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;
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 Environment_Task_Id : Task_Id;
87 -- A variable to hold Task_Id for the environment task
89 Locking_Policy : Character;
90 pragma Import (C, Locking_Policy, "__gl_locking_policy");
91 -- Value of the pragma Locking_Policy:
92 -- 'C' for Ceiling_Locking
93 -- 'I' for Inherit_Locking
96 Unblocked_Signal_Mask : aliased sigset_t;
97 -- The set of signals that should unblocked in all tasks
99 -- The followings are internal configuration constants needed
101 Next_Serial_Number : Task_Serial_Number := 100;
102 -- We start at 100, to reserve some special values for
103 -- using in error checking.
105 Time_Slice_Val : Integer;
106 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
108 Dispatching_Policy : Character;
109 pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
111 Foreign_Task_Elaborated : aliased Boolean := True;
112 -- Used to identified fake tasks (i.e., non-Ada Threads)
114 Use_Alternate_Stack : constant Boolean := Alternate_Stack_Size /= 0;
115 -- Whether to use an alternate signal stack for stack overflows
117 Abort_Handler_Installed : Boolean := False;
118 -- True if a handler for the abort signal is installed
126 procedure Initialize (Environment_Task : Task_Id);
127 pragma Inline (Initialize);
128 -- Initialize various data needed by this package
130 function Is_Valid_Task return Boolean;
131 pragma Inline (Is_Valid_Task);
132 -- Does executing thread have a TCB?
134 procedure Set (Self_Id : Task_Id);
136 -- Set the self id for the current task
138 function Self return Task_Id;
139 pragma Inline (Self);
140 -- Return a pointer to the Ada Task Control Block of the calling task
144 package body Specific is separate;
145 -- The body of this package is target specific
147 ---------------------------------
148 -- Support for foreign threads --
149 ---------------------------------
151 function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
152 -- Allocate and Initialize a new ATCB for the current Thread
154 function Register_Foreign_Thread
155 (Thread : Thread_Id) return Task_Id is separate;
157 -----------------------
158 -- Local Subprograms --
159 -----------------------
161 procedure Abort_Handler (Sig : Signal);
162 -- Signal handler used to implement asynchronous abort.
163 -- See also comment before body, below.
165 function To_Address is
166 new Ada.Unchecked_Conversion (Task_Id, System.Address);
172 -- Target-dependent binding of inter-thread Abort signal to the raising of
173 -- the Abort_Signal exception.
175 -- The technical issues and alternatives here are essentially the
176 -- same as for raising exceptions in response to other signals
177 -- (e.g. Storage_Error). See code and comments in the package body
178 -- System.Interrupt_Management.
180 -- Some implementations may not allow an exception to be propagated out of
181 -- a handler, and others might leave the signal or interrupt that invoked
182 -- this handler masked after the exceptional return to the application
185 -- GNAT exceptions are originally implemented using setjmp()/longjmp(). On
186 -- most UNIX systems, this will allow transfer out of a signal handler,
187 -- which is usually the only mechanism available for implementing
188 -- asynchronous handlers of this kind. However, some systems do not
189 -- restore the signal mask on longjmp(), leaving the abort signal masked.
191 procedure Abort_Handler (Sig : Signal) is
192 pragma Unreferenced (Sig);
194 T : constant Task_Id := Self;
195 Old_Set : aliased sigset_t;
197 Result : Interfaces.C.int;
198 pragma Warnings (Off, Result);
201 -- It's not safe to raise an exception when using GCC ZCX mechanism.
202 -- Note that we still need to install a signal handler, since in some
203 -- cases (e.g. shutdown of the Server_Task in System.Interrupts) we
204 -- need to send the Abort signal to a task.
206 if ZCX_By_Default and then GCC_ZCX_Support then
210 if T.Deferral_Level = 0
211 and then T.Pending_ATC_Level < T.ATC_Nesting_Level and then
216 -- Make sure signals used for RTS internal purpose are unmasked
218 Result := pthread_sigmask (SIG_UNBLOCK,
219 Unblocked_Signal_Mask'Access, Old_Set'Access);
220 pragma Assert (Result = 0);
222 raise Standard'Abort_Signal;
230 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
231 Stack_Base : constant Address := Get_Stack_Base (T.Common.LL.Thread);
232 Guard_Page_Address : Address;
234 Res : Interfaces.C.int;
237 if Stack_Base_Available then
239 -- Compute the guard page address
241 Guard_Page_Address :=
242 Stack_Base - (Stack_Base mod Get_Page_Size) + Get_Page_Size;
245 mprotect (Guard_Page_Address, Get_Page_Size,
246 prot => (if On then PROT_ON else PROT_OFF));
247 pragma Assert (Res = 0);
255 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
257 return T.Common.LL.Thread;
264 function Self return Task_Id renames Specific.Self;
266 ---------------------
267 -- Initialize_Lock --
268 ---------------------
270 -- Note: mutexes and cond_variables needed per-task basis are
271 -- initialized in Initialize_TCB and the Storage_Error is
272 -- handled. Other mutexes (such as RTS_Lock, Memory_Lock...)
273 -- used in RTS is initialized before any status change of RTS.
274 -- Therefore raising Storage_Error in the following routines
275 -- should be able to be handled safely.
277 procedure Initialize_Lock
278 (Prio : System.Any_Priority;
279 L : not null access Lock)
281 Attributes : aliased pthread_mutexattr_t;
282 Result : Interfaces.C.int;
285 Result := pthread_mutexattr_init (Attributes'Access);
286 pragma Assert (Result = 0 or else Result = ENOMEM);
288 if Result = ENOMEM then
292 if Locking_Policy = 'C' then
293 Result := pthread_mutexattr_setprotocol
294 (Attributes'Access, PTHREAD_PRIO_PROTECT);
295 pragma Assert (Result = 0);
297 Result := pthread_mutexattr_setprioceiling
298 (Attributes'Access, Interfaces.C.int (Prio));
299 pragma Assert (Result = 0);
301 elsif Locking_Policy = 'I' then
302 Result := pthread_mutexattr_setprotocol
303 (Attributes'Access, PTHREAD_PRIO_INHERIT);
304 pragma Assert (Result = 0);
307 Result := pthread_mutex_init (L, Attributes'Access);
308 pragma Assert (Result = 0 or else Result = ENOMEM);
310 if Result = ENOMEM then
311 Result := pthread_mutexattr_destroy (Attributes'Access);
315 Result := pthread_mutexattr_destroy (Attributes'Access);
316 pragma Assert (Result = 0);
319 procedure Initialize_Lock
320 (L : not null access RTS_Lock; Level : Lock_Level)
322 pragma Unreferenced (Level);
324 Attributes : aliased pthread_mutexattr_t;
325 Result : Interfaces.C.int;
328 Result := pthread_mutexattr_init (Attributes'Access);
329 pragma Assert (Result = 0 or else Result = ENOMEM);
331 if Result = ENOMEM then
335 if Locking_Policy = 'C' then
336 Result := pthread_mutexattr_setprotocol
337 (Attributes'Access, PTHREAD_PRIO_PROTECT);
338 pragma Assert (Result = 0);
340 Result := pthread_mutexattr_setprioceiling
341 (Attributes'Access, Interfaces.C.int (System.Any_Priority'Last));
342 pragma Assert (Result = 0);
344 elsif Locking_Policy = 'I' then
345 Result := pthread_mutexattr_setprotocol
346 (Attributes'Access, PTHREAD_PRIO_INHERIT);
347 pragma Assert (Result = 0);
350 Result := pthread_mutex_init (L, Attributes'Access);
351 pragma Assert (Result = 0 or else Result = ENOMEM);
353 if Result = ENOMEM then
354 Result := pthread_mutexattr_destroy (Attributes'Access);
358 Result := pthread_mutexattr_destroy (Attributes'Access);
359 pragma Assert (Result = 0);
366 procedure Finalize_Lock (L : not null access Lock) is
367 Result : Interfaces.C.int;
369 Result := pthread_mutex_destroy (L);
370 pragma Assert (Result = 0);
373 procedure Finalize_Lock (L : not null access RTS_Lock) is
374 Result : Interfaces.C.int;
376 Result := pthread_mutex_destroy (L);
377 pragma Assert (Result = 0);
385 (L : not null access Lock; Ceiling_Violation : out Boolean)
387 Result : Interfaces.C.int;
390 Result := pthread_mutex_lock (L);
392 -- Assume that the cause of EINVAL is a priority ceiling violation
394 Ceiling_Violation := (Result = EINVAL);
395 pragma Assert (Result = 0 or else Result = EINVAL);
399 (L : not null access RTS_Lock;
400 Global_Lock : Boolean := False)
402 Result : Interfaces.C.int;
404 if not Single_Lock or else Global_Lock then
405 Result := pthread_mutex_lock (L);
406 pragma Assert (Result = 0);
410 procedure Write_Lock (T : Task_Id) is
411 Result : Interfaces.C.int;
413 if not Single_Lock then
414 Result := pthread_mutex_lock (T.Common.LL.L'Access);
415 pragma Assert (Result = 0);
424 (L : not null access Lock; Ceiling_Violation : out Boolean) is
426 Write_Lock (L, Ceiling_Violation);
433 procedure Unlock (L : not null access Lock) is
434 Result : Interfaces.C.int;
436 Result := pthread_mutex_unlock (L);
437 pragma Assert (Result = 0);
441 (L : not null access RTS_Lock; Global_Lock : Boolean := False)
443 Result : Interfaces.C.int;
445 if not Single_Lock or else Global_Lock then
446 Result := pthread_mutex_unlock (L);
447 pragma Assert (Result = 0);
451 procedure Unlock (T : Task_Id) is
452 Result : Interfaces.C.int;
454 if not Single_Lock then
455 Result := pthread_mutex_unlock (T.Common.LL.L'Access);
456 pragma Assert (Result = 0);
464 -- Dynamic priority ceilings are not supported by the underlying system
466 procedure Set_Ceiling
467 (L : not null access Lock;
468 Prio : System.Any_Priority)
470 pragma Unreferenced (L, Prio);
481 Reason : System.Tasking.Task_States)
483 pragma Unreferenced (Reason);
485 Result : Interfaces.C.int;
490 (cond => Self_ID.Common.LL.CV'Access,
491 mutex => (if Single_Lock
492 then Single_RTS_Lock'Access
493 else Self_ID.Common.LL.L'Access));
495 -- EINTR is not considered a failure
497 pragma Assert (Result = 0 or else Result = EINTR);
504 -- This is for use within the run-time system, so abort is
505 -- assumed to be already deferred, and the caller should be
506 -- holding its own ATCB lock.
508 procedure Timed_Sleep
511 Mode : ST.Delay_Modes;
512 Reason : Task_States;
513 Timedout : out Boolean;
514 Yielded : out Boolean)
516 pragma Unreferenced (Reason);
518 Base_Time : constant Duration := Monotonic_Clock;
519 Check_Time : Duration := Base_Time;
522 Request : aliased timespec;
523 Result : Interfaces.C.int;
529 if Mode = Relative then
530 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
532 if Relative_Timed_Wait then
533 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
537 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
539 if Relative_Timed_Wait then
540 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
544 if Abs_Time > Check_Time then
546 To_Timespec (if Relative_Timed_Wait then Rel_Time else Abs_Time);
549 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
552 pthread_cond_timedwait
553 (cond => Self_ID.Common.LL.CV'Access,
554 mutex => (if Single_Lock
555 then Single_RTS_Lock'Access
556 else Self_ID.Common.LL.L'Access),
557 abstime => Request'Access);
559 Check_Time := Monotonic_Clock;
560 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
562 if Result = 0 or Result = EINTR then
564 -- Somebody may have called Wakeup for us
570 pragma Assert (Result = ETIMEDOUT);
579 -- This is for use in implementing delay statements, so we assume the
580 -- caller is abort-deferred but is holding no locks.
582 procedure Timed_Delay
585 Mode : ST.Delay_Modes)
587 Base_Time : constant Duration := Monotonic_Clock;
588 Check_Time : Duration := Base_Time;
591 Request : aliased timespec;
593 Result : Interfaces.C.int;
594 pragma Warnings (Off, Result);
601 Write_Lock (Self_ID);
603 if Mode = Relative then
604 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
606 if Relative_Timed_Wait then
607 Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
611 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
613 if Relative_Timed_Wait then
614 Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
618 if Abs_Time > Check_Time then
620 To_Timespec (if Relative_Timed_Wait then Rel_Time else Abs_Time);
621 Self_ID.Common.State := Delay_Sleep;
624 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
627 pthread_cond_timedwait
628 (cond => Self_ID.Common.LL.CV'Access,
629 mutex => (if Single_Lock
630 then Single_RTS_Lock'Access
631 else Self_ID.Common.LL.L'Access),
632 abstime => Request'Access);
634 Check_Time := Monotonic_Clock;
635 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
637 pragma Assert (Result = 0
638 or else Result = ETIMEDOUT
639 or else Result = EINTR);
642 Self_ID.Common.State := Runnable;
651 Result := sched_yield;
654 ---------------------
655 -- Monotonic_Clock --
656 ---------------------
658 function Monotonic_Clock return Duration is
659 TS : aliased timespec;
660 Result : Interfaces.C.int;
662 Result := clock_gettime
663 (clock_id => CLOCK_REALTIME, tp => TS'Unchecked_Access);
664 pragma Assert (Result = 0);
665 return To_Duration (TS);
672 function RT_Resolution return Duration is
681 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
682 pragma Unreferenced (Reason);
683 Result : Interfaces.C.int;
685 Result := pthread_cond_signal (T.Common.LL.CV'Access);
686 pragma Assert (Result = 0);
693 procedure Yield (Do_Yield : Boolean := True) is
694 Result : Interfaces.C.int;
695 pragma Unreferenced (Result);
698 Result := sched_yield;
706 procedure Set_Priority
708 Prio : System.Any_Priority;
709 Loss_Of_Inheritance : Boolean := False)
711 pragma Unreferenced (Loss_Of_Inheritance);
713 Result : Interfaces.C.int;
714 Param : aliased struct_sched_param;
716 function Get_Policy (Prio : System.Any_Priority) return Character;
717 pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
718 -- Get priority specific dispatching policy
720 Priority_Specific_Policy : constant Character := Get_Policy (Prio);
721 -- Upper case first character of the policy name corresponding to the
722 -- task as set by a Priority_Specific_Dispatching pragma.
725 T.Common.Current_Priority := Prio;
726 Param.sched_priority := To_Target_Priority (Prio);
728 if Time_Slice_Supported
729 and then (Dispatching_Policy = 'R'
730 or else Priority_Specific_Policy = 'R'
731 or else Time_Slice_Val > 0)
733 Result := pthread_setschedparam
734 (T.Common.LL.Thread, SCHED_RR, Param'Access);
736 elsif Dispatching_Policy = 'F'
737 or else Priority_Specific_Policy = 'F'
738 or else Time_Slice_Val = 0
740 Result := pthread_setschedparam
741 (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
744 Result := pthread_setschedparam
745 (T.Common.LL.Thread, SCHED_OTHER, Param'Access);
748 pragma Assert (Result = 0);
755 function Get_Priority (T : Task_Id) return System.Any_Priority is
757 return T.Common.Current_Priority;
764 procedure Enter_Task (Self_ID : Task_Id) is
766 Self_ID.Common.LL.Thread := pthread_self;
767 Self_ID.Common.LL.LWP := lwp_self;
769 Specific.Set (Self_ID);
771 if Use_Alternate_Stack then
773 Stack : aliased stack_t;
774 Result : Interfaces.C.int;
776 Stack.ss_sp := Self_ID.Common.Task_Alternate_Stack;
777 Stack.ss_size := Alternate_Stack_Size;
779 Result := sigaltstack (Stack'Access, null);
780 pragma Assert (Result = 0);
789 function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
791 return new Ada_Task_Control_Block (Entry_Num);
798 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
800 -----------------------------
801 -- Register_Foreign_Thread --
802 -----------------------------
804 function Register_Foreign_Thread return Task_Id is
806 if Is_Valid_Task then
809 return Register_Foreign_Thread (pthread_self);
811 end Register_Foreign_Thread;
817 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
818 Mutex_Attr : aliased pthread_mutexattr_t;
819 Result : Interfaces.C.int;
820 Cond_Attr : aliased pthread_condattr_t;
823 -- Give the task a unique serial number
825 Self_ID.Serial_Number := Next_Serial_Number;
826 Next_Serial_Number := Next_Serial_Number + 1;
827 pragma Assert (Next_Serial_Number /= 0);
829 if not Single_Lock then
830 Result := pthread_mutexattr_init (Mutex_Attr'Access);
831 pragma Assert (Result = 0 or else Result = ENOMEM);
834 if Locking_Policy = 'C' then
836 pthread_mutexattr_setprotocol
838 PTHREAD_PRIO_PROTECT);
839 pragma Assert (Result = 0);
842 pthread_mutexattr_setprioceiling
844 Interfaces.C.int (System.Any_Priority'Last));
845 pragma Assert (Result = 0);
847 elsif Locking_Policy = 'I' then
849 pthread_mutexattr_setprotocol
851 PTHREAD_PRIO_INHERIT);
852 pragma Assert (Result = 0);
857 (Self_ID.Common.LL.L'Access,
859 pragma Assert (Result = 0 or else Result = ENOMEM);
867 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
868 pragma Assert (Result = 0);
871 Result := pthread_condattr_init (Cond_Attr'Access);
872 pragma Assert (Result = 0 or else Result = ENOMEM);
877 (Self_ID.Common.LL.CV'Access, Cond_Attr'Access);
878 pragma Assert (Result = 0 or else Result = ENOMEM);
884 if not Single_Lock then
885 Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
886 pragma Assert (Result = 0);
892 Result := pthread_condattr_destroy (Cond_Attr'Access);
893 pragma Assert (Result = 0);
900 procedure Create_Task
902 Wrapper : System.Address;
903 Stack_Size : System.Parameters.Size_Type;
904 Priority : System.Any_Priority;
905 Succeeded : out Boolean)
907 Attributes : aliased pthread_attr_t;
908 Adjusted_Stack_Size : Interfaces.C.size_t;
909 Page_Size : constant Interfaces.C.size_t := Get_Page_Size;
910 Result : Interfaces.C.int;
912 function Thread_Body_Access is new
913 Ada.Unchecked_Conversion (System.Address, Thread_Body);
915 use System.Task_Info;
918 Adjusted_Stack_Size :=
919 Interfaces.C.size_t (Stack_Size + Alternate_Stack_Size);
921 if Stack_Base_Available then
923 -- If Stack Checking is supported then allocate 2 additional pages:
925 -- In the worst case, stack is allocated at something like
926 -- N * Get_Page_Size - epsilon, we need to add the size for 2 pages
927 -- to be sure the effective stack size is greater than what
930 Adjusted_Stack_Size := Adjusted_Stack_Size + 2 * Page_Size;
933 -- Round stack size as this is required by some OSes (Darwin)
935 Adjusted_Stack_Size := Adjusted_Stack_Size + Page_Size - 1;
936 Adjusted_Stack_Size :=
937 Adjusted_Stack_Size - Adjusted_Stack_Size mod Page_Size;
939 Result := pthread_attr_init (Attributes'Access);
940 pragma Assert (Result = 0 or else Result = ENOMEM);
948 pthread_attr_setdetachstate
949 (Attributes'Access, PTHREAD_CREATE_DETACHED);
950 pragma Assert (Result = 0);
953 pthread_attr_setstacksize
954 (Attributes'Access, Adjusted_Stack_Size);
955 pragma Assert (Result = 0);
957 if T.Common.Task_Info /= Default_Scope then
958 case T.Common.Task_Info is
959 when System.Task_Info.Process_Scope =>
961 pthread_attr_setscope
962 (Attributes'Access, PTHREAD_SCOPE_PROCESS);
964 when System.Task_Info.System_Scope =>
966 pthread_attr_setscope
967 (Attributes'Access, PTHREAD_SCOPE_SYSTEM);
969 when System.Task_Info.Default_Scope =>
973 pragma Assert (Result = 0);
976 -- Since the initial signal mask of a thread is inherited from the
977 -- creator, and the Environment task has all its signals masked, we
978 -- do not need to manipulate caller's signal mask at this point.
979 -- All tasks in RTS will have All_Tasks_Mask initially.
981 Result := pthread_create
982 (T.Common.LL.Thread'Access,
984 Thread_Body_Access (Wrapper),
986 pragma Assert (Result = 0 or else Result = EAGAIN);
988 Succeeded := Result = 0;
990 Result := pthread_attr_destroy (Attributes'Access);
991 pragma Assert (Result = 0);
994 Set_Priority (T, Priority);
1002 procedure Finalize_TCB (T : Task_Id) is
1003 Result : Interfaces.C.int;
1005 Is_Self : constant Boolean := T = Self;
1007 procedure Free is new
1008 Ada.Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
1011 if not Single_Lock then
1012 Result := pthread_mutex_destroy (T.Common.LL.L'Access);
1013 pragma Assert (Result = 0);
1016 Result := pthread_cond_destroy (T.Common.LL.CV'Access);
1017 pragma Assert (Result = 0);
1019 if T.Known_Tasks_Index /= -1 then
1020 Known_Tasks (T.Known_Tasks_Index) := null;
1026 Specific.Set (null);
1034 procedure Exit_Task is
1036 -- Mark this task as unknown, so that if Self is called, it won't
1037 -- return a dangling pointer.
1039 Specific.Set (null);
1046 procedure Abort_Task (T : Task_Id) is
1047 Result : Interfaces.C.int;
1049 if Abort_Handler_Installed then
1052 (T.Common.LL.Thread,
1053 Signal (System.Interrupt_Management.Abort_Task_Interrupt));
1054 pragma Assert (Result = 0);
1062 procedure Initialize (S : in out Suspension_Object) is
1063 Mutex_Attr : aliased pthread_mutexattr_t;
1064 Cond_Attr : aliased pthread_condattr_t;
1065 Result : Interfaces.C.int;
1068 -- Initialize internal state (always to False (RM D.10 (6)))
1073 -- Initialize internal mutex
1075 Result := pthread_mutexattr_init (Mutex_Attr'Access);
1076 pragma Assert (Result = 0 or else Result = ENOMEM);
1078 if Result = ENOMEM then
1079 raise Storage_Error;
1082 Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
1083 pragma Assert (Result = 0 or else Result = ENOMEM);
1085 if Result = ENOMEM then
1086 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1087 pragma Assert (Result = 0);
1089 raise Storage_Error;
1092 Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
1093 pragma Assert (Result = 0);
1095 -- Initialize internal condition variable
1097 Result := pthread_condattr_init (Cond_Attr'Access);
1098 pragma Assert (Result = 0 or else Result = ENOMEM);
1101 Result := pthread_mutex_destroy (S.L'Access);
1102 pragma Assert (Result = 0);
1104 if Result = ENOMEM then
1105 raise Storage_Error;
1109 Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
1110 pragma Assert (Result = 0 or else Result = ENOMEM);
1113 Result := pthread_mutex_destroy (S.L'Access);
1114 pragma Assert (Result = 0);
1116 if Result = ENOMEM then
1117 Result := pthread_condattr_destroy (Cond_Attr'Access);
1118 pragma Assert (Result = 0);
1119 raise Storage_Error;
1123 Result := pthread_condattr_destroy (Cond_Attr'Access);
1124 pragma Assert (Result = 0);
1131 procedure Finalize (S : in out Suspension_Object) is
1132 Result : Interfaces.C.int;
1135 -- Destroy internal mutex
1137 Result := pthread_mutex_destroy (S.L'Access);
1138 pragma Assert (Result = 0);
1140 -- Destroy internal condition variable
1142 Result := pthread_cond_destroy (S.CV'Access);
1143 pragma Assert (Result = 0);
1150 function Current_State (S : Suspension_Object) return Boolean is
1152 -- We do not want to use lock on this read operation. State is marked
1153 -- as Atomic so that we ensure that the value retrieved is correct.
1162 procedure Set_False (S : in out Suspension_Object) is
1163 Result : Interfaces.C.int;
1166 SSL.Abort_Defer.all;
1168 Result := pthread_mutex_lock (S.L'Access);
1169 pragma Assert (Result = 0);
1173 Result := pthread_mutex_unlock (S.L'Access);
1174 pragma Assert (Result = 0);
1176 SSL.Abort_Undefer.all;
1183 procedure Set_True (S : in out Suspension_Object) is
1184 Result : Interfaces.C.int;
1187 SSL.Abort_Defer.all;
1189 Result := pthread_mutex_lock (S.L'Access);
1190 pragma Assert (Result = 0);
1192 -- If there is already a task waiting on this suspension object then
1193 -- we resume it, leaving the state of the suspension object to False,
1194 -- as it is specified in (RM D.10(9)). Otherwise, it just leaves
1195 -- the state to True.
1201 Result := pthread_cond_signal (S.CV'Access);
1202 pragma Assert (Result = 0);
1208 Result := pthread_mutex_unlock (S.L'Access);
1209 pragma Assert (Result = 0);
1211 SSL.Abort_Undefer.all;
1214 ------------------------
1215 -- Suspend_Until_True --
1216 ------------------------
1218 procedure Suspend_Until_True (S : in out Suspension_Object) is
1219 Result : Interfaces.C.int;
1222 SSL.Abort_Defer.all;
1224 Result := pthread_mutex_lock (S.L'Access);
1225 pragma Assert (Result = 0);
1229 -- Program_Error must be raised upon calling Suspend_Until_True
1230 -- if another task is already waiting on that suspension object
1233 Result := pthread_mutex_unlock (S.L'Access);
1234 pragma Assert (Result = 0);
1236 SSL.Abort_Undefer.all;
1238 raise Program_Error;
1241 -- Suspend the task if the state is False. Otherwise, the task
1242 -- continues its execution, and the state of the suspension object
1243 -- is set to False (ARM D.10 par. 9).
1251 -- Loop in case pthread_cond_wait returns earlier than expected
1252 -- (e.g. in case of EINTR caused by a signal).
1254 Result := pthread_cond_wait (S.CV'Access, S.L'Access);
1255 pragma Assert (Result = 0 or else Result = EINTR);
1257 exit when not S.Waiting;
1261 Result := pthread_mutex_unlock (S.L'Access);
1262 pragma Assert (Result = 0);
1264 SSL.Abort_Undefer.all;
1266 end Suspend_Until_True;
1274 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1275 pragma Unreferenced (Self_ID);
1280 --------------------
1281 -- Check_No_Locks --
1282 --------------------
1284 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1285 pragma Unreferenced (Self_ID);
1290 ----------------------
1291 -- Environment_Task --
1292 ----------------------
1294 function Environment_Task return Task_Id is
1296 return Environment_Task_Id;
1297 end Environment_Task;
1303 procedure Lock_RTS is
1305 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
1312 procedure Unlock_RTS is
1314 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
1321 function Suspend_Task
1323 Thread_Self : Thread_Id) return Boolean
1325 pragma Unreferenced (T, Thread_Self);
1334 function Resume_Task
1336 Thread_Self : Thread_Id) return Boolean
1338 pragma Unreferenced (T, Thread_Self);
1343 --------------------
1344 -- Stop_All_Tasks --
1345 --------------------
1347 procedure Stop_All_Tasks is
1356 function Stop_Task (T : ST.Task_Id) return Boolean is
1357 pragma Unreferenced (T);
1366 function Continue_Task (T : ST.Task_Id) return Boolean is
1367 pragma Unreferenced (T);
1376 procedure Initialize (Environment_Task : Task_Id) is
1377 act : aliased struct_sigaction;
1378 old_act : aliased struct_sigaction;
1379 Tmp_Set : aliased sigset_t;
1380 Result : Interfaces.C.int;
1383 (Int : System.Interrupt_Management.Interrupt_ID) return Character;
1384 pragma Import (C, State, "__gnat_get_interrupt_state");
1385 -- Get interrupt state. Defined in a-init.c
1386 -- The input argument is the interrupt number,
1387 -- and the result is one of the following:
1389 Default : constant Character := 's';
1390 -- 'n' this interrupt not set by any Interrupt_State pragma
1391 -- 'u' Interrupt_State pragma set state to User
1392 -- 'r' Interrupt_State pragma set state to Runtime
1393 -- 's' Interrupt_State pragma set state to System (use "default"
1397 Environment_Task_Id := Environment_Task;
1399 Interrupt_Management.Initialize;
1401 -- Prepare the set of signals that should unblocked in all tasks
1403 Result := sigemptyset (Unblocked_Signal_Mask'Access);
1404 pragma Assert (Result = 0);
1406 for J in Interrupt_Management.Interrupt_ID loop
1407 if System.Interrupt_Management.Keep_Unmasked (J) then
1408 Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
1409 pragma Assert (Result = 0);
1413 -- Initialize the lock used to synchronize chain of all ATCBs
1415 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1417 Specific.Initialize (Environment_Task);
1419 if Use_Alternate_Stack then
1420 Environment_Task.Common.Task_Alternate_Stack :=
1421 Alternate_Stack'Address;
1424 -- Make environment task known here because it doesn't go through
1425 -- Activate_Tasks, which does it for all other tasks.
1427 Known_Tasks (Known_Tasks'First) := Environment_Task;
1428 Environment_Task.Known_Tasks_Index := Known_Tasks'First;
1430 Enter_Task (Environment_Task);
1433 (System.Interrupt_Management.Abort_Task_Interrupt) /= Default
1436 act.sa_handler := Abort_Handler'Address;
1438 Result := sigemptyset (Tmp_Set'Access);
1439 pragma Assert (Result = 0);
1440 act.sa_mask := Tmp_Set;
1444 (Signal (System.Interrupt_Management.Abort_Task_Interrupt),
1445 act'Unchecked_Access,
1446 old_act'Unchecked_Access);
1447 pragma Assert (Result = 0);
1448 Abort_Handler_Installed := True;
1452 end System.Task_Primitives.Operations;