task_Interrupt));
220 pragma Assert (Result = 0);
221 Result := sigaddset (Unblocked_Mask'Access, SIGBUS);
222 pragma Assert (Result = 0);
223 Result := sigaddset (Unblocked_Mask'Access, SIGFPE);
224 pragma Assert (Result = 0);
225 Result := sigaddset (Unblocked_Mask'Access, SIGILL);
226 pragma Assert (Result = 0);
227 Result := sigaddset (Unblocked_Mask'Access, SIGSEGV);
228 pragma Assert (Result = 0);
229
230 Result :=
231 pthread_sigmask
232 (SIG_UNBLOCK,
233 Unblocked_Mask'Access,
234 Old_Set'Access);
235 pragma Assert (Result = 0);
236
237 raise Standard'Abort_Signal;
238 end if;
239 end Abort_Handler;
240
241 -----------------
242 -- Stack_Guard --
243 -----------------
244
245 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
246 pragma Unreferenced (T);
247 pragma Unreferenced (On);
248
249 begin
250 -- Nothing needed (why not???)
251
252 null;
253 end Stack_Guard;
254
255 -------------------
256 -- Get_Thread_Id --
257 -------------------
258
259 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
260 begin
261 return T.Common.LL.Thread;
262 end Get_Thread_Id;
263
264 ----------
265 -- Self --
266 ----------
267
268 function Self return Task_Id renames Specific.Self;
269
270 -----------------------------
271 -- Install_Signal_Handlers --
272 -----------------------------
273
274 procedure Install_Signal_Handlers is
275 act : aliased struct_sigaction;
276 old_act : aliased struct_sigaction;
277 Tmp_Set : aliased sigset_t;
278 Result : int;
279
280 begin
281 act.sa_flags := 0;
282 act.sa_handler := Abort_Handler'Address;
283
284 Result := sigemptyset (Tmp_Set'Access);
285 pragma Assert (Result = 0);
286 act.sa_mask := Tmp_Set;
287
288 Result :=
289 sigaction
290 (Signal (Interrupt_Management.Abort_Task_Interrupt),
291 act'Unchecked_Access,
292 old_act'Unchecked_Access);
293 pragma Assert (Result = 0);
294
295 Interrupt_Management.Initialize_Interrupts;
296 end Install_Signal_Handlers;
297
298 ---------------------
299 -- Initialize_Lock --
300 ---------------------
301
302 procedure Initialize_Lock
303 (Prio : System.Any_Priority;
304 L : not null access Lock)
305 is
306 begin
307 L.Mutex := semMCreate (SEM_Q_PRIORITY + SEM_INVERSION_SAFE);
308 L.Prio_Ceiling := int (Prio);
309 L.Protocol := Mutex_Protocol;
310 pragma Assert (L.Mutex /= 0);
311 end Initialize_Lock;
312
313 procedure Initialize_Lock
314 (L : not null access RTS_Lock;
315 Level : Lock_Level)
316 is
317 pragma Unreferenced (Level);
318 begin
319 L.Mutex := semMCreate (SEM_Q_PRIORITY + SEM_INVERSION_SAFE);
320 L.Prio_Ceiling := int (System.Any_Priority'Last);
321 L.Protocol := Mutex_Protocol;
322 pragma Assert (L.Mutex /= 0);
323 end Initialize_Lock;
324
325 -------------------
326 -- Finalize_Lock --
327 -------------------
328
329 procedure Finalize_Lock (L : not null access Lock) is
330 Result : int;
331 begin
332 Result := semDelete (L.Mutex);
333 pragma Assert (Result = 0);
334 end Finalize_Lock;
335
336 procedure Finalize_Lock (L : not null access RTS_Lock) is
337 Result : int;
338 begin
339 Result := semDelete (L.Mutex);
340 pragma Assert (Result = 0);
341 end Finalize_Lock;
342
343 ----------------
344 -- Write_Lock --
345 ----------------
346
347 procedure Write_Lock
348 (L : not null access Lock;
349 Ceiling_Violation : out Boolean)
350 is
351 Result : int;
352
353 begin
354 if L.Protocol = Prio_Protect
355 and then int (Self.Common.Current_Priority) > L.Prio_Ceiling
356 then
357 Ceiling_Violation := True;
358 return;
359 else
360 Ceiling_Violation := False;
361 end if;
362
363 Result := semTake (L.Mutex, WAIT_FOREVER);
364 pragma Assert (Result = 0);
365 end Write_Lock;
366
367 procedure Write_Lock
368 (L : not null access RTS_Lock;
369 Global_Lock : Boolean := False)
370 is
371 Result : int;
372 begin
373 if not Single_Lock or else Global_Lock then
374 Result := semTake (L.Mutex, WAIT_FOREVER);
375 pragma Assert (Result = 0);
376 end if;
377 end Write_Lock;
378
379 procedure Write_Lock (T : Task_Id) is
380 Result : int;
381 begin
382 if not Single_Lock then
383 Result := semTake (T.Common.LL.L.Mutex, WAIT_FOREVER);
384 pragma Assert (Result = 0);
385 end if;
386 end Write_Lock;
387
388 ---------------
389 -- Read_Lock --
390 ---------------
391
392 procedure Read_Lock
393 (L : not null access Lock;
394 Ceiling_Violation : out Boolean)
395 is
396 begin
397 Write_Lock (L, Ceiling_Violation);
398 end Read_Lock;
399
400 ------------
401 -- Unlock --
402 ------------
403
404 procedure Unlock (L : not null access Lock) is
405 Result : int;
406 begin
407 Result := semGive (L.Mutex);
408 pragma Assert (Result = 0);
409 end Unlock;
410
411 procedure Unlock
412 (L : not null access RTS_Lock;
413 Global_Lock : Boolean := False)
414 is
415 Result : int;
416 begin
417 if not Single_Lock or else Global_Lock then
418 Result := semGive (L.Mutex);
419 pragma Assert (Result = 0);
420 end if;
421 end Unlock;
422
423 procedure Unlock (T : Task_Id) is
424 Result : int;
425 begin
426 if not Single_Lock then
427 Result := semGive (T.Common.LL.L.Mutex);
428 pragma Assert (Result = 0);
429 end if;
430 end Unlock;
431
432 -----------------
433 -- Set_Ceiling --
434 -----------------
435
436 -- Dynamic priority ceilings are not supported by the underlying system
437
438 procedure Set_Ceiling
439 (L : not null access Lock;
440 Prio : System.Any_Priority)
441 is
442 pragma Unreferenced (L, Prio);
443 begin
444 null;
445 end Set_Ceiling;
446
447 -----------
448 -- Sleep --
449 -----------
450
451 procedure Sleep (Self_ID : Task_Id; Reason : System.Tasking.Task_States) is
452 pragma Unreferenced (Reason);
453
454 Result : int;
455
456 begin
457 pragma Assert (Self_ID = Self);
458
459 -- Release the mutex before sleeping
460
461 Result :=
462 semGive (if Single_Lock
463 then Single_RTS_Lock.Mutex
464 else Self_ID.Common.LL.L.Mutex);
465 pragma Assert (Result = 0);
466
467 -- Perform a blocking operation to take the CV semaphore. Note that a
468 -- blocking operation in VxWorks will reenable task scheduling. When we
469 -- are no longer blocked and control is returned, task scheduling will
470 -- again be disabled.
471
472 Result := semTake (Self_ID.Common.LL.CV, WAIT_FOREVER);
473 pragma Assert (Result = 0);
474
475 -- Take the mutex back
476
477 Result :=
478 semTake ((if Single_Lock
479 then Single_RTS_Lock.Mutex
480 else Self_ID.Common.LL.L.Mutex), WAIT_FOREVER);
481 pragma Assert (Result = 0);
482 end Sleep;
483
484 -----------------
485 -- Timed_Sleep --
486 -----------------
487
488 -- This is for use within the run-time system, so abort is assumed to be
489 -- already deferred, and the caller should be holding its own ATCB lock.
490
491 procedure Timed_Sleep
492 (Self_ID : Task_Id;
493 Time : Duration;
494 Mode : ST.Delay_Modes;
495 Reason : System.Tasking.Task_States;
496 Timedout : out Boolean;
497 Yielded : out Boolean)
498 is
499 pragma Unreferenced (Reason);
500
501 Orig : constant Duration := Monotonic_Clock;
502 Absolute : Duration;
503 Ticks : int;
504 Result : int;
505 Wakeup : Boolean := False;
506
507 begin
508 Timedout := False;
509 Yielded := True;
510
511 if Mode = Relative then
512 Absolute := Orig + Time;
513
514 -- Systematically add one since the first tick will delay *at most*
515 -- 1 / Rate_Duration seconds, so we need to add one to be on the
516 -- safe side.
517
518 Ticks := To_Clock_Ticks (Time);
519
520 if Ticks > 0 and then Ticks < int'Last then
521 Ticks := Ticks + 1;
522 end if;
523
524 else
525 Absolute := Time;
526 Ticks := To_Clock_Ticks (Time - Monotonic_Clock);
527 end if;
528
529 if Ticks > 0 then
530 loop
531 -- Release the mutex before sleeping
532
533 Result :=
534 semGive (if Single_Lock
535 then Single_RTS_Lock.Mutex
536 else Self_ID.Common.LL.L.Mutex);
537 pragma Assert (Result = 0);
538
539 -- Perform a blocking operation to take the CV semaphore. Note
540 -- that a blocking operation in VxWorks will reenable task
541 -- scheduling. When we are no longer blocked and control is
542 -- returned, task scheduling will again be disabled.
543
544 Result := semTake (Self_ID.Common.LL.CV, Ticks);
545
546 if Result = 0 then
547
548 -- Somebody may have called Wakeup for us
549
550 Wakeup := True;
551
552 else
553 if errno /= S_objLib_OBJ_TIMEOUT then
554 Wakeup := True;
555
556 else
557 -- If Ticks = int'last, it was most probably truncated so
558 -- let's make another round after recomputing Ticks from
559 -- the absolute time.
560
561 if Ticks /= int'Last then
562 Timedout := True;
563
564 else
565 Ticks := To_Clock_Ticks (Absolute - Monotonic_Clock);
566
567 if Ticks < 0 then
568 Timedout := True;
569 end if;
570 end if;
571 end if;
572 end if;
573
574 -- Take the mutex back
575
576 Result :=
577 semTake ((if Single_Lock
578 then Single_RTS_Lock.Mutex
579 else Self_ID.Common.LL.L.Mutex), WAIT_FOREVER);
580 pragma Assert (Result = 0);
581
582 exit when Timedout or Wakeup;
583 end loop;
584
585 else
586 Timedout := True;
587
588 -- Should never hold a lock while yielding
589
590 if Single_Lock then
591 Result := semGive (Single_RTS_Lock.Mutex);
592 Result := taskDelay (0);
593 Result := semTake (Single_RTS_Lock.Mutex, WAIT_FOREVER);
594
595 else
596 Result := semGive (Self_ID.Common.LL.L.Mutex);
597 Result := taskDelay (0);
598 Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER);
599 end if;
600 end if;
601 end Timed_Sleep;
602
603 -----------------
604 -- Timed_Delay --
605 -----------------
606
607 -- This is for use in implementing delay statements, so we assume the
608 -- caller is holding no locks.
609
610 procedure Timed_Delay
611 (Self_ID : Task_Id;
612 Time : Duration;
613 Mode : ST.Delay_Modes)
614 is
615 Orig : constant Duration := Monotonic_Clock;
616 Absolute : Duration;
617 Ticks : int;
618 Timedout : Boolean;
619 Aborted : Boolean := False;
620
621 Result : int;
622 pragma Warnings (Off, Result);
623
624 begin
625 if Mode = Relative then
626 Absolute := Orig + Time;
627 Ticks := To_Clock_Ticks (Time);
628
629 if Ticks > 0 and then Ticks < int'Last then
630
631 -- First tick will delay anytime between 0 and 1 / sysClkRateGet
632 -- seconds, so we need to add one to be on the safe side.
633
634 Ticks := Ticks + 1;
635 end if;
636
637 else
638 Absolute := Time;
639 Ticks := To_Clock_Ticks (Time - Orig);
640 end if;
641
642 if Ticks > 0 then
643
644 -- Modifying State, locking the TCB
645
646 Result :=
647 semTake ((if Single_Lock
648 then Single_RTS_Lock.Mutex
649 else Self_ID.Common.LL.L.Mutex), WAIT_FOREVER);
650
651 pragma Assert (Result = 0);
652
653 Self_ID.Common.State := Delay_Sleep;
654 Timedout := False;
655
656 loop
657 Aborted := Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
658
659 -- Release the TCB before sleeping
660
661 Result :=
662 semGive (if Single_Lock
663 then Single_RTS_Lock.Mutex
664 else Self_ID.Common.LL.L.Mutex);
665 pragma Assert (Result = 0);
666
667 exit when Aborted;
668
669 Result := semTake (Self_ID.Common.LL.CV, Ticks);
670
671 if Result /= 0 then
672
673 -- If Ticks = int'last, it was most probably truncated, so make
674 -- another round after recomputing Ticks from absolute time.
675
676 if errno = S_objLib_OBJ_TIMEOUT and then Ticks /= int'Last then
677 Timedout := True;
678 else
679 Ticks := To_Clock_Ticks (Absolute - Monotonic_Clock);
680
681 if Ticks < 0 then
682 Timedout := True;
683 end if;
684 end if;
685 end if;
686
687 -- Take back the lock after having slept, to protect further
688 -- access to Self_ID.
689
690 Result :=
691 semTake
692 ((if Single_Lock
693 then Single_RTS_Lock.Mutex
694 else Self_ID.Common.LL.L.Mutex), WAIT_FOREVER);
695
696 pragma Assert (Result = 0);
697
698 exit when Timedout;
699 end loop;
700
701 Self_ID.Common.State := Runnable;
702
703 Result :=
704 semGive
705 (if Single_Lock
706 then Single_RTS_Lock.Mutex
707 else Self_ID.Common.LL.L.Mutex);
708
709 else
710 Result := taskDelay (0);
711 end if;
712 end Timed_Delay;
713
714 ---------------------
715 -- Monotonic_Clock --
716 ---------------------
717
718 function Monotonic_Clock return Duration is
719 TS : aliased timespec;
720 Result : int;
721 begin
722 Result := clock_gettime (OSC.CLOCK_RT_Ada, TS'Unchecked_Access);
723 pragma Assert (Result = 0);
724 return To_Duration (TS);
725 end Monotonic_Clock;
726
727 -------------------
728 -- RT_Resolution --
729 -------------------
730
731 function RT_Resolution return Duration is
732 begin
733 return 1.0 / Duration (sysClkRateGet);
734 end RT_Resolution;
735
736 ------------
737 -- Wakeup --
738 ------------
739
740 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
741 pragma Unreferenced (Reason);
742 Result : int;
743 begin
744 Result := semGive (T.Common.LL.CV);
745 pragma Assert (Result = 0);
746 end Wakeup;
747
748 -----------
749 -- Yield --
750 -----------
751
752 procedure Yield (Do_Yield : Boolean := True) is
753 pragma Unreferenced (Do_Yield);
754 Result : int;
755 pragma Unreferenced (Result);
756 begin
757 Result := taskDelay (0);
758 end Yield;
759
760 ------------------
761 -- Set_Priority --
762 ------------------
763
764 procedure Set_Priority
765 (T : Task_Id;
766 Prio : System.Any_Priority;
767 Loss_Of_Inheritance : Boolean := False)
768 is
769 pragma Unreferenced (Loss_Of_Inheritance);
770
771 Result : int;
772
773 begin
774 Result :=
775 taskPrioritySet
776 (T.Common.LL.Thread, To_VxWorks_Priority (int (Prio)));
777 pragma Assert (Result = 0);
778
779 -- Note: in VxWorks 6.6 (or earlier), the task is placed at the end of
780 -- the priority queue instead of the head. This is not the behavior
781 -- required by Annex D (RM D.2.3(5/2)), but we consider it an acceptable
782 -- variation (RM 1.1.3(6)), given this is the built-in behavior of the
783 -- operating system. VxWorks versions starting from 6.7 implement the
784 -- required Annex D semantics.
785
786 -- In older versions we attempted to better approximate the Annex D
787 -- required behavior, but this simulation was not entirely accurate,
788 -- and it seems better to live with the standard VxWorks semantics.
789
790 T.Common.Current_Priority := Prio;
791 end Set_Priority;
792
793 ------------------
794 -- Get_Priority --
795 ------------------
796
797 function Get_Priority (T : Task_Id) return System.Any_Priority is
798 begin
799 return T.Common.Current_Priority;
800 end Get_Priority;
801
802 ----------------
803 -- Enter_Task --
804 ----------------
805
806 procedure Enter_Task (Self_ID : Task_Id) is
807 begin
808 -- Store the user-level task id in the Thread field (to be used
809 -- internally by the run-time system) and the kernel-level task id in
810 -- the LWP field (to be used by the debugger).
811
812 Self_ID.Common.LL.Thread := taskIdSelf;
813 Self_ID.Common.LL.LWP := getpid;
814
815 Specific.Set (Self_ID);
816
817 -- Properly initializes the FPU for PPC/MIPS systems
818
819 System.Float_Control.Reset;
820
821 -- Install the signal handlers
822
823 -- This is called for each task since there is no signal inheritance
824 -- between VxWorks tasks.
825
826 Install_Signal_Handlers;
827
828 -- If stack checking is enabled, set the stack limit for this task
829
830 if Set_Stack_Limit_Hook /= null then
831 Set_Stack_Limit_Hook.all;
832 end if;
833 end Enter_Task;
834
835 -------------------
836 -- Is_Valid_Task --
837 -------------------
838
839 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
840
841 -----------------------------
842 -- Register_Foreign_Thread --
843 -----------------------------
844
845 function Register_Foreign_Thread return Task_Id is
846 begin
847 if Is_Valid_Task then
848 return Self;
849 else
850 return Register_Foreign_Thread (taskIdSelf);
851 end if;
852 end Register_Foreign_Thread;
853
854 --------------------
855 -- Initialize_TCB --
856 --------------------
857
858 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
859 begin
860 Self_ID.Common.LL.CV := semBCreate (SEM_Q_PRIORITY, SEM_EMPTY);
861 Self_ID.Common.LL.Thread := Null_Thread_Id;
862
863 if Self_ID.Common.LL.CV = 0 then
864 Succeeded := False;
865
866 else
867 Succeeded := True;
868
869 if not Single_Lock then
870 Initialize_Lock (Self_ID.Common.LL.L'Access, ATCB_Level);
871 end if;
872 end if;
873 end Initialize_TCB;
874
875 -----------------
876 -- Create_Task --
877 -----------------
878
879 procedure Create_Task
880 (T : Task_Id;
881 Wrapper : System.Address;
882 Stack_Size : System.Parameters.Size_Type;
883 Priority : System.Any_Priority;
884 Succeeded : out Boolean)
885 is
886 Adjusted_Stack_Size : size_t;
887
888 use type System.Multiprocessors.CPU_Range;
889
890 begin
891 -- Check whether both Dispatching_Domain and CPU are specified for
892 -- the task, and the CPU value is not contained within the range of
893 -- processors for the domain.
894
895 if T.Common.Domain /= null
896 and then T.Common.Base_CPU /= System.Multiprocessors.Not_A_Specific_CPU
897 and then
898 (T.Common.Base_CPU not in T.Common.Domain'Range
899 or else not T.Common.Domain (T.Common.Base_CPU))
900 then
901 Succeeded := False;
902 return;
903 end if;
904
905 -- Ask for four extra bytes of stack space so that the ATCB pointer can
906 -- be stored below the stack limit, plus extra space for the frame of
907 -- Task_Wrapper. This is so the user gets the amount of stack requested
908 -- exclusive of the needs.
909
910 -- We also have to allocate n more bytes for the task name storage and
911 -- enough space for the Wind Task Control Block which is around 0x778
912 -- bytes. VxWorks also seems to carve out additional space, so use 2048
913 -- as a nice round number. We might want to increment to the nearest
914 -- page size in case we ever support VxVMI.
915
916 -- ??? - we should come back and visit this so we can set the task name
917 -- to something appropriate.
918
919 Adjusted_Stack_Size := size_t (Stack_Size) + 2048;
920
921 -- Since the initial signal mask of a thread is inherited from the
922 -- creator, and the Environment task has all its signals masked, we do
923 -- not need to manipulate caller's signal mask at this point. All tasks
924 -- in RTS will have All_Tasks_Mask initially.
925
926 -- We now compute the VxWorks task name and options, then spawn ...
927
928 declare
929 Name : aliased String (1 .. T.Common.Task_Image_Len + 1);
930 Name_Address : System.Address;
931 -- Task name we are going to hand down to VxWorks
932
933 function Get_Task_Options return int;
934 pragma Import (C, Get_Task_Options, "__gnat_get_task_options");
935 -- Function that returns the options to be set for the task that we
936 -- are creating. We fetch the options assigned to the current task,
937 -- so offering some user level control over the options for a task
938 -- hierarchy, and force VX_FP_TASK because it is almost always
939 -- required.
940
941 begin
942 -- If there is no Ada task name handy, let VxWorks choose one.
943 -- Otherwise, tell VxWorks what the Ada task name is.
944
945 if T.Common.Task_Image_Len = 0 then
946 Name_Address := System.Null_Address;
947 else
948 Name (1 .. Name'Last - 1) :=
949 T.Common.Task_Image (1 .. T.Common.Task_Image_Len);
950 Name (Name'Last) := ASCII.NUL;
951 Name_Address := Name'Address;
952 end if;
953
954 -- Now spawn the VxWorks task for real
955
956 T.Common.LL.Thread :=
957 taskSpawn
958 (Name_Address,
959 To_VxWorks_Priority (int (Priority)),
960 Get_Task_Options,
961 Adjusted_Stack_Size,
962 Wrapper,
963 To_Address (T));
964 end;
965
966 -- Set processor affinity
967
968 Set_Task_Affinity (T);
969
970 -- Only case of failure is if taskSpawn returned 0 (aka Null_Thread_Id)
971
972 if T.Common.LL.Thread = Null_Thread_Id then
973 Succeeded := False;
974 else
975 Succeeded := True;
976 Task_Creation_Hook (T.Common.LL.Thread);
977 Set_Priority (T, Priority);
978 end if;
979 end Create_Task;
980
981 ------------------
982 -- Finalize_TCB --
983 ------------------
984
985 procedure Finalize_TCB (T : Task_Id) is
986 Result : int;
987
988 begin
989 if not Single_Lock then
990 Result := semDelete (T.Common.LL.L.Mutex);
991 pragma Assert (Result = 0);
992 end if;
993
994 T.Common.LL.Thread := Null_Thread_Id;
995
996 Result := semDelete (T.Common.LL.CV);
997 pragma Assert (Result = 0);
998
999 if T.Known_Tasks_Index /= -1 then
1000 Known_Tasks (T.Known_Tasks_Index) := null;
1001 end if;
1002
1003 ATCB_Allocation.Free_ATCB (T);
1004 end Finalize_TCB;
1005
1006 ---------------
1007 -- Exit_Task --
1008 ---------------
1009
1010 procedure Exit_Task is
1011 begin
1012 Specific.Set (null);
1013 end Exit_Task;
1014
1015 ----------------
1016 -- Abort_Task --
1017 ----------------
1018
1019 procedure Abort_Task (T : Task_Id) is
1020 Result : int;
1021 begin
1022 Result :=
1023 kill
1024 (T.Common.LL.Thread,
1025 Signal (Interrupt_Management.Abort_Task_Interrupt));
1026 pragma Assert (Result = 0);
1027 end Abort_Task;
1028
1029 ----------------
1030 -- Initialize --
1031 ----------------
1032
1033 procedure Initialize (S : in out Suspension_Object) is
1034 begin
1035 -- Initialize internal state (always to False (RM D.10(6)))
1036
1037 S.State := False;
1038 S.Waiting := False;
1039
1040 -- Initialize internal mutex
1041
1042 -- Use simpler binary semaphore instead of VxWorks mutual exclusion
1043 -- semaphore, because we don't need the fancier semantics and their
1044 -- overhead.
1045
1046 S.L := semBCreate (SEM_Q_FIFO, SEM_FULL);
1047
1048 -- Initialize internal condition variable
1049
1050 S.CV := semBCreate (SEM_Q_FIFO, SEM_EMPTY);
1051 end Initialize;
1052
1053 --------------
1054 -- Finalize --
1055 --------------
1056
1057 procedure Finalize (S : in out Suspension_Object) is
1058 pragma Unmodified (S);
1059 -- S may be modified on other targets, but not on VxWorks
1060
1061 Result : STATUS;
1062
1063 begin
1064 -- Destroy internal mutex
1065
1066 Result := semDelete (S.L);
1067 pragma Assert (Result = OK);
1068
1069 -- Destroy internal condition variable
1070
1071 Result := semDelete (S.CV);
1072 pragma Assert (Result = OK);
1073 end Finalize;
1074
1075 -------------------
1076 -- Current_State --
1077 -------------------
1078
1079 function Current_State (S : Suspension_Object) return Boolean is
1080 begin
1081 -- We do not want to use lock on this read operation. State is marked
1082 -- as Atomic so that we ensure that the value retrieved is correct.
1083
1084 return S.State;
1085 end Current_State;
1086
1087 ---------------
1088 -- Set_False --
1089 ---------------
1090
1091 procedure Set_False (S : in out Suspension_Object) is
1092 Result : STATUS;
1093
1094 begin
1095 SSL.Abort_Defer.all;
1096
1097 Result := semTake (S.L, WAIT_FOREVER);
1098 pragma Assert (Result = OK);
1099
1100 S.State := False;
1101
1102 Result := semGive (S.L);
1103 pragma Assert (Result = OK);
1104
1105 SSL.Abort_Undefer.all;
1106 end Set_False;
1107
1108 --------------
1109 -- Set_True --
1110 --------------
1111
1112 procedure Set_True (S : in out Suspension_Object) is
1113 Result : STATUS;
1114
1115 begin
1116 -- Set_True can be called from an interrupt context, in which case
1117 -- Abort_Defer is undefined.
1118
1119 if Is_Task_Context then
1120 SSL.Abort_Defer.all;
1121 end if;
1122
1123 Result := semTake (S.L, WAIT_FOREVER);
1124 pragma Assert (Result = OK);
1125
1126 -- If there is already a task waiting on this suspension object then we
1127 -- resume it, leaving the state of the suspension object to False, as it
1128 -- is specified in (RM D.10 (9)). Otherwise, it just leaves the state to
1129 -- True.
1130
1131 if S.Waiting then
1132 S.Waiting := False;
1133 S.State := False;
1134
1135 Result := semGive (S.CV);
1136 pragma Assert (Result = OK);
1137 else
1138 S.State := True;
1139 end if;
1140
1141 Result := semGive (S.L);
1142 pragma Assert (Result = OK);
1143
1144 -- Set_True can be called from an interrupt context, in which case
1145 -- Abort_Undefer is undefined.
1146
1147 if Is_Task_Context then
1148 SSL.Abort_Undefer.all;
1149 end if;
1150
1151 end Set_True;
1152
1153 ------------------------
1154 -- Suspend_Until_True --
1155 ------------------------
1156
1157 procedure Suspend_Until_True (S : in out Suspension_Object) is
1158 Result : STATUS;
1159
1160 begin
1161 SSL.Abort_Defer.all;
1162
1163 Result := semTake (S.L, WAIT_FOREVER);
1164
1165 if S.Waiting then
1166
1167 -- Program_Error must be raised upon calling Suspend_Until_True
1168 -- if another task is already waiting on that suspension object
1169 -- (RM D.10(10)).
1170
1171 Result := semGive (S.L);
1172 pragma Assert (Result = OK);
1173
1174 SSL.Abort_Undefer.all;
1175
1176 raise Program_Error;
1177
1178 else
1179 -- Suspend the task if the state is False. Otherwise, the task
1180 -- continues its execution, and the state of the suspension object
1181 -- is set to False (RM D.10 (9)).
1182
1183 if S.State then
1184 S.State := False;
1185
1186 Result := semGive (S.L);
1187 pragma Assert (Result = 0);
1188
1189 SSL.Abort_Undefer.all;
1190
1191 else
1192 S.Waiting := True;
1193
1194 -- Release the mutex before sleeping
1195
1196 Result := semGive (S.L);
1197 pragma Assert (Result = OK);
1198
1199 SSL.Abort_Undefer.all;
1200
1201 Result := semTake (S.CV, WAIT_FOREVER);
1202 pragma Assert (Result = 0);
1203 end if;
1204 end if;
1205 end Suspend_Until_True;
1206
1207 ----------------
1208 -- Check_Exit --
1209 ----------------
1210
1211 -- Dummy version
1212
1213 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1214 pragma Unreferenced (Self_ID);
1215 begin
1216 return True;
1217 end Check_Exit;
1218
1219 --------------------
1220 -- Check_No_Locks --
1221 --------------------
1222
1223 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1224 pragma Unreferenced (Self_ID);
1225 begin
1226 return True;
1227 end Check_No_Locks;
1228
1229 ----------------------
1230 -- Environment_Task --
1231 ----------------------
1232
1233 function Environment_Task return Task_Id is
1234 begin
1235 return Environment_Task_Id;
1236 end Environment_Task;
1237
1238 --------------
1239 -- Lock_RTS --
1240 --------------
1241
1242 procedure Lock_RTS is
1243 begin
1244 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
1245 end Lock_RTS;
1246
1247 ----------------
1248 -- Unlock_RTS --
1249 ----------------
1250
1251 procedure Unlock_RTS is
1252 begin
1253 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
1254 end Unlock_RTS;
1255
1256 ------------------
1257 -- Suspend_Task --
1258 ------------------
1259
1260 function Suspend_Task
1261 (T : ST.Task_Id;
1262 Thread_Self : Thread_Id) return Boolean
1263 is
1264 begin
1265 if T.Common.LL.Thread /= Null_Thread_Id
1266 and then T.Common.LL.Thread /= Thread_Self
1267 then
1268 return taskSuspend (T.Common.LL.Thread) = 0;
1269 else
1270 return True;
1271 end if;
1272 end Suspend_Task;
1273
1274 -----------------
1275 -- Resume_Task --
1276 -----------------
1277
1278 function Resume_Task
1279 (T : ST.Task_Id;
1280 Thread_Self : Thread_Id) return Boolean
1281 is
1282 begin
1283 if T.Common.LL.Thread /= Null_Thread_Id
1284 and then T.Common.LL.Thread /= Thread_Self
1285 then
1286 return taskResume (T.Common.LL.Thread) = 0;
1287 else
1288 return True;
1289 end if;
1290 end Resume_Task;
1291
1292 --------------------
1293 -- Stop_All_Tasks --
1294 --------------------
1295
1296 procedure Stop_All_Tasks
1297 is
1298 Thread_Self : constant Thread_Id := taskIdSelf;
1299 C : Task_Id;
1300
1301 Dummy : int;
1302 Old : int;
1303
1304 begin
1305 Old := Int_Lock;
1306
1307 C := All_Tasks_List;
1308 while C /= null loop
1309 if C.Common.LL.Thread /= Null_Thread_Id
1310 and then C.Common.LL.Thread /= Thread_Self
1311 then
1312 Dummy := Task_Stop (C.Common.LL.Thread);
1313 end if;
1314
1315 C := C.Common.All_Tasks_Link;
1316 end loop;
1317
1318 Dummy := Int_Unlock (Old);
1319 end Stop_All_Tasks;
1320
1321 ---------------
1322 -- Stop_Task --
1323 ---------------
1324
1325 function Stop_Task (T : ST.Task_Id) return Boolean is
1326 begin
1327 if T.Common.LL.Thread /= Null_Thread_Id then
1328 return Task_Stop (T.Common.LL.Thread) = 0;
1329 else
1330 return True;
1331 end if;
1332 end Stop_Task;
1333
1334 -------------------
1335 -- Continue_Task --
1336 -------------------
1337
1338 function Continue_Task (T : ST.Task_Id) return Boolean
1339 is
1340 begin
1341 if T.Common.LL.Thread /= Null_Thread_Id then
1342 return Task_Cont (T.Common.LL.Thread) = 0;
1343 else
1344 return True;
1345 end if;
1346 end Continue_Task;
1347
1348 ---------------------
1349 -- Is_Task_Context --
1350 ---------------------
1351
1352 function Is_Task_Context return Boolean is
1353 begin
1354 return System.OS_Interface.Interrupt_Context /= 1;
1355 end Is_Task_Context;
1356
1357 ----------------
1358 -- Initialize --
1359 ----------------
1360
1361 procedure Initialize (Environment_Task : Task_Id) is
1362 Result : int;
1363 pragma Unreferenced (Result);
1364
1365 begin
1366 Environment_Task_Id := Environment_Task;
1367
1368 Interrupt_Management.Initialize;
1369 Specific.Initialize;
1370
1371 if Locking_Policy = 'C' then
1372 Mutex_Protocol := Prio_Protect;
1373 elsif Locking_Policy = 'I' then
1374 Mutex_Protocol := Prio_Inherit;
1375 else
1376 Mutex_Protocol := Prio_None;
1377 end if;
1378
1379 if Time_Slice_Val > 0 then
1380 Result :=
1381 Set_Time_Slice
1382 (To_Clock_Ticks
1383 (Duration (Time_Slice_Val) / Duration (1_000_000.0)));
1384
1385 elsif Dispatching_Policy = 'R' then
1386 Result := Set_Time_Slice (To_Clock_Ticks (0.01));
1387
1388 end if;
1389
1390 -- Initialize the lock used to synchronize chain of all ATCBs
1391
1392 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1393
1394 -- Make environment task known here because it doesn't go through
1395 -- Activate_Tasks, which does it for all other tasks.
1396
1397 Known_Tasks (Known_Tasks'First) := Environment_Task;
1398 Environment_Task.Known_Tasks_Index := Known_Tasks'First;
1399
1400 Enter_Task (Environment_Task);
1401
1402 -- Set processor affinity
1403
1404 Set_Task_Affinity (Environment_Task);
1405 end Initialize;
1406
1407 -----------------------
1408 -- Set_Task_Affinity --
1409 -----------------------
1410
1411 procedure Set_Task_Affinity (T : ST.Task_Id) is
1412 Result : int := 0;
1413 pragma Unreferenced (Result);
1414
1415 use System.Task_Info;
1416 use type System.Multiprocessors.CPU_Range;
1417
1418 begin
1419 -- Do nothing if the underlying thread has not yet been created. If the
1420 -- thread has not yet been created then the proper affinity will be set
1421 -- during its creation.
1422
1423 if T.Common.LL.Thread = Null_Thread_Id then
1424 null;
1425
1426 -- pragma CPU
1427
1428 elsif T.Common.Base_CPU /= Multiprocessors.Not_A_Specific_CPU then
1429
1430 -- Ada 2012 pragma CPU uses CPU numbers starting from 1, while on
1431 -- VxWorks the first CPU is identified by a 0, so we need to adjust.
1432
1433 Result :=
1434 taskCpuAffinitySet
1435 (T.Common.LL.Thread, int (T.Common.Base_CPU) - 1);
1436
1437 -- Task_Info
1438
1439 elsif T.Common.Task_Info /= Unspecified_Task_Info then
1440 Result := taskCpuAffinitySet (T.Common.LL.Thread, T.Common.Task_Info);
1441
1442 -- Handle dispatching domains
1443
1444 elsif T.Common.Domain /= null
1445 and then (T.Common.Domain /= ST.System_Domain
1446 or else T.Common.Domain.all /=
1447 (Multiprocessors.CPU'First ..
1448 Multiprocessors.Number_Of_CPUs => True))
1449 then
1450 declare
1451 CPU_Set : unsigned := 0;
1452
1453 begin
1454 -- Set the affinity to all the processors belonging to the
1455 -- dispatching domain.
1456
1457 for Proc in T.Common.Domain'Range loop
1458 if T.Common.Domain (Proc) then
1459
1460 -- The thread affinity mask is a bit vector in which each
1461 -- bit represents a logical processor.
1462
1463 CPU_Set := CPU_Set + 2 ** (Integer (Proc) - 1);
1464 end if;
1465 end loop;
1466
1467 Result := taskMaskAffinitySet (T.Common.LL.Thread, CPU_Set);
1468 end;
1469 end if;
1470 end Set_Task_Affinity;
1471
1472 end System.Task_Primitives.Operations;