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) 1992-2011, 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;
51 with System.Tasking.Debug;
52 with System.Interrupt_Management;
53 with System.OS_Constants;
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 OSC renames System.OS_Constants;
66 package SSL renames System.Soft_Links;
68 use System.Tasking.Debug;
71 use System.OS_Interface;
72 use System.Parameters;
73 use System.OS_Primitives;
79 -- The followings are logically constants, but need to be initialized
82 Single_RTS_Lock : aliased RTS_Lock;
83 -- This is a lock to allow only one thread of control in the RTS at
84 -- a time; it is used to execute in mutual exclusion from all other tasks.
85 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
87 Environment_Task_Id : Task_Id;
88 -- A variable to hold Task_Id for the environment task
90 Locking_Policy : Character;
91 pragma Import (C, Locking_Policy, "__gl_locking_policy");
92 -- Value of the pragma Locking_Policy:
93 -- 'C' for Ceiling_Locking
94 -- 'I' for Inherit_Locking
97 Unblocked_Signal_Mask : aliased sigset_t;
98 -- The set of signals that should unblocked in all tasks
100 -- The followings are internal configuration constants needed
102 Next_Serial_Number : Task_Serial_Number := 100;
103 -- We start at 100, to reserve some special values for
104 -- using in error checking.
106 Time_Slice_Val : Integer;
107 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
109 Dispatching_Policy : Character;
110 pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
112 Foreign_Task_Elaborated : aliased Boolean := True;
113 -- Used to identified fake tasks (i.e., non-Ada Threads)
115 Use_Alternate_Stack : constant Boolean := Alternate_Stack_Size /= 0;
116 -- Whether to use an alternate signal stack for stack overflows
118 Abort_Handler_Installed : Boolean := False;
119 -- True if a handler for the abort signal is installed
127 procedure Initialize (Environment_Task : Task_Id);
128 pragma Inline (Initialize);
129 -- Initialize various data needed by this package
131 function Is_Valid_Task return Boolean;
132 pragma Inline (Is_Valid_Task);
133 -- Does executing thread have a TCB?
135 procedure Set (Self_Id : Task_Id);
137 -- Set the self id for the current task
139 function Self return Task_Id;
140 pragma Inline (Self);
141 -- Return a pointer to the Ada Task Control Block of the calling task
145 package body Specific is separate;
146 -- The body of this package is target specific
148 ----------------------------------
149 -- ATCB allocation/deallocation --
150 ----------------------------------
152 package body ATCB_Allocation is separate;
153 -- The body of this package is shared across several targets
155 ---------------------------------
156 -- Support for foreign threads --
157 ---------------------------------
159 function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
160 -- Allocate and Initialize a new ATCB for the current Thread
162 function Register_Foreign_Thread
163 (Thread : Thread_Id) return Task_Id is separate;
165 -----------------------
166 -- Local Subprograms --
167 -----------------------
169 procedure Abort_Handler (Sig : Signal);
170 -- Signal handler used to implement asynchronous abort.
171 -- See also comment before body, below.
173 function To_Address is
174 new Ada.Unchecked_Conversion (Task_Id, System.Address);
176 function GNAT_pthread_condattr_setup
177 (attr : access pthread_condattr_t) return int;
179 GNAT_pthread_condattr_setup, "__gnat_pthread_condattr_setup");
185 -- Target-dependent binding of inter-thread Abort signal to the raising of
186 -- the Abort_Signal exception.
188 -- The technical issues and alternatives here are essentially the
189 -- same as for raising exceptions in response to other signals
190 -- (e.g. Storage_Error). See code and comments in the package body
191 -- System.Interrupt_Management.
193 -- Some implementations may not allow an exception to be propagated out of
194 -- a handler, and others might leave the signal or interrupt that invoked
195 -- this handler masked after the exceptional return to the application
198 -- GNAT exceptions are originally implemented using setjmp()/longjmp(). On
199 -- most UNIX systems, this will allow transfer out of a signal handler,
200 -- which is usually the only mechanism available for implementing
201 -- asynchronous handlers of this kind. However, some systems do not
202 -- restore the signal mask on longjmp(), leaving the abort signal masked.
204 procedure Abort_Handler (Sig : Signal) is
205 pragma Unreferenced (Sig);
207 T : constant Task_Id := Self;
208 Old_Set : aliased sigset_t;
210 Result : Interfaces.C.int;
211 pragma Warnings (Off, Result);
214 -- It's not safe to raise an exception when using GCC ZCX mechanism.
215 -- Note that we still need to install a signal handler, since in some
216 -- cases (e.g. shutdown of the Server_Task in System.Interrupts) we
217 -- need to send the Abort signal to a task.
219 if ZCX_By_Default then
223 if T.Deferral_Level = 0
224 and then T.Pending_ATC_Level < T.ATC_Nesting_Level and then
229 -- Make sure signals used for RTS internal purpose are unmasked
231 Result := pthread_sigmask (SIG_UNBLOCK,
232 Unblocked_Signal_Mask'Access, Old_Set'Access);
233 pragma Assert (Result = 0);
235 raise Standard'Abort_Signal;
243 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
244 Stack_Base : constant Address := Get_Stack_Base (T.Common.LL.Thread);
245 Guard_Page_Address : Address;
247 Res : Interfaces.C.int;
250 if Stack_Base_Available then
252 -- Compute the guard page address
254 Guard_Page_Address :=
255 Stack_Base - (Stack_Base mod Get_Page_Size) + Get_Page_Size;
258 mprotect (Guard_Page_Address, Get_Page_Size,
259 prot => (if On then PROT_ON else PROT_OFF));
260 pragma Assert (Res = 0);
268 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
270 return T.Common.LL.Thread;
277 function Self return Task_Id renames Specific.Self;
279 ---------------------
280 -- Initialize_Lock --
281 ---------------------
283 -- Note: mutexes and cond_variables needed per-task basis are
284 -- initialized in Initialize_TCB and the Storage_Error is
285 -- handled. Other mutexes (such as RTS_Lock, Memory_Lock...)
286 -- used in RTS is initialized before any status change of RTS.
287 -- Therefore raising Storage_Error in the following routines
288 -- should be able to be handled safely.
290 procedure Initialize_Lock
291 (Prio : System.Any_Priority;
292 L : not null access Lock)
294 Attributes : aliased pthread_mutexattr_t;
295 Result : Interfaces.C.int;
298 Result := pthread_mutexattr_init (Attributes'Access);
299 pragma Assert (Result = 0 or else Result = ENOMEM);
301 if Result = ENOMEM then
305 if Locking_Policy = 'C' then
306 Result := pthread_mutexattr_setprotocol
307 (Attributes'Access, PTHREAD_PRIO_PROTECT);
308 pragma Assert (Result = 0);
310 Result := pthread_mutexattr_setprioceiling
311 (Attributes'Access, Interfaces.C.int (Prio));
312 pragma Assert (Result = 0);
314 elsif Locking_Policy = 'I' then
315 Result := pthread_mutexattr_setprotocol
316 (Attributes'Access, PTHREAD_PRIO_INHERIT);
317 pragma Assert (Result = 0);
320 Result := pthread_mutex_init (L.WO'Access, Attributes'Access);
321 pragma Assert (Result = 0 or else Result = ENOMEM);
323 if Result = ENOMEM then
324 Result := pthread_mutexattr_destroy (Attributes'Access);
328 Result := pthread_mutexattr_destroy (Attributes'Access);
329 pragma Assert (Result = 0);
332 procedure Initialize_Lock
333 (L : not null access RTS_Lock; Level : Lock_Level)
335 pragma Unreferenced (Level);
337 Attributes : aliased pthread_mutexattr_t;
338 Result : Interfaces.C.int;
341 Result := pthread_mutexattr_init (Attributes'Access);
342 pragma Assert (Result = 0 or else Result = ENOMEM);
344 if Result = ENOMEM then
348 if Locking_Policy = 'C' then
349 Result := pthread_mutexattr_setprotocol
350 (Attributes'Access, PTHREAD_PRIO_PROTECT);
351 pragma Assert (Result = 0);
353 Result := pthread_mutexattr_setprioceiling
354 (Attributes'Access, Interfaces.C.int (System.Any_Priority'Last));
355 pragma Assert (Result = 0);
357 elsif Locking_Policy = 'I' then
358 Result := pthread_mutexattr_setprotocol
359 (Attributes'Access, PTHREAD_PRIO_INHERIT);
360 pragma Assert (Result = 0);
363 Result := pthread_mutex_init (L, Attributes'Access);
364 pragma Assert (Result = 0 or else Result = ENOMEM);
366 if Result = ENOMEM then
367 Result := pthread_mutexattr_destroy (Attributes'Access);
371 Result := pthread_mutexattr_destroy (Attributes'Access);
372 pragma Assert (Result = 0);
379 procedure Finalize_Lock (L : not null access Lock) is
380 Result : Interfaces.C.int;
382 Result := pthread_mutex_destroy (L.WO'Access);
383 pragma Assert (Result = 0);
386 procedure Finalize_Lock (L : not null access RTS_Lock) is
387 Result : Interfaces.C.int;
389 Result := pthread_mutex_destroy (L);
390 pragma Assert (Result = 0);
398 (L : not null access Lock; Ceiling_Violation : out Boolean)
400 Result : Interfaces.C.int;
403 Result := pthread_mutex_lock (L.WO'Access);
405 -- Assume that the cause of EINVAL is a priority ceiling violation
407 Ceiling_Violation := (Result = EINVAL);
408 pragma Assert (Result = 0 or else Result = EINVAL);
412 (L : not null access RTS_Lock;
413 Global_Lock : Boolean := False)
415 Result : Interfaces.C.int;
417 if not Single_Lock or else Global_Lock then
418 Result := pthread_mutex_lock (L);
419 pragma Assert (Result = 0);
423 procedure Write_Lock (T : Task_Id) is
424 Result : Interfaces.C.int;
426 if not Single_Lock then
427 Result := pthread_mutex_lock (T.Common.LL.L'Access);
428 pragma Assert (Result = 0);
437 (L : not null access Lock; Ceiling_Violation : out Boolean) is
439 Write_Lock (L, Ceiling_Violation);
446 procedure Unlock (L : not null access Lock) is
447 Result : Interfaces.C.int;
449 Result := pthread_mutex_unlock (L.WO'Access);
450 pragma Assert (Result = 0);
454 (L : not null access RTS_Lock; Global_Lock : Boolean := False)
456 Result : Interfaces.C.int;
458 if not Single_Lock or else Global_Lock then
459 Result := pthread_mutex_unlock (L);
460 pragma Assert (Result = 0);
464 procedure Unlock (T : Task_Id) is
465 Result : Interfaces.C.int;
467 if not Single_Lock then
468 Result := pthread_mutex_unlock (T.Common.LL.L'Access);
469 pragma Assert (Result = 0);
477 -- Dynamic priority ceilings are not supported by the underlying system
479 procedure Set_Ceiling
480 (L : not null access Lock;
481 Prio : System.Any_Priority)
483 pragma Unreferenced (L, Prio);
494 Reason : System.Tasking.Task_States)
496 pragma Unreferenced (Reason);
498 Result : Interfaces.C.int;
503 (cond => Self_ID.Common.LL.CV'Access,
504 mutex => (if Single_Lock
505 then Single_RTS_Lock'Access
506 else Self_ID.Common.LL.L'Access));
508 -- EINTR is not considered a failure
510 pragma Assert (Result = 0 or else Result = EINTR);
517 -- This is for use within the run-time system, so abort is
518 -- assumed to be already deferred, and the caller should be
519 -- holding its own ATCB lock.
521 procedure Timed_Sleep
524 Mode : ST.Delay_Modes;
525 Reason : Task_States;
526 Timedout : out Boolean;
527 Yielded : out Boolean)
529 pragma Unreferenced (Reason);
531 Base_Time : constant Duration := Monotonic_Clock;
532 Check_Time : Duration := Base_Time;
535 Request : aliased timespec;
536 Result : Interfaces.C.int;
542 if Mode = Relative then
543 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
545 if Relative_Timed_Wait then
546 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
550 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
552 if Relative_Timed_Wait then
553 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
557 if Abs_Time > Check_Time then
559 To_Timespec (if Relative_Timed_Wait then Rel_Time else Abs_Time);
562 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
565 pthread_cond_timedwait
566 (cond => Self_ID.Common.LL.CV'Access,
567 mutex => (if Single_Lock
568 then Single_RTS_Lock'Access
569 else Self_ID.Common.LL.L'Access),
570 abstime => Request'Access);
572 Check_Time := Monotonic_Clock;
573 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
575 if Result = 0 or Result = EINTR then
577 -- Somebody may have called Wakeup for us
583 pragma Assert (Result = ETIMEDOUT);
592 -- This is for use in implementing delay statements, so we assume the
593 -- caller is abort-deferred but is holding no locks.
595 procedure Timed_Delay
598 Mode : ST.Delay_Modes)
600 Base_Time : constant Duration := Monotonic_Clock;
601 Check_Time : Duration := Base_Time;
604 Request : aliased timespec;
606 Result : Interfaces.C.int;
607 pragma Warnings (Off, Result);
614 Write_Lock (Self_ID);
616 if Mode = Relative then
617 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
619 if Relative_Timed_Wait then
620 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
624 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
626 if Relative_Timed_Wait then
627 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
631 if Abs_Time > Check_Time then
633 To_Timespec (if Relative_Timed_Wait then Rel_Time else Abs_Time);
634 Self_ID.Common.State := Delay_Sleep;
637 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
640 pthread_cond_timedwait
641 (cond => Self_ID.Common.LL.CV'Access,
642 mutex => (if Single_Lock
643 then Single_RTS_Lock'Access
644 else Self_ID.Common.LL.L'Access),
645 abstime => Request'Access);
647 Check_Time := Monotonic_Clock;
648 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
650 pragma Assert (Result = 0
651 or else Result = ETIMEDOUT
652 or else Result = EINTR);
655 Self_ID.Common.State := Runnable;
664 Result := sched_yield;
667 ---------------------
668 -- Monotonic_Clock --
669 ---------------------
671 function Monotonic_Clock return Duration is
672 TS : aliased timespec;
673 Result : Interfaces.C.int;
675 Result := clock_gettime
676 (clock_id => OSC.CLOCK_RT_Ada, tp => TS'Unchecked_Access);
677 pragma Assert (Result = 0);
678 return To_Duration (TS);
685 function RT_Resolution return Duration is
694 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
695 pragma Unreferenced (Reason);
696 Result : Interfaces.C.int;
698 Result := pthread_cond_signal (T.Common.LL.CV'Access);
699 pragma Assert (Result = 0);
706 procedure Yield (Do_Yield : Boolean := True) is
707 Result : Interfaces.C.int;
708 pragma Unreferenced (Result);
711 Result := sched_yield;
719 procedure Set_Priority
721 Prio : System.Any_Priority;
722 Loss_Of_Inheritance : Boolean := False)
724 pragma Unreferenced (Loss_Of_Inheritance);
726 Result : Interfaces.C.int;
727 Param : aliased struct_sched_param;
729 function Get_Policy (Prio : System.Any_Priority) return Character;
730 pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
731 -- Get priority specific dispatching policy
733 Priority_Specific_Policy : constant Character := Get_Policy (Prio);
734 -- Upper case first character of the policy name corresponding to the
735 -- task as set by a Priority_Specific_Dispatching pragma.
738 T.Common.Current_Priority := Prio;
739 Param.sched_priority := To_Target_Priority (Prio);
741 if Time_Slice_Supported
742 and then (Dispatching_Policy = 'R'
743 or else Priority_Specific_Policy = 'R'
744 or else Time_Slice_Val > 0)
746 Result := pthread_setschedparam
747 (T.Common.LL.Thread, SCHED_RR, Param'Access);
749 elsif Dispatching_Policy = 'F'
750 or else Priority_Specific_Policy = 'F'
751 or else Time_Slice_Val = 0
753 Result := pthread_setschedparam
754 (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
757 Result := pthread_setschedparam
758 (T.Common.LL.Thread, SCHED_OTHER, Param'Access);
761 pragma Assert (Result = 0);
768 function Get_Priority (T : Task_Id) return System.Any_Priority is
770 return T.Common.Current_Priority;
777 procedure Enter_Task (Self_ID : Task_Id) is
779 Self_ID.Common.LL.Thread := pthread_self;
780 Self_ID.Common.LL.LWP := lwp_self;
782 Specific.Set (Self_ID);
784 if Use_Alternate_Stack then
786 Stack : aliased stack_t;
787 Result : Interfaces.C.int;
789 Stack.ss_sp := Self_ID.Common.Task_Alternate_Stack;
790 Stack.ss_size := Alternate_Stack_Size;
792 Result := sigaltstack (Stack'Access, null);
793 pragma Assert (Result = 0);
802 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
804 -----------------------------
805 -- Register_Foreign_Thread --
806 -----------------------------
808 function Register_Foreign_Thread return Task_Id is
810 if Is_Valid_Task then
813 return Register_Foreign_Thread (pthread_self);
815 end Register_Foreign_Thread;
821 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
822 Mutex_Attr : aliased pthread_mutexattr_t;
823 Result : Interfaces.C.int;
824 Cond_Attr : aliased pthread_condattr_t;
827 -- Give the task a unique serial number
829 Self_ID.Serial_Number := Next_Serial_Number;
830 Next_Serial_Number := Next_Serial_Number + 1;
831 pragma Assert (Next_Serial_Number /= 0);
833 if not Single_Lock then
834 Result := pthread_mutexattr_init (Mutex_Attr'Access);
835 pragma Assert (Result = 0 or else Result = ENOMEM);
838 if Locking_Policy = 'C' then
840 pthread_mutexattr_setprotocol
842 PTHREAD_PRIO_PROTECT);
843 pragma Assert (Result = 0);
846 pthread_mutexattr_setprioceiling
848 Interfaces.C.int (System.Any_Priority'Last));
849 pragma Assert (Result = 0);
851 elsif Locking_Policy = 'I' then
853 pthread_mutexattr_setprotocol
855 PTHREAD_PRIO_INHERIT);
856 pragma Assert (Result = 0);
861 (Self_ID.Common.LL.L'Access,
863 pragma Assert (Result = 0 or else Result = ENOMEM);
871 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
872 pragma Assert (Result = 0);
875 Result := pthread_condattr_init (Cond_Attr'Access);
876 pragma Assert (Result = 0 or else Result = ENOMEM);
879 Result := GNAT_pthread_condattr_setup (Cond_Attr'Access);
880 pragma Assert (Result = 0);
884 (Self_ID.Common.LL.CV'Access, Cond_Attr'Access);
885 pragma Assert (Result = 0 or else Result = ENOMEM);
891 if not Single_Lock then
892 Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
893 pragma Assert (Result = 0);
899 Result := pthread_condattr_destroy (Cond_Attr'Access);
900 pragma Assert (Result = 0);
907 procedure Create_Task
909 Wrapper : System.Address;
910 Stack_Size : System.Parameters.Size_Type;
911 Priority : System.Any_Priority;
912 Succeeded : out Boolean)
914 Attributes : aliased pthread_attr_t;
915 Adjusted_Stack_Size : Interfaces.C.size_t;
916 Page_Size : constant Interfaces.C.size_t := Get_Page_Size;
917 Result : Interfaces.C.int;
919 function Thread_Body_Access is new
920 Ada.Unchecked_Conversion (System.Address, Thread_Body);
922 use System.Task_Info;
925 Adjusted_Stack_Size :=
926 Interfaces.C.size_t (Stack_Size + Alternate_Stack_Size);
928 if Stack_Base_Available then
930 -- If Stack Checking is supported then allocate 2 additional pages:
932 -- In the worst case, stack is allocated at something like
933 -- N * Get_Page_Size - epsilon, we need to add the size for 2 pages
934 -- to be sure the effective stack size is greater than what
937 Adjusted_Stack_Size := Adjusted_Stack_Size + 2 * Page_Size;
940 -- Round stack size as this is required by some OSes (Darwin)
942 Adjusted_Stack_Size := Adjusted_Stack_Size + Page_Size - 1;
943 Adjusted_Stack_Size :=
944 Adjusted_Stack_Size - Adjusted_Stack_Size mod Page_Size;
946 Result := pthread_attr_init (Attributes'Access);
947 pragma Assert (Result = 0 or else Result = ENOMEM);
955 pthread_attr_setdetachstate
956 (Attributes'Access, PTHREAD_CREATE_DETACHED);
957 pragma Assert (Result = 0);
960 pthread_attr_setstacksize
961 (Attributes'Access, Adjusted_Stack_Size);
962 pragma Assert (Result = 0);
964 if T.Common.Task_Info /= Default_Scope then
965 case T.Common.Task_Info is
966 when System.Task_Info.Process_Scope =>
968 pthread_attr_setscope
969 (Attributes'Access, PTHREAD_SCOPE_PROCESS);
971 when System.Task_Info.System_Scope =>
973 pthread_attr_setscope
974 (Attributes'Access, PTHREAD_SCOPE_SYSTEM);
976 when System.Task_Info.Default_Scope =>
980 pragma Assert (Result = 0);
983 -- Since the initial signal mask of a thread is inherited from the
984 -- creator, and the Environment task has all its signals masked, we
985 -- do not need to manipulate caller's signal mask at this point.
986 -- All tasks in RTS will have All_Tasks_Mask initially.
988 -- Note: the use of Unrestricted_Access in the following call is needed
989 -- because otherwise we have an error of getting a access-to-volatile
990 -- value which points to a non-volatile object. But in this case it is
991 -- safe to do this, since we know we have no problems with aliasing and
992 -- Unrestricted_Access bypasses this check.
994 Result := pthread_create
995 (T.Common.LL.Thread'Unrestricted_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;
1019 if not Single_Lock then
1020 Result := pthread_mutex_destroy (T.Common.LL.L'Access);
1021 pragma Assert (Result = 0);
1024 Result := pthread_cond_destroy (T.Common.LL.CV'Access);
1025 pragma Assert (Result = 0);
1027 if T.Known_Tasks_Index /= -1 then
1028 Known_Tasks (T.Known_Tasks_Index) := null;
1031 ATCB_Allocation.Free_ATCB (T);
1038 procedure Exit_Task is
1040 -- Mark this task as unknown, so that if Self is called, it won't
1041 -- return a dangling pointer.
1043 Specific.Set (null);
1050 procedure Abort_Task (T : Task_Id) is
1051 Result : Interfaces.C.int;
1053 if Abort_Handler_Installed then
1056 (T.Common.LL.Thread,
1057 Signal (System.Interrupt_Management.Abort_Task_Interrupt));
1058 pragma Assert (Result = 0);
1066 procedure Initialize (S : in out Suspension_Object) is
1067 Mutex_Attr : aliased pthread_mutexattr_t;
1068 Cond_Attr : aliased pthread_condattr_t;
1069 Result : Interfaces.C.int;
1072 -- Initialize internal state (always to False (RM D.10 (6)))
1077 -- Initialize internal mutex
1079 Result := pthread_mutexattr_init (Mutex_Attr'Access);
1080 pragma Assert (Result = 0 or else Result = ENOMEM);
1082 if Result = ENOMEM then
1083 raise Storage_Error;
1086 Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
1087 pragma Assert (Result = 0 or else Result = ENOMEM);
1089 if Result = ENOMEM then
1090 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1091 pragma Assert (Result = 0);
1093 raise Storage_Error;
1096 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1097 pragma Assert (Result = 0);
1099 -- Initialize internal condition variable
1101 Result := pthread_condattr_init (Cond_Attr'Access);
1102 pragma Assert (Result = 0 or else Result = ENOMEM);
1105 Result := pthread_mutex_destroy (S.L'Access);
1106 pragma Assert (Result = 0);
1108 -- Storage_Error is propagated as intended if the allocation of the
1109 -- underlying OS entities fails.
1111 raise Storage_Error;
1114 Result := GNAT_pthread_condattr_setup (Cond_Attr'Access);
1115 pragma Assert (Result = 0);
1118 Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
1119 pragma Assert (Result = 0 or else Result = ENOMEM);
1122 Result := pthread_mutex_destroy (S.L'Access);
1123 pragma Assert (Result = 0);
1125 Result := pthread_condattr_destroy (Cond_Attr'Access);
1126 pragma Assert (Result = 0);
1128 -- Storage_Error is propagated as intended if the allocation of the
1129 -- underlying OS entities fails.
1131 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);
1444 (System.Interrupt_Management.Abort_Task_Interrupt) /= Default
1447 act.sa_handler := Abort_Handler'Address;
1449 Result := sigemptyset (Tmp_Set'Access);
1450 pragma Assert (Result = 0);
1451 act.sa_mask := Tmp_Set;
1455 (Signal (System.Interrupt_Management.Abort_Task_Interrupt),
1456 act'Unchecked_Access,
1457 old_act'Unchecked_Access);
1458 pragma Assert (Result = 0);
1459 Abort_Handler_Installed := True;
1463 -----------------------
1464 -- Set_Task_Affinity --
1465 -----------------------
1467 procedure Set_Task_Affinity (T : ST.Task_Id) is
1468 pragma Unreferenced (T);
1471 -- Setting task affinity is not supported by the underlying system
1474 end Set_Task_Affinity;
1476 end System.Task_Primitives.Operations;