1 ------------------------------------------------------------------------------
3 -- GNU ADA 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) 1992-2001, 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 2, or (at your option) any later ver- --
14 -- sion. GNARL 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. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNARL; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNARL was developed by the GNARL team at Florida State University. --
30 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
32 ------------------------------------------------------------------------------
34 -- This is a HP-UX DCE threads version of this package
36 -- This package contains all the GNULL primitives that interface directly
37 -- with the underlying OS.
40 -- Turn off polling, we do not want ATC polling to take place during
41 -- tasking operations. It causes infinite loops and other problems.
43 with System
.Tasking
.Debug
;
44 -- used for Known_Tasks
50 with System
.Interrupt_Management
;
51 -- used for Keep_Unmasked
52 -- Abort_Task_Interrupt
55 with System
.Interrupt_Management
.Operations
;
56 -- used for Set_Interrupt_Mask
58 pragma Elaborate_All
(System
.Interrupt_Management
.Operations
);
60 with System
.Parameters
;
63 with System
.Task_Primitives
.Interrupt_Operations
;
64 -- used for Get_Interrupt_ID
67 -- used for Ada_Task_Control_Block
70 with System
.Soft_Links
;
71 -- used for Defer/Undefer_Abort
73 -- Note that we do not use System.Tasking.Initialization directly since
74 -- this is a higher level package that we shouldn't depend on. For example
75 -- when using the restricted run time, it is replaced by
76 -- System.Tasking.Restricted.Initialization
78 with System
.OS_Primitives
;
79 -- used for Delay_Modes
81 with Unchecked_Conversion
;
82 with Unchecked_Deallocation
;
84 package body System
.Task_Primitives
.Operations
is
86 use System
.Tasking
.Debug
;
89 use System
.OS_Interface
;
90 use System
.Parameters
;
91 use System
.OS_Primitives
;
93 package PIO
renames System
.Task_Primitives
.Interrupt_Operations
;
94 package SSL
renames System
.Soft_Links
;
100 -- The followings are logically constants, but need to be initialized
103 ATCB_Key
: aliased pthread_key_t
;
104 -- Key used to find the Ada Task_ID associated with a thread
106 Single_RTS_Lock
: aliased RTS_Lock
;
107 -- This is a lock to allow only one thread of control in the RTS at
108 -- a time; it is used to execute in mutual exclusion from all other tasks.
109 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
111 Environment_Task_ID
: Task_ID
;
112 -- A variable to hold Task_ID for the environment task.
114 Unblocked_Signal_Mask
: aliased sigset_t
;
115 -- The set of signals that should unblocked in all tasks
117 Time_Slice_Val
: Integer;
118 pragma Import
(C
, Time_Slice_Val
, "__gl_time_slice_val");
120 Locking_Policy
: Character;
121 pragma Import
(C
, Locking_Policy
, "__gl_locking_policy");
123 Dispatching_Policy
: Character;
124 pragma Import
(C
, Dispatching_Policy
, "__gl_task_dispatching_policy");
126 FIFO_Within_Priorities
: constant Boolean := Dispatching_Policy
= 'F';
127 -- Indicates whether FIFO_Within_Priorities is set.
129 -- The followings are internal configuration constants needed.
131 -----------------------
132 -- Local Subprograms --
133 -----------------------
135 procedure Abort_Handler
(Sig
: Signal
);
137 function To_Task_ID
is new Unchecked_Conversion
(System
.Address
, Task_ID
);
139 function To_Address
is new Unchecked_Conversion
(Task_ID
, System
.Address
);
145 procedure Abort_Handler
(Sig
: Signal
) is
146 Self_Id
: constant Task_ID
:= Self
;
147 Result
: Interfaces
.C
.int
;
148 Old_Set
: aliased sigset_t
;
151 if Self_Id
.Deferral_Level
= 0
152 and then Self_Id
.Pending_ATC_Level
< Self_Id
.ATC_Nesting_Level
and then
155 Self_Id
.Aborting
:= True;
157 -- Make sure signals used for RTS internal purpose are unmasked
159 Result
:= pthread_sigmask
(SIG_UNBLOCK
,
160 Unblocked_Signal_Mask
'Unchecked_Access, Old_Set
'Unchecked_Access);
161 pragma Assert
(Result
= 0);
163 raise Standard
'Abort_Signal;
171 -- The underlying thread system sets a guard page at the
172 -- bottom of a thread stack, so nothing is needed.
173 -- ??? Check the comment above
175 procedure Stack_Guard
(T
: ST
.Task_ID
; On
: Boolean) is
184 function Get_Thread_Id
(T
: ST
.Task_ID
) return OSI
.Thread_Id
is
186 return T
.Common
.LL
.Thread
;
193 function Self
return Task_ID
is
194 Result
: System
.Address
;
196 Result
:= pthread_getspecific
(ATCB_Key
);
197 pragma Assert
(Result
/= System
.Null_Address
);
198 return To_Task_ID
(Result
);
201 ---------------------
202 -- Initialize_Lock --
203 ---------------------
205 -- Note: mutexes and cond_variables needed per-task basis are
206 -- initialized in Initialize_TCB and the Storage_Error is
207 -- handled. Other mutexes (such as RTS_Lock, Memory_Lock...)
208 -- used in RTS is initialized before any status change of RTS.
209 -- Therefore rasing Storage_Error in the following routines
210 -- should be able to be handled safely.
212 procedure Initialize_Lock
213 (Prio
: System
.Any_Priority
;
216 Attributes
: aliased pthread_mutexattr_t
;
217 Result
: Interfaces
.C
.int
;
220 Result
:= pthread_mutexattr_init
(Attributes
'Access);
221 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
223 if Result
= ENOMEM
then
229 Result
:= pthread_mutex_init
(L
.L
'Access, Attributes
'Access);
230 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
232 if Result
= ENOMEM
then
236 Result
:= pthread_mutexattr_destroy
(Attributes
'Access);
237 pragma Assert
(Result
= 0);
240 procedure Initialize_Lock
(L
: access RTS_Lock
; Level
: Lock_Level
) is
241 Attributes
: aliased pthread_mutexattr_t
;
242 Result
: Interfaces
.C
.int
;
245 Result
:= pthread_mutexattr_init
(Attributes
'Access);
246 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
248 if Result
= ENOMEM
then
252 Result
:= pthread_mutex_init
(L
, Attributes
'Access);
254 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
256 if Result
= ENOMEM
then
260 Result
:= pthread_mutexattr_destroy
(Attributes
'Access);
261 pragma Assert
(Result
= 0);
268 procedure Finalize_Lock
(L
: access Lock
) is
269 Result
: Interfaces
.C
.int
;
271 Result
:= pthread_mutex_destroy
(L
.L
'Access);
272 pragma Assert
(Result
= 0);
275 procedure Finalize_Lock
(L
: access RTS_Lock
) is
276 Result
: Interfaces
.C
.int
;
278 Result
:= pthread_mutex_destroy
(L
);
279 pragma Assert
(Result
= 0);
286 procedure Write_Lock
(L
: access Lock
; Ceiling_Violation
: out Boolean) is
287 Result
: Interfaces
.C
.int
;
289 L
.Owner_Priority
:= Get_Priority
(Self
);
291 if L
.Priority
< L
.Owner_Priority
then
292 Ceiling_Violation
:= True;
296 Result
:= pthread_mutex_lock
(L
.L
'Access);
297 pragma Assert
(Result
= 0);
298 Ceiling_Violation
:= False;
302 (L
: access RTS_Lock
; Global_Lock
: Boolean := False)
304 Result
: Interfaces
.C
.int
;
306 if not Single_Lock
or else Global_Lock
then
307 Result
:= pthread_mutex_lock
(L
);
308 pragma Assert
(Result
= 0);
312 procedure Write_Lock
(T
: Task_ID
) is
313 Result
: Interfaces
.C
.int
;
315 if not Single_Lock
then
316 Result
:= pthread_mutex_lock
(T
.Common
.LL
.L
'Access);
317 pragma Assert
(Result
= 0);
325 procedure Read_Lock
(L
: access Lock
; Ceiling_Violation
: out Boolean) is
327 Write_Lock
(L
, Ceiling_Violation
);
334 procedure Unlock
(L
: access Lock
) is
335 Result
: Interfaces
.C
.int
;
337 Result
:= pthread_mutex_unlock
(L
.L
'Access);
338 pragma Assert
(Result
= 0);
341 procedure Unlock
(L
: access RTS_Lock
; Global_Lock
: Boolean := False) is
342 Result
: Interfaces
.C
.int
;
344 if not Single_Lock
or else Global_Lock
then
345 Result
:= pthread_mutex_unlock
(L
);
346 pragma Assert
(Result
= 0);
350 procedure Unlock
(T
: Task_ID
) is
351 Result
: Interfaces
.C
.int
;
353 if not Single_Lock
then
354 Result
:= pthread_mutex_unlock
(T
.Common
.LL
.L
'Access);
355 pragma Assert
(Result
= 0);
365 Reason
: System
.Tasking
.Task_States
)
367 Result
: Interfaces
.C
.int
;
370 Result
:= pthread_cond_wait
371 (Self_ID
.Common
.LL
.CV
'Access, Single_RTS_Lock
'Access);
373 Result
:= pthread_cond_wait
374 (Self_ID
.Common
.LL
.CV
'Access, Self_ID
.Common
.LL
.L
'Access);
377 -- EINTR is not considered a failure.
378 pragma Assert
(Result
= 0 or else Result
= EINTR
);
385 procedure Timed_Sleep
388 Mode
: ST
.Delay_Modes
;
389 Reason
: System
.Tasking
.Task_States
;
390 Timedout
: out Boolean;
391 Yielded
: out Boolean)
393 Check_Time
: constant Duration := Monotonic_Clock
;
395 Request
: aliased timespec
;
396 Result
: Interfaces
.C
.int
;
402 if Mode
= Relative
then
403 Abs_Time
:= Duration'Min (Time
, Max_Sensible_Delay
) + Check_Time
;
405 Abs_Time
:= Duration'Min (Check_Time
+ Max_Sensible_Delay
, Time
);
408 if Abs_Time
> Check_Time
then
409 Request
:= To_Timespec
(Abs_Time
);
412 exit when Self_ID
.Pending_ATC_Level
< Self_ID
.ATC_Nesting_Level
413 or else Self_ID
.Pending_Priority_Change
;
416 Result
:= pthread_cond_timedwait
417 (Self_ID
.Common
.LL
.CV
'Access, Single_RTS_Lock
'Access,
421 Result
:= pthread_cond_timedwait
422 (Self_ID
.Common
.LL
.CV
'Access, Self_ID
.Common
.LL
.L
'Access,
426 exit when Abs_Time
<= Monotonic_Clock
;
428 if Result
= 0 or Result
= EINTR
then
429 -- somebody may have called Wakeup for us
434 pragma Assert
(Result
= ETIMEDOUT
);
443 procedure Timed_Delay
446 Mode
: ST
.Delay_Modes
)
448 Check_Time
: constant Duration := Monotonic_Clock
;
450 Request
: aliased timespec
;
451 Result
: Interfaces
.C
.int
;
454 -- Only the little window between deferring abort and
455 -- locking Self_ID is the reason we need to
456 -- check for pending abort and priority change below! :(
464 Write_Lock
(Self_ID
);
466 if Mode
= Relative
then
467 Abs_Time
:= Time
+ Check_Time
;
469 Abs_Time
:= Duration'Min (Check_Time
+ Max_Sensible_Delay
, Time
);
472 if Abs_Time
> Check_Time
then
473 Request
:= To_Timespec
(Abs_Time
);
474 Self_ID
.Common
.State
:= Delay_Sleep
;
477 if Self_ID
.Pending_Priority_Change
then
478 Self_ID
.Pending_Priority_Change
:= False;
479 Self_ID
.Common
.Base_Priority
:= Self_ID
.New_Base_Priority
;
480 Set_Priority
(Self_ID
, Self_ID
.Common
.Base_Priority
);
483 exit when Self_ID
.Pending_ATC_Level
< Self_ID
.ATC_Nesting_Level
;
486 Result
:= pthread_cond_timedwait
(Self_ID
.Common
.LL
.CV
'Access,
487 Single_RTS_Lock
'Access, Request
'Access);
489 Result
:= pthread_cond_timedwait
(Self_ID
.Common
.LL
.CV
'Access,
490 Self_ID
.Common
.LL
.L
'Access, Request
'Access);
493 exit when Abs_Time
<= Monotonic_Clock
;
495 pragma Assert
(Result
= 0 or else
496 Result
= ETIMEDOUT
or else
500 Self_ID
.Common
.State
:= Runnable
;
509 Result
:= sched_yield
;
510 SSL
.Abort_Undefer
.all;
513 ---------------------
514 -- Monotonic_Clock --
515 ---------------------
517 function Monotonic_Clock
return Duration is
518 TS
: aliased timespec
;
519 Result
: Interfaces
.C
.int
;
522 Result
:= Clock_Gettime
(CLOCK_REALTIME
, TS
'Unchecked_Access);
523 pragma Assert
(Result
= 0);
524 return To_Duration
(TS
);
531 function RT_Resolution
return Duration is
540 procedure Wakeup
(T
: Task_ID
; Reason
: System
.Tasking
.Task_States
) is
541 Result
: Interfaces
.C
.int
;
543 Result
:= pthread_cond_signal
(T
.Common
.LL
.CV
'Access);
544 pragma Assert
(Result
= 0);
551 procedure Yield
(Do_Yield
: Boolean := True) is
552 Result
: Interfaces
.C
.int
;
555 Result
:= sched_yield
;
563 type Prio_Array_Type
is array (System
.Any_Priority
) of Integer;
564 pragma Atomic_Components
(Prio_Array_Type
);
566 Prio_Array
: Prio_Array_Type
;
567 -- Global array containing the id of the currently running task for
570 -- Note: we assume that we are on a single processor with run-til-blocked
573 procedure Set_Priority
575 Prio
: System
.Any_Priority
;
576 Loss_Of_Inheritance
: Boolean := False)
578 Result
: Interfaces
.C
.int
;
579 Array_Item
: Integer;
580 Param
: aliased struct_sched_param
;
583 Param
.sched_priority
:= Interfaces
.C
.int
(Underlying_Priorities
(Prio
));
585 if Time_Slice_Val
> 0 then
586 Result
:= pthread_setschedparam
587 (T
.Common
.LL
.Thread
, SCHED_RR
, Param
'Access);
589 elsif FIFO_Within_Priorities
or else Time_Slice_Val
= 0 then
590 Result
:= pthread_setschedparam
591 (T
.Common
.LL
.Thread
, SCHED_FIFO
, Param
'Access);
594 Result
:= pthread_setschedparam
595 (T
.Common
.LL
.Thread
, SCHED_OTHER
, Param
'Access);
598 pragma Assert
(Result
= 0);
600 if FIFO_Within_Priorities
then
602 -- Annex D requirement [RM D.2.2 par. 9]:
603 -- If the task drops its priority due to the loss of inherited
604 -- priority, it is added at the head of the ready queue for its
605 -- new active priority.
607 if Loss_Of_Inheritance
608 and then Prio
< T
.Common
.Current_Priority
610 Array_Item
:= Prio_Array
(T
.Common
.Base_Priority
) + 1;
611 Prio_Array
(T
.Common
.Base_Priority
) := Array_Item
;
614 -- Let some processes a chance to arrive
618 -- Then wait for our turn to proceed
620 exit when Array_Item
= Prio_Array
(T
.Common
.Base_Priority
)
621 or else Prio_Array
(T
.Common
.Base_Priority
) = 1;
624 Prio_Array
(T
.Common
.Base_Priority
) :=
625 Prio_Array
(T
.Common
.Base_Priority
) - 1;
629 T
.Common
.Current_Priority
:= Prio
;
636 function Get_Priority
(T
: Task_ID
) return System
.Any_Priority
is
638 return T
.Common
.Current_Priority
;
645 procedure Enter_Task
(Self_ID
: Task_ID
) is
646 Result
: Interfaces
.C
.int
;
649 Self_ID
.Common
.LL
.Thread
:= pthread_self
;
651 Result
:= pthread_setspecific
(ATCB_Key
, To_Address
(Self_ID
));
652 pragma Assert
(Result
= 0);
656 for J
in Known_Tasks
'Range loop
657 if Known_Tasks
(J
) = null then
658 Known_Tasks
(J
) := Self_ID
;
659 Self_ID
.Known_Tasks_Index
:= J
;
671 function New_ATCB
(Entry_Num
: Task_Entry_Index
) return Task_ID
is
673 return new Ada_Task_Control_Block
(Entry_Num
);
680 procedure Initialize_TCB
(Self_ID
: Task_ID
; Succeeded
: out Boolean) is
681 Mutex_Attr
: aliased pthread_mutexattr_t
;
682 Result
: Interfaces
.C
.int
;
683 Cond_Attr
: aliased pthread_condattr_t
;
686 if not Single_Lock
then
687 Result
:= pthread_mutexattr_init
(Mutex_Attr
'Access);
688 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
691 Result
:= pthread_mutex_init
(Self_ID
.Common
.LL
.L
'Access,
693 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
701 Result
:= pthread_mutexattr_destroy
(Mutex_Attr
'Access);
702 pragma Assert
(Result
= 0);
705 Result
:= pthread_condattr_init
(Cond_Attr
'Access);
706 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
709 Result
:= pthread_cond_init
(Self_ID
.Common
.LL
.CV
'Access,
711 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
717 if not Single_Lock
then
718 Result
:= pthread_mutex_destroy
(Self_ID
.Common
.LL
.L
'Access);
719 pragma Assert
(Result
= 0);
725 Result
:= pthread_condattr_destroy
(Cond_Attr
'Access);
726 pragma Assert
(Result
= 0);
733 procedure Create_Task
735 Wrapper
: System
.Address
;
736 Stack_Size
: System
.Parameters
.Size_Type
;
737 Priority
: System
.Any_Priority
;
738 Succeeded
: out Boolean)
740 Attributes
: aliased pthread_attr_t
;
741 Adjusted_Stack_Size
: Interfaces
.C
.size_t
;
742 Result
: Interfaces
.C
.int
;
744 function Thread_Body_Access
is new
745 Unchecked_Conversion
(System
.Address
, Thread_Body
);
748 if Stack_Size
= Unspecified_Size
then
749 Adjusted_Stack_Size
:= Interfaces
.C
.size_t
(Default_Stack_Size
);
751 elsif Stack_Size
< Minimum_Stack_Size
then
752 Adjusted_Stack_Size
:= Interfaces
.C
.size_t
(Minimum_Stack_Size
);
755 Adjusted_Stack_Size
:= Interfaces
.C
.size_t
(Stack_Size
);
758 Result
:= pthread_attr_init
(Attributes
'Access);
759 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
766 Result
:= pthread_attr_setstacksize
767 (Attributes
'Access, Adjusted_Stack_Size
);
768 pragma Assert
(Result
= 0);
770 -- Since the initial signal mask of a thread is inherited from the
771 -- creator, and the Environment task has all its signals masked, we
772 -- do not need to manipulate caller's signal mask at this point.
773 -- All tasks in RTS will have All_Tasks_Mask initially.
775 Result
:= pthread_create
776 (T
.Common
.LL
.Thread
'Access,
778 Thread_Body_Access
(Wrapper
),
780 pragma Assert
(Result
= 0 or else Result
= EAGAIN
);
782 Succeeded
:= Result
= 0;
784 pthread_detach
(T
.Common
.LL
.Thread
'Access);
785 -- Detach the thread using pthread_detach, sinc DCE threads do not have
786 -- pthread_attr_set_detachstate.
788 Result
:= pthread_attr_destroy
(Attributes
'Access);
789 pragma Assert
(Result
= 0);
791 Set_Priority
(T
, Priority
);
798 procedure Finalize_TCB
(T
: Task_ID
) is
799 Result
: Interfaces
.C
.int
;
802 procedure Free
is new
803 Unchecked_Deallocation
(Ada_Task_Control_Block
, Task_ID
);
806 if not Single_Lock
then
807 Result
:= pthread_mutex_destroy
(T
.Common
.LL
.L
'Access);
808 pragma Assert
(Result
= 0);
811 Result
:= pthread_cond_destroy
(T
.Common
.LL
.CV
'Access);
812 pragma Assert
(Result
= 0);
814 if T
.Known_Tasks_Index
/= -1 then
815 Known_Tasks
(T
.Known_Tasks_Index
) := null;
825 procedure Exit_Task
is
827 pthread_exit
(System
.Null_Address
);
834 procedure Abort_Task
(T
: Task_ID
) is
837 -- Interrupt Server_Tasks may be waiting on an "event" flag (signal)
839 if T
.Common
.State
= Interrupt_Server_Blocked_On_Event_Flag
then
840 System
.Interrupt_Management
.Operations
.Interrupt_Self_Process
841 (System
.Interrupt_Management
.Interrupt_ID
842 (PIO
.Get_Interrupt_ID
(T
)));
850 -- Dummy versions. The only currently working versions is for solaris
853 function Check_Exit
(Self_ID
: ST
.Task_ID
) return Boolean is
862 function Check_No_Locks
(Self_ID
: ST
.Task_ID
) return Boolean is
867 ----------------------
868 -- Environment_Task --
869 ----------------------
871 function Environment_Task
return Task_ID
is
873 return Environment_Task_ID
;
874 end Environment_Task
;
880 procedure Lock_RTS
is
882 Write_Lock
(Single_RTS_Lock
'Access, Global_Lock
=> True);
889 procedure Unlock_RTS
is
891 Unlock
(Single_RTS_Lock
'Access, Global_Lock
=> True);
898 function Suspend_Task
900 Thread_Self
: Thread_Id
) return Boolean is
911 Thread_Self
: Thread_Id
) return Boolean is
920 procedure Initialize
(Environment_Task
: Task_ID
) is
921 act
: aliased struct_sigaction
;
922 old_act
: aliased struct_sigaction
;
923 Tmp_Set
: aliased sigset_t
;
924 Result
: Interfaces
.C
.int
;
928 Environment_Task_ID
:= Environment_Task
;
930 Initialize_Lock
(Single_RTS_Lock
'Access, RTS_Lock_Level
);
931 -- Initialize the lock used to synchronize chain of all ATCBs.
933 Enter_Task
(Environment_Task
);
935 -- Install the abort-signal handler
938 act
.sa_handler
:= Abort_Handler
'Address;
940 Result
:= sigemptyset
(Tmp_Set
'Access);
941 pragma Assert
(Result
= 0);
942 act
.sa_mask
:= Tmp_Set
;
946 Signal
(System
.Interrupt_Management
.Abort_Task_Interrupt
),
947 act
'Unchecked_Access,
948 old_act
'Unchecked_Access);
949 pragma Assert
(Result
= 0);
952 procedure do_nothing
(arg
: System
.Address
);
954 procedure do_nothing
(arg
: System
.Address
) is
961 Result
: Interfaces
.C
.int
;
963 -- NOTE: Unlike other pthread implementations, we do *not* mask all
964 -- signals here since we handle signals using the process-wide primitive
965 -- signal, rather than using sigthreadmask and sigwait. The reason of
966 -- this difference is that sigwait doesn't work when some critical
967 -- signals (SIGABRT, SIGPIPE) are masked.
969 Result
:= pthread_key_create
(ATCB_Key
'Access, do_nothing
'Access);
970 pragma Assert
(Result
= 0);
972 end System
.Task_Primitives
.Operations
;