1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
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 --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
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. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
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/>. --
27 -- GNARL was developed by the GNARL team at Florida State University. --
28 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
30 ------------------------------------------------------------------------------
32 -- This is the VxWorks version of this package
34 -- This package contains all the GNULL primitives that interface directly with
38 -- Turn off polling, we do not want ATC polling to take place during tasking
39 -- operations. It causes infinite loops and other problems.
41 with Ada
.Unchecked_Conversion
;
42 with Ada
.Unchecked_Deallocation
;
46 with System
.Multiprocessors
;
47 with System
.Tasking
.Debug
;
48 with System
.Interrupt_Management
;
50 with System
.Soft_Links
;
51 -- We use System.Soft_Links instead of System.Tasking.Initialization
52 -- because the later is a higher level package that we shouldn't depend
53 -- on. For example when using the restricted run time, it is replaced by
54 -- System.Tasking.Restricted.Stages.
56 with System
.Task_Info
;
57 with System
.VxWorks
.Ext
;
59 package body System
.Task_Primitives
.Operations
is
61 package SSL
renames System
.Soft_Links
;
63 use System
.Tasking
.Debug
;
65 use System
.OS_Interface
;
66 use System
.Parameters
;
67 use type System
.VxWorks
.Ext
.t_id
;
68 use type Interfaces
.C
.int
;
70 subtype int
is System
.OS_Interface
.int
;
72 Relative
: constant := 0;
78 -- The followings are logically constants, but need to be initialized at
81 Single_RTS_Lock
: aliased RTS_Lock
;
82 -- This is a lock to allow only one thread of control in the RTS at a
83 -- time; it is used to execute in mutual exclusion from all other tasks.
84 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
86 Environment_Task_Id
: Task_Id
;
87 -- A variable to hold Task_Id for the environment task
89 Unblocked_Signal_Mask
: aliased sigset_t
;
90 -- The set of signals that should unblocked in all tasks
92 -- The followings are internal configuration constants needed
94 Time_Slice_Val
: Integer;
95 pragma Import
(C
, Time_Slice_Val
, "__gl_time_slice_val");
97 Locking_Policy
: Character;
98 pragma Import
(C
, Locking_Policy
, "__gl_locking_policy");
100 Dispatching_Policy
: Character;
101 pragma Import
(C
, Dispatching_Policy
, "__gl_task_dispatching_policy");
103 Mutex_Protocol
: Priority_Type
;
105 Foreign_Task_Elaborated
: aliased Boolean := True;
106 -- Used to identified fake tasks (i.e., non-Ada Threads)
108 type Set_Stack_Limit_Proc_Acc
is access procedure;
109 pragma Convention
(C
, Set_Stack_Limit_Proc_Acc
);
111 Set_Stack_Limit_Hook
: Set_Stack_Limit_Proc_Acc
;
112 pragma Import
(C
, Set_Stack_Limit_Hook
, "__gnat_set_stack_limit_hook");
113 -- Procedure to be called when a task is created to set stack
122 procedure Initialize
;
123 pragma Inline
(Initialize
);
124 -- Initialize task specific data
126 function Is_Valid_Task
return Boolean;
127 pragma Inline
(Is_Valid_Task
);
128 -- Does executing thread have a TCB?
130 procedure Set
(Self_Id
: Task_Id
);
132 -- Set the self id for the current task
135 pragma Inline
(Delete
);
136 -- Delete the task specific data associated with the current task
138 function Self
return Task_Id
;
139 pragma Inline
(Self
);
140 -- Return a pointer to the Ada Task Control Block of the calling task
144 package body Specific
is separate;
145 -- The body of this package is target specific
147 ---------------------------------
148 -- Support for foreign threads --
149 ---------------------------------
151 function Register_Foreign_Thread
(Thread
: Thread_Id
) return Task_Id
;
152 -- Allocate and Initialize a new ATCB for the current Thread
154 function Register_Foreign_Thread
155 (Thread
: Thread_Id
) return Task_Id
is separate;
157 -----------------------
158 -- Local Subprograms --
159 -----------------------
161 procedure Abort_Handler
(signo
: Signal
);
162 -- Handler for the abort (SIGABRT) signal to handle asynchronous abort
164 procedure Install_Signal_Handlers
;
165 -- Install the default signal handlers for the current task
167 function Is_Task_Context
return Boolean;
168 -- This function returns True if the current execution is in the context
169 -- of a task, and False if it is an interrupt context.
171 function To_Address
is
172 new Ada
.Unchecked_Conversion
(Task_Id
, System
.Address
);
178 procedure Abort_Handler
(signo
: Signal
) is
179 pragma Unreferenced
(signo
);
181 Self_ID
: constant Task_Id
:= Self
;
182 Old_Set
: aliased sigset_t
;
185 pragma Warnings
(Off
, Result
);
188 -- It is not safe to raise an exception when using ZCX and the GCC
189 -- exception handling mechanism.
191 if ZCX_By_Default
and then GCC_ZCX_Support
then
195 if Self_ID
.Deferral_Level
= 0
196 and then Self_ID
.Pending_ATC_Level
< Self_ID
.ATC_Nesting_Level
197 and then not Self_ID
.Aborting
199 Self_ID
.Aborting
:= True;
201 -- Make sure signals used for RTS internal purpose are unmasked
206 Unblocked_Signal_Mask
'Access,
208 pragma Assert
(Result
= 0);
210 raise Standard
'Abort_Signal;
218 procedure Stack_Guard
(T
: ST
.Task_Id
; On
: Boolean) is
219 pragma Unreferenced
(T
);
220 pragma Unreferenced
(On
);
223 -- Nothing needed (why not???)
232 function Get_Thread_Id
(T
: ST
.Task_Id
) return OSI
.Thread_Id
is
234 return T
.Common
.LL
.Thread
;
241 function Self
return Task_Id
renames Specific
.Self
;
243 -----------------------------
244 -- Install_Signal_Handlers --
245 -----------------------------
247 procedure Install_Signal_Handlers
is
248 act
: aliased struct_sigaction
;
249 old_act
: aliased struct_sigaction
;
250 Tmp_Set
: aliased sigset_t
;
255 act
.sa_handler
:= Abort_Handler
'Address;
257 Result
:= sigemptyset
(Tmp_Set
'Access);
258 pragma Assert
(Result
= 0);
259 act
.sa_mask
:= Tmp_Set
;
263 (Signal
(Interrupt_Management
.Abort_Task_Interrupt
),
264 act
'Unchecked_Access,
265 old_act
'Unchecked_Access);
266 pragma Assert
(Result
= 0);
268 Interrupt_Management
.Initialize_Interrupts
;
269 end Install_Signal_Handlers
;
271 ---------------------
272 -- Initialize_Lock --
273 ---------------------
275 procedure Initialize_Lock
276 (Prio
: System
.Any_Priority
;
277 L
: not null access Lock
)
280 L
.Mutex
:= semMCreate
(SEM_Q_PRIORITY
+ SEM_INVERSION_SAFE
);
281 L
.Prio_Ceiling
:= int
(Prio
);
282 L
.Protocol
:= Mutex_Protocol
;
283 pragma Assert
(L
.Mutex
/= 0);
286 procedure Initialize_Lock
287 (L
: not null access RTS_Lock
;
290 pragma Unreferenced
(Level
);
292 L
.Mutex
:= semMCreate
(SEM_Q_PRIORITY
+ SEM_INVERSION_SAFE
);
293 L
.Prio_Ceiling
:= int
(System
.Any_Priority
'Last);
294 L
.Protocol
:= Mutex_Protocol
;
295 pragma Assert
(L
.Mutex
/= 0);
302 procedure Finalize_Lock
(L
: not null access Lock
) is
305 Result
:= semDelete
(L
.Mutex
);
306 pragma Assert
(Result
= 0);
309 procedure Finalize_Lock
(L
: not null access RTS_Lock
) is
312 Result
:= semDelete
(L
.Mutex
);
313 pragma Assert
(Result
= 0);
321 (L
: not null access Lock
;
322 Ceiling_Violation
: out Boolean)
327 if L
.Protocol
= Prio_Protect
328 and then int
(Self
.Common
.Current_Priority
) > L
.Prio_Ceiling
330 Ceiling_Violation
:= True;
333 Ceiling_Violation
:= False;
336 Result
:= semTake
(L
.Mutex
, WAIT_FOREVER
);
337 pragma Assert
(Result
= 0);
341 (L
: not null access RTS_Lock
;
342 Global_Lock
: Boolean := False)
346 if not Single_Lock
or else Global_Lock
then
347 Result
:= semTake
(L
.Mutex
, WAIT_FOREVER
);
348 pragma Assert
(Result
= 0);
352 procedure Write_Lock
(T
: Task_Id
) is
355 if not Single_Lock
then
356 Result
:= semTake
(T
.Common
.LL
.L
.Mutex
, WAIT_FOREVER
);
357 pragma Assert
(Result
= 0);
366 (L
: not null access Lock
;
367 Ceiling_Violation
: out Boolean)
370 Write_Lock
(L
, Ceiling_Violation
);
377 procedure Unlock
(L
: not null access Lock
) is
380 Result
:= semGive
(L
.Mutex
);
381 pragma Assert
(Result
= 0);
385 (L
: not null access RTS_Lock
;
386 Global_Lock
: Boolean := False)
390 if not Single_Lock
or else Global_Lock
then
391 Result
:= semGive
(L
.Mutex
);
392 pragma Assert
(Result
= 0);
396 procedure Unlock
(T
: Task_Id
) is
399 if not Single_Lock
then
400 Result
:= semGive
(T
.Common
.LL
.L
.Mutex
);
401 pragma Assert
(Result
= 0);
409 -- Dynamic priority ceilings are not supported by the underlying system
411 procedure Set_Ceiling
412 (L
: not null access Lock
;
413 Prio
: System
.Any_Priority
)
415 pragma Unreferenced
(L
, Prio
);
424 procedure Sleep
(Self_ID
: Task_Id
; Reason
: System
.Tasking
.Task_States
) is
425 pragma Unreferenced
(Reason
);
430 pragma Assert
(Self_ID
= Self
);
432 -- Release the mutex before sleeping
435 semGive
(if Single_Lock
436 then Single_RTS_Lock
.Mutex
437 else Self_ID
.Common
.LL
.L
.Mutex
);
438 pragma Assert
(Result
= 0);
440 -- Perform a blocking operation to take the CV semaphore. Note that a
441 -- blocking operation in VxWorks will reenable task scheduling. When we
442 -- are no longer blocked and control is returned, task scheduling will
443 -- again be disabled.
445 Result
:= semTake
(Self_ID
.Common
.LL
.CV
, WAIT_FOREVER
);
446 pragma Assert
(Result
= 0);
448 -- Take the mutex back
451 semTake
((if Single_Lock
452 then Single_RTS_Lock
.Mutex
453 else Self_ID
.Common
.LL
.L
.Mutex
), WAIT_FOREVER
);
454 pragma Assert
(Result
= 0);
461 -- This is for use within the run-time system, so abort is assumed to be
462 -- already deferred, and the caller should be holding its own ATCB lock.
464 procedure Timed_Sleep
467 Mode
: ST
.Delay_Modes
;
468 Reason
: System
.Tasking
.Task_States
;
469 Timedout
: out Boolean;
470 Yielded
: out Boolean)
472 pragma Unreferenced
(Reason
);
474 Orig
: constant Duration := Monotonic_Clock
;
478 Wakeup
: Boolean := False;
484 if Mode
= Relative
then
485 Absolute
:= Orig
+ Time
;
487 -- Systematically add one since the first tick will delay *at most*
488 -- 1 / Rate_Duration seconds, so we need to add one to be on the
491 Ticks
:= To_Clock_Ticks
(Time
);
493 if Ticks
> 0 and then Ticks
< int
'Last then
499 Ticks
:= To_Clock_Ticks
(Time
- Monotonic_Clock
);
504 -- Release the mutex before sleeping
507 semGive
(if Single_Lock
508 then Single_RTS_Lock
.Mutex
509 else Self_ID
.Common
.LL
.L
.Mutex
);
510 pragma Assert
(Result
= 0);
512 -- Perform a blocking operation to take the CV semaphore. Note
513 -- that a blocking operation in VxWorks will reenable task
514 -- scheduling. When we are no longer blocked and control is
515 -- returned, task scheduling will again be disabled.
517 Result
:= semTake
(Self_ID
.Common
.LL
.CV
, Ticks
);
521 -- Somebody may have called Wakeup for us
526 if errno
/= S_objLib_OBJ_TIMEOUT
then
530 -- If Ticks = int'last, it was most probably truncated so
531 -- let's make another round after recomputing Ticks from
532 -- the absolute time.
534 if Ticks
/= int
'Last then
538 Ticks
:= To_Clock_Ticks
(Absolute
- Monotonic_Clock
);
547 -- Take the mutex back
550 semTake
((if Single_Lock
551 then Single_RTS_Lock
.Mutex
552 else Self_ID
.Common
.LL
.L
.Mutex
), WAIT_FOREVER
);
553 pragma Assert
(Result
= 0);
555 exit when Timedout
or Wakeup
;
561 -- Should never hold a lock while yielding
564 Result
:= semGive
(Single_RTS_Lock
.Mutex
);
566 Result
:= semTake
(Single_RTS_Lock
.Mutex
, WAIT_FOREVER
);
569 Result
:= semGive
(Self_ID
.Common
.LL
.L
.Mutex
);
571 Result
:= semTake
(Self_ID
.Common
.LL
.L
.Mutex
, WAIT_FOREVER
);
580 -- This is for use in implementing delay statements, so we assume the
581 -- caller is holding no locks.
583 procedure Timed_Delay
586 Mode
: ST
.Delay_Modes
)
588 Orig
: constant Duration := Monotonic_Clock
;
592 Aborted
: Boolean := False;
595 pragma Warnings
(Off
, Result
);
598 if Mode
= Relative
then
599 Absolute
:= Orig
+ Time
;
600 Ticks
:= To_Clock_Ticks
(Time
);
602 if Ticks
> 0 and then Ticks
< int
'Last then
604 -- First tick will delay anytime between 0 and 1 / sysClkRateGet
605 -- seconds, so we need to add one to be on the safe side.
612 Ticks
:= To_Clock_Ticks
(Time
- Orig
);
617 -- Modifying State, locking the TCB
620 semTake
((if Single_Lock
621 then Single_RTS_Lock
.Mutex
622 else Self_ID
.Common
.LL
.L
.Mutex
), WAIT_FOREVER
);
624 pragma Assert
(Result
= 0);
626 Self_ID
.Common
.State
:= Delay_Sleep
;
630 Aborted
:= Self_ID
.Pending_ATC_Level
< Self_ID
.ATC_Nesting_Level
;
632 -- Release the TCB before sleeping
635 semGive
(if Single_Lock
636 then Single_RTS_Lock
.Mutex
637 else Self_ID
.Common
.LL
.L
.Mutex
);
638 pragma Assert
(Result
= 0);
642 Result
:= semTake
(Self_ID
.Common
.LL
.CV
, Ticks
);
646 -- If Ticks = int'last, it was most probably truncated
647 -- so let's make another round after recomputing Ticks
648 -- from the absolute time.
650 if errno
= S_objLib_OBJ_TIMEOUT
and then Ticks
/= int
'Last then
653 Ticks
:= To_Clock_Ticks
(Absolute
- Monotonic_Clock
);
661 -- Take back the lock after having slept, to protect further
662 -- access to Self_ID.
667 then Single_RTS_Lock
.Mutex
668 else Self_ID
.Common
.LL
.L
.Mutex
), WAIT_FOREVER
);
670 pragma Assert
(Result
= 0);
675 Self_ID
.Common
.State
:= Runnable
;
680 then Single_RTS_Lock
.Mutex
681 else Self_ID
.Common
.LL
.L
.Mutex
);
688 ---------------------
689 -- Monotonic_Clock --
690 ---------------------
692 function Monotonic_Clock
return Duration is
693 TS
: aliased timespec
;
696 Result
:= clock_gettime
(CLOCK_REALTIME
, TS
'Unchecked_Access);
697 pragma Assert
(Result
= 0);
698 return To_Duration
(TS
);
705 function RT_Resolution
return Duration is
707 return 1.0 / Duration (sysClkRateGet
);
714 procedure Wakeup
(T
: Task_Id
; Reason
: System
.Tasking
.Task_States
) is
715 pragma Unreferenced
(Reason
);
718 Result
:= semGive
(T
.Common
.LL
.CV
);
719 pragma Assert
(Result
= 0);
726 procedure Yield
(Do_Yield
: Boolean := True) is
727 pragma Unreferenced
(Do_Yield
);
729 pragma Unreferenced
(Result
);
731 Result
:= taskDelay
(0);
738 procedure Set_Priority
740 Prio
: System
.Any_Priority
;
741 Loss_Of_Inheritance
: Boolean := False)
743 pragma Unreferenced
(Loss_Of_Inheritance
);
750 (T
.Common
.LL
.Thread
, To_VxWorks_Priority
(int
(Prio
)));
751 pragma Assert
(Result
= 0);
753 -- Note: in VxWorks 6.6 (or earlier), the task is placed at the end of
754 -- the priority queue instead of the head. This is not the behavior
755 -- required by Annex D (RM D.2.3(5/2)), but we consider it an acceptable
756 -- variation (RM 1.1.3(6)), given this is the built-in behavior of the
757 -- operating system. VxWorks versions starting from 6.7 implement the
758 -- required Annex D semantics.
760 -- In older versions we attempted to better approximate the Annex D
761 -- required behavior, but this simulation was not entirely accurate,
762 -- and it seems better to live with the standard VxWorks semantics.
764 T
.Common
.Current_Priority
:= Prio
;
771 function Get_Priority
(T
: Task_Id
) return System
.Any_Priority
is
773 return T
.Common
.Current_Priority
;
780 procedure Enter_Task
(Self_ID
: Task_Id
) is
781 procedure Init_Float
;
782 pragma Import
(C
, Init_Float
, "__gnat_init_float");
783 -- Properly initializes the FPU for PPC/MIPS systems
786 -- Store the user-level task id in the Thread field (to be used
787 -- internally by the run-time system) and the kernel-level task id in
788 -- the LWP field (to be used by the debugger).
790 Self_ID
.Common
.LL
.Thread
:= taskIdSelf
;
791 Self_ID
.Common
.LL
.LWP
:= getpid
;
793 Specific
.Set
(Self_ID
);
797 -- Install the signal handlers
799 -- This is called for each task since there is no signal inheritance
800 -- between VxWorks tasks.
802 Install_Signal_Handlers
;
804 -- If stack checking is enabled, set the stack limit for this task
806 if Set_Stack_Limit_Hook
/= null then
807 Set_Stack_Limit_Hook
.all;
815 function New_ATCB
(Entry_Num
: Task_Entry_Index
) return Task_Id
is
817 return new Ada_Task_Control_Block
(Entry_Num
);
824 function Is_Valid_Task
return Boolean renames Specific
.Is_Valid_Task
;
826 -----------------------------
827 -- Register_Foreign_Thread --
828 -----------------------------
830 function Register_Foreign_Thread
return Task_Id
is
832 if Is_Valid_Task
then
835 return Register_Foreign_Thread
(taskIdSelf
);
837 end Register_Foreign_Thread
;
843 procedure Initialize_TCB
(Self_ID
: Task_Id
; Succeeded
: out Boolean) is
845 Self_ID
.Common
.LL
.CV
:= semBCreate
(SEM_Q_PRIORITY
, SEM_EMPTY
);
846 Self_ID
.Common
.LL
.Thread
:= 0;
848 if Self_ID
.Common
.LL
.CV
= 0 then
854 if not Single_Lock
then
855 Initialize_Lock
(Self_ID
.Common
.LL
.L
'Access, ATCB_Level
);
864 procedure Create_Task
866 Wrapper
: System
.Address
;
867 Stack_Size
: System
.Parameters
.Size_Type
;
868 Priority
: System
.Any_Priority
;
869 Succeeded
: out Boolean)
871 Adjusted_Stack_Size
: size_t
;
874 use System
.Task_Info
;
875 use type System
.Multiprocessors
.CPU_Range
;
878 -- Ask for four extra bytes of stack space so that the ATCB pointer can
879 -- be stored below the stack limit, plus extra space for the frame of
880 -- Task_Wrapper. This is so the user gets the amount of stack requested
881 -- exclusive of the needs.
883 -- We also have to allocate n more bytes for the task name storage and
884 -- enough space for the Wind Task Control Block which is around 0x778
885 -- bytes. VxWorks also seems to carve out additional space, so use 2048
886 -- as a nice round number. We might want to increment to the nearest
887 -- page size in case we ever support VxVMI.
889 -- ??? - we should come back and visit this so we can set the task name
890 -- to something appropriate.
892 Adjusted_Stack_Size
:= size_t
(Stack_Size
) + 2048;
894 -- Since the initial signal mask of a thread is inherited from the
895 -- creator, and the Environment task has all its signals masked, we do
896 -- not need to manipulate caller's signal mask at this point. All tasks
897 -- in RTS will have All_Tasks_Mask initially.
899 -- We now compute the VxWorks task name and options, then spawn ...
902 Name
: aliased String (1 .. T
.Common
.Task_Image_Len
+ 1);
903 Name_Address
: System
.Address
;
904 -- Task name we are going to hand down to VxWorks
906 function Get_Task_Options
return int
;
907 pragma Import
(C
, Get_Task_Options
, "__gnat_get_task_options");
908 -- Function that returns the options to be set for the task that we
909 -- are creating. We fetch the options assigned to the current task,
910 -- so offering some user level control over the options for a task
911 -- hierarchy, and force VX_FP_TASK because it is almost always
915 -- If there is no Ada task name handy, let VxWorks choose one.
916 -- Otherwise, tell VxWorks what the Ada task name is.
918 if T
.Common
.Task_Image_Len
= 0 then
919 Name_Address
:= System
.Null_Address
;
921 Name
(1 .. Name
'Last - 1) :=
922 T
.Common
.Task_Image
(1 .. T
.Common
.Task_Image_Len
);
923 Name
(Name
'Last) := ASCII
.NUL
;
924 Name_Address
:= Name
'Address;
927 -- Now spawn the VxWorks task for real
929 T
.Common
.LL
.Thread
:=
932 To_VxWorks_Priority
(int
(Priority
)),
939 -- Set processor affinity
941 if T
.Common
.Base_CPU
/= System
.Multiprocessors
.Not_A_Specific_CPU
then
943 taskCpuAffinitySet
(T
.Common
.LL
.Thread
, int
(T
.Common
.Base_CPU
));
945 elsif T
.Common
.Task_Info
/= Unspecified_Task_Info
then
947 taskCpuAffinitySet
(T
.Common
.LL
.Thread
, T
.Common
.Task_Info
);
951 taskDelete
(T
.Common
.LL
.Thread
);
952 T
.Common
.LL
.Thread
:= -1;
955 if T
.Common
.LL
.Thread
= -1 then
959 Task_Creation_Hook
(T
.Common
.LL
.Thread
);
960 Set_Priority
(T
, Priority
);
968 procedure Finalize_TCB
(T
: Task_Id
) is
971 Is_Self
: constant Boolean := (T
= Self
);
973 procedure Free
is new
974 Ada
.Unchecked_Deallocation
(Ada_Task_Control_Block
, Task_Id
);
977 if not Single_Lock
then
978 Result
:= semDelete
(T
.Common
.LL
.L
.Mutex
);
979 pragma Assert
(Result
= 0);
982 T
.Common
.LL
.Thread
:= 0;
984 Result
:= semDelete
(T
.Common
.LL
.CV
);
985 pragma Assert
(Result
= 0);
987 if T
.Known_Tasks_Index
/= -1 then
988 Known_Tasks
(T
.Known_Tasks_Index
) := null;
1002 procedure Exit_Task
is
1004 Specific
.Set
(null);
1011 procedure Abort_Task
(T
: Task_Id
) is
1016 (T
.Common
.LL
.Thread
,
1017 Signal
(Interrupt_Management
.Abort_Task_Interrupt
));
1018 pragma Assert
(Result
= 0);
1025 procedure Initialize
(S
: in out Suspension_Object
) is
1027 -- Initialize internal state (always to False (RM D.10(6)))
1032 -- Initialize internal mutex
1034 -- Use simpler binary semaphore instead of VxWorks
1035 -- mutual exclusion semaphore, because we don't need
1036 -- the fancier semantics and their overhead.
1038 S
.L
:= semBCreate
(SEM_Q_FIFO
, SEM_FULL
);
1040 -- Initialize internal condition variable
1042 S
.CV
:= semBCreate
(SEM_Q_FIFO
, SEM_EMPTY
);
1049 procedure Finalize
(S
: in out Suspension_Object
) is
1050 pragma Unmodified
(S
);
1051 -- S may be modified on other targets, but not on VxWorks
1056 -- Destroy internal mutex
1058 Result
:= semDelete
(S
.L
);
1059 pragma Assert
(Result
= OK
);
1061 -- Destroy internal condition variable
1063 Result
:= semDelete
(S
.CV
);
1064 pragma Assert
(Result
= OK
);
1071 function Current_State
(S
: Suspension_Object
) return Boolean is
1073 -- We do not want to use lock on this read operation. State is marked
1074 -- as Atomic so that we ensure that the value retrieved is correct.
1083 procedure Set_False
(S
: in out Suspension_Object
) is
1087 SSL
.Abort_Defer
.all;
1089 Result
:= semTake
(S
.L
, WAIT_FOREVER
);
1090 pragma Assert
(Result
= OK
);
1094 Result
:= semGive
(S
.L
);
1095 pragma Assert
(Result
= OK
);
1097 SSL
.Abort_Undefer
.all;
1104 procedure Set_True
(S
: in out Suspension_Object
) is
1108 -- Set_True can be called from an interrupt context, in which case
1109 -- Abort_Defer is undefined.
1111 if Is_Task_Context
then
1112 SSL
.Abort_Defer
.all;
1115 Result
:= semTake
(S
.L
, WAIT_FOREVER
);
1116 pragma Assert
(Result
= OK
);
1118 -- If there is already a task waiting on this suspension object then
1119 -- we resume it, leaving the state of the suspension object to False,
1120 -- as it is specified in ARM D.10 par. 9. Otherwise, it just leaves
1121 -- the state to True.
1127 Result
:= semGive
(S
.CV
);
1128 pragma Assert
(Result
= OK
);
1133 Result
:= semGive
(S
.L
);
1134 pragma Assert
(Result
= OK
);
1136 -- Set_True can be called from an interrupt context, in which case
1137 -- Abort_Undefer is undefined.
1139 if Is_Task_Context
then
1140 SSL
.Abort_Undefer
.all;
1145 ------------------------
1146 -- Suspend_Until_True --
1147 ------------------------
1149 procedure Suspend_Until_True
(S
: in out Suspension_Object
) is
1153 SSL
.Abort_Defer
.all;
1155 Result
:= semTake
(S
.L
, WAIT_FOREVER
);
1159 -- Program_Error must be raised upon calling Suspend_Until_True
1160 -- if another task is already waiting on that suspension object
1161 -- (ARM D.10 par. 10).
1163 Result
:= semGive
(S
.L
);
1164 pragma Assert
(Result
= OK
);
1166 SSL
.Abort_Undefer
.all;
1168 raise Program_Error
;
1171 -- Suspend the task if the state is False. Otherwise, the task
1172 -- continues its execution, and the state of the suspension object
1173 -- is set to False (ARM D.10 par. 9).
1178 Result
:= semGive
(S
.L
);
1179 pragma Assert
(Result
= 0);
1181 SSL
.Abort_Undefer
.all;
1186 -- Release the mutex before sleeping
1188 Result
:= semGive
(S
.L
);
1189 pragma Assert
(Result
= OK
);
1191 SSL
.Abort_Undefer
.all;
1193 Result
:= semTake
(S
.CV
, WAIT_FOREVER
);
1194 pragma Assert
(Result
= 0);
1197 end Suspend_Until_True
;
1205 function Check_Exit
(Self_ID
: ST
.Task_Id
) return Boolean is
1206 pragma Unreferenced
(Self_ID
);
1211 --------------------
1212 -- Check_No_Locks --
1213 --------------------
1215 function Check_No_Locks
(Self_ID
: ST
.Task_Id
) return Boolean is
1216 pragma Unreferenced
(Self_ID
);
1221 ----------------------
1222 -- Environment_Task --
1223 ----------------------
1225 function Environment_Task
return Task_Id
is
1227 return Environment_Task_Id
;
1228 end Environment_Task
;
1234 procedure Lock_RTS
is
1236 Write_Lock
(Single_RTS_Lock
'Access, Global_Lock
=> True);
1243 procedure Unlock_RTS
is
1245 Unlock
(Single_RTS_Lock
'Access, Global_Lock
=> True);
1252 function Suspend_Task
1254 Thread_Self
: Thread_Id
) return Boolean
1257 if T
.Common
.LL
.Thread
/= 0
1258 and then T
.Common
.LL
.Thread
/= Thread_Self
1260 return taskSuspend
(T
.Common
.LL
.Thread
) = 0;
1270 function Resume_Task
1272 Thread_Self
: Thread_Id
) return Boolean
1275 if T
.Common
.LL
.Thread
/= 0
1276 and then T
.Common
.LL
.Thread
/= Thread_Self
1278 return taskResume
(T
.Common
.LL
.Thread
) = 0;
1284 --------------------
1285 -- Stop_All_Tasks --
1286 --------------------
1288 procedure Stop_All_Tasks
1290 Thread_Self
: constant Thread_Id
:= taskIdSelf
;
1294 pragma Unreferenced
(Dummy
);
1299 C
:= All_Tasks_List
;
1300 while C
/= null loop
1301 if C
.Common
.LL
.Thread
/= 0
1302 and then C
.Common
.LL
.Thread
/= Thread_Self
1304 Dummy
:= Task_Stop
(C
.Common
.LL
.Thread
);
1307 C
:= C
.Common
.All_Tasks_Link
;
1310 Dummy
:= Int_Unlock
;
1317 function Stop_Task
(T
: ST
.Task_Id
) return Boolean is
1319 if T
.Common
.LL
.Thread
/= 0 then
1320 return Task_Stop
(T
.Common
.LL
.Thread
) = 0;
1330 function Continue_Task
(T
: ST
.Task_Id
) return Boolean
1333 if T
.Common
.LL
.Thread
/= 0 then
1334 return Task_Cont
(T
.Common
.LL
.Thread
) = 0;
1340 ---------------------
1341 -- Is_Task_Context --
1342 ---------------------
1344 function Is_Task_Context
return Boolean is
1346 return System
.OS_Interface
.Interrupt_Context
/= 1;
1347 end Is_Task_Context
;
1353 procedure Initialize
(Environment_Task
: Task_Id
) is
1356 use type System
.Multiprocessors
.CPU_Range
;
1359 Environment_Task_Id
:= Environment_Task
;
1361 Interrupt_Management
.Initialize
;
1362 Specific
.Initialize
;
1364 if Locking_Policy
= 'C' then
1365 Mutex_Protocol
:= Prio_Protect
;
1366 elsif Locking_Policy
= 'I' then
1367 Mutex_Protocol
:= Prio_Inherit
;
1369 Mutex_Protocol
:= Prio_None
;
1372 if Time_Slice_Val
> 0 then
1376 (Duration (Time_Slice_Val
) / Duration (1_000_000
.0
)));
1378 elsif Dispatching_Policy
= 'R' then
1379 Result
:= Set_Time_Slice
(To_Clock_Ticks
(0.01));
1383 Result
:= sigemptyset
(Unblocked_Signal_Mask
'Access);
1384 pragma Assert
(Result
= 0);
1386 for J
in Interrupt_Management
.Signal_ID
loop
1387 if System
.Interrupt_Management
.Keep_Unmasked
(J
) then
1388 Result
:= sigaddset
(Unblocked_Signal_Mask
'Access, Signal
(J
));
1389 pragma Assert
(Result
= 0);
1393 -- Initialize the lock used to synchronize chain of all ATCBs
1395 Initialize_Lock
(Single_RTS_Lock
'Access, RTS_Lock_Level
);
1397 -- Make environment task known here because it doesn't go through
1398 -- Activate_Tasks, which does it for all other tasks.
1400 Known_Tasks
(Known_Tasks
'First) := Environment_Task
;
1401 Environment_Task
.Known_Tasks_Index
:= Known_Tasks
'First;
1403 Enter_Task
(Environment_Task
);
1405 -- Set processor affinity
1407 if Environment_Task
.Common
.Base_CPU
/=
1408 System
.Multiprocessors
.Not_A_Specific_CPU
1412 (Environment_Task
.Common
.LL
.Thread
,
1413 int
(Environment_Task
.Common
.Base_CPU
));
1414 pragma Assert
(Result
/= -1);
1418 end System
.Task_Primitives
.Operations
;