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) 1992-2006, 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, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, 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 POSIX-like version of this package
36 -- This package contains all the GNULL primitives that interface directly
37 -- with the underlying OS.
39 -- Note: this file can only be used for POSIX compliant systems that
40 -- implement SCHED_FIFO and Ceiling Locking correctly.
42 -- For configurations where SCHED_FIFO and priority ceiling are not a
43 -- requirement, this file can also be used (e.g AiX threads)
46 -- Turn off polling, we do not want ATC polling to take place during
47 -- tasking operations. It causes infinite loops and other problems.
49 with System
.Tasking
.Debug
;
50 -- used for Known_Tasks
52 with System
.Interrupt_Management
;
53 -- used for Keep_Unmasked
54 -- Abort_Task_Interrupt
57 with System
.OS_Primitives
;
58 -- used for Delay_Modes
60 with System
.Task_Info
;
61 -- used for Task_Info_Type
67 with System
.Soft_Links
;
68 -- used for Abort_Defer/Undefer
70 -- We use System.Soft_Links instead of System.Tasking.Initialization
71 -- because the later is a higher level package that we shouldn't depend on.
72 -- For example when using the restricted run time, it is replaced by
73 -- System.Tasking.Restricted.Stages.
75 with Unchecked_Conversion
;
76 with Unchecked_Deallocation
;
78 package body System
.Task_Primitives
.Operations
is
80 package SSL
renames System
.Soft_Links
;
82 use System
.Tasking
.Debug
;
85 use System
.OS_Interface
;
86 use System
.Parameters
;
87 use System
.OS_Primitives
;
93 -- The followings are logically constants, but need to be initialized
96 Single_RTS_Lock
: aliased RTS_Lock
;
97 -- This is a lock to allow only one thread of control in the RTS at
98 -- a time; it is used to execute in mutual exclusion from all other tasks.
99 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
101 ATCB_Key
: aliased pthread_key_t
;
102 -- Key used to find the Ada Task_Id associated with a thread
104 Environment_Task_Id
: Task_Id
;
105 -- A variable to hold Task_Id for the environment task
107 Locking_Policy
: Character;
108 pragma Import
(C
, Locking_Policy
, "__gl_locking_policy");
109 -- Value of the pragma Locking_Policy:
110 -- 'C' for Ceiling_Locking
111 -- 'I' for Inherit_Locking
114 Unblocked_Signal_Mask
: aliased sigset_t
;
115 -- The set of signals that should unblocked in all tasks
117 -- The followings are internal configuration constants needed
119 Next_Serial_Number
: Task_Serial_Number
:= 100;
120 -- We start at 100, to reserve some special values for
121 -- using in error checking.
123 Time_Slice_Val
: Integer;
124 pragma Import
(C
, Time_Slice_Val
, "__gl_time_slice_val");
126 Dispatching_Policy
: Character;
127 pragma Import
(C
, Dispatching_Policy
, "__gl_task_dispatching_policy");
129 Foreign_Task_Elaborated
: aliased Boolean := True;
130 -- Used to identified fake tasks (i.e., non-Ada Threads)
138 procedure Initialize
(Environment_Task
: Task_Id
);
139 pragma Inline
(Initialize
);
140 -- Initialize various data needed by this package
142 function Is_Valid_Task
return Boolean;
143 pragma Inline
(Is_Valid_Task
);
144 -- Does executing thread have a TCB?
146 procedure Set
(Self_Id
: Task_Id
);
148 -- Set the self id for the current task
150 function Self
return Task_Id
;
151 pragma Inline
(Self
);
152 -- Return a pointer to the Ada Task Control Block of the calling task
156 package body Specific
is separate;
157 -- The body of this package is target specific
159 ---------------------------------
160 -- Support for foreign threads --
161 ---------------------------------
163 function Register_Foreign_Thread
(Thread
: Thread_Id
) return Task_Id
;
164 -- Allocate and Initialize a new ATCB for the current Thread
166 function Register_Foreign_Thread
167 (Thread
: Thread_Id
) return Task_Id
is separate;
169 -----------------------
170 -- Local Subprograms --
171 -----------------------
173 procedure Abort_Handler
(Sig
: Signal
);
174 -- Signal handler used to implement asynchronous abort.
175 -- See also comment before body, below.
177 function To_Address
is new Unchecked_Conversion
(Task_Id
, System
.Address
);
183 -- Target-dependent binding of inter-thread Abort signal to
184 -- the raising of the Abort_Signal exception.
186 -- The technical issues and alternatives here are essentially
187 -- the same as for raising exceptions in response to other
188 -- signals (e.g. Storage_Error). See code and comments in
189 -- the package body System.Interrupt_Management.
191 -- Some implementations may not allow an exception to be propagated
192 -- out of a handler, and others might leave the signal or
193 -- interrupt that invoked this handler masked after the exceptional
194 -- return to the application code.
196 -- GNAT exceptions are originally implemented using setjmp()/longjmp().
197 -- On most UNIX systems, this will allow transfer out of a signal handler,
198 -- which is usually the only mechanism available for implementing
199 -- asynchronous handlers of this kind. However, some
200 -- systems do not restore the signal mask on longjmp(), leaving the
201 -- abort signal masked.
203 procedure Abort_Handler
(Sig
: Signal
) is
204 pragma Warnings
(Off
, Sig
);
206 T
: constant Task_Id
:= Self
;
207 Result
: Interfaces
.C
.int
;
208 Old_Set
: aliased sigset_t
;
211 -- It is not safe to raise an exception when using ZCX and the GCC
212 -- exception handling mechanism.
214 if ZCX_By_Default
and then GCC_ZCX_Support
then
218 if T
.Deferral_Level
= 0
219 and then T
.Pending_ATC_Level
< T
.ATC_Nesting_Level
and then
224 -- Make sure signals used for RTS internal purpose are unmasked
226 Result
:= pthread_sigmask
(SIG_UNBLOCK
,
227 Unblocked_Signal_Mask
'Unchecked_Access, Old_Set
'Unchecked_Access);
228 pragma Assert
(Result
= 0);
230 raise Standard
'Abort_Signal;
238 procedure Stack_Guard
(T
: ST
.Task_Id
; On
: Boolean) is
239 Stack_Base
: constant Address
:= Get_Stack_Base
(T
.Common
.LL
.Thread
);
240 Guard_Page_Address
: Address
;
242 Res
: Interfaces
.C
.int
;
245 if Stack_Base_Available
then
247 -- Compute the guard page address
249 Guard_Page_Address
:=
250 Stack_Base
- (Stack_Base
mod Get_Page_Size
) + Get_Page_Size
;
253 Res
:= mprotect
(Guard_Page_Address
, Get_Page_Size
, PROT_ON
);
255 Res
:= mprotect
(Guard_Page_Address
, Get_Page_Size
, PROT_OFF
);
258 pragma Assert
(Res
= 0);
266 function Get_Thread_Id
(T
: ST
.Task_Id
) return OSI
.Thread_Id
is
268 return T
.Common
.LL
.Thread
;
275 function Self
return Task_Id
renames Specific
.Self
;
277 ---------------------
278 -- Initialize_Lock --
279 ---------------------
281 -- Note: mutexes and cond_variables needed per-task basis are
282 -- initialized in Intialize_TCB and the Storage_Error is
283 -- handled. Other mutexes (such as RTS_Lock, Memory_Lock...)
284 -- used in RTS is initialized before any status change of RTS.
285 -- Therefore rasing Storage_Error in the following routines
286 -- should be able to be handled safely.
288 procedure Initialize_Lock
289 (Prio
: System
.Any_Priority
;
292 Attributes
: aliased pthread_mutexattr_t
;
293 Result
: Interfaces
.C
.int
;
296 Result
:= pthread_mutexattr_init
(Attributes
'Access);
297 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
299 if Result
= ENOMEM
then
303 if Locking_Policy
= 'C' then
304 Result
:= pthread_mutexattr_setprotocol
305 (Attributes
'Access, PTHREAD_PRIO_PROTECT
);
306 pragma Assert
(Result
= 0);
308 Result
:= pthread_mutexattr_setprioceiling
309 (Attributes
'Access, Interfaces
.C
.int
(Prio
));
310 pragma Assert
(Result
= 0);
312 elsif Locking_Policy
= 'I' then
313 Result
:= pthread_mutexattr_setprotocol
314 (Attributes
'Access, PTHREAD_PRIO_INHERIT
);
315 pragma Assert
(Result
= 0);
318 Result
:= pthread_mutex_init
(L
, Attributes
'Access);
319 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
321 if Result
= ENOMEM
then
322 Result
:= pthread_mutexattr_destroy
(Attributes
'Access);
326 Result
:= pthread_mutexattr_destroy
(Attributes
'Access);
327 pragma Assert
(Result
= 0);
330 procedure Initialize_Lock
(L
: access RTS_Lock
; Level
: Lock_Level
) is
331 pragma Warnings
(Off
, Level
);
333 Attributes
: aliased pthread_mutexattr_t
;
334 Result
: Interfaces
.C
.int
;
337 Result
:= pthread_mutexattr_init
(Attributes
'Access);
338 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
340 if Result
= ENOMEM
then
344 if Locking_Policy
= 'C' then
345 Result
:= pthread_mutexattr_setprotocol
346 (Attributes
'Access, PTHREAD_PRIO_PROTECT
);
347 pragma Assert
(Result
= 0);
349 Result
:= pthread_mutexattr_setprioceiling
350 (Attributes
'Access, Interfaces
.C
.int
(System
.Any_Priority
'Last));
351 pragma Assert
(Result
= 0);
353 elsif Locking_Policy
= 'I' then
354 Result
:= pthread_mutexattr_setprotocol
355 (Attributes
'Access, PTHREAD_PRIO_INHERIT
);
356 pragma Assert
(Result
= 0);
359 Result
:= pthread_mutex_init
(L
, Attributes
'Access);
360 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
362 if Result
= ENOMEM
then
363 Result
:= pthread_mutexattr_destroy
(Attributes
'Access);
367 Result
:= pthread_mutexattr_destroy
(Attributes
'Access);
368 pragma Assert
(Result
= 0);
375 procedure Finalize_Lock
(L
: access Lock
) is
376 Result
: Interfaces
.C
.int
;
379 Result
:= pthread_mutex_destroy
(L
);
380 pragma Assert
(Result
= 0);
383 procedure Finalize_Lock
(L
: access RTS_Lock
) is
384 Result
: Interfaces
.C
.int
;
387 Result
:= pthread_mutex_destroy
(L
);
388 pragma Assert
(Result
= 0);
395 procedure Write_Lock
(L
: access Lock
; Ceiling_Violation
: out Boolean) is
396 Result
: Interfaces
.C
.int
;
399 Result
:= pthread_mutex_lock
(L
);
401 -- Assume that the cause of EINVAL is a priority ceiling violation
403 Ceiling_Violation
:= (Result
= EINVAL
);
404 pragma Assert
(Result
= 0 or else Result
= EINVAL
);
408 (L
: access RTS_Lock
;
409 Global_Lock
: Boolean := False)
411 Result
: Interfaces
.C
.int
;
414 if not Single_Lock
or else Global_Lock
then
415 Result
:= pthread_mutex_lock
(L
);
416 pragma Assert
(Result
= 0);
420 procedure Write_Lock
(T
: Task_Id
) is
421 Result
: Interfaces
.C
.int
;
424 if not Single_Lock
then
425 Result
:= pthread_mutex_lock
(T
.Common
.LL
.L
'Access);
426 pragma Assert
(Result
= 0);
434 procedure Read_Lock
(L
: access Lock
; Ceiling_Violation
: out Boolean) is
436 Write_Lock
(L
, Ceiling_Violation
);
443 procedure Unlock
(L
: access Lock
) is
444 Result
: Interfaces
.C
.int
;
447 Result
:= pthread_mutex_unlock
(L
);
448 pragma Assert
(Result
= 0);
451 procedure Unlock
(L
: access RTS_Lock
; Global_Lock
: Boolean := False) is
452 Result
: Interfaces
.C
.int
;
455 if not Single_Lock
or else Global_Lock
then
456 Result
:= pthread_mutex_unlock
(L
);
457 pragma Assert
(Result
= 0);
461 procedure Unlock
(T
: Task_Id
) is
462 Result
: Interfaces
.C
.int
;
465 if not Single_Lock
then
466 Result
:= pthread_mutex_unlock
(T
.Common
.LL
.L
'Access);
467 pragma Assert
(Result
= 0);
477 Reason
: System
.Tasking
.Task_States
)
479 pragma Warnings
(Off
, Reason
);
481 Result
: Interfaces
.C
.int
;
485 Result
:= pthread_cond_wait
486 (Self_ID
.Common
.LL
.CV
'Access, Single_RTS_Lock
'Access);
488 Result
:= pthread_cond_wait
489 (Self_ID
.Common
.LL
.CV
'Access, Self_ID
.Common
.LL
.L
'Access);
492 -- EINTR is not considered a failure
494 pragma Assert
(Result
= 0 or else Result
= EINTR
);
501 -- This is for use within the run-time system, so abort is
502 -- assumed to be already deferred, and the caller should be
503 -- holding its own ATCB lock.
505 procedure Timed_Sleep
508 Mode
: ST
.Delay_Modes
;
509 Reason
: Task_States
;
510 Timedout
: out Boolean;
511 Yielded
: out Boolean)
513 pragma Warnings
(Off
, Reason
);
515 Check_Time
: constant Duration := Monotonic_Clock
;
518 Request
: aliased timespec
;
519 Result
: Interfaces
.C
.int
;
525 if Mode
= Relative
then
526 Abs_Time
:= Duration'Min (Time
, Max_Sensible_Delay
) + Check_Time
;
528 if Relative_Timed_Wait
then
529 Rel_Time
:= Duration'Min (Max_Sensible_Delay
, Time
);
533 Abs_Time
:= Duration'Min (Check_Time
+ Max_Sensible_Delay
, Time
);
535 if Relative_Timed_Wait
then
536 Rel_Time
:= Duration'Min (Max_Sensible_Delay
, Time
- Check_Time
);
540 if Abs_Time
> Check_Time
then
541 if Relative_Timed_Wait
then
542 Request
:= To_Timespec
(Rel_Time
);
544 Request
:= To_Timespec
(Abs_Time
);
548 exit when Self_ID
.Pending_ATC_Level
< Self_ID
.ATC_Nesting_Level
549 or else Self_ID
.Pending_Priority_Change
;
552 Result
:= pthread_cond_timedwait
553 (Self_ID
.Common
.LL
.CV
'Access, Single_RTS_Lock
'Access,
557 Result
:= pthread_cond_timedwait
558 (Self_ID
.Common
.LL
.CV
'Access, Self_ID
.Common
.LL
.L
'Access,
562 exit when Abs_Time
<= Monotonic_Clock
;
564 if Result
= 0 or Result
= EINTR
then
566 -- Somebody may have called Wakeup for us
572 pragma Assert
(Result
= ETIMEDOUT
);
581 -- This is for use in implementing delay statements, so we assume the
582 -- caller is abort-deferred but is holding no locks.
584 procedure Timed_Delay
587 Mode
: ST
.Delay_Modes
)
589 Check_Time
: constant Duration := Monotonic_Clock
;
592 Request
: aliased timespec
;
594 Result
: Interfaces
.C
.int
;
595 pragma Warnings
(Off
, Result
);
602 Write_Lock
(Self_ID
);
604 if Mode
= Relative
then
605 Abs_Time
:= Duration'Min (Time
, Max_Sensible_Delay
) + Check_Time
;
607 if Relative_Timed_Wait
then
608 Rel_Time
:= Duration'Min (Max_Sensible_Delay
, Time
);
612 Abs_Time
:= Duration'Min (Check_Time
+ Max_Sensible_Delay
, Time
);
614 if Relative_Timed_Wait
then
615 Rel_Time
:= Duration'Min (Max_Sensible_Delay
, Time
- Check_Time
);
619 if Abs_Time
> Check_Time
then
620 if Relative_Timed_Wait
then
621 Request
:= To_Timespec
(Rel_Time
);
623 Request
:= To_Timespec
(Abs_Time
);
626 Self_ID
.Common
.State
:= Delay_Sleep
;
629 if Self_ID
.Pending_Priority_Change
then
630 Self_ID
.Pending_Priority_Change
:= False;
631 Self_ID
.Common
.Base_Priority
:= Self_ID
.New_Base_Priority
;
632 Set_Priority
(Self_ID
, Self_ID
.Common
.Base_Priority
);
635 exit when Self_ID
.Pending_ATC_Level
< Self_ID
.ATC_Nesting_Level
;
638 Result
:= pthread_cond_timedwait
639 (Self_ID
.Common
.LL
.CV
'Access,
640 Single_RTS_Lock
'Access,
643 Result
:= pthread_cond_timedwait
644 (Self_ID
.Common
.LL
.CV
'Access,
645 Self_ID
.Common
.LL
.L
'Access,
649 exit when Abs_Time
<= Monotonic_Clock
;
651 pragma Assert
(Result
= 0
652 or else Result
= ETIMEDOUT
653 or else Result
= EINTR
);
656 Self_ID
.Common
.State
:= Runnable
;
665 Result
:= sched_yield
;
668 ---------------------
669 -- Monotonic_Clock --
670 ---------------------
672 function Monotonic_Clock
return Duration is
673 TS
: aliased timespec
;
674 Result
: Interfaces
.C
.int
;
676 Result
:= clock_gettime
677 (clock_id
=> CLOCK_REALTIME
, tp
=> TS
'Unchecked_Access);
678 pragma Assert
(Result
= 0);
679 return To_Duration
(TS
);
686 function RT_Resolution
return Duration is
695 procedure Wakeup
(T
: Task_Id
; Reason
: System
.Tasking
.Task_States
) is
696 pragma Warnings
(Off
, Reason
);
697 Result
: Interfaces
.C
.int
;
699 Result
:= pthread_cond_signal
(T
.Common
.LL
.CV
'Access);
700 pragma Assert
(Result
= 0);
707 procedure Yield
(Do_Yield
: Boolean := True) is
708 Result
: Interfaces
.C
.int
;
709 pragma Unreferenced
(Result
);
712 Result
:= sched_yield
;
720 procedure Set_Priority
722 Prio
: System
.Any_Priority
;
723 Loss_Of_Inheritance
: Boolean := False)
725 pragma Warnings
(Off
, Loss_Of_Inheritance
);
727 Result
: Interfaces
.C
.int
;
728 Param
: aliased struct_sched_param
;
730 function Get_Policy
(Prio
: System
.Any_Priority
) return Character;
731 pragma Import
(C
, Get_Policy
, "__gnat_get_specific_dispatching");
732 -- Get priority specific dispatching policy
734 Priority_Specific_Policy
: constant Character := Get_Policy
(Prio
);
735 -- Upper case first character of the policy name corresponding to the
736 -- task as set by a Priority_Specific_Dispatching pragma.
739 T
.Common
.Current_Priority
:= Prio
;
740 Param
.sched_priority
:= To_Target_Priority
(Prio
);
742 if Time_Slice_Supported
743 and then (Dispatching_Policy
= 'R'
744 or else Priority_Specific_Policy
= 'R'
745 or else Time_Slice_Val
> 0)
747 Result
:= pthread_setschedparam
748 (T
.Common
.LL
.Thread
, SCHED_RR
, Param
'Access);
750 elsif Dispatching_Policy
= 'F'
751 or else Priority_Specific_Policy
= 'F'
752 or else Time_Slice_Val
= 0
754 Result
:= pthread_setschedparam
755 (T
.Common
.LL
.Thread
, SCHED_FIFO
, Param
'Access);
758 Result
:= pthread_setschedparam
759 (T
.Common
.LL
.Thread
, SCHED_OTHER
, Param
'Access);
762 pragma Assert
(Result
= 0);
769 function Get_Priority
(T
: Task_Id
) return System
.Any_Priority
is
771 return T
.Common
.Current_Priority
;
778 procedure Enter_Task
(Self_ID
: Task_Id
) is
780 Self_ID
.Common
.LL
.Thread
:= pthread_self
;
781 Self_ID
.Common
.LL
.LWP
:= lwp_self
;
783 Specific
.Set
(Self_ID
);
787 for J
in Known_Tasks
'Range loop
788 if Known_Tasks
(J
) = null then
789 Known_Tasks
(J
) := Self_ID
;
790 Self_ID
.Known_Tasks_Index
:= J
;
802 function New_ATCB
(Entry_Num
: Task_Entry_Index
) return Task_Id
is
804 return new Ada_Task_Control_Block
(Entry_Num
);
811 function Is_Valid_Task
return Boolean renames Specific
.Is_Valid_Task
;
813 -----------------------------
814 -- Register_Foreign_Thread --
815 -----------------------------
817 function Register_Foreign_Thread
return Task_Id
is
819 if Is_Valid_Task
then
822 return Register_Foreign_Thread
(pthread_self
);
824 end Register_Foreign_Thread
;
830 procedure Initialize_TCB
(Self_ID
: Task_Id
; Succeeded
: out Boolean) is
831 Mutex_Attr
: aliased pthread_mutexattr_t
;
832 Result
: Interfaces
.C
.int
;
833 Cond_Attr
: aliased pthread_condattr_t
;
836 -- Give the task a unique serial number
838 Self_ID
.Serial_Number
:= Next_Serial_Number
;
839 Next_Serial_Number
:= Next_Serial_Number
+ 1;
840 pragma Assert
(Next_Serial_Number
/= 0);
842 if not Single_Lock
then
843 Result
:= pthread_mutexattr_init
(Mutex_Attr
'Access);
844 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
847 if Locking_Policy
= 'C' then
848 Result
:= pthread_mutexattr_setprotocol
849 (Mutex_Attr
'Access, PTHREAD_PRIO_PROTECT
);
850 pragma Assert
(Result
= 0);
852 Result
:= pthread_mutexattr_setprioceiling
854 Interfaces
.C
.int
(System
.Any_Priority
'Last));
855 pragma Assert
(Result
= 0);
857 elsif Locking_Policy
= 'I' then
858 Result
:= pthread_mutexattr_setprotocol
859 (Mutex_Attr
'Access, PTHREAD_PRIO_INHERIT
);
860 pragma Assert
(Result
= 0);
863 Result
:= pthread_mutex_init
(Self_ID
.Common
.LL
.L
'Access,
865 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
873 Result
:= pthread_mutexattr_destroy
(Mutex_Attr
'Access);
874 pragma Assert
(Result
= 0);
877 Result
:= pthread_condattr_init
(Cond_Attr
'Access);
878 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
881 Result
:= pthread_cond_init
(Self_ID
.Common
.LL
.CV
'Access,
883 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
889 if not Single_Lock
then
890 Result
:= pthread_mutex_destroy
(Self_ID
.Common
.LL
.L
'Access);
891 pragma Assert
(Result
= 0);
897 Result
:= pthread_condattr_destroy
(Cond_Attr
'Access);
898 pragma Assert
(Result
= 0);
905 procedure Create_Task
907 Wrapper
: System
.Address
;
908 Stack_Size
: System
.Parameters
.Size_Type
;
909 Priority
: System
.Any_Priority
;
910 Succeeded
: out Boolean)
912 Attributes
: aliased pthread_attr_t
;
913 Adjusted_Stack_Size
: Interfaces
.C
.size_t
;
914 Result
: Interfaces
.C
.int
;
916 function Thread_Body_Access
is new
917 Unchecked_Conversion
(System
.Address
, Thread_Body
);
919 use System
.Task_Info
;
922 Adjusted_Stack_Size
:= Interfaces
.C
.size_t
(Stack_Size
);
924 if Stack_Base_Available
then
925 -- If Stack Checking is supported then allocate 2 additional pages:
927 -- In the worst case, stack is allocated at something like
928 -- N * Get_Page_Size - epsilon, we need to add the size for 2 pages
929 -- to be sure the effective stack size is greater than what
932 Adjusted_Stack_Size
:= Adjusted_Stack_Size
+ 2 * Get_Page_Size
;
935 Result
:= pthread_attr_init
(Attributes
'Access);
936 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
943 Result
:= pthread_attr_setdetachstate
944 (Attributes
'Access, PTHREAD_CREATE_DETACHED
);
945 pragma Assert
(Result
= 0);
947 Result
:= pthread_attr_setstacksize
948 (Attributes
'Access, Adjusted_Stack_Size
);
949 pragma Assert
(Result
= 0);
951 if T
.Common
.Task_Info
/= Default_Scope
then
953 -- We are assuming that Scope_Type has the same values than the
954 -- corresponding C macros
956 Result
:= pthread_attr_setscope
957 (Attributes
'Access, Task_Info_Type
'Pos (T
.Common
.Task_Info
));
958 pragma Assert
(Result
= 0);
961 -- Since the initial signal mask of a thread is inherited from the
962 -- creator, and the Environment task has all its signals masked, we
963 -- do not need to manipulate caller's signal mask at this point.
964 -- All tasks in RTS will have All_Tasks_Mask initially.
966 Result
:= pthread_create
967 (T
.Common
.LL
.Thread
'Access,
969 Thread_Body_Access
(Wrapper
),
971 pragma Assert
(Result
= 0 or else Result
= EAGAIN
);
973 Succeeded
:= Result
= 0;
975 Result
:= pthread_attr_destroy
(Attributes
'Access);
976 pragma Assert
(Result
= 0);
978 Set_Priority
(T
, Priority
);
985 procedure Finalize_TCB
(T
: Task_Id
) is
986 Result
: Interfaces
.C
.int
;
988 Is_Self
: constant Boolean := T
= Self
;
990 procedure Free
is new
991 Unchecked_Deallocation
(Ada_Task_Control_Block
, Task_Id
);
994 if not Single_Lock
then
995 Result
:= pthread_mutex_destroy
(T
.Common
.LL
.L
'Access);
996 pragma Assert
(Result
= 0);
999 Result
:= pthread_cond_destroy
(T
.Common
.LL
.CV
'Access);
1000 pragma Assert
(Result
= 0);
1002 if T
.Known_Tasks_Index
/= -1 then
1003 Known_Tasks
(T
.Known_Tasks_Index
) := null;
1009 Specific
.Set
(null);
1017 procedure Exit_Task
is
1019 -- Mark this task as unknown, so that if Self is called, it won't
1020 -- return a dangling pointer.
1022 Specific
.Set
(null);
1029 procedure Abort_Task
(T
: Task_Id
) is
1030 Result
: Interfaces
.C
.int
;
1032 Result
:= pthread_kill
(T
.Common
.LL
.Thread
,
1033 Signal
(System
.Interrupt_Management
.Abort_Task_Interrupt
));
1034 pragma Assert
(Result
= 0);
1041 procedure Initialize
(S
: in out Suspension_Object
) is
1042 Mutex_Attr
: aliased pthread_mutexattr_t
;
1043 Cond_Attr
: aliased pthread_condattr_t
;
1044 Result
: Interfaces
.C
.int
;
1046 -- Initialize internal state. It is always initialized to False (ARM
1052 -- Initialize internal mutex
1054 Result
:= pthread_mutexattr_init
(Mutex_Attr
'Access);
1055 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
1057 if Result
= ENOMEM
then
1058 raise Storage_Error
;
1061 Result
:= pthread_mutex_init
(S
.L
'Access, Mutex_Attr
'Access);
1062 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
1064 if Result
= ENOMEM
then
1065 Result
:= pthread_mutexattr_destroy
(Mutex_Attr
'Access);
1066 pragma Assert
(Result
= 0);
1068 raise Storage_Error
;
1071 Result
:= pthread_mutexattr_destroy
(Mutex_Attr
'Access);
1072 pragma Assert
(Result
= 0);
1074 -- Initialize internal condition variable
1076 Result
:= pthread_condattr_init
(Cond_Attr
'Access);
1077 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
1080 Result
:= pthread_mutex_destroy
(S
.L
'Access);
1081 pragma Assert
(Result
= 0);
1083 if Result
= ENOMEM
then
1084 raise Storage_Error
;
1088 Result
:= pthread_cond_init
(S
.CV
'Access, Cond_Attr
'Access);
1089 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
1092 Result
:= pthread_mutex_destroy
(S
.L
'Access);
1093 pragma Assert
(Result
= 0);
1095 if Result
= ENOMEM
then
1096 Result
:= pthread_condattr_destroy
(Cond_Attr
'Access);
1097 pragma Assert
(Result
= 0);
1099 raise Storage_Error
;
1103 Result
:= pthread_condattr_destroy
(Cond_Attr
'Access);
1104 pragma Assert
(Result
= 0);
1111 procedure Finalize
(S
: in out Suspension_Object
) is
1112 Result
: Interfaces
.C
.int
;
1114 -- Destroy internal mutex
1116 Result
:= pthread_mutex_destroy
(S
.L
'Access);
1117 pragma Assert
(Result
= 0);
1119 -- Destroy internal condition variable
1121 Result
:= pthread_cond_destroy
(S
.CV
'Access);
1122 pragma Assert
(Result
= 0);
1129 function Current_State
(S
: Suspension_Object
) return Boolean is
1131 -- We do not want to use lock on this read operation. State is marked
1132 -- as Atomic so that we ensure that the value retrieved is correct.
1141 procedure Set_False
(S
: in out Suspension_Object
) is
1142 Result
: Interfaces
.C
.int
;
1144 SSL
.Abort_Defer
.all;
1146 Result
:= pthread_mutex_lock
(S
.L
'Access);
1147 pragma Assert
(Result
= 0);
1151 Result
:= pthread_mutex_unlock
(S
.L
'Access);
1152 pragma Assert
(Result
= 0);
1154 SSL
.Abort_Undefer
.all;
1161 procedure Set_True
(S
: in out Suspension_Object
) is
1162 Result
: Interfaces
.C
.int
;
1164 SSL
.Abort_Defer
.all;
1166 Result
:= pthread_mutex_lock
(S
.L
'Access);
1167 pragma Assert
(Result
= 0);
1169 -- If there is already a task waiting on this suspension object then
1170 -- we resume it, leaving the state of the suspension object to False,
1171 -- as it is specified in ARM D.10 par. 9. Otherwise, it just leaves
1172 -- the state to True.
1178 Result
:= pthread_cond_signal
(S
.CV
'Access);
1179 pragma Assert
(Result
= 0);
1184 Result
:= pthread_mutex_unlock
(S
.L
'Access);
1185 pragma Assert
(Result
= 0);
1187 SSL
.Abort_Undefer
.all;
1190 ------------------------
1191 -- Suspend_Until_True --
1192 ------------------------
1194 procedure Suspend_Until_True
(S
: in out Suspension_Object
) is
1195 Result
: Interfaces
.C
.int
;
1197 SSL
.Abort_Defer
.all;
1199 Result
:= pthread_mutex_lock
(S
.L
'Access);
1200 pragma Assert
(Result
= 0);
1203 -- Program_Error must be raised upon calling Suspend_Until_True
1204 -- if another task is already waiting on that suspension object
1205 -- (ARM D.10 par. 10).
1207 Result
:= pthread_mutex_unlock
(S
.L
'Access);
1208 pragma Assert
(Result
= 0);
1210 SSL
.Abort_Undefer
.all;
1212 raise Program_Error
;
1214 -- Suspend the task if the state is False. Otherwise, the task
1215 -- continues its execution, and the state of the suspension object
1216 -- is set to False (ARM D.10 par. 9).
1222 Result
:= pthread_cond_wait
(S
.CV
'Access, S
.L
'Access);
1225 Result
:= pthread_mutex_unlock
(S
.L
'Access);
1226 pragma Assert
(Result
= 0);
1228 SSL
.Abort_Undefer
.all;
1230 end Suspend_Until_True
;
1238 function Check_Exit
(Self_ID
: ST
.Task_Id
) return Boolean is
1239 pragma Warnings
(Off
, Self_ID
);
1244 --------------------
1245 -- Check_No_Locks --
1246 --------------------
1248 function Check_No_Locks
(Self_ID
: ST
.Task_Id
) return Boolean is
1249 pragma Warnings
(Off
, Self_ID
);
1254 ----------------------
1255 -- Environment_Task --
1256 ----------------------
1258 function Environment_Task
return Task_Id
is
1260 return Environment_Task_Id
;
1261 end Environment_Task
;
1267 procedure Lock_RTS
is
1269 Write_Lock
(Single_RTS_Lock
'Access, Global_Lock
=> True);
1276 procedure Unlock_RTS
is
1278 Unlock
(Single_RTS_Lock
'Access, Global_Lock
=> True);
1285 function Suspend_Task
1287 Thread_Self
: Thread_Id
) return Boolean
1289 pragma Warnings
(Off
, T
);
1290 pragma Warnings
(Off
, Thread_Self
);
1299 function Resume_Task
1301 Thread_Self
: Thread_Id
) return Boolean
1303 pragma Warnings
(Off
, T
);
1304 pragma Warnings
(Off
, Thread_Self
);
1313 procedure Initialize
(Environment_Task
: Task_Id
) is
1314 act
: aliased struct_sigaction
;
1315 old_act
: aliased struct_sigaction
;
1316 Tmp_Set
: aliased sigset_t
;
1317 Result
: Interfaces
.C
.int
;
1320 (Int
: System
.Interrupt_Management
.Interrupt_ID
) return Character;
1321 pragma Import
(C
, State
, "__gnat_get_interrupt_state");
1322 -- Get interrupt state. Defined in a-init.c
1323 -- The input argument is the interrupt number,
1324 -- and the result is one of the following:
1326 Default
: constant Character := 's';
1327 -- 'n' this interrupt not set by any Interrupt_State pragma
1328 -- 'u' Interrupt_State pragma set state to User
1329 -- 'r' Interrupt_State pragma set state to Runtime
1330 -- 's' Interrupt_State pragma set state to System (use "default"
1334 Environment_Task_Id
:= Environment_Task
;
1336 Interrupt_Management
.Initialize
;
1338 -- Prepare the set of signals that should unblocked in all tasks
1340 Result
:= sigemptyset
(Unblocked_Signal_Mask
'Access);
1341 pragma Assert
(Result
= 0);
1343 for J
in Interrupt_Management
.Interrupt_ID
loop
1344 if System
.Interrupt_Management
.Keep_Unmasked
(J
) then
1345 Result
:= sigaddset
(Unblocked_Signal_Mask
'Access, Signal
(J
));
1346 pragma Assert
(Result
= 0);
1350 -- Initialize the lock used to synchronize chain of all ATCBs
1352 Initialize_Lock
(Single_RTS_Lock
'Access, RTS_Lock_Level
);
1354 Specific
.Initialize
(Environment_Task
);
1356 Enter_Task
(Environment_Task
);
1358 -- Install the abort-signal handler
1360 if State
(System
.Interrupt_Management
.Abort_Task_Interrupt
)
1364 act
.sa_handler
:= Abort_Handler
'Address;
1366 Result
:= sigemptyset
(Tmp_Set
'Access);
1367 pragma Assert
(Result
= 0);
1368 act
.sa_mask
:= Tmp_Set
;
1372 (Signal
(System
.Interrupt_Management
.Abort_Task_Interrupt
),
1373 act
'Unchecked_Access,
1374 old_act
'Unchecked_Access);
1375 pragma Assert
(Result
= 0);
1379 end System
.Task_Primitives
.Operations
;