1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
5 -- S Y S T E M . T A S K _ P R I M I T I V E S . O P E R A T I O N S --
9 -- Copyright (C) 1992-2005, Free Software Foundation, Inc. --
11 -- GNARL is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNARL; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNARL was developed by the GNARL team at Florida State University. --
30 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
32 ------------------------------------------------------------------------------
34 -- This is a POSIX-like version of this package
36 -- This package contains all the GNULL primitives that interface directly
37 -- with the underlying OS.
39 -- Note: this file can only be used for POSIX compliant systems that
40 -- implement SCHED_FIFO and Ceiling Locking correctly.
42 -- For configurations where SCHED_FIFO and priority ceiling are not a
43 -- requirement, this file can also be used (e.g AiX threads)
46 -- Turn off polling, we do not want ATC polling to take place during
47 -- tasking operations. It causes infinite loops and other problems.
49 with System.Tasking.Debug;
50 -- used for Known_Tasks
52 with System.Interrupt_Management;
53 -- used for Keep_Unmasked
54 -- Abort_Task_Interrupt
57 with System.OS_Primitives;
58 -- used for Delay_Modes
60 with System.Task_Info;
61 -- used for Task_Info_Type
67 with System.Parameters;
70 with Unchecked_Conversion;
71 with Unchecked_Deallocation;
73 package body System.Task_Primitives.Operations is
75 use System.Tasking.Debug;
78 use System.OS_Interface;
79 use System.Parameters;
80 use System.OS_Primitives;
86 -- The followings are logically constants, but need to be initialized
89 Single_RTS_Lock : aliased RTS_Lock;
90 -- This is a lock to allow only one thread of control in the RTS at
91 -- a time; it is used to execute in mutual exclusion from all other tasks.
92 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
94 ATCB_Key : aliased pthread_key_t;
95 -- Key used to find the Ada Task_Id associated with a thread
97 Environment_Task_Id : Task_Id;
98 -- A variable to hold Task_Id for the environment task.
100 Locking_Policy : Character;
101 pragma Import (C, Locking_Policy, "__gl_locking_policy");
102 -- Value of the pragma Locking_Policy:
103 -- 'C' for Ceiling_Locking
104 -- 'I' for Inherit_Locking
107 Unblocked_Signal_Mask : aliased sigset_t;
108 -- The set of signals that should unblocked in all tasks
110 -- The followings are internal configuration constants needed.
112 Next_Serial_Number : Task_Serial_Number := 100;
113 -- We start at 100, to reserve some special values for
114 -- using in error checking.
116 Time_Slice_Val : Integer;
117 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
119 Dispatching_Policy : Character;
120 pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
122 Foreign_Task_Elaborated : aliased Boolean := True;
123 -- Used to identified fake tasks (i.e., non-Ada Threads).
131 procedure Initialize (Environment_Task : Task_Id);
132 pragma Inline (Initialize);
133 -- Initialize various data needed by this package.
135 function Is_Valid_Task return Boolean;
136 pragma Inline (Is_Valid_Task);
137 -- Does executing thread have a TCB?
139 procedure Set (Self_Id : Task_Id);
141 -- Set the self id for the current task.
143 function Self return Task_Id;
144 pragma Inline (Self);
145 -- Return a pointer to the Ada Task Control Block of the calling task.
149 package body Specific is separate;
150 -- The body of this package is target specific.
152 ---------------------------------
153 -- Support for foreign threads --
154 ---------------------------------
156 function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
157 -- Allocate and Initialize a new ATCB for the current Thread.
159 function Register_Foreign_Thread
160 (Thread : Thread_Id) return Task_Id is separate;
162 -----------------------
163 -- Local Subprograms --
164 -----------------------
166 procedure Abort_Handler (Sig : Signal);
167 -- Signal handler used to implement asynchronous abort.
168 -- See also comment before body, below.
170 function To_Address is new Unchecked_Conversion (Task_Id, System.Address);
176 -- Target-dependent binding of inter-thread Abort signal to
177 -- the raising of the Abort_Signal exception.
179 -- The technical issues and alternatives here are essentially
180 -- the same as for raising exceptions in response to other
181 -- signals (e.g. Storage_Error). See code and comments in
182 -- the package body System.Interrupt_Management.
184 -- Some implementations may not allow an exception to be propagated
185 -- out of a handler, and others might leave the signal or
186 -- interrupt that invoked this handler masked after the exceptional
187 -- return to the application code.
189 -- GNAT exceptions are originally implemented using setjmp()/longjmp().
190 -- On most UNIX systems, this will allow transfer out of a signal handler,
191 -- which is usually the only mechanism available for implementing
192 -- asynchronous handlers of this kind. However, some
193 -- systems do not restore the signal mask on longjmp(), leaving the
194 -- abort signal masked.
196 procedure Abort_Handler (Sig : Signal) is
197 pragma Warnings (Off, Sig);
199 T : constant Task_Id := Self;
200 Result : Interfaces.C.int;
201 Old_Set : aliased sigset_t;
204 -- It is not safe to raise an exception when using ZCX and the GCC
205 -- exception handling mechanism.
207 if ZCX_By_Default and then GCC_ZCX_Support then
211 if T.Deferral_Level = 0
212 and then T.Pending_ATC_Level < T.ATC_Nesting_Level and then
217 -- Make sure signals used for RTS internal purpose are unmasked
219 Result := pthread_sigmask (SIG_UNBLOCK,
220 Unblocked_Signal_Mask'Unchecked_Access, Old_Set'Unchecked_Access);
221 pragma Assert (Result = 0);
223 raise Standard'Abort_Signal;
231 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
232 Stack_Base : constant Address := Get_Stack_Base (T.Common.LL.Thread);
233 Guard_Page_Address : Address;
235 Res : Interfaces.C.int;
238 if Stack_Base_Available then
240 -- Compute the guard page address
242 Guard_Page_Address :=
243 Stack_Base - (Stack_Base mod Get_Page_Size) + Get_Page_Size;
246 Res := mprotect (Guard_Page_Address, Get_Page_Size, PROT_ON);
248 Res := mprotect (Guard_Page_Address, Get_Page_Size, PROT_OFF);
251 pragma Assert (Res = 0);
259 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
261 return T.Common.LL.Thread;
268 function Self return Task_Id renames Specific.Self;
270 ---------------------
271 -- Initialize_Lock --
272 ---------------------
274 -- Note: mutexes and cond_variables needed per-task basis are
275 -- initialized in Intialize_TCB and the Storage_Error is
276 -- handled. Other mutexes (such as RTS_Lock, Memory_Lock...)
277 -- used in RTS is initialized before any status change of RTS.
278 -- Therefore rasing Storage_Error in the following routines
279 -- should be able to be handled safely.
281 procedure Initialize_Lock
282 (Prio : System.Any_Priority;
285 Attributes : aliased pthread_mutexattr_t;
286 Result : Interfaces.C.int;
289 Result := pthread_mutexattr_init (Attributes'Access);
290 pragma Assert (Result = 0 or else Result = ENOMEM);
292 if Result = ENOMEM then
296 if Locking_Policy = 'C' then
297 Result := pthread_mutexattr_setprotocol
298 (Attributes'Access, PTHREAD_PRIO_PROTECT);
299 pragma Assert (Result = 0);
301 Result := pthread_mutexattr_setprioceiling
302 (Attributes'Access, Interfaces.C.int (Prio));
303 pragma Assert (Result = 0);
305 elsif Locking_Policy = 'I' then
306 Result := pthread_mutexattr_setprotocol
307 (Attributes'Access, PTHREAD_PRIO_INHERIT);
308 pragma Assert (Result = 0);
311 Result := pthread_mutex_init (L, Attributes'Access);
312 pragma Assert (Result = 0 or else Result = ENOMEM);
314 if Result = ENOMEM then
315 Result := pthread_mutexattr_destroy (Attributes'Access);
319 Result := pthread_mutexattr_destroy (Attributes'Access);
320 pragma Assert (Result = 0);
323 procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level) is
324 pragma Warnings (Off, Level);
326 Attributes : aliased pthread_mutexattr_t;
327 Result : Interfaces.C.int;
330 Result := pthread_mutexattr_init (Attributes'Access);
331 pragma Assert (Result = 0 or else Result = ENOMEM);
333 if Result = ENOMEM then
337 if Locking_Policy = 'C' then
338 Result := pthread_mutexattr_setprotocol
339 (Attributes'Access, PTHREAD_PRIO_PROTECT);
340 pragma Assert (Result = 0);
342 Result := pthread_mutexattr_setprioceiling
343 (Attributes'Access, Interfaces.C.int (System.Any_Priority'Last));
344 pragma Assert (Result = 0);
346 elsif Locking_Policy = 'I' then
347 Result := pthread_mutexattr_setprotocol
348 (Attributes'Access, PTHREAD_PRIO_INHERIT);
349 pragma Assert (Result = 0);
352 Result := pthread_mutex_init (L, Attributes'Access);
353 pragma Assert (Result = 0 or else Result = ENOMEM);
355 if Result = ENOMEM then
356 Result := pthread_mutexattr_destroy (Attributes'Access);
360 Result := pthread_mutexattr_destroy (Attributes'Access);
361 pragma Assert (Result = 0);
368 procedure Finalize_Lock (L : access Lock) is
369 Result : Interfaces.C.int;
372 Result := pthread_mutex_destroy (L);
373 pragma Assert (Result = 0);
376 procedure Finalize_Lock (L : access RTS_Lock) is
377 Result : Interfaces.C.int;
380 Result := pthread_mutex_destroy (L);
381 pragma Assert (Result = 0);
388 procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
389 Result : Interfaces.C.int;
392 Result := pthread_mutex_lock (L);
394 -- Assume that the cause of EINVAL is a priority ceiling violation
396 Ceiling_Violation := (Result = EINVAL);
397 pragma Assert (Result = 0 or else Result = EINVAL);
401 (L : access RTS_Lock;
402 Global_Lock : Boolean := False)
404 Result : Interfaces.C.int;
407 if not Single_Lock or else Global_Lock then
408 Result := pthread_mutex_lock (L);
409 pragma Assert (Result = 0);
413 procedure Write_Lock (T : Task_Id) is
414 Result : Interfaces.C.int;
417 if not Single_Lock then
418 Result := pthread_mutex_lock (T.Common.LL.L'Access);
419 pragma Assert (Result = 0);
427 procedure Read_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
429 Write_Lock (L, Ceiling_Violation);
436 procedure Unlock (L : access Lock) is
437 Result : Interfaces.C.int;
440 Result := pthread_mutex_unlock (L);
441 pragma Assert (Result = 0);
444 procedure Unlock (L : access RTS_Lock; Global_Lock : Boolean := False) is
445 Result : Interfaces.C.int;
448 if not Single_Lock or else Global_Lock then
449 Result := pthread_mutex_unlock (L);
450 pragma Assert (Result = 0);
454 procedure Unlock (T : Task_Id) is
455 Result : Interfaces.C.int;
458 if not Single_Lock then
459 Result := pthread_mutex_unlock (T.Common.LL.L'Access);
460 pragma Assert (Result = 0);
470 Reason : System.Tasking.Task_States)
472 pragma Warnings (Off, Reason);
474 Result : Interfaces.C.int;
478 Result := pthread_cond_wait
479 (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access);
481 Result := pthread_cond_wait
482 (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access);
485 -- EINTR is not considered a failure.
487 pragma Assert (Result = 0 or else Result = EINTR);
494 -- This is for use within the run-time system, so abort is
495 -- assumed to be already deferred, and the caller should be
496 -- holding its own ATCB lock.
498 procedure Timed_Sleep
501 Mode : ST.Delay_Modes;
502 Reason : Task_States;
503 Timedout : out Boolean;
504 Yielded : out Boolean)
506 pragma Warnings (Off, Reason);
508 Check_Time : constant Duration := Monotonic_Clock;
511 Request : aliased timespec;
512 Result : Interfaces.C.int;
518 if Mode = Relative then
519 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
521 if Relative_Timed_Wait then
522 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
526 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
528 if Relative_Timed_Wait then
529 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
533 if Abs_Time > Check_Time then
534 if Relative_Timed_Wait then
535 Request := To_Timespec (Rel_Time);
537 Request := To_Timespec (Abs_Time);
541 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
542 or else Self_ID.Pending_Priority_Change;
545 Result := pthread_cond_timedwait
546 (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access,
550 Result := pthread_cond_timedwait
551 (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access,
555 exit when Abs_Time <= Monotonic_Clock;
557 if Result = 0 or Result = EINTR then
559 -- Somebody may have called Wakeup for us
565 pragma Assert (Result = ETIMEDOUT);
574 -- This is for use in implementing delay statements, so
575 -- we assume the caller is abort-deferred but is holding
578 procedure Timed_Delay
581 Mode : ST.Delay_Modes)
583 Check_Time : constant Duration := Monotonic_Clock;
586 Request : aliased timespec;
587 Result : Interfaces.C.int;
594 Write_Lock (Self_ID);
596 if Mode = Relative then
597 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
599 if Relative_Timed_Wait then
600 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
604 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
606 if Relative_Timed_Wait then
607 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
611 if Abs_Time > Check_Time then
612 if Relative_Timed_Wait then
613 Request := To_Timespec (Rel_Time);
615 Request := To_Timespec (Abs_Time);
618 Self_ID.Common.State := Delay_Sleep;
621 if Self_ID.Pending_Priority_Change then
622 Self_ID.Pending_Priority_Change := False;
623 Self_ID.Common.Base_Priority := Self_ID.New_Base_Priority;
624 Set_Priority (Self_ID, Self_ID.Common.Base_Priority);
627 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
630 Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access,
631 Single_RTS_Lock'Access, Request'Access);
633 Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access,
634 Self_ID.Common.LL.L'Access, Request'Access);
637 exit when Abs_Time <= Monotonic_Clock;
639 pragma Assert (Result = 0
640 or else Result = ETIMEDOUT
641 or else Result = EINTR);
644 Self_ID.Common.State := Runnable;
653 Result := sched_yield;
656 ---------------------
657 -- Monotonic_Clock --
658 ---------------------
660 function Monotonic_Clock return Duration is
661 TS : aliased timespec;
662 Result : Interfaces.C.int;
664 Result := clock_gettime
665 (clock_id => CLOCK_REALTIME, tp => TS'Unchecked_Access);
666 pragma Assert (Result = 0);
667 return To_Duration (TS);
674 function RT_Resolution return Duration is
683 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
684 pragma Warnings (Off, Reason);
685 Result : Interfaces.C.int;
687 Result := pthread_cond_signal (T.Common.LL.CV'Access);
688 pragma Assert (Result = 0);
695 procedure Yield (Do_Yield : Boolean := True) is
696 Result : Interfaces.C.int;
697 pragma Unreferenced (Result);
700 Result := sched_yield;
708 procedure Set_Priority
710 Prio : System.Any_Priority;
711 Loss_Of_Inheritance : Boolean := False)
713 pragma Warnings (Off, Loss_Of_Inheritance);
715 Result : Interfaces.C.int;
716 Param : aliased struct_sched_param;
719 T.Common.Current_Priority := Prio;
720 Param.sched_priority := Interfaces.C.int (Prio);
722 if Time_Slice_Supported and then Time_Slice_Val > 0 then
723 Result := pthread_setschedparam
724 (T.Common.LL.Thread, SCHED_RR, Param'Access);
726 elsif Dispatching_Policy = 'F' or else Time_Slice_Val = 0 then
727 Result := pthread_setschedparam
728 (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
731 Result := pthread_setschedparam
732 (T.Common.LL.Thread, SCHED_OTHER, Param'Access);
735 pragma Assert (Result = 0);
742 function Get_Priority (T : Task_Id) return System.Any_Priority is
744 return T.Common.Current_Priority;
751 procedure Enter_Task (Self_ID : Task_Id) is
753 Self_ID.Common.LL.Thread := pthread_self;
754 Self_ID.Common.LL.LWP := lwp_self;
756 Specific.Set (Self_ID);
760 for J in Known_Tasks'Range loop
761 if Known_Tasks (J) = null then
762 Known_Tasks (J) := Self_ID;
763 Self_ID.Known_Tasks_Index := J;
775 function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
777 return new Ada_Task_Control_Block (Entry_Num);
784 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
786 -----------------------------
787 -- Register_Foreign_Thread --
788 -----------------------------
790 function Register_Foreign_Thread return Task_Id is
792 if Is_Valid_Task then
795 return Register_Foreign_Thread (pthread_self);
797 end Register_Foreign_Thread;
803 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
804 Mutex_Attr : aliased pthread_mutexattr_t;
805 Result : Interfaces.C.int;
806 Cond_Attr : aliased pthread_condattr_t;
809 -- Give the task a unique serial number.
811 Self_ID.Serial_Number := Next_Serial_Number;
812 Next_Serial_Number := Next_Serial_Number + 1;
813 pragma Assert (Next_Serial_Number /= 0);
815 if not Single_Lock then
816 Result := pthread_mutexattr_init (Mutex_Attr'Access);
817 pragma Assert (Result = 0 or else Result = ENOMEM);
820 if Locking_Policy = 'C' then
821 Result := pthread_mutexattr_setprotocol
822 (Mutex_Attr'Access, PTHREAD_PRIO_PROTECT);
823 pragma Assert (Result = 0);
825 Result := pthread_mutexattr_setprioceiling
827 Interfaces.C.int (System.Any_Priority'Last));
828 pragma Assert (Result = 0);
830 elsif Locking_Policy = 'I' then
831 Result := pthread_mutexattr_setprotocol
832 (Mutex_Attr'Access, PTHREAD_PRIO_INHERIT);
833 pragma Assert (Result = 0);
836 Result := pthread_mutex_init (Self_ID.Common.LL.L'Access,
838 pragma Assert (Result = 0 or else Result = ENOMEM);
846 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
847 pragma Assert (Result = 0);
850 Result := pthread_condattr_init (Cond_Attr'Access);
851 pragma Assert (Result = 0 or else Result = ENOMEM);
854 Result := pthread_cond_init (Self_ID.Common.LL.CV'Access,
856 pragma Assert (Result = 0 or else Result = ENOMEM);
862 if not Single_Lock then
863 Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
864 pragma Assert (Result = 0);
870 Result := pthread_condattr_destroy (Cond_Attr'Access);
871 pragma Assert (Result = 0);
878 procedure Create_Task
880 Wrapper : System.Address;
881 Stack_Size : System.Parameters.Size_Type;
882 Priority : System.Any_Priority;
883 Succeeded : out Boolean)
885 Attributes : aliased pthread_attr_t;
886 Adjusted_Stack_Size : Interfaces.C.size_t;
887 Result : Interfaces.C.int;
889 function Thread_Body_Access is new
890 Unchecked_Conversion (System.Address, Thread_Body);
892 use System.Task_Info;
895 if Stack_Size = Unspecified_Size then
896 Adjusted_Stack_Size := Interfaces.C.size_t (Default_Stack_Size);
898 elsif Stack_Size < Minimum_Stack_Size then
899 Adjusted_Stack_Size := Interfaces.C.size_t (Minimum_Stack_Size);
902 Adjusted_Stack_Size := Interfaces.C.size_t (Stack_Size);
905 if Stack_Base_Available then
906 -- If Stack Checking is supported then allocate 2 additional pages:
908 -- In the worst case, stack is allocated at something like
909 -- N * Get_Page_Size - epsilon, we need to add the size for 2 pages
910 -- to be sure the effective stack size is greater than what
913 Adjusted_Stack_Size := Adjusted_Stack_Size + 2 * Get_Page_Size;
916 Result := pthread_attr_init (Attributes'Access);
917 pragma Assert (Result = 0 or else Result = ENOMEM);
924 Result := pthread_attr_setdetachstate
925 (Attributes'Access, PTHREAD_CREATE_DETACHED);
926 pragma Assert (Result = 0);
928 Result := pthread_attr_setstacksize
929 (Attributes'Access, Adjusted_Stack_Size);
930 pragma Assert (Result = 0);
932 if T.Common.Task_Info /= Default_Scope then
934 -- We are assuming that Scope_Type has the same values than the
935 -- corresponding C macros
937 Result := pthread_attr_setscope
938 (Attributes'Access, Task_Info_Type'Pos (T.Common.Task_Info));
939 pragma Assert (Result = 0);
942 -- Since the initial signal mask of a thread is inherited from the
943 -- creator, and the Environment task has all its signals masked, we
944 -- do not need to manipulate caller's signal mask at this point.
945 -- All tasks in RTS will have All_Tasks_Mask initially.
947 Result := pthread_create
948 (T.Common.LL.Thread'Access,
950 Thread_Body_Access (Wrapper),
952 pragma Assert (Result = 0 or else Result = EAGAIN);
954 Succeeded := Result = 0;
956 Result := pthread_attr_destroy (Attributes'Access);
957 pragma Assert (Result = 0);
959 Set_Priority (T, Priority);
966 procedure Finalize_TCB (T : Task_Id) is
967 Result : Interfaces.C.int;
969 Is_Self : constant Boolean := T = Self;
971 procedure Free is new
972 Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
975 if not Single_Lock then
976 Result := pthread_mutex_destroy (T.Common.LL.L'Access);
977 pragma Assert (Result = 0);
980 Result := pthread_cond_destroy (T.Common.LL.CV'Access);
981 pragma Assert (Result = 0);
983 if T.Known_Tasks_Index /= -1 then
984 Known_Tasks (T.Known_Tasks_Index) := null;
998 procedure Exit_Task is
1000 -- Mark this task as unknown, so that if Self is called, it won't
1001 -- return a dangling pointer.
1003 Specific.Set (null);
1010 procedure Abort_Task (T : Task_Id) is
1011 Result : Interfaces.C.int;
1013 Result := pthread_kill (T.Common.LL.Thread,
1014 Signal (System.Interrupt_Management.Abort_Task_Interrupt));
1015 pragma Assert (Result = 0);
1022 procedure Initialize (S : in out Suspension_Object) is
1023 Mutex_Attr : aliased pthread_mutexattr_t;
1024 Cond_Attr : aliased pthread_condattr_t;
1025 Result : Interfaces.C.int;
1027 -- Initialize internal state. It is always initialized to False (ARM
1033 -- Initialize internal mutex
1035 Result := pthread_mutexattr_init (Mutex_Attr'Access);
1036 pragma Assert (Result = 0 or else Result = ENOMEM);
1038 if Result = ENOMEM then
1039 raise Storage_Error;
1042 Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
1043 pragma Assert (Result = 0 or else Result = ENOMEM);
1045 if Result = ENOMEM then
1046 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1047 pragma Assert (Result = 0);
1049 raise Storage_Error;
1052 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1053 pragma Assert (Result = 0);
1055 -- Initialize internal condition variable
1057 Result := pthread_condattr_init (Cond_Attr'Access);
1058 pragma Assert (Result = 0 or else Result = ENOMEM);
1061 Result := pthread_mutex_destroy (S.L'Access);
1062 pragma Assert (Result = 0);
1064 if Result = ENOMEM then
1065 raise Storage_Error;
1069 Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
1070 pragma Assert (Result = 0 or else Result = ENOMEM);
1073 Result := pthread_mutex_destroy (S.L'Access);
1074 pragma Assert (Result = 0);
1076 if Result = ENOMEM then
1077 Result := pthread_condattr_destroy (Cond_Attr'Access);
1078 pragma Assert (Result = 0);
1080 raise Storage_Error;
1084 Result := pthread_condattr_destroy (Cond_Attr'Access);
1085 pragma Assert (Result = 0);
1092 procedure Finalize (S : in out Suspension_Object) is
1093 Result : Interfaces.C.int;
1095 -- Destroy internal mutex
1097 Result := pthread_mutex_destroy (S.L'Access);
1098 pragma Assert (Result = 0);
1100 -- Destroy internal condition variable
1102 Result := pthread_cond_destroy (S.CV'Access);
1103 pragma Assert (Result = 0);
1110 function Current_State (S : Suspension_Object) return Boolean is
1112 -- We do not want to use lock on this read operation. State is marked
1113 -- as Atomic so that we ensure that the value retrieved is correct.
1122 procedure Set_False (S : in out Suspension_Object) is
1123 Result : Interfaces.C.int;
1125 Result := pthread_mutex_lock (S.L'Access);
1126 pragma Assert (Result = 0);
1130 Result := pthread_mutex_unlock (S.L'Access);
1131 pragma Assert (Result = 0);
1138 procedure Set_True (S : in out Suspension_Object) is
1139 Result : Interfaces.C.int;
1141 Result := pthread_mutex_lock (S.L'Access);
1142 pragma Assert (Result = 0);
1144 -- If there is already a task waiting on this suspension object then
1145 -- we resume it, leaving the state of the suspension object to False,
1146 -- as it is specified in ARM D.10 par. 9. Otherwise, it just leaves
1147 -- the state to True.
1153 Result := pthread_cond_signal (S.CV'Access);
1154 pragma Assert (Result = 0);
1159 Result := pthread_mutex_unlock (S.L'Access);
1160 pragma Assert (Result = 0);
1163 ------------------------
1164 -- Suspend_Until_True --
1165 ------------------------
1167 procedure Suspend_Until_True (S : in out Suspension_Object) is
1168 Result : Interfaces.C.int;
1170 Result := pthread_mutex_lock (S.L'Access);
1171 pragma Assert (Result = 0);
1174 -- Program_Error must be raised upon calling Suspend_Until_True
1175 -- if another task is already waiting on that suspension object
1176 -- (ARM D.10 par. 10).
1178 Result := pthread_mutex_unlock (S.L'Access);
1179 pragma Assert (Result = 0);
1181 raise Program_Error;
1183 -- Suspend the task if the state is False. Otherwise, the task
1184 -- continues its execution, and the state of the suspension object
1185 -- is set to False (ARM D.10 par. 9).
1191 Result := pthread_cond_wait (S.CV'Access, S.L'Access);
1195 Result := pthread_mutex_unlock (S.L'Access);
1196 pragma Assert (Result = 0);
1197 end Suspend_Until_True;
1205 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1206 pragma Warnings (Off, Self_ID);
1211 --------------------
1212 -- Check_No_Locks --
1213 --------------------
1215 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1216 pragma Warnings (Off, Self_ID);
1221 ----------------------
1222 -- Environment_Task --
1223 ----------------------
1225 function Environment_Task return Task_Id is
1227 return Environment_Task_Id;
1228 end Environment_Task;
1234 procedure Lock_RTS is
1236 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
1243 procedure Unlock_RTS is
1245 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
1252 function Suspend_Task
1254 Thread_Self : Thread_Id) return Boolean
1256 pragma Warnings (Off, T);
1257 pragma Warnings (Off, Thread_Self);
1266 function Resume_Task
1268 Thread_Self : Thread_Id) return Boolean
1270 pragma Warnings (Off, T);
1271 pragma Warnings (Off, Thread_Self);
1280 procedure Initialize (Environment_Task : Task_Id) is
1281 act : aliased struct_sigaction;
1282 old_act : aliased struct_sigaction;
1283 Tmp_Set : aliased sigset_t;
1284 Result : Interfaces.C.int;
1287 (Int : System.Interrupt_Management.Interrupt_ID) return Character;
1288 pragma Import (C, State, "__gnat_get_interrupt_state");
1289 -- Get interrupt state. Defined in a-init.c
1290 -- The input argument is the interrupt number,
1291 -- and the result is one of the following:
1293 Default : constant Character := 's';
1294 -- 'n' this interrupt not set by any Interrupt_State pragma
1295 -- 'u' Interrupt_State pragma set state to User
1296 -- 'r' Interrupt_State pragma set state to Runtime
1297 -- 's' Interrupt_State pragma set state to System (use "default"
1301 Environment_Task_Id := Environment_Task;
1303 Interrupt_Management.Initialize;
1305 -- Prepare the set of signals that should unblocked in all tasks
1307 Result := sigemptyset (Unblocked_Signal_Mask'Access);
1308 pragma Assert (Result = 0);
1310 for J in Interrupt_Management.Interrupt_ID loop
1311 if System.Interrupt_Management.Keep_Unmasked (J) then
1312 Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
1313 pragma Assert (Result = 0);
1317 -- Initialize the lock used to synchronize chain of all ATCBs.
1319 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1321 Specific.Initialize (Environment_Task);
1323 Enter_Task (Environment_Task);
1325 -- Install the abort-signal handler
1327 if State (System.Interrupt_Management.Abort_Task_Interrupt)
1331 act.sa_handler := Abort_Handler'Address;
1333 Result := sigemptyset (Tmp_Set'Access);
1334 pragma Assert (Result = 0);
1335 act.sa_mask := Tmp_Set;
1339 (Signal (System.Interrupt_Management.Abort_Task_Interrupt),
1340 act'Unchecked_Access,
1341 old_act'Unchecked_Access);
1342 pragma Assert (Result = 0);
1346 end System.Task_Primitives.Operations;