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) 1992-2009, 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 3, or (at your option) any later ver- --
14 -- sion. GNAT 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. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
27 -- GNARL was developed by the GNARL team at Florida State University. --
28 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
30 ------------------------------------------------------------------------------
32 -- This is a POSIX-like version of this package
34 -- This package contains all the GNULL primitives that interface directly with
37 -- Note: this file can only be used for POSIX compliant systems that implement
38 -- SCHED_FIFO and Ceiling Locking correctly.
40 -- For configurations where SCHED_FIFO and priority ceiling are not a
41 -- requirement, this file can also be used (e.g AiX threads)
44 -- Turn off polling, we do not want ATC polling to take place during tasking
45 -- operations. It causes infinite loops and other problems.
47 with Ada.Unchecked_Conversion;
48 with Ada.Unchecked_Deallocation;
52 with System.Tasking.Debug;
53 with System.Interrupt_Management;
54 with System.OS_Primitives;
55 with System.Task_Info;
57 with System.Soft_Links;
58 -- We use System.Soft_Links instead of System.Tasking.Initialization
59 -- because the later is a higher level package that we shouldn't depend on.
60 -- For example when using the restricted run time, it is replaced by
61 -- System.Tasking.Restricted.Stages.
63 package body System.Task_Primitives.Operations is
65 package SSL renames System.Soft_Links;
67 use System.Tasking.Debug;
70 use System.OS_Interface;
71 use System.Parameters;
72 use System.OS_Primitives;
74 Use_Alternate_Stack : constant Boolean := Alternate_Stack_Size /= 0;
75 -- Whether to use an alternate signal stack for stack overflows
81 -- The followings are logically constants, but need to be initialized
84 Single_RTS_Lock : aliased RTS_Lock;
85 -- This is a lock to allow only one thread of control in the RTS at
86 -- a time; it is used to execute in mutual exclusion from all other tasks.
87 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
89 ATCB_Key : aliased pthread_key_t;
90 -- Key used to find the Ada Task_Id associated with a thread
92 Environment_Task_Id : Task_Id;
93 -- A variable to hold Task_Id for the environment task
95 Locking_Policy : Character;
96 pragma Import (C, Locking_Policy, "__gl_locking_policy");
97 -- Value of the pragma Locking_Policy:
98 -- 'C' for Ceiling_Locking
99 -- 'I' for Inherit_Locking
102 Unblocked_Signal_Mask : aliased sigset_t;
103 -- The set of signals that should unblocked in all tasks
105 -- The followings are internal configuration constants needed
107 Next_Serial_Number : Task_Serial_Number := 100;
108 -- We start at 100, to reserve some special values for
109 -- using in error checking.
111 Time_Slice_Val : Integer;
112 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
114 Dispatching_Policy : Character;
115 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.
163 -- See also comment before body, below.
165 function To_Address is
166 new Ada.Unchecked_Conversion (Task_Id, System.Address);
172 -- Target-dependent binding of inter-thread Abort signal to the raising of
173 -- the Abort_Signal exception.
175 -- The technical issues and alternatives here are essentially the
176 -- same as for raising exceptions in response to other signals
177 -- (e.g. Storage_Error). See code and comments in the package body
178 -- System.Interrupt_Management.
180 -- Some implementations may not allow an exception to be propagated out of
181 -- a handler, and others might leave the signal or interrupt that invoked
182 -- this handler masked after the exceptional return to the application
185 -- GNAT exceptions are originally implemented using setjmp()/longjmp(). On
186 -- most UNIX systems, this will allow transfer out of a signal handler,
187 -- which is usually the only mechanism available for implementing
188 -- asynchronous handlers of this kind. However, some systems do not
189 -- restore the signal mask on longjmp(), leaving the abort signal masked.
191 procedure Abort_Handler (Sig : Signal) is
192 pragma Unreferenced (Sig);
194 T : constant Task_Id := Self;
195 Old_Set : aliased sigset_t;
197 Result : Interfaces.C.int;
198 pragma Warnings (Off, Result);
201 -- It is not safe to raise an exception when using ZCX and the GCC
202 -- exception handling mechanism.
204 if ZCX_By_Default and then GCC_ZCX_Support then
208 if T.Deferral_Level = 0
209 and then T.Pending_ATC_Level < T.ATC_Nesting_Level and then
214 -- Make sure signals used for RTS internal purpose are unmasked
216 Result := pthread_sigmask (SIG_UNBLOCK,
217 Unblocked_Signal_Mask'Access, Old_Set'Access);
218 pragma Assert (Result = 0);
220 raise Standard'Abort_Signal;
228 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
229 Stack_Base : constant Address := Get_Stack_Base (T.Common.LL.Thread);
230 Guard_Page_Address : Address;
232 Res : Interfaces.C.int;
235 if Stack_Base_Available then
237 -- Compute the guard page address
239 Guard_Page_Address :=
240 Stack_Base - (Stack_Base mod Get_Page_Size) + Get_Page_Size;
243 Res := mprotect (Guard_Page_Address, Get_Page_Size, PROT_ON);
245 Res := mprotect (Guard_Page_Address, Get_Page_Size, PROT_OFF);
248 pragma Assert (Res = 0);
256 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
258 return T.Common.LL.Thread;
265 function Self return Task_Id renames Specific.Self;
267 ---------------------
268 -- Initialize_Lock --
269 ---------------------
271 -- Note: mutexes and cond_variables needed per-task basis are
272 -- initialized in Initialize_TCB and the Storage_Error is
273 -- handled. Other mutexes (such as RTS_Lock, Memory_Lock...)
274 -- used in RTS is initialized before any status change of RTS.
275 -- Therefore raising Storage_Error in the following routines
276 -- should be able to be handled safely.
278 procedure Initialize_Lock
279 (Prio : System.Any_Priority;
280 L : not null access Lock)
282 Attributes : aliased pthread_mutexattr_t;
283 Result : Interfaces.C.int;
286 Result := pthread_mutexattr_init (Attributes'Access);
287 pragma Assert (Result = 0 or else Result = ENOMEM);
289 if Result = ENOMEM then
293 if Locking_Policy = 'C' then
294 Result := pthread_mutexattr_setprotocol
295 (Attributes'Access, PTHREAD_PRIO_PROTECT);
296 pragma Assert (Result = 0);
298 Result := pthread_mutexattr_setprioceiling
299 (Attributes'Access, Interfaces.C.int (Prio));
300 pragma Assert (Result = 0);
302 elsif Locking_Policy = 'I' then
303 Result := pthread_mutexattr_setprotocol
304 (Attributes'Access, PTHREAD_PRIO_INHERIT);
305 pragma Assert (Result = 0);
308 Result := pthread_mutex_init (L, Attributes'Access);
309 pragma Assert (Result = 0 or else Result = ENOMEM);
311 if Result = ENOMEM then
312 Result := pthread_mutexattr_destroy (Attributes'Access);
316 Result := pthread_mutexattr_destroy (Attributes'Access);
317 pragma Assert (Result = 0);
320 procedure Initialize_Lock
321 (L : not null access RTS_Lock; Level : Lock_Level)
323 pragma Unreferenced (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 : not null access Lock) is
368 Result : Interfaces.C.int;
370 Result := pthread_mutex_destroy (L);
371 pragma Assert (Result = 0);
374 procedure Finalize_Lock (L : not null access RTS_Lock) is
375 Result : Interfaces.C.int;
377 Result := pthread_mutex_destroy (L);
378 pragma Assert (Result = 0);
386 (L : not null access Lock; Ceiling_Violation : out Boolean)
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 : not null access RTS_Lock;
401 Global_Lock : Boolean := False)
403 Result : Interfaces.C.int;
405 if not Single_Lock or else Global_Lock then
406 Result := pthread_mutex_lock (L);
407 pragma Assert (Result = 0);
411 procedure Write_Lock (T : Task_Id) is
412 Result : Interfaces.C.int;
414 if not Single_Lock then
415 Result := pthread_mutex_lock (T.Common.LL.L'Access);
416 pragma Assert (Result = 0);
425 (L : not null access Lock; Ceiling_Violation : out Boolean) is
427 Write_Lock (L, Ceiling_Violation);
434 procedure Unlock (L : not null access Lock) is
435 Result : Interfaces.C.int;
437 Result := pthread_mutex_unlock (L);
438 pragma Assert (Result = 0);
442 (L : not null access RTS_Lock; Global_Lock : Boolean := False)
444 Result : Interfaces.C.int;
446 if not Single_Lock or else Global_Lock then
447 Result := pthread_mutex_unlock (L);
448 pragma Assert (Result = 0);
452 procedure Unlock (T : Task_Id) is
453 Result : Interfaces.C.int;
455 if not Single_Lock then
456 Result := pthread_mutex_unlock (T.Common.LL.L'Access);
457 pragma Assert (Result = 0);
465 -- Dynamic priority ceilings are not supported by the underlying system
467 procedure Set_Ceiling
468 (L : not null access Lock;
469 Prio : System.Any_Priority)
471 pragma Unreferenced (L, Prio);
482 Reason : System.Tasking.Task_States)
484 pragma Unreferenced (Reason);
486 Result : Interfaces.C.int;
492 (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access);
496 (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access);
499 -- EINTR is not considered a failure
501 pragma Assert (Result = 0 or else Result = EINTR);
508 -- This is for use within the run-time system, so abort is
509 -- assumed to be already deferred, and the caller should be
510 -- holding its own ATCB lock.
512 procedure Timed_Sleep
515 Mode : ST.Delay_Modes;
516 Reason : Task_States;
517 Timedout : out Boolean;
518 Yielded : out Boolean)
520 pragma Unreferenced (Reason);
522 Base_Time : constant Duration := Monotonic_Clock;
523 Check_Time : Duration := Base_Time;
526 Request : aliased timespec;
527 Result : Interfaces.C.int;
533 if Mode = Relative then
534 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
536 if Relative_Timed_Wait then
537 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
541 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
543 if Relative_Timed_Wait then
544 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
548 if Abs_Time > Check_Time then
549 if Relative_Timed_Wait then
550 Request := To_Timespec (Rel_Time);
552 Request := To_Timespec (Abs_Time);
556 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
560 pthread_cond_timedwait
561 (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access,
566 pthread_cond_timedwait
567 (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access,
571 Check_Time := Monotonic_Clock;
572 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
574 if Result = 0 or Result = EINTR then
576 -- Somebody may have called Wakeup for us
582 pragma Assert (Result = ETIMEDOUT);
591 -- This is for use in implementing delay statements, so we assume the
592 -- caller is abort-deferred but is holding no locks.
594 procedure Timed_Delay
597 Mode : ST.Delay_Modes)
599 Base_Time : constant Duration := Monotonic_Clock;
600 Check_Time : Duration := Base_Time;
603 Request : aliased timespec;
605 Result : Interfaces.C.int;
606 pragma Warnings (Off, Result);
613 Write_Lock (Self_ID);
615 if Mode = Relative then
616 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
618 if Relative_Timed_Wait then
619 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
623 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
625 if Relative_Timed_Wait then
626 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
630 if Abs_Time > Check_Time then
631 if Relative_Timed_Wait then
632 Request := To_Timespec (Rel_Time);
634 Request := To_Timespec (Abs_Time);
637 Self_ID.Common.State := Delay_Sleep;
640 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
643 Result := pthread_cond_timedwait
644 (Self_ID.Common.LL.CV'Access,
645 Single_RTS_Lock'Access,
648 Result := pthread_cond_timedwait
649 (Self_ID.Common.LL.CV'Access,
650 Self_ID.Common.LL.L'Access,
654 Check_Time := Monotonic_Clock;
655 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
657 pragma Assert (Result = 0
658 or else Result = ETIMEDOUT
659 or else Result = EINTR);
662 Self_ID.Common.State := Runnable;
671 Result := sched_yield;
674 ---------------------
675 -- Monotonic_Clock --
676 ---------------------
678 function Monotonic_Clock return Duration is
679 TS : aliased timespec;
680 Result : Interfaces.C.int;
682 Result := clock_gettime
683 (clock_id => CLOCK_REALTIME, tp => TS'Unchecked_Access);
684 pragma Assert (Result = 0);
685 return To_Duration (TS);
692 function RT_Resolution return Duration is
701 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
702 pragma Unreferenced (Reason);
703 Result : Interfaces.C.int;
705 Result := pthread_cond_signal (T.Common.LL.CV'Access);
706 pragma Assert (Result = 0);
713 procedure Yield (Do_Yield : Boolean := True) is
714 Result : Interfaces.C.int;
715 pragma Unreferenced (Result);
718 Result := sched_yield;
726 procedure Set_Priority
728 Prio : System.Any_Priority;
729 Loss_Of_Inheritance : Boolean := False)
731 pragma Unreferenced (Loss_Of_Inheritance);
733 Result : Interfaces.C.int;
734 Param : aliased struct_sched_param;
736 function Get_Policy (Prio : System.Any_Priority) return Character;
737 pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
738 -- Get priority specific dispatching policy
740 Priority_Specific_Policy : constant Character := Get_Policy (Prio);
741 -- Upper case first character of the policy name corresponding to the
742 -- task as set by a Priority_Specific_Dispatching pragma.
745 T.Common.Current_Priority := Prio;
746 Param.sched_priority := To_Target_Priority (Prio);
748 if Time_Slice_Supported
749 and then (Dispatching_Policy = 'R'
750 or else Priority_Specific_Policy = 'R'
751 or else Time_Slice_Val > 0)
753 Result := pthread_setschedparam
754 (T.Common.LL.Thread, SCHED_RR, Param'Access);
756 elsif Dispatching_Policy = 'F'
757 or else Priority_Specific_Policy = 'F'
758 or else Time_Slice_Val = 0
760 Result := pthread_setschedparam
761 (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
764 Result := pthread_setschedparam
765 (T.Common.LL.Thread, SCHED_OTHER, Param'Access);
768 pragma Assert (Result = 0);
775 function Get_Priority (T : Task_Id) return System.Any_Priority is
777 return T.Common.Current_Priority;
784 procedure Enter_Task (Self_ID : Task_Id) is
786 Self_ID.Common.LL.Thread := pthread_self;
787 Self_ID.Common.LL.LWP := lwp_self;
789 Specific.Set (Self_ID);
791 if Use_Alternate_Stack then
793 Stack : aliased stack_t;
794 Result : Interfaces.C.int;
796 Stack.ss_sp := Self_ID.Common.Task_Alternate_Stack;
797 Stack.ss_size := Alternate_Stack_Size;
799 Result := sigaltstack (Stack'Access, null);
800 pragma Assert (Result = 0);
809 function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
811 return new Ada_Task_Control_Block (Entry_Num);
818 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
820 -----------------------------
821 -- Register_Foreign_Thread --
822 -----------------------------
824 function Register_Foreign_Thread return Task_Id is
826 if Is_Valid_Task then
829 return Register_Foreign_Thread (pthread_self);
831 end Register_Foreign_Thread;
837 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
838 Mutex_Attr : aliased pthread_mutexattr_t;
839 Result : Interfaces.C.int;
840 Cond_Attr : aliased pthread_condattr_t;
843 -- Give the task a unique serial number
845 Self_ID.Serial_Number := Next_Serial_Number;
846 Next_Serial_Number := Next_Serial_Number + 1;
847 pragma Assert (Next_Serial_Number /= 0);
849 if not Single_Lock then
850 Result := pthread_mutexattr_init (Mutex_Attr'Access);
851 pragma Assert (Result = 0 or else Result = ENOMEM);
854 if Locking_Policy = 'C' then
856 pthread_mutexattr_setprotocol
858 PTHREAD_PRIO_PROTECT);
859 pragma Assert (Result = 0);
862 pthread_mutexattr_setprioceiling
864 Interfaces.C.int (System.Any_Priority'Last));
865 pragma Assert (Result = 0);
867 elsif Locking_Policy = 'I' then
869 pthread_mutexattr_setprotocol
871 PTHREAD_PRIO_INHERIT);
872 pragma Assert (Result = 0);
877 (Self_ID.Common.LL.L'Access,
879 pragma Assert (Result = 0 or else Result = ENOMEM);
887 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
888 pragma Assert (Result = 0);
891 Result := pthread_condattr_init (Cond_Attr'Access);
892 pragma Assert (Result = 0 or else Result = ENOMEM);
897 (Self_ID.Common.LL.CV'Access, Cond_Attr'Access);
898 pragma Assert (Result = 0 or else Result = ENOMEM);
904 if not Single_Lock then
905 Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
906 pragma Assert (Result = 0);
912 Result := pthread_condattr_destroy (Cond_Attr'Access);
913 pragma Assert (Result = 0);
920 procedure Create_Task
922 Wrapper : System.Address;
923 Stack_Size : System.Parameters.Size_Type;
924 Priority : System.Any_Priority;
925 Succeeded : out Boolean)
927 Attributes : aliased pthread_attr_t;
928 Adjusted_Stack_Size : Interfaces.C.size_t;
929 Result : Interfaces.C.int;
931 function Thread_Body_Access is new
932 Ada.Unchecked_Conversion (System.Address, Thread_Body);
934 use System.Task_Info;
937 Adjusted_Stack_Size :=
938 Interfaces.C.size_t (Stack_Size + Alternate_Stack_Size);
940 if Stack_Base_Available then
942 -- If Stack Checking is supported then allocate 2 additional pages:
944 -- In the worst case, stack is allocated at something like
945 -- N * Get_Page_Size - epsilon, we need to add the size for 2 pages
946 -- to be sure the effective stack size is greater than what
949 Adjusted_Stack_Size := Adjusted_Stack_Size + 2 * Get_Page_Size;
952 Result := pthread_attr_init (Attributes'Access);
953 pragma Assert (Result = 0 or else Result = ENOMEM);
961 pthread_attr_setdetachstate
962 (Attributes'Access, PTHREAD_CREATE_DETACHED);
963 pragma Assert (Result = 0);
966 pthread_attr_setstacksize
967 (Attributes'Access, Adjusted_Stack_Size);
968 pragma Assert (Result = 0);
970 if T.Common.Task_Info /= Default_Scope then
971 case T.Common.Task_Info is
972 when System.Task_Info.Process_Scope =>
974 pthread_attr_setscope
975 (Attributes'Access, PTHREAD_SCOPE_PROCESS);
977 when System.Task_Info.System_Scope =>
979 pthread_attr_setscope
980 (Attributes'Access, PTHREAD_SCOPE_SYSTEM);
982 when System.Task_Info.Default_Scope =>
986 pragma Assert (Result = 0);
989 -- Since the initial signal mask of a thread is inherited from the
990 -- creator, and the Environment task has all its signals masked, we
991 -- do not need to manipulate caller's signal mask at this point.
992 -- All tasks in RTS will have All_Tasks_Mask initially.
994 Result := pthread_create
995 (T.Common.LL.Thread'Access,
997 Thread_Body_Access (Wrapper),
999 pragma Assert (Result = 0 or else Result = EAGAIN);
1001 Succeeded := Result = 0;
1003 Result := pthread_attr_destroy (Attributes'Access);
1004 pragma Assert (Result = 0);
1007 Set_Priority (T, Priority);
1015 procedure Finalize_TCB (T : Task_Id) is
1016 Result : Interfaces.C.int;
1018 Is_Self : constant Boolean := T = Self;
1020 procedure Free is new
1021 Ada.Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
1024 if not Single_Lock then
1025 Result := pthread_mutex_destroy (T.Common.LL.L'Access);
1026 pragma Assert (Result = 0);
1029 Result := pthread_cond_destroy (T.Common.LL.CV'Access);
1030 pragma Assert (Result = 0);
1032 if T.Known_Tasks_Index /= -1 then
1033 Known_Tasks (T.Known_Tasks_Index) := null;
1039 Specific.Set (null);
1047 procedure Exit_Task is
1049 -- Mark this task as unknown, so that if Self is called, it won't
1050 -- return a dangling pointer.
1052 Specific.Set (null);
1059 procedure Abort_Task (T : Task_Id) is
1060 Result : Interfaces.C.int;
1064 (T.Common.LL.Thread,
1065 Signal (System.Interrupt_Management.Abort_Task_Interrupt));
1066 pragma Assert (Result = 0);
1073 procedure Initialize (S : in out Suspension_Object) is
1074 Mutex_Attr : aliased pthread_mutexattr_t;
1075 Cond_Attr : aliased pthread_condattr_t;
1076 Result : Interfaces.C.int;
1079 -- Initialize internal state (always to False (RM D.10 (6)))
1084 -- Initialize internal mutex
1086 Result := pthread_mutexattr_init (Mutex_Attr'Access);
1087 pragma Assert (Result = 0 or else Result = ENOMEM);
1089 if Result = ENOMEM then
1090 raise Storage_Error;
1093 Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
1094 pragma Assert (Result = 0 or else Result = ENOMEM);
1096 if Result = ENOMEM then
1097 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1098 pragma Assert (Result = 0);
1100 raise Storage_Error;
1103 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1104 pragma Assert (Result = 0);
1106 -- Initialize internal condition variable
1108 Result := pthread_condattr_init (Cond_Attr'Access);
1109 pragma Assert (Result = 0 or else Result = ENOMEM);
1112 Result := pthread_mutex_destroy (S.L'Access);
1113 pragma Assert (Result = 0);
1115 if Result = ENOMEM then
1116 raise Storage_Error;
1120 Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
1121 pragma Assert (Result = 0 or else Result = ENOMEM);
1124 Result := pthread_mutex_destroy (S.L'Access);
1125 pragma Assert (Result = 0);
1127 if Result = ENOMEM then
1128 Result := pthread_condattr_destroy (Cond_Attr'Access);
1129 pragma Assert (Result = 0);
1130 raise Storage_Error;
1134 Result := pthread_condattr_destroy (Cond_Attr'Access);
1135 pragma Assert (Result = 0);
1142 procedure Finalize (S : in out Suspension_Object) is
1143 Result : Interfaces.C.int;
1146 -- Destroy internal mutex
1148 Result := pthread_mutex_destroy (S.L'Access);
1149 pragma Assert (Result = 0);
1151 -- Destroy internal condition variable
1153 Result := pthread_cond_destroy (S.CV'Access);
1154 pragma Assert (Result = 0);
1161 function Current_State (S : Suspension_Object) return Boolean is
1163 -- We do not want to use lock on this read operation. State is marked
1164 -- as Atomic so that we ensure that the value retrieved is correct.
1173 procedure Set_False (S : in out Suspension_Object) is
1174 Result : Interfaces.C.int;
1177 SSL.Abort_Defer.all;
1179 Result := pthread_mutex_lock (S.L'Access);
1180 pragma Assert (Result = 0);
1184 Result := pthread_mutex_unlock (S.L'Access);
1185 pragma Assert (Result = 0);
1187 SSL.Abort_Undefer.all;
1194 procedure Set_True (S : in out Suspension_Object) is
1195 Result : Interfaces.C.int;
1198 SSL.Abort_Defer.all;
1200 Result := pthread_mutex_lock (S.L'Access);
1201 pragma Assert (Result = 0);
1203 -- If there is already a task waiting on this suspension object then
1204 -- we resume it, leaving the state of the suspension object to False,
1205 -- as it is specified in (RM D.10(9)). Otherwise, it just leaves
1206 -- the state to True.
1212 Result := pthread_cond_signal (S.CV'Access);
1213 pragma Assert (Result = 0);
1219 Result := pthread_mutex_unlock (S.L'Access);
1220 pragma Assert (Result = 0);
1222 SSL.Abort_Undefer.all;
1225 ------------------------
1226 -- Suspend_Until_True --
1227 ------------------------
1229 procedure Suspend_Until_True (S : in out Suspension_Object) is
1230 Result : Interfaces.C.int;
1233 SSL.Abort_Defer.all;
1235 Result := pthread_mutex_lock (S.L'Access);
1236 pragma Assert (Result = 0);
1240 -- Program_Error must be raised upon calling Suspend_Until_True
1241 -- if another task is already waiting on that suspension object
1244 Result := pthread_mutex_unlock (S.L'Access);
1245 pragma Assert (Result = 0);
1247 SSL.Abort_Undefer.all;
1249 raise Program_Error;
1252 -- Suspend the task if the state is False. Otherwise, the task
1253 -- continues its execution, and the state of the suspension object
1254 -- is set to False (ARM D.10 par. 9).
1262 -- Loop in case pthread_cond_wait returns earlier than expected
1263 -- (e.g. in case of EINTR caused by a signal).
1265 Result := pthread_cond_wait (S.CV'Access, S.L'Access);
1266 pragma Assert (Result = 0 or else Result = EINTR);
1268 exit when not S.Waiting;
1272 Result := pthread_mutex_unlock (S.L'Access);
1273 pragma Assert (Result = 0);
1275 SSL.Abort_Undefer.all;
1277 end Suspend_Until_True;
1285 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1286 pragma Unreferenced (Self_ID);
1291 --------------------
1292 -- Check_No_Locks --
1293 --------------------
1295 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1296 pragma Unreferenced (Self_ID);
1301 ----------------------
1302 -- Environment_Task --
1303 ----------------------
1305 function Environment_Task return Task_Id is
1307 return Environment_Task_Id;
1308 end Environment_Task;
1314 procedure Lock_RTS is
1316 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
1323 procedure Unlock_RTS is
1325 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
1332 function Suspend_Task
1334 Thread_Self : Thread_Id) return Boolean
1336 pragma Unreferenced (T, Thread_Self);
1345 function Resume_Task
1347 Thread_Self : Thread_Id) return Boolean
1349 pragma Unreferenced (T, Thread_Self);
1354 --------------------
1355 -- Stop_All_Tasks --
1356 --------------------
1358 procedure Stop_All_Tasks is
1367 function Stop_Task (T : ST.Task_Id) return Boolean is
1368 pragma Unreferenced (T);
1377 function Continue_Task (T : ST.Task_Id) return Boolean is
1378 pragma Unreferenced (T);
1387 procedure Initialize (Environment_Task : Task_Id) is
1388 act : aliased struct_sigaction;
1389 old_act : aliased struct_sigaction;
1390 Tmp_Set : aliased sigset_t;
1391 Result : Interfaces.C.int;
1394 (Int : System.Interrupt_Management.Interrupt_ID) return Character;
1395 pragma Import (C, State, "__gnat_get_interrupt_state");
1396 -- Get interrupt state. Defined in a-init.c
1397 -- The input argument is the interrupt number,
1398 -- and the result is one of the following:
1400 Default : constant Character := 's';
1401 -- 'n' this interrupt not set by any Interrupt_State pragma
1402 -- 'u' Interrupt_State pragma set state to User
1403 -- 'r' Interrupt_State pragma set state to Runtime
1404 -- 's' Interrupt_State pragma set state to System (use "default"
1408 Environment_Task_Id := Environment_Task;
1410 Interrupt_Management.Initialize;
1412 -- Prepare the set of signals that should unblocked in all tasks
1414 Result := sigemptyset (Unblocked_Signal_Mask'Access);
1415 pragma Assert (Result = 0);
1417 for J in Interrupt_Management.Interrupt_ID loop
1418 if System.Interrupt_Management.Keep_Unmasked (J) then
1419 Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
1420 pragma Assert (Result = 0);
1424 -- Initialize the lock used to synchronize chain of all ATCBs
1426 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1428 Specific.Initialize (Environment_Task);
1430 if Use_Alternate_Stack then
1431 Environment_Task.Common.Task_Alternate_Stack :=
1432 Alternate_Stack'Address;
1435 -- Make environment task known here because it doesn't go through
1436 -- Activate_Tasks, which does it for all other tasks.
1438 Known_Tasks (Known_Tasks'First) := Environment_Task;
1439 Environment_Task.Known_Tasks_Index := Known_Tasks'First;
1441 Enter_Task (Environment_Task);
1443 -- Install the abort-signal handler
1446 (System.Interrupt_Management.Abort_Task_Interrupt) /= Default
1449 act.sa_handler := Abort_Handler'Address;
1451 Result := sigemptyset (Tmp_Set'Access);
1452 pragma Assert (Result = 0);
1453 act.sa_mask := Tmp_Set;
1457 (Signal (System.Interrupt_Management.Abort_Task_Interrupt),
1458 act'Unchecked_Access,
1459 old_act'Unchecked_Access);
1460 pragma Assert (Result = 0);
1464 end System.Task_Primitives.Operations;