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;
78 -- The followings are logically constants, but need to be initialized
81 Single_RTS_Lock : aliased RTS_Lock;
82 -- This is a lock to allow only one thread of control in the RTS at
83 -- a time; it is used to execute in mutual exclusion from all other tasks.
84 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
86 ATCB_Key : aliased pthread_key_t;
87 -- Key used to find the Ada Task_Id associated with a thread
89 Environment_Task_Id : Task_Id;
90 -- A variable to hold Task_Id for the environment task
92 Locking_Policy : Character;
93 pragma Import (C, Locking_Policy, "__gl_locking_policy");
94 -- Value of the pragma Locking_Policy:
95 -- 'C' for Ceiling_Locking
96 -- 'I' for Inherit_Locking
99 Unblocked_Signal_Mask : aliased sigset_t;
100 -- The set of signals that should unblocked in all tasks
102 -- The followings are internal configuration constants needed
104 Next_Serial_Number : Task_Serial_Number := 100;
105 -- We start at 100, to reserve some special values for
106 -- using in error checking.
108 Time_Slice_Val : Integer;
109 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
111 Dispatching_Policy : Character;
112 pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
114 Foreign_Task_Elaborated : aliased Boolean := True;
115 -- Used to identified fake tasks (i.e., non-Ada Threads)
117 Use_Alternate_Stack : constant Boolean := Alternate_Stack_Size /= 0;
118 -- Whether to use an alternate signal stack for stack overflows
120 Abort_Handler_Installed : Boolean := False;
121 -- True if a handler for the abort signal is installed
129 procedure Initialize (Environment_Task : Task_Id);
130 pragma Inline (Initialize);
131 -- Initialize various data needed by this package
133 function Is_Valid_Task return Boolean;
134 pragma Inline (Is_Valid_Task);
135 -- Does executing thread have a TCB?
137 procedure Set (Self_Id : Task_Id);
139 -- Set the self id for the current task
141 function Self return Task_Id;
142 pragma Inline (Self);
143 -- Return a pointer to the Ada Task Control Block of the calling task
147 package body Specific is separate;
148 -- The body of this package is target specific
150 ---------------------------------
151 -- Support for foreign threads --
152 ---------------------------------
154 function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
155 -- Allocate and Initialize a new ATCB for the current Thread
157 function Register_Foreign_Thread
158 (Thread : Thread_Id) return Task_Id is separate;
160 -----------------------
161 -- Local Subprograms --
162 -----------------------
164 procedure Abort_Handler (Sig : Signal);
165 -- Signal handler used to implement asynchronous abort.
166 -- See also comment before body, below.
168 function To_Address is
169 new Ada.Unchecked_Conversion (Task_Id, System.Address);
175 -- Target-dependent binding of inter-thread Abort signal to the raising of
176 -- the Abort_Signal exception.
178 -- The technical issues and alternatives here are essentially the
179 -- same as for raising exceptions in response to other signals
180 -- (e.g. Storage_Error). See code and comments in the package body
181 -- System.Interrupt_Management.
183 -- Some implementations may not allow an exception to be propagated out of
184 -- a handler, and others might leave the signal or interrupt that invoked
185 -- this handler masked after the exceptional return to the application
188 -- GNAT exceptions are originally implemented using setjmp()/longjmp(). On
189 -- most UNIX systems, this will allow transfer out of a signal handler,
190 -- which is usually the only mechanism available for implementing
191 -- asynchronous handlers of this kind. However, some systems do not
192 -- restore the signal mask on longjmp(), leaving the abort signal masked.
194 procedure Abort_Handler (Sig : Signal) is
195 pragma Unreferenced (Sig);
197 T : constant Task_Id := Self;
198 Old_Set : aliased sigset_t;
200 Result : Interfaces.C.int;
201 pragma Warnings (Off, Result);
204 -- It's not safe to raise an exception when using GCC ZCX mechanism.
205 -- Note that we still need to install a signal handler, since in some
206 -- cases (e.g. shutdown of the Server_Task in System.Interrupts) we
207 -- need to send the Abort signal to a task.
209 if ZCX_By_Default and then GCC_ZCX_Support then
213 if T.Deferral_Level = 0
214 and then T.Pending_ATC_Level < T.ATC_Nesting_Level and then
219 -- Make sure signals used for RTS internal purpose are unmasked
221 Result := pthread_sigmask (SIG_UNBLOCK,
222 Unblocked_Signal_Mask'Access, Old_Set'Access);
223 pragma Assert (Result = 0);
225 raise Standard'Abort_Signal;
233 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
234 Stack_Base : constant Address := Get_Stack_Base (T.Common.LL.Thread);
235 Guard_Page_Address : Address;
237 Res : Interfaces.C.int;
240 if Stack_Base_Available then
242 -- Compute the guard page address
244 Guard_Page_Address :=
245 Stack_Base - (Stack_Base mod Get_Page_Size) + Get_Page_Size;
248 mprotect (Guard_Page_Address, Get_Page_Size,
249 prot => (if On then PROT_ON else PROT_OFF));
250 pragma Assert (Res = 0);
258 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
260 return T.Common.LL.Thread;
267 function Self return Task_Id renames Specific.Self;
269 ---------------------
270 -- Initialize_Lock --
271 ---------------------
273 -- Note: mutexes and cond_variables needed per-task basis are
274 -- initialized in Initialize_TCB and the Storage_Error is
275 -- handled. Other mutexes (such as RTS_Lock, Memory_Lock...)
276 -- used in RTS is initialized before any status change of RTS.
277 -- Therefore raising Storage_Error in the following routines
278 -- should be able to be handled safely.
280 procedure Initialize_Lock
281 (Prio : System.Any_Priority;
282 L : not null access Lock)
284 Attributes : aliased pthread_mutexattr_t;
285 Result : Interfaces.C.int;
288 Result := pthread_mutexattr_init (Attributes'Access);
289 pragma Assert (Result = 0 or else Result = ENOMEM);
291 if Result = ENOMEM then
295 if Locking_Policy = 'C' then
296 Result := pthread_mutexattr_setprotocol
297 (Attributes'Access, PTHREAD_PRIO_PROTECT);
298 pragma Assert (Result = 0);
300 Result := pthread_mutexattr_setprioceiling
301 (Attributes'Access, Interfaces.C.int (Prio));
302 pragma Assert (Result = 0);
304 elsif Locking_Policy = 'I' then
305 Result := pthread_mutexattr_setprotocol
306 (Attributes'Access, PTHREAD_PRIO_INHERIT);
307 pragma Assert (Result = 0);
310 Result := pthread_mutex_init (L, Attributes'Access);
311 pragma Assert (Result = 0 or else Result = ENOMEM);
313 if Result = ENOMEM then
314 Result := pthread_mutexattr_destroy (Attributes'Access);
318 Result := pthread_mutexattr_destroy (Attributes'Access);
319 pragma Assert (Result = 0);
322 procedure Initialize_Lock
323 (L : not null access RTS_Lock; Level : Lock_Level)
325 pragma Unreferenced (Level);
327 Attributes : aliased pthread_mutexattr_t;
328 Result : Interfaces.C.int;
331 Result := pthread_mutexattr_init (Attributes'Access);
332 pragma Assert (Result = 0 or else Result = ENOMEM);
334 if Result = ENOMEM then
338 if Locking_Policy = 'C' then
339 Result := pthread_mutexattr_setprotocol
340 (Attributes'Access, PTHREAD_PRIO_PROTECT);
341 pragma Assert (Result = 0);
343 Result := pthread_mutexattr_setprioceiling
344 (Attributes'Access, Interfaces.C.int (System.Any_Priority'Last));
345 pragma Assert (Result = 0);
347 elsif Locking_Policy = 'I' then
348 Result := pthread_mutexattr_setprotocol
349 (Attributes'Access, PTHREAD_PRIO_INHERIT);
350 pragma Assert (Result = 0);
353 Result := pthread_mutex_init (L, Attributes'Access);
354 pragma Assert (Result = 0 or else Result = ENOMEM);
356 if Result = ENOMEM then
357 Result := pthread_mutexattr_destroy (Attributes'Access);
361 Result := pthread_mutexattr_destroy (Attributes'Access);
362 pragma Assert (Result = 0);
369 procedure Finalize_Lock (L : not null access Lock) is
370 Result : Interfaces.C.int;
372 Result := pthread_mutex_destroy (L);
373 pragma Assert (Result = 0);
376 procedure Finalize_Lock (L : not null access RTS_Lock) is
377 Result : Interfaces.C.int;
379 Result := pthread_mutex_destroy (L);
380 pragma Assert (Result = 0);
388 (L : not null access Lock; Ceiling_Violation : out Boolean)
390 Result : Interfaces.C.int;
393 Result := pthread_mutex_lock (L);
395 -- Assume that the cause of EINVAL is a priority ceiling violation
397 Ceiling_Violation := (Result = EINVAL);
398 pragma Assert (Result = 0 or else Result = EINVAL);
402 (L : not null access RTS_Lock;
403 Global_Lock : Boolean := False)
405 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;
416 if not Single_Lock then
417 Result := pthread_mutex_lock (T.Common.LL.L'Access);
418 pragma Assert (Result = 0);
427 (L : not null access Lock; Ceiling_Violation : out Boolean) is
429 Write_Lock (L, Ceiling_Violation);
436 procedure Unlock (L : not null access Lock) is
437 Result : Interfaces.C.int;
439 Result := pthread_mutex_unlock (L);
440 pragma Assert (Result = 0);
444 (L : not null access RTS_Lock; Global_Lock : Boolean := False)
446 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;
457 if not Single_Lock then
458 Result := pthread_mutex_unlock (T.Common.LL.L'Access);
459 pragma Assert (Result = 0);
467 -- Dynamic priority ceilings are not supported by the underlying system
469 procedure Set_Ceiling
470 (L : not null access Lock;
471 Prio : System.Any_Priority)
473 pragma Unreferenced (L, Prio);
484 Reason : System.Tasking.Task_States)
486 pragma Unreferenced (Reason);
488 Result : Interfaces.C.int;
493 (cond => Self_ID.Common.LL.CV'Access,
494 mutex => (if Single_Lock
495 then Single_RTS_Lock'Access
496 else Self_ID.Common.LL.L'Access));
498 -- EINTR is not considered a failure
500 pragma Assert (Result = 0 or else Result = EINTR);
507 -- This is for use within the run-time system, so abort is
508 -- assumed to be already deferred, and the caller should be
509 -- holding its own ATCB lock.
511 procedure Timed_Sleep
514 Mode : ST.Delay_Modes;
515 Reason : Task_States;
516 Timedout : out Boolean;
517 Yielded : out Boolean)
519 pragma Unreferenced (Reason);
521 Base_Time : constant Duration := Monotonic_Clock;
522 Check_Time : Duration := Base_Time;
525 Request : aliased timespec;
526 Result : Interfaces.C.int;
532 if Mode = Relative then
533 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
535 if Relative_Timed_Wait then
536 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
540 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
542 if Relative_Timed_Wait then
543 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
547 if Abs_Time > Check_Time then
549 To_Timespec (if Relative_Timed_Wait then Rel_Time else Abs_Time);
552 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
555 pthread_cond_timedwait
556 (cond => Self_ID.Common.LL.CV'Access,
557 mutex => (if Single_Lock
558 then Single_RTS_Lock'Access
559 else Self_ID.Common.LL.L'Access),
560 abstime => Request'Access);
562 Check_Time := Monotonic_Clock;
563 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
565 if Result = 0 or Result = EINTR then
567 -- Somebody may have called Wakeup for us
573 pragma Assert (Result = ETIMEDOUT);
582 -- This is for use in implementing delay statements, so we assume the
583 -- caller is abort-deferred but is holding no locks.
585 procedure Timed_Delay
588 Mode : ST.Delay_Modes)
590 Base_Time : constant Duration := Monotonic_Clock;
591 Check_Time : Duration := Base_Time;
594 Request : aliased timespec;
596 Result : Interfaces.C.int;
597 pragma Warnings (Off, Result);
604 Write_Lock (Self_ID);
606 if Mode = Relative then
607 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
609 if Relative_Timed_Wait then
610 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
614 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
616 if Relative_Timed_Wait then
617 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
621 if Abs_Time > Check_Time then
623 To_Timespec (if Relative_Timed_Wait then Rel_Time else Abs_Time);
624 Self_ID.Common.State := Delay_Sleep;
627 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
630 pthread_cond_timedwait
631 (cond => Self_ID.Common.LL.CV'Access,
632 mutex => (if Single_Lock
633 then Single_RTS_Lock'Access
634 else Self_ID.Common.LL.L'Access),
635 abstime => Request'Access);
637 Check_Time := Monotonic_Clock;
638 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
640 pragma Assert (Result = 0
641 or else Result = ETIMEDOUT
642 or else Result = EINTR);
645 Self_ID.Common.State := Runnable;
654 Result := sched_yield;
657 ---------------------
658 -- Monotonic_Clock --
659 ---------------------
661 function Monotonic_Clock return Duration is
662 TS : aliased timespec;
663 Result : Interfaces.C.int;
665 Result := clock_gettime
666 (clock_id => CLOCK_REALTIME, tp => TS'Unchecked_Access);
667 pragma Assert (Result = 0);
668 return To_Duration (TS);
675 function RT_Resolution return Duration is
684 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
685 pragma Unreferenced (Reason);
686 Result : Interfaces.C.int;
688 Result := pthread_cond_signal (T.Common.LL.CV'Access);
689 pragma Assert (Result = 0);
696 procedure Yield (Do_Yield : Boolean := True) is
697 Result : Interfaces.C.int;
698 pragma Unreferenced (Result);
701 Result := sched_yield;
709 procedure Set_Priority
711 Prio : System.Any_Priority;
712 Loss_Of_Inheritance : Boolean := False)
714 pragma Unreferenced (Loss_Of_Inheritance);
716 Result : Interfaces.C.int;
717 Param : aliased struct_sched_param;
719 function Get_Policy (Prio : System.Any_Priority) return Character;
720 pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
721 -- Get priority specific dispatching policy
723 Priority_Specific_Policy : constant Character := Get_Policy (Prio);
724 -- Upper case first character of the policy name corresponding to the
725 -- task as set by a Priority_Specific_Dispatching pragma.
728 T.Common.Current_Priority := Prio;
729 Param.sched_priority := To_Target_Priority (Prio);
731 if Time_Slice_Supported
732 and then (Dispatching_Policy = 'R'
733 or else Priority_Specific_Policy = 'R'
734 or else Time_Slice_Val > 0)
736 Result := pthread_setschedparam
737 (T.Common.LL.Thread, SCHED_RR, Param'Access);
739 elsif Dispatching_Policy = 'F'
740 or else Priority_Specific_Policy = 'F'
741 or else Time_Slice_Val = 0
743 Result := pthread_setschedparam
744 (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
747 Result := pthread_setschedparam
748 (T.Common.LL.Thread, SCHED_OTHER, Param'Access);
751 pragma Assert (Result = 0);
758 function Get_Priority (T : Task_Id) return System.Any_Priority is
760 return T.Common.Current_Priority;
767 procedure Enter_Task (Self_ID : Task_Id) is
769 Self_ID.Common.LL.Thread := pthread_self;
770 Self_ID.Common.LL.LWP := lwp_self;
772 Specific.Set (Self_ID);
774 if Use_Alternate_Stack then
776 Stack : aliased stack_t;
777 Result : Interfaces.C.int;
779 Stack.ss_sp := Self_ID.Common.Task_Alternate_Stack;
780 Stack.ss_size := Alternate_Stack_Size;
782 Result := sigaltstack (Stack'Access, null);
783 pragma Assert (Result = 0);
792 function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
794 return new Ada_Task_Control_Block (Entry_Num);
801 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
803 -----------------------------
804 -- Register_Foreign_Thread --
805 -----------------------------
807 function Register_Foreign_Thread return Task_Id is
809 if Is_Valid_Task then
812 return Register_Foreign_Thread (pthread_self);
814 end Register_Foreign_Thread;
820 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
821 Mutex_Attr : aliased pthread_mutexattr_t;
822 Result : Interfaces.C.int;
823 Cond_Attr : aliased pthread_condattr_t;
826 -- Give the task a unique serial number
828 Self_ID.Serial_Number := Next_Serial_Number;
829 Next_Serial_Number := Next_Serial_Number + 1;
830 pragma Assert (Next_Serial_Number /= 0);
832 if not Single_Lock then
833 Result := pthread_mutexattr_init (Mutex_Attr'Access);
834 pragma Assert (Result = 0 or else Result = ENOMEM);
837 if Locking_Policy = 'C' then
839 pthread_mutexattr_setprotocol
841 PTHREAD_PRIO_PROTECT);
842 pragma Assert (Result = 0);
845 pthread_mutexattr_setprioceiling
847 Interfaces.C.int (System.Any_Priority'Last));
848 pragma Assert (Result = 0);
850 elsif Locking_Policy = 'I' then
852 pthread_mutexattr_setprotocol
854 PTHREAD_PRIO_INHERIT);
855 pragma Assert (Result = 0);
860 (Self_ID.Common.LL.L'Access,
862 pragma Assert (Result = 0 or else Result = ENOMEM);
870 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
871 pragma Assert (Result = 0);
874 Result := pthread_condattr_init (Cond_Attr'Access);
875 pragma Assert (Result = 0 or else Result = ENOMEM);
880 (Self_ID.Common.LL.CV'Access, Cond_Attr'Access);
881 pragma Assert (Result = 0 or else Result = ENOMEM);
887 if not Single_Lock then
888 Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
889 pragma Assert (Result = 0);
895 Result := pthread_condattr_destroy (Cond_Attr'Access);
896 pragma Assert (Result = 0);
903 procedure Create_Task
905 Wrapper : System.Address;
906 Stack_Size : System.Parameters.Size_Type;
907 Priority : System.Any_Priority;
908 Succeeded : out Boolean)
910 Attributes : aliased pthread_attr_t;
911 Adjusted_Stack_Size : Interfaces.C.size_t;
912 Page_Size : constant Interfaces.C.size_t := Get_Page_Size;
913 Result : Interfaces.C.int;
915 function Thread_Body_Access is new
916 Ada.Unchecked_Conversion (System.Address, Thread_Body);
918 use System.Task_Info;
921 Adjusted_Stack_Size :=
922 Interfaces.C.size_t (Stack_Size + Alternate_Stack_Size);
924 if Stack_Base_Available then
926 -- If Stack Checking is supported then allocate 2 additional pages:
928 -- In the worst case, stack is allocated at something like
929 -- N * Get_Page_Size - epsilon, we need to add the size for 2 pages
930 -- to be sure the effective stack size is greater than what
933 Adjusted_Stack_Size := Adjusted_Stack_Size + 2 * Page_Size;
936 -- Round stack size as this is required by some OSes (Darwin)
938 Adjusted_Stack_Size := Adjusted_Stack_Size + Page_Size - 1;
939 Adjusted_Stack_Size :=
940 Adjusted_Stack_Size - Adjusted_Stack_Size mod Page_Size;
942 Result := pthread_attr_init (Attributes'Access);
943 pragma Assert (Result = 0 or else Result = ENOMEM);
951 pthread_attr_setdetachstate
952 (Attributes'Access, PTHREAD_CREATE_DETACHED);
953 pragma Assert (Result = 0);
956 pthread_attr_setstacksize
957 (Attributes'Access, Adjusted_Stack_Size);
958 pragma Assert (Result = 0);
960 if T.Common.Task_Info /= Default_Scope then
961 case T.Common.Task_Info is
962 when System.Task_Info.Process_Scope =>
964 pthread_attr_setscope
965 (Attributes'Access, PTHREAD_SCOPE_PROCESS);
967 when System.Task_Info.System_Scope =>
969 pthread_attr_setscope
970 (Attributes'Access, PTHREAD_SCOPE_SYSTEM);
972 when System.Task_Info.Default_Scope =>
976 pragma Assert (Result = 0);
979 -- Since the initial signal mask of a thread is inherited from the
980 -- creator, and the Environment task has all its signals masked, we
981 -- do not need to manipulate caller's signal mask at this point.
982 -- All tasks in RTS will have All_Tasks_Mask initially.
984 Result := pthread_create
985 (T.Common.LL.Thread'Access,
987 Thread_Body_Access (Wrapper),
989 pragma Assert (Result = 0 or else Result = EAGAIN);
991 Succeeded := Result = 0;
993 Result := pthread_attr_destroy (Attributes'Access);
994 pragma Assert (Result = 0);
997 Set_Priority (T, Priority);
1005 procedure Finalize_TCB (T : Task_Id) is
1006 Result : Interfaces.C.int;
1008 Is_Self : constant Boolean := T = Self;
1010 procedure Free is new
1011 Ada.Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
1014 if not Single_Lock then
1015 Result := pthread_mutex_destroy (T.Common.LL.L'Access);
1016 pragma Assert (Result = 0);
1019 Result := pthread_cond_destroy (T.Common.LL.CV'Access);
1020 pragma Assert (Result = 0);
1022 if T.Known_Tasks_Index /= -1 then
1023 Known_Tasks (T.Known_Tasks_Index) := null;
1029 Specific.Set (null);
1037 procedure Exit_Task is
1039 -- Mark this task as unknown, so that if Self is called, it won't
1040 -- return a dangling pointer.
1042 Specific.Set (null);
1049 procedure Abort_Task (T : Task_Id) is
1050 Result : Interfaces.C.int;
1052 if Abort_Handler_Installed then
1055 (T.Common.LL.Thread,
1056 Signal (System.Interrupt_Management.Abort_Task_Interrupt));
1057 pragma Assert (Result = 0);
1065 procedure Initialize (S : in out Suspension_Object) is
1066 Mutex_Attr : aliased pthread_mutexattr_t;
1067 Cond_Attr : aliased pthread_condattr_t;
1068 Result : Interfaces.C.int;
1071 -- Initialize internal state (always to False (RM D.10 (6)))
1076 -- Initialize internal mutex
1078 Result := pthread_mutexattr_init (Mutex_Attr'Access);
1079 pragma Assert (Result = 0 or else Result = ENOMEM);
1081 if Result = ENOMEM then
1082 raise Storage_Error;
1085 Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
1086 pragma Assert (Result = 0 or else Result = ENOMEM);
1088 if Result = ENOMEM then
1089 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1090 pragma Assert (Result = 0);
1092 raise Storage_Error;
1095 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1096 pragma Assert (Result = 0);
1098 -- Initialize internal condition variable
1100 Result := pthread_condattr_init (Cond_Attr'Access);
1101 pragma Assert (Result = 0 or else Result = ENOMEM);
1104 Result := pthread_mutex_destroy (S.L'Access);
1105 pragma Assert (Result = 0);
1107 if Result = ENOMEM then
1108 raise Storage_Error;
1112 Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
1113 pragma Assert (Result = 0 or else Result = ENOMEM);
1116 Result := pthread_mutex_destroy (S.L'Access);
1117 pragma Assert (Result = 0);
1119 if Result = ENOMEM then
1120 Result := pthread_condattr_destroy (Cond_Attr'Access);
1121 pragma Assert (Result = 0);
1122 raise Storage_Error;
1126 Result := pthread_condattr_destroy (Cond_Attr'Access);
1127 pragma Assert (Result = 0);
1134 procedure Finalize (S : in out Suspension_Object) is
1135 Result : Interfaces.C.int;
1138 -- Destroy internal mutex
1140 Result := pthread_mutex_destroy (S.L'Access);
1141 pragma Assert (Result = 0);
1143 -- Destroy internal condition variable
1145 Result := pthread_cond_destroy (S.CV'Access);
1146 pragma Assert (Result = 0);
1153 function Current_State (S : Suspension_Object) return Boolean is
1155 -- We do not want to use lock on this read operation. State is marked
1156 -- as Atomic so that we ensure that the value retrieved is correct.
1165 procedure Set_False (S : in out Suspension_Object) is
1166 Result : Interfaces.C.int;
1169 SSL.Abort_Defer.all;
1171 Result := pthread_mutex_lock (S.L'Access);
1172 pragma Assert (Result = 0);
1176 Result := pthread_mutex_unlock (S.L'Access);
1177 pragma Assert (Result = 0);
1179 SSL.Abort_Undefer.all;
1186 procedure Set_True (S : in out Suspension_Object) is
1187 Result : Interfaces.C.int;
1190 SSL.Abort_Defer.all;
1192 Result := pthread_mutex_lock (S.L'Access);
1193 pragma Assert (Result = 0);
1195 -- If there is already a task waiting on this suspension object then
1196 -- we resume it, leaving the state of the suspension object to False,
1197 -- as it is specified in (RM D.10(9)). Otherwise, it just leaves
1198 -- the state to True.
1204 Result := pthread_cond_signal (S.CV'Access);
1205 pragma Assert (Result = 0);
1211 Result := pthread_mutex_unlock (S.L'Access);
1212 pragma Assert (Result = 0);
1214 SSL.Abort_Undefer.all;
1217 ------------------------
1218 -- Suspend_Until_True --
1219 ------------------------
1221 procedure Suspend_Until_True (S : in out Suspension_Object) is
1222 Result : Interfaces.C.int;
1225 SSL.Abort_Defer.all;
1227 Result := pthread_mutex_lock (S.L'Access);
1228 pragma Assert (Result = 0);
1232 -- Program_Error must be raised upon calling Suspend_Until_True
1233 -- if another task is already waiting on that suspension object
1236 Result := pthread_mutex_unlock (S.L'Access);
1237 pragma Assert (Result = 0);
1239 SSL.Abort_Undefer.all;
1241 raise Program_Error;
1244 -- Suspend the task if the state is False. Otherwise, the task
1245 -- continues its execution, and the state of the suspension object
1246 -- is set to False (ARM D.10 par. 9).
1254 -- Loop in case pthread_cond_wait returns earlier than expected
1255 -- (e.g. in case of EINTR caused by a signal).
1257 Result := pthread_cond_wait (S.CV'Access, S.L'Access);
1258 pragma Assert (Result = 0 or else Result = EINTR);
1260 exit when not S.Waiting;
1264 Result := pthread_mutex_unlock (S.L'Access);
1265 pragma Assert (Result = 0);
1267 SSL.Abort_Undefer.all;
1269 end Suspend_Until_True;
1277 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1278 pragma Unreferenced (Self_ID);
1283 --------------------
1284 -- Check_No_Locks --
1285 --------------------
1287 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1288 pragma Unreferenced (Self_ID);
1293 ----------------------
1294 -- Environment_Task --
1295 ----------------------
1297 function Environment_Task return Task_Id is
1299 return Environment_Task_Id;
1300 end Environment_Task;
1306 procedure Lock_RTS is
1308 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
1315 procedure Unlock_RTS is
1317 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
1324 function Suspend_Task
1326 Thread_Self : Thread_Id) return Boolean
1328 pragma Unreferenced (T, Thread_Self);
1337 function Resume_Task
1339 Thread_Self : Thread_Id) return Boolean
1341 pragma Unreferenced (T, Thread_Self);
1346 --------------------
1347 -- Stop_All_Tasks --
1348 --------------------
1350 procedure Stop_All_Tasks is
1359 function Stop_Task (T : ST.Task_Id) return Boolean is
1360 pragma Unreferenced (T);
1369 function Continue_Task (T : ST.Task_Id) return Boolean is
1370 pragma Unreferenced (T);
1379 procedure Initialize (Environment_Task : Task_Id) is
1380 act : aliased struct_sigaction;
1381 old_act : aliased struct_sigaction;
1382 Tmp_Set : aliased sigset_t;
1383 Result : Interfaces.C.int;
1386 (Int : System.Interrupt_Management.Interrupt_ID) return Character;
1387 pragma Import (C, State, "__gnat_get_interrupt_state");
1388 -- Get interrupt state. Defined in a-init.c
1389 -- The input argument is the interrupt number,
1390 -- and the result is one of the following:
1392 Default : constant Character := 's';
1393 -- 'n' this interrupt not set by any Interrupt_State pragma
1394 -- 'u' Interrupt_State pragma set state to User
1395 -- 'r' Interrupt_State pragma set state to Runtime
1396 -- 's' Interrupt_State pragma set state to System (use "default"
1400 Environment_Task_Id := Environment_Task;
1402 Interrupt_Management.Initialize;
1404 -- Prepare the set of signals that should unblocked in all tasks
1406 Result := sigemptyset (Unblocked_Signal_Mask'Access);
1407 pragma Assert (Result = 0);
1409 for J in Interrupt_Management.Interrupt_ID loop
1410 if System.Interrupt_Management.Keep_Unmasked (J) then
1411 Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
1412 pragma Assert (Result = 0);
1416 -- Initialize the lock used to synchronize chain of all ATCBs
1418 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1420 Specific.Initialize (Environment_Task);
1422 if Use_Alternate_Stack then
1423 Environment_Task.Common.Task_Alternate_Stack :=
1424 Alternate_Stack'Address;
1427 -- Make environment task known here because it doesn't go through
1428 -- Activate_Tasks, which does it for all other tasks.
1430 Known_Tasks (Known_Tasks'First) := Environment_Task;
1431 Environment_Task.Known_Tasks_Index := Known_Tasks'First;
1433 Enter_Task (Environment_Task);
1436 (System.Interrupt_Management.Abort_Task_Interrupt) /= Default
1439 act.sa_handler := Abort_Handler'Address;
1441 Result := sigemptyset (Tmp_Set'Access);
1442 pragma Assert (Result = 0);
1443 act.sa_mask := Tmp_Set;
1447 (Signal (System.Interrupt_Management.Abort_Task_Interrupt),
1448 act'Unchecked_Access,
1449 old_act'Unchecked_Access);
1450 pragma Assert (Result = 0);
1451 Abort_Handler_Installed := True;
1455 end System.Task_Primitives.Operations;