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) 1992-2007, 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 Ada.Unchecked_Conversion;
76 with Ada.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
178 new Ada.Unchecked_Conversion (Task_Id, System.Address);
184 -- Target-dependent binding of inter-thread Abort signal to the raising of
185 -- the Abort_Signal exception.
187 -- The technical issues and alternatives here are essentially the
188 -- same as for raising exceptions in response to other signals
189 -- (e.g. Storage_Error). See code and comments in the package body
190 -- System.Interrupt_Management.
192 -- Some implementations may not allow an exception to be propagated out of
193 -- a handler, and others might leave the signal or interrupt that invoked
194 -- this handler masked after the exceptional return to the application
197 -- GNAT exceptions are originally implemented using setjmp()/longjmp(). On
198 -- most UNIX systems, this will allow transfer out of a signal handler,
199 -- which is usually the only mechanism available for implementing
200 -- asynchronous handlers of this kind. However, some systems do not
201 -- restore the signal mask on longjmp(), leaving the abort signal masked.
203 procedure Abort_Handler (Sig : Signal) is
204 pragma Unreferenced (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;
290 L : not null access Lock)
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
331 (L : not null access RTS_Lock; Level : Lock_Level)
333 pragma Unreferenced (Level);
335 Attributes : aliased pthread_mutexattr_t;
336 Result : Interfaces.C.int;
339 Result := pthread_mutexattr_init (Attributes'Access);
340 pragma Assert (Result = 0 or else Result = ENOMEM);
342 if Result = ENOMEM then
346 if Locking_Policy = 'C' then
347 Result := pthread_mutexattr_setprotocol
348 (Attributes'Access, PTHREAD_PRIO_PROTECT);
349 pragma Assert (Result = 0);
351 Result := pthread_mutexattr_setprioceiling
352 (Attributes'Access, Interfaces.C.int (System.Any_Priority'Last));
353 pragma Assert (Result = 0);
355 elsif Locking_Policy = 'I' then
356 Result := pthread_mutexattr_setprotocol
357 (Attributes'Access, PTHREAD_PRIO_INHERIT);
358 pragma Assert (Result = 0);
361 Result := pthread_mutex_init (L, Attributes'Access);
362 pragma Assert (Result = 0 or else Result = ENOMEM);
364 if Result = ENOMEM then
365 Result := pthread_mutexattr_destroy (Attributes'Access);
369 Result := pthread_mutexattr_destroy (Attributes'Access);
370 pragma Assert (Result = 0);
377 procedure Finalize_Lock (L : not null access Lock) is
378 Result : Interfaces.C.int;
380 Result := pthread_mutex_destroy (L);
381 pragma Assert (Result = 0);
384 procedure Finalize_Lock (L : not null access RTS_Lock) is
385 Result : Interfaces.C.int;
387 Result := pthread_mutex_destroy (L);
388 pragma Assert (Result = 0);
396 (L : not null access Lock; Ceiling_Violation : out Boolean)
398 Result : Interfaces.C.int;
401 Result := pthread_mutex_lock (L);
403 -- Assume that the cause of EINVAL is a priority ceiling violation
405 Ceiling_Violation := (Result = EINVAL);
406 pragma Assert (Result = 0 or else Result = EINVAL);
410 (L : not null access RTS_Lock;
411 Global_Lock : Boolean := False)
413 Result : Interfaces.C.int;
415 if not Single_Lock or else Global_Lock then
416 Result := pthread_mutex_lock (L);
417 pragma Assert (Result = 0);
421 procedure Write_Lock (T : Task_Id) is
422 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);
435 (L : not null access Lock; Ceiling_Violation : out Boolean) is
437 Write_Lock (L, Ceiling_Violation);
444 procedure Unlock (L : not null access Lock) is
445 Result : Interfaces.C.int;
447 Result := pthread_mutex_unlock (L);
448 pragma Assert (Result = 0);
452 (L : not null access RTS_Lock; Global_Lock : Boolean := False)
454 Result : Interfaces.C.int;
456 if not Single_Lock or else Global_Lock then
457 Result := pthread_mutex_unlock (L);
458 pragma Assert (Result = 0);
462 procedure Unlock (T : Task_Id) is
463 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);
475 -- Dynamic priority ceilings are not supported by the underlying system
477 procedure Set_Ceiling
478 (L : not null access Lock;
479 Prio : System.Any_Priority)
481 pragma Unreferenced (L, Prio);
492 Reason : System.Tasking.Task_States)
494 pragma Unreferenced (Reason);
496 Result : Interfaces.C.int;
502 (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access);
506 (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access);
509 -- EINTR is not considered a failure
511 pragma Assert (Result = 0 or else Result = EINTR);
518 -- This is for use within the run-time system, so abort is
519 -- assumed to be already deferred, and the caller should be
520 -- holding its own ATCB lock.
522 procedure Timed_Sleep
525 Mode : ST.Delay_Modes;
526 Reason : Task_States;
527 Timedout : out Boolean;
528 Yielded : out Boolean)
530 pragma Unreferenced (Reason);
532 Base_Time : constant Duration := Monotonic_Clock;
533 Check_Time : Duration := Base_Time;
536 Request : aliased timespec;
537 Result : Interfaces.C.int;
543 if Mode = Relative then
544 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
546 if Relative_Timed_Wait then
547 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
551 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
553 if Relative_Timed_Wait then
554 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
558 if Abs_Time > Check_Time then
559 if Relative_Timed_Wait then
560 Request := To_Timespec (Rel_Time);
562 Request := To_Timespec (Abs_Time);
566 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
570 pthread_cond_timedwait
571 (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access,
576 pthread_cond_timedwait
577 (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access,
581 Check_Time := Monotonic_Clock;
582 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
584 if Result = 0 or Result = EINTR then
586 -- Somebody may have called Wakeup for us
592 pragma Assert (Result = ETIMEDOUT);
601 -- This is for use in implementing delay statements, so we assume the
602 -- caller is abort-deferred but is holding no locks.
604 procedure Timed_Delay
607 Mode : ST.Delay_Modes)
609 Base_Time : constant Duration := Monotonic_Clock;
610 Check_Time : Duration := Base_Time;
613 Request : aliased timespec;
615 Result : Interfaces.C.int;
616 pragma Warnings (Off, Result);
623 Write_Lock (Self_ID);
625 if Mode = Relative then
626 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
628 if Relative_Timed_Wait then
629 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
633 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
635 if Relative_Timed_Wait then
636 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
640 if Abs_Time > Check_Time then
641 if Relative_Timed_Wait then
642 Request := To_Timespec (Rel_Time);
644 Request := To_Timespec (Abs_Time);
647 Self_ID.Common.State := Delay_Sleep;
650 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
653 Result := pthread_cond_timedwait
654 (Self_ID.Common.LL.CV'Access,
655 Single_RTS_Lock'Access,
658 Result := pthread_cond_timedwait
659 (Self_ID.Common.LL.CV'Access,
660 Self_ID.Common.LL.L'Access,
664 Check_Time := Monotonic_Clock;
665 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
667 pragma Assert (Result = 0
668 or else Result = ETIMEDOUT
669 or else Result = EINTR);
672 Self_ID.Common.State := Runnable;
681 Result := sched_yield;
684 ---------------------
685 -- Monotonic_Clock --
686 ---------------------
688 function Monotonic_Clock return Duration is
689 TS : aliased timespec;
690 Result : Interfaces.C.int;
692 Result := clock_gettime
693 (clock_id => CLOCK_REALTIME, tp => TS'Unchecked_Access);
694 pragma Assert (Result = 0);
695 return To_Duration (TS);
702 function RT_Resolution return Duration is
711 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
712 pragma Unreferenced (Reason);
713 Result : Interfaces.C.int;
715 Result := pthread_cond_signal (T.Common.LL.CV'Access);
716 pragma Assert (Result = 0);
723 procedure Yield (Do_Yield : Boolean := True) is
724 Result : Interfaces.C.int;
725 pragma Unreferenced (Result);
728 Result := sched_yield;
736 procedure Set_Priority
738 Prio : System.Any_Priority;
739 Loss_Of_Inheritance : Boolean := False)
741 pragma Unreferenced (Loss_Of_Inheritance);
743 Result : Interfaces.C.int;
744 Param : aliased struct_sched_param;
746 function Get_Policy (Prio : System.Any_Priority) return Character;
747 pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
748 -- Get priority specific dispatching policy
750 Priority_Specific_Policy : constant Character := Get_Policy (Prio);
751 -- Upper case first character of the policy name corresponding to the
752 -- task as set by a Priority_Specific_Dispatching pragma.
755 T.Common.Current_Priority := Prio;
756 Param.sched_priority := To_Target_Priority (Prio);
758 if Time_Slice_Supported
759 and then (Dispatching_Policy = 'R'
760 or else Priority_Specific_Policy = 'R'
761 or else Time_Slice_Val > 0)
763 Result := pthread_setschedparam
764 (T.Common.LL.Thread, SCHED_RR, Param'Access);
766 elsif Dispatching_Policy = 'F'
767 or else Priority_Specific_Policy = 'F'
768 or else Time_Slice_Val = 0
770 Result := pthread_setschedparam
771 (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
774 Result := pthread_setschedparam
775 (T.Common.LL.Thread, SCHED_OTHER, Param'Access);
778 pragma Assert (Result = 0);
785 function Get_Priority (T : Task_Id) return System.Any_Priority is
787 return T.Common.Current_Priority;
794 procedure Enter_Task (Self_ID : Task_Id) is
796 Self_ID.Common.LL.Thread := pthread_self;
797 Self_ID.Common.LL.LWP := lwp_self;
799 Specific.Set (Self_ID);
803 for J in Known_Tasks'Range loop
804 if Known_Tasks (J) = null then
805 Known_Tasks (J) := Self_ID;
806 Self_ID.Known_Tasks_Index := J;
818 function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
820 return new Ada_Task_Control_Block (Entry_Num);
827 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
829 -----------------------------
830 -- Register_Foreign_Thread --
831 -----------------------------
833 function Register_Foreign_Thread return Task_Id is
835 if Is_Valid_Task then
838 return Register_Foreign_Thread (pthread_self);
840 end Register_Foreign_Thread;
846 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
847 Mutex_Attr : aliased pthread_mutexattr_t;
848 Result : Interfaces.C.int;
849 Cond_Attr : aliased pthread_condattr_t;
852 -- Give the task a unique serial number
854 Self_ID.Serial_Number := Next_Serial_Number;
855 Next_Serial_Number := Next_Serial_Number + 1;
856 pragma Assert (Next_Serial_Number /= 0);
858 if not Single_Lock then
859 Result := pthread_mutexattr_init (Mutex_Attr'Access);
860 pragma Assert (Result = 0 or else Result = ENOMEM);
863 if Locking_Policy = 'C' then
865 pthread_mutexattr_setprotocol
867 PTHREAD_PRIO_PROTECT);
868 pragma Assert (Result = 0);
871 pthread_mutexattr_setprioceiling
873 Interfaces.C.int (System.Any_Priority'Last));
874 pragma Assert (Result = 0);
876 elsif Locking_Policy = 'I' then
878 pthread_mutexattr_setprotocol
880 PTHREAD_PRIO_INHERIT);
881 pragma Assert (Result = 0);
886 (Self_ID.Common.LL.L'Access,
888 pragma Assert (Result = 0 or else Result = ENOMEM);
896 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
897 pragma Assert (Result = 0);
900 Result := pthread_condattr_init (Cond_Attr'Access);
901 pragma Assert (Result = 0 or else Result = ENOMEM);
906 (Self_ID.Common.LL.CV'Access, Cond_Attr'Access);
907 pragma Assert (Result = 0 or else Result = ENOMEM);
913 if not Single_Lock then
914 Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
915 pragma Assert (Result = 0);
921 Result := pthread_condattr_destroy (Cond_Attr'Access);
922 pragma Assert (Result = 0);
929 procedure Create_Task
931 Wrapper : System.Address;
932 Stack_Size : System.Parameters.Size_Type;
933 Priority : System.Any_Priority;
934 Succeeded : out Boolean)
936 Attributes : aliased pthread_attr_t;
937 Adjusted_Stack_Size : Interfaces.C.size_t;
938 Result : Interfaces.C.int;
940 function Thread_Body_Access is new
941 Ada.Unchecked_Conversion (System.Address, Thread_Body);
943 use System.Task_Info;
946 Adjusted_Stack_Size := Interfaces.C.size_t (Stack_Size);
948 if Stack_Base_Available then
950 -- If Stack Checking is supported then allocate 2 additional pages:
952 -- In the worst case, stack is allocated at something like
953 -- N * Get_Page_Size - epsilon, we need to add the size for 2 pages
954 -- to be sure the effective stack size is greater than what
957 Adjusted_Stack_Size := Adjusted_Stack_Size + 2 * Get_Page_Size;
960 Result := pthread_attr_init (Attributes'Access);
961 pragma Assert (Result = 0 or else Result = ENOMEM);
969 pthread_attr_setdetachstate
970 (Attributes'Access, PTHREAD_CREATE_DETACHED);
971 pragma Assert (Result = 0);
974 pthread_attr_setstacksize
975 (Attributes'Access, Adjusted_Stack_Size);
976 pragma Assert (Result = 0);
978 if T.Common.Task_Info /= Default_Scope then
979 case T.Common.Task_Info is
980 when System.Task_Info.Process_Scope =>
982 pthread_attr_setscope
983 (Attributes'Access, PTHREAD_SCOPE_PROCESS);
985 when System.Task_Info.System_Scope =>
987 pthread_attr_setscope
988 (Attributes'Access, PTHREAD_SCOPE_SYSTEM);
990 when System.Task_Info.Default_Scope =>
994 pragma Assert (Result = 0);
997 -- Since the initial signal mask of a thread is inherited from the
998 -- creator, and the Environment task has all its signals masked, we
999 -- do not need to manipulate caller's signal mask at this point.
1000 -- All tasks in RTS will have All_Tasks_Mask initially.
1002 Result := pthread_create
1003 (T.Common.LL.Thread'Access,
1005 Thread_Body_Access (Wrapper),
1007 pragma Assert (Result = 0 or else Result = EAGAIN);
1009 Succeeded := Result = 0;
1011 Result := pthread_attr_destroy (Attributes'Access);
1012 pragma Assert (Result = 0);
1014 Set_Priority (T, Priority);
1021 procedure Finalize_TCB (T : Task_Id) is
1022 Result : Interfaces.C.int;
1024 Is_Self : constant Boolean := T = Self;
1026 procedure Free is new
1027 Ada.Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
1030 if not Single_Lock then
1031 Result := pthread_mutex_destroy (T.Common.LL.L'Access);
1032 pragma Assert (Result = 0);
1035 Result := pthread_cond_destroy (T.Common.LL.CV'Access);
1036 pragma Assert (Result = 0);
1038 if T.Known_Tasks_Index /= -1 then
1039 Known_Tasks (T.Known_Tasks_Index) := null;
1045 Specific.Set (null);
1053 procedure Exit_Task is
1055 -- Mark this task as unknown, so that if Self is called, it won't
1056 -- return a dangling pointer.
1058 Specific.Set (null);
1065 procedure Abort_Task (T : Task_Id) is
1066 Result : Interfaces.C.int;
1070 (T.Common.LL.Thread,
1071 Signal (System.Interrupt_Management.Abort_Task_Interrupt));
1072 pragma Assert (Result = 0);
1079 procedure Initialize (S : in out Suspension_Object) is
1080 Mutex_Attr : aliased pthread_mutexattr_t;
1081 Cond_Attr : aliased pthread_condattr_t;
1082 Result : Interfaces.C.int;
1085 -- Initialize internal state (always to False (RM D.10 (6)))
1090 -- Initialize internal mutex
1092 Result := pthread_mutexattr_init (Mutex_Attr'Access);
1093 pragma Assert (Result = 0 or else Result = ENOMEM);
1095 if Result = ENOMEM then
1096 raise Storage_Error;
1099 Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
1100 pragma Assert (Result = 0 or else Result = ENOMEM);
1102 if Result = ENOMEM then
1103 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1104 pragma Assert (Result = 0);
1106 raise Storage_Error;
1109 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1110 pragma Assert (Result = 0);
1112 -- Initialize internal condition variable
1114 Result := pthread_condattr_init (Cond_Attr'Access);
1115 pragma Assert (Result = 0 or else Result = ENOMEM);
1118 Result := pthread_mutex_destroy (S.L'Access);
1119 pragma Assert (Result = 0);
1121 if Result = ENOMEM then
1122 raise Storage_Error;
1126 Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
1127 pragma Assert (Result = 0 or else Result = ENOMEM);
1130 Result := pthread_mutex_destroy (S.L'Access);
1131 pragma Assert (Result = 0);
1133 if Result = ENOMEM then
1134 Result := pthread_condattr_destroy (Cond_Attr'Access);
1135 pragma Assert (Result = 0);
1136 raise Storage_Error;
1140 Result := pthread_condattr_destroy (Cond_Attr'Access);
1141 pragma Assert (Result = 0);
1148 procedure Finalize (S : in out Suspension_Object) is
1149 Result : Interfaces.C.int;
1152 -- Destroy internal mutex
1154 Result := pthread_mutex_destroy (S.L'Access);
1155 pragma Assert (Result = 0);
1157 -- Destroy internal condition variable
1159 Result := pthread_cond_destroy (S.CV'Access);
1160 pragma Assert (Result = 0);
1167 function Current_State (S : Suspension_Object) return Boolean is
1169 -- We do not want to use lock on this read operation. State is marked
1170 -- as Atomic so that we ensure that the value retrieved is correct.
1179 procedure Set_False (S : in out Suspension_Object) is
1180 Result : Interfaces.C.int;
1183 SSL.Abort_Defer.all;
1185 Result := pthread_mutex_lock (S.L'Access);
1186 pragma Assert (Result = 0);
1190 Result := pthread_mutex_unlock (S.L'Access);
1191 pragma Assert (Result = 0);
1193 SSL.Abort_Undefer.all;
1200 procedure Set_True (S : in out Suspension_Object) is
1201 Result : Interfaces.C.int;
1204 SSL.Abort_Defer.all;
1206 Result := pthread_mutex_lock (S.L'Access);
1207 pragma Assert (Result = 0);
1209 -- If there is already a task waiting on this suspension object then
1210 -- we resume it, leaving the state of the suspension object to False,
1211 -- as it is specified in (RM D.10(9)). Otherwise, it just leaves
1212 -- the state to True.
1218 Result := pthread_cond_signal (S.CV'Access);
1219 pragma Assert (Result = 0);
1225 Result := pthread_mutex_unlock (S.L'Access);
1226 pragma Assert (Result = 0);
1228 SSL.Abort_Undefer.all;
1231 ------------------------
1232 -- Suspend_Until_True --
1233 ------------------------
1235 procedure Suspend_Until_True (S : in out Suspension_Object) is
1236 Result : Interfaces.C.int;
1239 SSL.Abort_Defer.all;
1241 Result := pthread_mutex_lock (S.L'Access);
1242 pragma Assert (Result = 0);
1246 -- Program_Error must be raised upon calling Suspend_Until_True
1247 -- if another task is already waiting on that suspension object
1250 Result := pthread_mutex_unlock (S.L'Access);
1251 pragma Assert (Result = 0);
1253 SSL.Abort_Undefer.all;
1255 raise Program_Error;
1258 -- Suspend the task if the state is False. Otherwise, the task
1259 -- continues its execution, and the state of the suspension object
1260 -- is set to False (ARM D.10 par. 9).
1266 Result := pthread_cond_wait (S.CV'Access, S.L'Access);
1269 Result := pthread_mutex_unlock (S.L'Access);
1270 pragma Assert (Result = 0);
1272 SSL.Abort_Undefer.all;
1274 end Suspend_Until_True;
1282 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1283 pragma Unreferenced (Self_ID);
1288 --------------------
1289 -- Check_No_Locks --
1290 --------------------
1292 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1293 pragma Unreferenced (Self_ID);
1298 ----------------------
1299 -- Environment_Task --
1300 ----------------------
1302 function Environment_Task return Task_Id is
1304 return Environment_Task_Id;
1305 end Environment_Task;
1311 procedure Lock_RTS is
1313 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
1320 procedure Unlock_RTS is
1322 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
1329 function Suspend_Task
1331 Thread_Self : Thread_Id) return Boolean
1333 pragma Unreferenced (T, Thread_Self);
1342 function Resume_Task
1344 Thread_Self : Thread_Id) return Boolean
1346 pragma Unreferenced (T, Thread_Self);
1355 procedure Initialize (Environment_Task : Task_Id) is
1356 act : aliased struct_sigaction;
1357 old_act : aliased struct_sigaction;
1358 Tmp_Set : aliased sigset_t;
1359 Result : Interfaces.C.int;
1362 (Int : System.Interrupt_Management.Interrupt_ID) return Character;
1363 pragma Import (C, State, "__gnat_get_interrupt_state");
1364 -- Get interrupt state. Defined in a-init.c
1365 -- The input argument is the interrupt number,
1366 -- and the result is one of the following:
1368 Default : constant Character := 's';
1369 -- 'n' this interrupt not set by any Interrupt_State pragma
1370 -- 'u' Interrupt_State pragma set state to User
1371 -- 'r' Interrupt_State pragma set state to Runtime
1372 -- 's' Interrupt_State pragma set state to System (use "default"
1376 Environment_Task_Id := Environment_Task;
1378 Interrupt_Management.Initialize;
1380 -- Prepare the set of signals that should unblocked in all tasks
1382 Result := sigemptyset (Unblocked_Signal_Mask'Access);
1383 pragma Assert (Result = 0);
1385 for J in Interrupt_Management.Interrupt_ID loop
1386 if System.Interrupt_Management.Keep_Unmasked (J) then
1387 Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
1388 pragma Assert (Result = 0);
1392 -- Initialize the lock used to synchronize chain of all ATCBs
1394 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1396 Specific.Initialize (Environment_Task);
1398 Enter_Task (Environment_Task);
1400 -- Install the abort-signal handler
1403 (System.Interrupt_Management.Abort_Task_Interrupt) /= Default
1406 act.sa_handler := Abort_Handler'Address;
1408 Result := sigemptyset (Tmp_Set'Access);
1409 pragma Assert (Result = 0);
1410 act.sa_mask := Tmp_Set;
1414 (Signal (System.Interrupt_Management.Abort_Task_Interrupt),
1415 act'Unchecked_Access,
1416 old_act'Unchecked_Access);
1417 pragma Assert (Result = 0);
1421 end System.Task_Primitives.Operations;