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) 1992-2005, 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.Parameters;
70 with Unchecked_Conversion;
71 with Unchecked_Deallocation;
73 package body System.Task_Primitives.Operations is
75 use System.Tasking.Debug;
78 use System.OS_Interface;
79 use System.Parameters;
80 use System.OS_Primitives;
86 -- The followings are logically constants, but need to be initialized
89 Single_RTS_Lock : aliased RTS_Lock;
90 -- This is a lock to allow only one thread of control in the RTS at
91 -- a time; it is used to execute in mutual exclusion from all other tasks.
92 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
94 ATCB_Key : aliased pthread_key_t;
95 -- Key used to find the Ada Task_Id associated with a thread
97 Environment_Task_Id : Task_Id;
98 -- A variable to hold Task_Id for the environment task.
100 Locking_Policy : Character;
101 pragma Import (C, Locking_Policy, "__gl_locking_policy");
102 -- Value of the pragma Locking_Policy:
103 -- 'C' for Ceiling_Locking
104 -- 'I' for Inherit_Locking
107 Unblocked_Signal_Mask : aliased sigset_t;
108 -- The set of signals that should unblocked in all tasks
110 -- The followings are internal configuration constants needed.
112 Next_Serial_Number : Task_Serial_Number := 100;
113 -- We start at 100, to reserve some special values for
114 -- using in error checking.
116 Time_Slice_Val : Integer;
117 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
119 Dispatching_Policy : Character;
120 pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
122 Foreign_Task_Elaborated : aliased Boolean := True;
123 -- Used to identified fake tasks (i.e., non-Ada Threads).
131 procedure Initialize (Environment_Task : Task_Id);
132 pragma Inline (Initialize);
133 -- Initialize various data needed by this package.
135 function Is_Valid_Task return Boolean;
136 pragma Inline (Is_Valid_Task);
137 -- Does executing thread have a TCB?
139 procedure Set (Self_Id : Task_Id);
141 -- Set the self id for the current task.
143 function Self return Task_Id;
144 pragma Inline (Self);
145 -- Return a pointer to the Ada Task Control Block of the calling task.
149 package body Specific is separate;
150 -- The body of this package is target specific.
152 ---------------------------------
153 -- Support for foreign threads --
154 ---------------------------------
156 function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
157 -- Allocate and Initialize a new ATCB for the current Thread.
159 function Register_Foreign_Thread
160 (Thread : Thread_Id) return Task_Id is separate;
162 -----------------------
163 -- Local Subprograms --
164 -----------------------
166 procedure Abort_Handler (Sig : Signal);
167 -- Signal handler used to implement asynchronous abort.
168 -- See also comment before body, below.
170 function To_Address is new Unchecked_Conversion (Task_Id, System.Address);
176 -- Target-dependent binding of inter-thread Abort signal to
177 -- the raising of the Abort_Signal exception.
179 -- The technical issues and alternatives here are essentially
180 -- the same as for raising exceptions in response to other
181 -- signals (e.g. Storage_Error). See code and comments in
182 -- the package body System.Interrupt_Management.
184 -- Some implementations may not allow an exception to be propagated
185 -- out of a handler, and others might leave the signal or
186 -- interrupt that invoked this handler masked after the exceptional
187 -- return to the application code.
189 -- GNAT exceptions are originally implemented using setjmp()/longjmp().
190 -- On most UNIX systems, this will allow transfer out of a signal handler,
191 -- which is usually the only mechanism available for implementing
192 -- asynchronous handlers of this kind. However, some
193 -- systems do not restore the signal mask on longjmp(), leaving the
194 -- abort signal masked.
196 procedure Abort_Handler (Sig : Signal) is
197 pragma Warnings (Off, Sig);
199 T : constant Task_Id := Self;
200 Result : Interfaces.C.int;
201 Old_Set : aliased sigset_t;
204 -- It is not safe to raise an exception when using ZCX and the GCC
205 -- exception handling mechanism.
207 if ZCX_By_Default and then GCC_ZCX_Support then
211 if T.Deferral_Level = 0
212 and then T.Pending_ATC_Level < T.ATC_Nesting_Level and then
217 -- Make sure signals used for RTS internal purpose are unmasked
219 Result := pthread_sigmask (SIG_UNBLOCK,
220 Unblocked_Signal_Mask'Unchecked_Access, Old_Set'Unchecked_Access);
221 pragma Assert (Result = 0);
223 raise Standard'Abort_Signal;
231 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
232 Stack_Base : constant Address := Get_Stack_Base (T.Common.LL.Thread);
233 Guard_Page_Address : Address;
235 Res : Interfaces.C.int;
238 if Stack_Base_Available then
240 -- Compute the guard page address
242 Guard_Page_Address :=
243 Stack_Base - (Stack_Base mod Get_Page_Size) + Get_Page_Size;
246 Res := mprotect (Guard_Page_Address, Get_Page_Size, PROT_ON);
248 Res := mprotect (Guard_Page_Address, Get_Page_Size, PROT_OFF);
251 pragma Assert (Res = 0);
259 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
261 return T.Common.LL.Thread;
268 function Self return Task_Id renames Specific.Self;
270 ---------------------
271 -- Initialize_Lock --
272 ---------------------
274 -- Note: mutexes and cond_variables needed per-task basis are
275 -- initialized in Intialize_TCB and the Storage_Error is
276 -- handled. Other mutexes (such as RTS_Lock, Memory_Lock...)
277 -- used in RTS is initialized before any status change of RTS.
278 -- Therefore rasing Storage_Error in the following routines
279 -- should be able to be handled safely.
281 procedure Initialize_Lock
282 (Prio : System.Any_Priority;
285 Attributes : aliased pthread_mutexattr_t;
286 Result : Interfaces.C.int;
289 Result := pthread_mutexattr_init (Attributes'Access);
290 pragma Assert (Result = 0 or else Result = ENOMEM);
292 if Result = ENOMEM then
296 if Locking_Policy = 'C' then
297 Result := pthread_mutexattr_setprotocol
298 (Attributes'Access, PTHREAD_PRIO_PROTECT);
299 pragma Assert (Result = 0);
301 Result := pthread_mutexattr_setprioceiling
302 (Attributes'Access, Interfaces.C.int (Prio));
303 pragma Assert (Result = 0);
305 elsif Locking_Policy = 'I' then
306 Result := pthread_mutexattr_setprotocol
307 (Attributes'Access, PTHREAD_PRIO_INHERIT);
308 pragma Assert (Result = 0);
311 Result := pthread_mutex_init (L, Attributes'Access);
312 pragma Assert (Result = 0 or else Result = ENOMEM);
314 if Result = ENOMEM then
318 Result := pthread_mutexattr_destroy (Attributes'Access);
319 pragma Assert (Result = 0);
322 procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level) is
323 pragma Warnings (Off, Level);
325 Attributes : aliased pthread_mutexattr_t;
326 Result : Interfaces.C.int;
329 Result := pthread_mutexattr_init (Attributes'Access);
330 pragma Assert (Result = 0 or else Result = ENOMEM);
332 if Result = ENOMEM then
336 if Locking_Policy = 'C' then
337 Result := pthread_mutexattr_setprotocol
338 (Attributes'Access, PTHREAD_PRIO_PROTECT);
339 pragma Assert (Result = 0);
341 Result := pthread_mutexattr_setprioceiling
342 (Attributes'Access, Interfaces.C.int (System.Any_Priority'Last));
343 pragma Assert (Result = 0);
345 elsif Locking_Policy = 'I' then
346 Result := pthread_mutexattr_setprotocol
347 (Attributes'Access, PTHREAD_PRIO_INHERIT);
348 pragma Assert (Result = 0);
351 Result := pthread_mutex_init (L, Attributes'Access);
352 pragma Assert (Result = 0 or else Result = ENOMEM);
354 if Result = ENOMEM then
355 Result := pthread_mutexattr_destroy (Attributes'Access);
359 Result := pthread_mutexattr_destroy (Attributes'Access);
360 pragma Assert (Result = 0);
367 procedure Finalize_Lock (L : access Lock) is
368 Result : Interfaces.C.int;
371 Result := pthread_mutex_destroy (L);
372 pragma Assert (Result = 0);
375 procedure Finalize_Lock (L : access RTS_Lock) is
376 Result : Interfaces.C.int;
379 Result := pthread_mutex_destroy (L);
380 pragma Assert (Result = 0);
387 procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
388 Result : Interfaces.C.int;
391 Result := pthread_mutex_lock (L);
393 -- Assume that the cause of EINVAL is a priority ceiling violation
395 Ceiling_Violation := (Result = EINVAL);
396 pragma Assert (Result = 0 or else Result = EINVAL);
400 (L : access RTS_Lock;
401 Global_Lock : Boolean := False)
403 Result : Interfaces.C.int;
406 if not Single_Lock or else Global_Lock then
407 Result := pthread_mutex_lock (L);
408 pragma Assert (Result = 0);
412 procedure Write_Lock (T : Task_Id) is
413 Result : Interfaces.C.int;
416 if not Single_Lock then
417 Result := pthread_mutex_lock (T.Common.LL.L'Access);
418 pragma Assert (Result = 0);
426 procedure Read_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
428 Write_Lock (L, Ceiling_Violation);
435 procedure Unlock (L : access Lock) is
436 Result : Interfaces.C.int;
439 Result := pthread_mutex_unlock (L);
440 pragma Assert (Result = 0);
443 procedure Unlock (L : access RTS_Lock; Global_Lock : Boolean := False) is
444 Result : Interfaces.C.int;
447 if not Single_Lock or else Global_Lock then
448 Result := pthread_mutex_unlock (L);
449 pragma Assert (Result = 0);
453 procedure Unlock (T : Task_Id) is
454 Result : Interfaces.C.int;
457 if not Single_Lock then
458 Result := pthread_mutex_unlock (T.Common.LL.L'Access);
459 pragma Assert (Result = 0);
469 Reason : System.Tasking.Task_States)
471 pragma Warnings (Off, Reason);
473 Result : Interfaces.C.int;
477 Result := pthread_cond_wait
478 (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access);
480 Result := pthread_cond_wait
481 (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access);
484 -- EINTR is not considered a failure.
486 pragma Assert (Result = 0 or else Result = EINTR);
493 -- This is for use within the run-time system, so abort is
494 -- assumed to be already deferred, and the caller should be
495 -- holding its own ATCB lock.
497 procedure Timed_Sleep
500 Mode : ST.Delay_Modes;
501 Reason : Task_States;
502 Timedout : out Boolean;
503 Yielded : out Boolean)
505 pragma Warnings (Off, Reason);
507 Check_Time : constant Duration := Monotonic_Clock;
510 Request : aliased timespec;
511 Result : Interfaces.C.int;
517 if Mode = Relative then
518 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
520 if Relative_Timed_Wait then
521 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
525 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
527 if Relative_Timed_Wait then
528 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
532 if Abs_Time > Check_Time then
533 if Relative_Timed_Wait then
534 Request := To_Timespec (Rel_Time);
536 Request := To_Timespec (Abs_Time);
540 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
541 or else Self_ID.Pending_Priority_Change;
544 Result := pthread_cond_timedwait
545 (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access,
549 Result := pthread_cond_timedwait
550 (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access,
554 exit when Abs_Time <= Monotonic_Clock;
556 if Result = 0 or Result = EINTR then
558 -- Somebody may have called Wakeup for us
564 pragma Assert (Result = ETIMEDOUT);
573 -- This is for use in implementing delay statements, so
574 -- we assume the caller is abort-deferred but is holding
577 procedure Timed_Delay
580 Mode : ST.Delay_Modes)
582 Check_Time : constant Duration := Monotonic_Clock;
585 Request : aliased timespec;
586 Result : Interfaces.C.int;
593 Write_Lock (Self_ID);
595 if Mode = Relative then
596 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
598 if Relative_Timed_Wait then
599 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
603 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
605 if Relative_Timed_Wait then
606 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
610 if Abs_Time > Check_Time then
611 if Relative_Timed_Wait then
612 Request := To_Timespec (Rel_Time);
614 Request := To_Timespec (Abs_Time);
617 Self_ID.Common.State := Delay_Sleep;
620 if Self_ID.Pending_Priority_Change then
621 Self_ID.Pending_Priority_Change := False;
622 Self_ID.Common.Base_Priority := Self_ID.New_Base_Priority;
623 Set_Priority (Self_ID, Self_ID.Common.Base_Priority);
626 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
629 Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access,
630 Single_RTS_Lock'Access, Request'Access);
632 Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access,
633 Self_ID.Common.LL.L'Access, Request'Access);
636 exit when Abs_Time <= Monotonic_Clock;
638 pragma Assert (Result = 0
639 or else Result = ETIMEDOUT
640 or else Result = EINTR);
643 Self_ID.Common.State := Runnable;
652 Result := sched_yield;
655 ---------------------
656 -- Monotonic_Clock --
657 ---------------------
659 function Monotonic_Clock return Duration is
660 TS : aliased timespec;
661 Result : Interfaces.C.int;
663 Result := clock_gettime
664 (clock_id => CLOCK_REALTIME, tp => TS'Unchecked_Access);
665 pragma Assert (Result = 0);
666 return To_Duration (TS);
673 function RT_Resolution return Duration is
682 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
683 pragma Warnings (Off, Reason);
684 Result : Interfaces.C.int;
686 Result := pthread_cond_signal (T.Common.LL.CV'Access);
687 pragma Assert (Result = 0);
694 procedure Yield (Do_Yield : Boolean := True) is
695 Result : Interfaces.C.int;
696 pragma Unreferenced (Result);
699 Result := sched_yield;
707 procedure Set_Priority
709 Prio : System.Any_Priority;
710 Loss_Of_Inheritance : Boolean := False)
712 pragma Warnings (Off, Loss_Of_Inheritance);
714 Result : Interfaces.C.int;
715 Param : aliased struct_sched_param;
718 T.Common.Current_Priority := Prio;
719 Param.sched_priority := Interfaces.C.int (Prio);
721 if Time_Slice_Supported and then Time_Slice_Val > 0 then
722 Result := pthread_setschedparam
723 (T.Common.LL.Thread, SCHED_RR, Param'Access);
725 elsif Dispatching_Policy = 'F' or else Time_Slice_Val = 0 then
726 Result := pthread_setschedparam
727 (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
730 Result := pthread_setschedparam
731 (T.Common.LL.Thread, SCHED_OTHER, Param'Access);
734 pragma Assert (Result = 0);
741 function Get_Priority (T : Task_Id) return System.Any_Priority is
743 return T.Common.Current_Priority;
750 procedure Enter_Task (Self_ID : Task_Id) is
752 Self_ID.Common.LL.Thread := pthread_self;
753 Self_ID.Common.LL.LWP := lwp_self;
755 Specific.Set (Self_ID);
759 for J in Known_Tasks'Range loop
760 if Known_Tasks (J) = null then
761 Known_Tasks (J) := Self_ID;
762 Self_ID.Known_Tasks_Index := J;
774 function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
776 return new Ada_Task_Control_Block (Entry_Num);
783 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
785 -----------------------------
786 -- Register_Foreign_Thread --
787 -----------------------------
789 function Register_Foreign_Thread return Task_Id is
791 if Is_Valid_Task then
794 return Register_Foreign_Thread (pthread_self);
796 end Register_Foreign_Thread;
802 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
803 Mutex_Attr : aliased pthread_mutexattr_t;
804 Result : Interfaces.C.int;
805 Cond_Attr : aliased pthread_condattr_t;
808 -- Give the task a unique serial number.
810 Self_ID.Serial_Number := Next_Serial_Number;
811 Next_Serial_Number := Next_Serial_Number + 1;
812 pragma Assert (Next_Serial_Number /= 0);
814 if not Single_Lock then
815 Result := pthread_mutexattr_init (Mutex_Attr'Access);
816 pragma Assert (Result = 0 or else Result = ENOMEM);
819 if Locking_Policy = 'C' then
820 Result := pthread_mutexattr_setprotocol
821 (Mutex_Attr'Access, PTHREAD_PRIO_PROTECT);
822 pragma Assert (Result = 0);
824 Result := pthread_mutexattr_setprioceiling
826 Interfaces.C.int (System.Any_Priority'Last));
827 pragma Assert (Result = 0);
829 elsif Locking_Policy = 'I' then
830 Result := pthread_mutexattr_setprotocol
831 (Mutex_Attr'Access, PTHREAD_PRIO_INHERIT);
832 pragma Assert (Result = 0);
835 Result := pthread_mutex_init (Self_ID.Common.LL.L'Access,
837 pragma Assert (Result = 0 or else Result = ENOMEM);
845 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
846 pragma Assert (Result = 0);
849 Result := pthread_condattr_init (Cond_Attr'Access);
850 pragma Assert (Result = 0 or else Result = ENOMEM);
853 Result := pthread_cond_init (Self_ID.Common.LL.CV'Access,
855 pragma Assert (Result = 0 or else Result = ENOMEM);
861 if not Single_Lock then
862 Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
863 pragma Assert (Result = 0);
869 Result := pthread_condattr_destroy (Cond_Attr'Access);
870 pragma Assert (Result = 0);
877 procedure Create_Task
879 Wrapper : System.Address;
880 Stack_Size : System.Parameters.Size_Type;
881 Priority : System.Any_Priority;
882 Succeeded : out Boolean)
884 Attributes : aliased pthread_attr_t;
885 Adjusted_Stack_Size : Interfaces.C.size_t;
886 Result : Interfaces.C.int;
888 function Thread_Body_Access is new
889 Unchecked_Conversion (System.Address, Thread_Body);
891 use System.Task_Info;
894 if Stack_Size = Unspecified_Size then
895 Adjusted_Stack_Size := Interfaces.C.size_t (Default_Stack_Size);
897 elsif Stack_Size < Minimum_Stack_Size then
898 Adjusted_Stack_Size := Interfaces.C.size_t (Minimum_Stack_Size);
901 Adjusted_Stack_Size := Interfaces.C.size_t (Stack_Size);
904 if Stack_Base_Available then
905 -- If Stack Checking is supported then allocate 2 additional pages:
907 -- In the worst case, stack is allocated at something like
908 -- N * Get_Page_Size - epsilon, we need to add the size for 2 pages
909 -- to be sure the effective stack size is greater than what
912 Adjusted_Stack_Size := Adjusted_Stack_Size + 2 * Get_Page_Size;
915 Result := pthread_attr_init (Attributes'Access);
916 pragma Assert (Result = 0 or else Result = ENOMEM);
923 Result := pthread_attr_setdetachstate
924 (Attributes'Access, PTHREAD_CREATE_DETACHED);
925 pragma Assert (Result = 0);
927 Result := pthread_attr_setstacksize
928 (Attributes'Access, Adjusted_Stack_Size);
929 pragma Assert (Result = 0);
931 if T.Common.Task_Info /= Default_Scope then
933 -- We are assuming that Scope_Type has the same values than the
934 -- corresponding C macros
936 Result := pthread_attr_setscope
937 (Attributes'Access, Task_Info_Type'Pos (T.Common.Task_Info));
938 pragma Assert (Result = 0);
941 -- Since the initial signal mask of a thread is inherited from the
942 -- creator, and the Environment task has all its signals masked, we
943 -- do not need to manipulate caller's signal mask at this point.
944 -- All tasks in RTS will have All_Tasks_Mask initially.
946 Result := pthread_create
947 (T.Common.LL.Thread'Access,
949 Thread_Body_Access (Wrapper),
951 pragma Assert (Result = 0 or else Result = EAGAIN);
953 Succeeded := Result = 0;
955 Result := pthread_attr_destroy (Attributes'Access);
956 pragma Assert (Result = 0);
958 Set_Priority (T, Priority);
965 procedure Finalize_TCB (T : Task_Id) is
966 Result : Interfaces.C.int;
968 Is_Self : constant Boolean := T = Self;
970 procedure Free is new
971 Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
974 if not Single_Lock then
975 Result := pthread_mutex_destroy (T.Common.LL.L'Access);
976 pragma Assert (Result = 0);
979 Result := pthread_cond_destroy (T.Common.LL.CV'Access);
980 pragma Assert (Result = 0);
982 if T.Known_Tasks_Index /= -1 then
983 Known_Tasks (T.Known_Tasks_Index) := null;
997 procedure Exit_Task is
999 -- Mark this task as unknown, so that if Self is called, it won't
1000 -- return a dangling pointer.
1002 Specific.Set (null);
1009 procedure Abort_Task (T : Task_Id) is
1010 Result : Interfaces.C.int;
1012 Result := pthread_kill (T.Common.LL.Thread,
1013 Signal (System.Interrupt_Management.Abort_Task_Interrupt));
1014 pragma Assert (Result = 0);
1021 procedure Initialize (S : in out Suspension_Object) is
1022 Mutex_Attr : aliased pthread_mutexattr_t;
1023 Cond_Attr : aliased pthread_condattr_t;
1024 Result : Interfaces.C.int;
1026 -- Initialize internal state. It is always initialized to False (ARM
1032 -- Initialize internal mutex
1034 Result := pthread_mutexattr_init (Mutex_Attr'Access);
1035 pragma Assert (Result = 0 or else Result = ENOMEM);
1037 if Result = ENOMEM then
1038 raise Storage_Error;
1041 Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
1042 pragma Assert (Result = 0 or else Result = ENOMEM);
1044 if Result = ENOMEM then
1045 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1046 pragma Assert (Result = 0);
1048 raise Storage_Error;
1051 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1052 pragma Assert (Result = 0);
1054 -- Initialize internal condition variable
1056 Result := pthread_condattr_init (Cond_Attr'Access);
1057 pragma Assert (Result = 0 or else Result = ENOMEM);
1060 Result := pthread_mutex_destroy (S.L'Access);
1061 pragma Assert (Result = 0);
1063 if Result = ENOMEM then
1064 raise Storage_Error;
1068 Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
1069 pragma Assert (Result = 0 or else Result = ENOMEM);
1072 Result := pthread_mutex_destroy (S.L'Access);
1073 pragma Assert (Result = 0);
1075 if Result = ENOMEM then
1076 Result := pthread_condattr_destroy (Cond_Attr'Access);
1077 pragma Assert (Result = 0);
1079 raise Storage_Error;
1083 Result := pthread_condattr_destroy (Cond_Attr'Access);
1084 pragma Assert (Result = 0);
1091 procedure Finalize (S : in out Suspension_Object) is
1092 Result : Interfaces.C.int;
1094 -- Destroy internal mutex
1096 Result := pthread_mutex_destroy (S.L'Access);
1097 pragma Assert (Result = 0);
1099 -- Destroy internal condition variable
1101 Result := pthread_cond_destroy (S.CV'Access);
1102 pragma Assert (Result = 0);
1109 function Current_State (S : Suspension_Object) return Boolean is
1111 -- We do not want to use lock on this read operation. State is marked
1112 -- as Atomic so that we ensure that the value retrieved is correct.
1121 procedure Set_False (S : in out Suspension_Object) is
1122 Result : Interfaces.C.int;
1124 Result := pthread_mutex_lock (S.L'Access);
1125 pragma Assert (Result = 0);
1129 Result := pthread_mutex_unlock (S.L'Access);
1130 pragma Assert (Result = 0);
1137 procedure Set_True (S : in out Suspension_Object) is
1138 Result : Interfaces.C.int;
1140 Result := pthread_mutex_lock (S.L'Access);
1141 pragma Assert (Result = 0);
1143 -- If there is already a task waiting on this suspension object then
1144 -- we resume it, leaving the state of the suspension object to False,
1145 -- as it is specified in ARM D.10 par. 9. Otherwise, it just leaves
1146 -- the state to True.
1152 Result := pthread_cond_signal (S.CV'Access);
1153 pragma Assert (Result = 0);
1158 Result := pthread_mutex_unlock (S.L'Access);
1159 pragma Assert (Result = 0);
1162 ------------------------
1163 -- Suspend_Until_True --
1164 ------------------------
1166 procedure Suspend_Until_True (S : in out Suspension_Object) is
1167 Result : Interfaces.C.int;
1169 Result := pthread_mutex_lock (S.L'Access);
1170 pragma Assert (Result = 0);
1173 -- Program_Error must be raised upon calling Suspend_Until_True
1174 -- if another task is already waiting on that suspension object
1175 -- (ARM D.10 par. 10).
1177 Result := pthread_mutex_unlock (S.L'Access);
1178 pragma Assert (Result = 0);
1180 raise Program_Error;
1182 -- Suspend the task if the state is False. Otherwise, the task
1183 -- continues its execution, and the state of the suspension object
1184 -- is set to False (ARM D.10 par. 9).
1190 Result := pthread_cond_wait (S.CV'Access, S.L'Access);
1194 Result := pthread_mutex_unlock (S.L'Access);
1195 pragma Assert (Result = 0);
1196 end Suspend_Until_True;
1204 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1205 pragma Warnings (Off, Self_ID);
1210 --------------------
1211 -- Check_No_Locks --
1212 --------------------
1214 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1215 pragma Warnings (Off, Self_ID);
1220 ----------------------
1221 -- Environment_Task --
1222 ----------------------
1224 function Environment_Task return Task_Id is
1226 return Environment_Task_Id;
1227 end Environment_Task;
1233 procedure Lock_RTS is
1235 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
1242 procedure Unlock_RTS is
1244 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
1251 function Suspend_Task
1253 Thread_Self : Thread_Id) return Boolean
1255 pragma Warnings (Off, T);
1256 pragma Warnings (Off, Thread_Self);
1265 function Resume_Task
1267 Thread_Self : Thread_Id) return Boolean
1269 pragma Warnings (Off, T);
1270 pragma Warnings (Off, Thread_Self);
1279 procedure Initialize (Environment_Task : Task_Id) is
1280 act : aliased struct_sigaction;
1281 old_act : aliased struct_sigaction;
1282 Tmp_Set : aliased sigset_t;
1283 Result : Interfaces.C.int;
1286 (Int : System.Interrupt_Management.Interrupt_ID) return Character;
1287 pragma Import (C, State, "__gnat_get_interrupt_state");
1288 -- Get interrupt state. Defined in a-init.c
1289 -- The input argument is the interrupt number,
1290 -- and the result is one of the following:
1292 Default : constant Character := 's';
1293 -- 'n' this interrupt not set by any Interrupt_State pragma
1294 -- 'u' Interrupt_State pragma set state to User
1295 -- 'r' Interrupt_State pragma set state to Runtime
1296 -- 's' Interrupt_State pragma set state to System (use "default"
1300 Environment_Task_Id := Environment_Task;
1302 Interrupt_Management.Initialize;
1304 -- Prepare the set of signals that should unblocked in all tasks
1306 Result := sigemptyset (Unblocked_Signal_Mask'Access);
1307 pragma Assert (Result = 0);
1309 for J in Interrupt_Management.Interrupt_ID loop
1310 if System.Interrupt_Management.Keep_Unmasked (J) then
1311 Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
1312 pragma Assert (Result = 0);
1316 -- Initialize the lock used to synchronize chain of all ATCBs.
1318 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1320 Specific.Initialize (Environment_Task);
1322 Enter_Task (Environment_Task);
1324 -- Install the abort-signal handler
1326 if State (System.Interrupt_Management.Abort_Task_Interrupt)
1330 act.sa_handler := Abort_Handler'Address;
1332 Result := sigemptyset (Tmp_Set'Access);
1333 pragma Assert (Result = 0);
1334 act.sa_mask := Tmp_Set;
1338 (Signal (System.Interrupt_Management.Abort_Task_Interrupt),
1339 act'Unchecked_Access,
1340 old_act'Unchecked_Access);
1341 pragma Assert (Result = 0);
1345 end System.Task_Primitives.Operations;