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 DEC Unix 4.0d 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
46 with System.Interrupt_Management;
47 -- used for Keep_Unmasked
48 -- Abort_Task_Interrupt
51 with System.OS_Primitives;
52 -- used for Delay_Modes
54 with System.Task_Info;
55 -- used for Task_Info_Type
58 -- used for Shift_Left
64 with System.Soft_Links;
65 -- used for Abort_Defer/Undefer
67 -- We use System.Soft_Links instead of System.Tasking.Initialization
68 -- because the later is a higher level package that we shouldn't depend on.
69 -- For example when using the restricted run time, it is replaced by
70 -- System.Tasking.Restricted.Stages.
72 with Unchecked_Deallocation;
74 package body System.Task_Primitives.Operations is
76 package SSL renames System.Soft_Links;
78 use System.Tasking.Debug;
81 use System.OS_Interface;
82 use System.Parameters;
83 use System.OS_Primitives;
89 -- The followings are logically constants, but need to be initialized
92 Single_RTS_Lock : aliased RTS_Lock;
93 -- This is a lock to allow only one thread of control in the RTS at
94 -- a time; it is used to execute in mutual exclusion from all other tasks.
95 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
97 ATCB_Key : aliased pthread_key_t;
98 -- Key used to find the Ada Task_Id associated with a thread
100 Environment_Task_Id : Task_Id;
101 -- A variable to hold Task_Id for the environment task
103 Unblocked_Signal_Mask : aliased sigset_t;
104 -- The set of signals that should unblocked in all tasks
106 Time_Slice_Val : Integer;
107 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
109 Locking_Policy : Character;
110 pragma Import (C, Locking_Policy, "__gl_locking_policy");
112 Dispatching_Policy : Character;
113 pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
117 Foreign_Task_Elaborated : aliased Boolean := True;
118 -- Used to identified fake tasks (i.e., non-Ada Threads)
126 procedure Initialize (Environment_Task : Task_Id);
127 pragma Inline (Initialize);
128 -- Initialize various data needed by this package
130 function Is_Valid_Task return Boolean;
131 pragma Inline (Is_Valid_Task);
132 -- Does executing thread have a TCB?
134 procedure Set (Self_Id : Task_Id);
136 -- Set the self id for 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 (Sig : Signal);
162 -- Signal handler used to implement asynchronous abort
168 procedure Abort_Handler (Sig : Signal) is
169 pragma Unreferenced (Sig);
171 T : constant Task_Id := Self;
172 Result : Interfaces.C.int;
173 Old_Set : aliased sigset_t;
176 -- It is not safe to raise an exception when using ZCX and the GCC
177 -- exception handling mechanism.
179 if ZCX_By_Default and then GCC_ZCX_Support then
183 if T.Deferral_Level = 0
184 and then T.Pending_ATC_Level < T.ATC_Nesting_Level and then
189 -- Make sure signals used for RTS internal purpose are unmasked
191 Result := pthread_sigmask (SIG_UNBLOCK,
192 Unblocked_Signal_Mask'Unchecked_Access, Old_Set'Unchecked_Access);
193 pragma Assert (Result = 0);
195 raise Standard'Abort_Signal;
203 -- The underlying thread system sets a guard page at the
204 -- bottom of a thread stack, so nothing is needed.
206 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
207 pragma Unreferenced (T);
208 pragma Unreferenced (On);
217 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
219 return T.Common.LL.Thread;
226 function Self return Task_Id renames Specific.Self;
228 ---------------------
229 -- Initialize_Lock --
230 ---------------------
232 -- Note: mutexes and cond_variables needed per-task basis are
233 -- initialized in Initialize_TCB and the Storage_Error is
234 -- handled. Other mutexes (such as RTS_Lock, Memory_Lock...)
235 -- used in RTS is initialized before any status change of RTS.
236 -- Therefore rasing Storage_Error in the following routines
237 -- should be able to be handled safely.
239 procedure Initialize_Lock
240 (Prio : System.Any_Priority;
243 Attributes : aliased pthread_mutexattr_t;
244 Result : Interfaces.C.int;
247 Result := pthread_mutexattr_init (Attributes'Access);
248 pragma Assert (Result = 0 or else Result = ENOMEM);
250 if Result = ENOMEM then
254 if Locking_Policy = 'C' then
255 L.Ceiling := Interfaces.C.int (Prio);
258 Result := pthread_mutex_init (L.L'Access, Attributes'Access);
259 pragma Assert (Result = 0 or else Result = ENOMEM);
261 if Result = ENOMEM then
262 Result := pthread_mutexattr_destroy (Attributes'Access);
266 Result := pthread_mutexattr_destroy (Attributes'Access);
267 pragma Assert (Result = 0);
270 procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level) is
271 pragma Unreferenced (Level);
273 Attributes : aliased pthread_mutexattr_t;
274 Result : Interfaces.C.int;
277 Result := pthread_mutexattr_init (Attributes'Access);
278 pragma Assert (Result = 0 or else Result = ENOMEM);
280 if Result = ENOMEM then
284 Result := pthread_mutex_init (L, Attributes'Access);
285 pragma Assert (Result = 0 or else Result = ENOMEM);
287 if Result = ENOMEM then
288 Result := pthread_mutexattr_destroy (Attributes'Access);
292 Result := pthread_mutexattr_destroy (Attributes'Access);
293 pragma Assert (Result = 0);
300 procedure Finalize_Lock (L : access Lock) is
301 Result : Interfaces.C.int;
303 Result := pthread_mutex_destroy (L.L'Access);
304 pragma Assert (Result = 0);
307 procedure Finalize_Lock (L : access RTS_Lock) is
308 Result : Interfaces.C.int;
310 Result := pthread_mutex_destroy (L);
311 pragma Assert (Result = 0);
318 procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
319 Result : Interfaces.C.int;
321 All_Tasks_Link : Task_Id;
322 Current_Prio : System.Any_Priority;
325 -- Perform ceiling checks only when this is the locking policy in use
327 if Locking_Policy = 'C' then
329 All_Tasks_Link := Self_ID.Common.All_Tasks_Link;
330 Current_Prio := Get_Priority (Self_ID);
332 -- If there is no other task, no need to check priorities
334 if All_Tasks_Link /= Null_Task
335 and then L.Ceiling < Interfaces.C.int (Current_Prio)
337 Ceiling_Violation := True;
342 Result := pthread_mutex_lock (L.L'Access);
343 pragma Assert (Result = 0);
345 Ceiling_Violation := False;
349 (L : access RTS_Lock; Global_Lock : Boolean := False)
351 Result : Interfaces.C.int;
353 if not Single_Lock or else Global_Lock then
354 Result := pthread_mutex_lock (L);
355 pragma Assert (Result = 0);
359 procedure Write_Lock (T : Task_Id) is
360 Result : Interfaces.C.int;
362 if not Single_Lock then
363 Result := pthread_mutex_lock (T.Common.LL.L'Access);
364 pragma Assert (Result = 0);
372 procedure Read_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
374 Write_Lock (L, Ceiling_Violation);
381 procedure Unlock (L : access Lock) is
382 Result : Interfaces.C.int;
384 Result := pthread_mutex_unlock (L.L'Access);
385 pragma Assert (Result = 0);
388 procedure Unlock (L : access RTS_Lock; Global_Lock : Boolean := False) is
389 Result : Interfaces.C.int;
391 if not Single_Lock or else Global_Lock then
392 Result := pthread_mutex_unlock (L);
393 pragma Assert (Result = 0);
397 procedure Unlock (T : Task_Id) is
398 Result : Interfaces.C.int;
400 if not Single_Lock then
401 Result := pthread_mutex_unlock (T.Common.LL.L'Access);
402 pragma Assert (Result = 0);
412 Reason : System.Tasking.Task_States)
414 pragma Unreferenced (Reason);
416 Result : Interfaces.C.int;
420 Result := pthread_cond_wait
421 (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access);
423 Result := pthread_cond_wait
424 (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access);
427 -- EINTR is not considered a failure
429 pragma Assert (Result = 0 or else Result = EINTR);
436 -- This is for use within the run-time system, so abort is
437 -- assumed to be already deferred, and the caller should be
438 -- holding its own ATCB lock.
440 procedure Timed_Sleep
443 Mode : ST.Delay_Modes;
444 Reason : System.Tasking.Task_States;
445 Timedout : out Boolean;
446 Yielded : out Boolean)
448 pragma Unreferenced (Reason);
450 Check_Time : constant Duration := Monotonic_Clock;
452 Request : aliased timespec;
453 Result : Interfaces.C.int;
459 if Mode = Relative then
460 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
462 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
465 if Abs_Time > Check_Time then
466 Request := To_Timespec (Abs_Time);
469 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
470 or else Self_ID.Pending_Priority_Change;
473 Result := pthread_cond_timedwait
474 (Self_ID.Common.LL.CV'Access,
475 Single_RTS_Lock'Access,
479 Result := pthread_cond_timedwait
480 (Self_ID.Common.LL.CV'Access,
481 Self_ID.Common.LL.L'Access,
485 exit when Abs_Time <= Monotonic_Clock;
487 if Result = 0 or Result = EINTR then
489 -- Somebody may have called Wakeup for us
495 pragma Assert (Result = ETIMEDOUT);
504 -- This is for use in implementing delay statements, so
505 -- we assume the caller is abort-deferred but is holding
508 procedure Timed_Delay
511 Mode : ST.Delay_Modes)
513 Check_Time : constant Duration := Monotonic_Clock;
515 Request : aliased timespec;
516 Result : Interfaces.C.int;
523 Write_Lock (Self_ID);
525 if Mode = Relative then
526 Abs_Time := Time + Check_Time;
528 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
531 if Abs_Time > Check_Time then
532 Request := To_Timespec (Abs_Time);
533 Self_ID.Common.State := Delay_Sleep;
536 if Self_ID.Pending_Priority_Change then
537 Self_ID.Pending_Priority_Change := False;
538 Self_ID.Common.Base_Priority := Self_ID.New_Base_Priority;
539 Set_Priority (Self_ID, Self_ID.Common.Base_Priority);
542 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
545 Result := pthread_cond_timedwait
546 (Self_ID.Common.LL.CV'Access,
547 Single_RTS_Lock'Access,
550 Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access,
551 Self_ID.Common.LL.L'Access, Request'Access);
554 exit when Abs_Time <= Monotonic_Clock;
556 pragma Assert (Result = 0 or else
557 Result = ETIMEDOUT or else
561 Self_ID.Common.State := Runnable;
573 ---------------------
574 -- Monotonic_Clock --
575 ---------------------
577 function Monotonic_Clock return Duration is
578 TS : aliased timespec;
579 Result : Interfaces.C.int;
581 Result := clock_gettime (CLOCK_REALTIME, TS'Unchecked_Access);
582 pragma Assert (Result = 0);
583 return To_Duration (TS);
590 function RT_Resolution return Duration is
592 -- Returned value must be an integral multiple of Duration'Small (1 ns)
593 -- The following is the best approximation of 1/1024. The clock on the
594 -- DEC Alpha ticks at 1024 Hz.
596 return 0.000_976_563;
603 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
604 pragma Unreferenced (Reason);
605 Result : Interfaces.C.int;
607 Result := pthread_cond_signal (T.Common.LL.CV'Access);
608 pragma Assert (Result = 0);
615 procedure Yield (Do_Yield : Boolean := True) is
616 Result : Interfaces.C.int;
617 pragma Unreferenced (Result);
620 Result := sched_yield;
628 procedure Set_Priority
630 Prio : System.Any_Priority;
631 Loss_Of_Inheritance : Boolean := False)
633 pragma Unreferenced (Loss_Of_Inheritance);
635 Result : Interfaces.C.int;
636 Param : aliased struct_sched_param;
639 T.Common.Current_Priority := Prio;
640 Param.sched_priority := Interfaces.C.int (Underlying_Priorities (Prio));
642 if Time_Slice_Val > 0 then
643 Result := pthread_setschedparam
644 (T.Common.LL.Thread, SCHED_RR, Param'Access);
646 elsif Dispatching_Policy = 'F' or else Time_Slice_Val = 0 then
647 Result := pthread_setschedparam
648 (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
651 Result := pthread_setschedparam
652 (T.Common.LL.Thread, SCHED_OTHER, Param'Access);
655 pragma Assert (Result = 0);
662 function Get_Priority (T : Task_Id) return System.Any_Priority is
664 return T.Common.Current_Priority;
671 procedure Enter_Task (Self_ID : Task_Id) is
674 Self_ID.Common.LL.Thread := pthread_self;
675 Specific.Set (Self_ID);
679 for J in Known_Tasks'Range loop
680 if Known_Tasks (J) = null then
681 Known_Tasks (J) := Self_ID;
682 Self_ID.Known_Tasks_Index := J;
694 function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
696 return new Ada_Task_Control_Block (Entry_Num);
703 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
705 -----------------------------
706 -- Register_Foreign_Thread --
707 -----------------------------
709 function Register_Foreign_Thread return Task_Id is
711 if Is_Valid_Task then
714 return Register_Foreign_Thread (pthread_self);
716 end Register_Foreign_Thread;
722 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
723 Mutex_Attr : aliased pthread_mutexattr_t;
724 Result : Interfaces.C.int;
725 Cond_Attr : aliased pthread_condattr_t;
728 if not Single_Lock then
729 Result := pthread_mutexattr_init (Mutex_Attr'Access);
730 pragma Assert (Result = 0 or else Result = ENOMEM);
733 Result := pthread_mutex_init
734 (Self_ID.Common.LL.L'Access, Mutex_Attr'Access);
735 pragma Assert (Result = 0 or else Result = ENOMEM);
743 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
744 pragma Assert (Result = 0);
747 Result := pthread_condattr_init (Cond_Attr'Access);
748 pragma Assert (Result = 0 or else Result = ENOMEM);
751 Result := pthread_cond_init
752 (Self_ID.Common.LL.CV'Access, Cond_Attr'Access);
753 pragma Assert (Result = 0 or else Result = ENOMEM);
759 if not Single_Lock then
760 Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
761 pragma Assert (Result = 0);
767 Result := pthread_condattr_destroy (Cond_Attr'Access);
768 pragma Assert (Result = 0);
775 procedure Create_Task
777 Wrapper : System.Address;
778 Stack_Size : System.Parameters.Size_Type;
779 Priority : System.Any_Priority;
780 Succeeded : out Boolean)
782 Attributes : aliased pthread_attr_t;
783 Adjusted_Stack_Size : Interfaces.C.size_t;
784 Result : Interfaces.C.int;
785 Param : aliased System.OS_Interface.struct_sched_param;
787 use System.Task_Info;
790 -- Account for the Yellow Zone (2 pages) and the guard page
791 -- right above. See Hide_Yellow_Zone for the rationale.
793 Adjusted_Stack_Size :=
794 Interfaces.C.size_t (Stack_Size) + 3 * Get_Page_Size;
796 Result := pthread_attr_init (Attributes'Access);
797 pragma Assert (Result = 0 or else Result = ENOMEM);
804 Result := pthread_attr_setdetachstate
805 (Attributes'Access, PTHREAD_CREATE_DETACHED);
806 pragma Assert (Result = 0);
808 Result := pthread_attr_setstacksize
809 (Attributes'Access, Adjusted_Stack_Size);
810 pragma Assert (Result = 0);
812 Param.sched_priority :=
813 Interfaces.C.int (Underlying_Priorities (Priority));
814 Result := pthread_attr_setschedparam
815 (Attributes'Access, Param'Access);
816 pragma Assert (Result = 0);
818 if Time_Slice_Val > 0 then
819 Result := pthread_attr_setschedpolicy
820 (Attributes'Access, System.OS_Interface.SCHED_RR);
822 elsif Dispatching_Policy = 'F' or else Time_Slice_Val = 0 then
823 Result := pthread_attr_setschedpolicy
824 (Attributes'Access, System.OS_Interface.SCHED_FIFO);
827 Result := pthread_attr_setschedpolicy
828 (Attributes'Access, System.OS_Interface.SCHED_OTHER);
831 pragma Assert (Result = 0);
833 -- Set the scheduling parameters explicitly, since this is the
834 -- only way to force the OS to take e.g. the sched policy and scope
835 -- attributes into account.
837 Result := pthread_attr_setinheritsched
838 (Attributes'Access, PTHREAD_EXPLICIT_SCHED);
839 pragma Assert (Result = 0);
841 T.Common.Current_Priority := Priority;
843 if T.Common.Task_Info /= null then
844 case T.Common.Task_Info.Contention_Scope is
845 when System.Task_Info.Process_Scope =>
846 Result := pthread_attr_setscope
847 (Attributes'Access, PTHREAD_SCOPE_PROCESS);
849 when System.Task_Info.System_Scope =>
850 Result := pthread_attr_setscope
851 (Attributes'Access, PTHREAD_SCOPE_SYSTEM);
853 when System.Task_Info.Default_Scope =>
857 pragma Assert (Result = 0);
860 -- Since the initial signal mask of a thread is inherited from the
861 -- creator, and the Environment task has all its signals masked, we
862 -- do not need to manipulate caller's signal mask at this point.
863 -- All tasks in RTS will have All_Tasks_Mask initially.
865 Result := pthread_create
866 (T.Common.LL.Thread'Access,
868 Thread_Body_Access (Wrapper),
870 pragma Assert (Result = 0 or else Result = EAGAIN);
872 Succeeded := Result = 0;
874 Result := pthread_attr_destroy (Attributes'Access);
875 pragma Assert (Result = 0);
877 if T.Common.Task_Info /= null then
878 -- ??? We're using a process-wide function to implement a task
879 -- specific characteristic.
881 if T.Common.Task_Info.Bind_To_Cpu_Number = 0 then
882 Result := bind_to_cpu (Curpid, 0);
883 elsif T.Common.Task_Info.Bind_To_Cpu_Number > 0 then
884 Result := bind_to_cpu
886 Interfaces.C.unsigned_long (
887 Interfaces.Shift_Left
888 (Interfaces.Unsigned_64'(1),
889 T.Common.Task_Info.Bind_To_Cpu_Number - 1)));
890 pragma Assert (Result = 0);
899 procedure Finalize_TCB (T : Task_Id) is
900 Result : Interfaces.C.int;
902 Is_Self : constant Boolean := T = Self;
904 procedure Free is new
905 Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
908 if not Single_Lock then
909 Result := pthread_mutex_destroy (T.Common.LL.L'Access);
910 pragma Assert (Result = 0);
913 Result := pthread_cond_destroy (T.Common.LL.CV'Access);
914 pragma Assert (Result = 0);
916 if T.Known_Tasks_Index /= -1 then
917 Known_Tasks (T.Known_Tasks_Index) := null;
931 procedure Exit_Task is
940 procedure Abort_Task (T : Task_Id) is
941 Result : Interfaces.C.int;
943 Result := pthread_kill (T.Common.LL.Thread,
944 Signal (System.Interrupt_Management.Abort_Task_Interrupt));
945 pragma Assert (Result = 0);
952 procedure Initialize (S : in out Suspension_Object) is
953 Mutex_Attr : aliased pthread_mutexattr_t;
954 Cond_Attr : aliased pthread_condattr_t;
955 Result : Interfaces.C.int;
957 -- Initialize internal state. It is always initialized to False (ARM
963 -- Initialize internal mutex
965 Result := pthread_mutexattr_init (Mutex_Attr'Access);
966 pragma Assert (Result = 0 or else Result = ENOMEM);
968 if Result = ENOMEM then
972 Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
973 pragma Assert (Result = 0 or else Result = ENOMEM);
975 if Result = ENOMEM then
976 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
980 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
981 pragma Assert (Result = 0);
983 -- Initialize internal condition variable
985 Result := pthread_condattr_init (Cond_Attr'Access);
986 pragma Assert (Result = 0 or else Result = ENOMEM);
988 Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
990 pragma Assert (Result = 0 or else Result = ENOMEM);
993 Result := pthread_mutex_destroy (S.L'Access);
994 pragma Assert (Result = 0);
996 if Result = ENOMEM then
1006 procedure Finalize (S : in out Suspension_Object) is
1007 Result : Interfaces.C.int;
1009 -- Destroy internal mutex
1011 Result := pthread_mutex_destroy (S.L'Access);
1012 pragma Assert (Result = 0);
1014 -- Destroy internal condition variable
1016 Result := pthread_cond_destroy (S.CV'Access);
1017 pragma Assert (Result = 0);
1024 function Current_State (S : Suspension_Object) return Boolean is
1026 -- We do not want to use lock on this read operation. State is marked
1027 -- as Atomic so that we ensure that the value retrieved is correct.
1036 procedure Set_False (S : in out Suspension_Object) is
1037 Result : Interfaces.C.int;
1039 SSL.Abort_Defer.all;
1041 Result := pthread_mutex_lock (S.L'Access);
1042 pragma Assert (Result = 0);
1046 Result := pthread_mutex_unlock (S.L'Access);
1047 pragma Assert (Result = 0);
1049 SSL.Abort_Undefer.all;
1056 procedure Set_True (S : in out Suspension_Object) is
1057 Result : Interfaces.C.int;
1059 SSL.Abort_Defer.all;
1061 Result := pthread_mutex_lock (S.L'Access);
1062 pragma Assert (Result = 0);
1064 -- If there is already a task waiting on this suspension object then
1065 -- we resume it, leaving the state of the suspension object to False,
1066 -- as it is specified in ARM D.10 par. 9. Otherwise, it just leaves
1067 -- the state to True.
1073 Result := pthread_cond_signal (S.CV'Access);
1074 pragma Assert (Result = 0);
1079 Result := pthread_mutex_unlock (S.L'Access);
1080 pragma Assert (Result = 0);
1082 SSL.Abort_Undefer.all;
1085 ------------------------
1086 -- Suspend_Until_True --
1087 ------------------------
1089 procedure Suspend_Until_True (S : in out Suspension_Object) is
1090 Result : Interfaces.C.int;
1092 SSL.Abort_Defer.all;
1094 Result := pthread_mutex_lock (S.L'Access);
1095 pragma Assert (Result = 0);
1098 -- Program_Error must be raised upon calling Suspend_Until_True
1099 -- if another task is already waiting on that suspension object
1100 -- (ARM D.10 par. 10).
1102 Result := pthread_mutex_unlock (S.L'Access);
1103 pragma Assert (Result = 0);
1105 SSL.Abort_Undefer.all;
1107 raise Program_Error;
1109 -- Suspend the task if the state is False. Otherwise, the task
1110 -- continues its execution, and the state of the suspension object
1111 -- is set to False (ARM D.10 par. 9).
1117 Result := pthread_cond_wait (S.CV'Access, S.L'Access);
1120 Result := pthread_mutex_unlock (S.L'Access);
1121 pragma Assert (Result = 0);
1123 SSL.Abort_Undefer.all;
1125 end Suspend_Until_True;
1133 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1134 pragma Unreferenced (Self_ID);
1139 --------------------
1140 -- Check_No_Locks --
1141 --------------------
1143 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1144 pragma Unreferenced (Self_ID);
1149 ----------------------
1150 -- Environment_Task --
1151 ----------------------
1153 function Environment_Task return Task_Id is
1155 return Environment_Task_Id;
1156 end Environment_Task;
1162 procedure Lock_RTS is
1164 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
1171 procedure Unlock_RTS is
1173 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
1180 function Suspend_Task
1182 Thread_Self : Thread_Id) return Boolean
1184 pragma Warnings (Off, T);
1185 pragma Warnings (Off, Thread_Self);
1194 function Resume_Task
1196 Thread_Self : Thread_Id) return Boolean
1198 pragma Warnings (Off, T);
1199 pragma Warnings (Off, Thread_Self);
1208 procedure Initialize (Environment_Task : Task_Id) is
1209 act : aliased struct_sigaction;
1210 old_act : aliased struct_sigaction;
1211 Tmp_Set : aliased sigset_t;
1212 Result : Interfaces.C.int;
1215 (Int : System.Interrupt_Management.Interrupt_ID) return Character;
1216 pragma Import (C, State, "__gnat_get_interrupt_state");
1217 -- Get interrupt state. Defined in a-init.c. The input argument is
1218 -- the interrupt number, and the result is one of the following:
1220 Default : constant Character := 's';
1221 -- 'n' this interrupt not set by any Interrupt_State pragma
1222 -- 'u' Interrupt_State pragma set state to User
1223 -- 'r' Interrupt_State pragma set state to Runtime
1224 -- 's' Interrupt_State pragma set state to System (use "default"
1228 Environment_Task_Id := Environment_Task;
1230 Interrupt_Management.Initialize;
1232 -- Prepare the set of signals that should unblocked in all tasks
1234 Result := sigemptyset (Unblocked_Signal_Mask'Access);
1235 pragma Assert (Result = 0);
1237 for J in Interrupt_Management.Interrupt_ID loop
1238 if System.Interrupt_Management.Keep_Unmasked (J) then
1239 Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
1240 pragma Assert (Result = 0);
1246 -- Initialize the lock used to synchronize chain of all ATCBs
1248 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1250 Specific.Initialize (Environment_Task);
1252 Enter_Task (Environment_Task);
1254 -- Install the abort-signal handler
1256 if State (System.Interrupt_Management.Abort_Task_Interrupt)
1260 act.sa_handler := Abort_Handler'Address;
1262 Result := sigemptyset (Tmp_Set'Access);
1263 pragma Assert (Result = 0);
1264 act.sa_mask := Tmp_Set;
1268 (Signal (System.Interrupt_Management.Abort_Task_Interrupt),
1269 act'Unchecked_Access,
1270 old_act'Unchecked_Access);
1271 pragma Assert (Result = 0);
1275 end System.Task_Primitives.Operations;