1 ------------------------------------------------------------------------------
3 -- GNU ADA 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 GNU/Linux (GNU/LinuxThreads) version of this package
34 -- This package contains all the GNULL primitives that interface directly with
38 -- Turn off polling, we do not want ATC polling to take place during tasking
39 -- operations. It causes infinite loops and other problems.
41 with Ada.Unchecked_Conversion;
42 with Ada.Unchecked_Deallocation;
46 with System.Task_Info;
47 with System.Tasking.Debug;
48 with System.Interrupt_Management;
49 with System.OS_Primitives;
50 with System.Stack_Checking.Operations;
52 with System.Soft_Links;
53 -- We use System.Soft_Links instead of System.Tasking.Initialization
54 -- because the later is a higher level package that we shouldn't depend on.
55 -- For example when using the restricted run time, it is replaced by
56 -- System.Tasking.Restricted.Stages.
58 package body System.Task_Primitives.Operations is
60 package SSL renames System.Soft_Links;
61 package SC renames System.Stack_Checking.Operations;
63 use System.Tasking.Debug;
66 use System.OS_Interface;
67 use System.Parameters;
68 use System.OS_Primitives;
71 Use_Alternate_Stack : constant Boolean := Alternate_Stack_Size /= 0;
72 -- Whether to use an alternate signal stack for stack overflows
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 Unblocked_Signal_Mask : aliased sigset_t;
93 -- The set of signals that should be unblocked in all tasks
95 -- The followings are internal configuration constants needed
97 Next_Serial_Number : Task_Serial_Number := 100;
98 -- We start at 100 (reserve some special values for using in error checks)
100 Time_Slice_Val : Integer;
101 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
103 Dispatching_Policy : Character;
104 pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
106 -- The following are effectively constants, but they need to be initialized
107 -- by calling a pthread_ function.
109 Mutex_Attr : aliased pthread_mutexattr_t;
110 Cond_Attr : aliased pthread_condattr_t;
112 Foreign_Task_Elaborated : aliased Boolean := True;
113 -- Used to identified fake tasks (i.e., non-Ada Threads)
121 procedure Initialize (Environment_Task : Task_Id);
122 pragma Inline (Initialize);
123 -- Initialize various data needed by this package
125 function Is_Valid_Task return Boolean;
126 pragma Inline (Is_Valid_Task);
127 -- Does executing thread have a TCB?
129 procedure Set (Self_Id : Task_Id);
131 -- Set the self id for the current task
133 function Self return Task_Id;
134 pragma Inline (Self);
135 -- Return a pointer to the Ada Task Control Block of the calling task
139 package body Specific is separate;
140 -- The body of this package is target specific
142 ---------------------------------
143 -- Support for foreign threads --
144 ---------------------------------
146 function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
147 -- Allocate and Initialize a new ATCB for the current Thread
149 function Register_Foreign_Thread
150 (Thread : Thread_Id) return Task_Id is separate;
152 -----------------------
153 -- Local Subprograms --
154 -----------------------
156 subtype unsigned_long is Interfaces.C.unsigned_long;
158 procedure Abort_Handler (signo : Signal);
160 function To_pthread_t is new Ada.Unchecked_Conversion
161 (unsigned_long, System.OS_Interface.pthread_t);
167 procedure Abort_Handler (signo : Signal) is
168 pragma Unreferenced (signo);
170 Self_Id : constant Task_Id := Self;
171 Result : Interfaces.C.int;
172 Old_Set : aliased sigset_t;
175 if ZCX_By_Default and then GCC_ZCX_Support then
179 if Self_Id.Deferral_Level = 0
180 and then Self_Id.Pending_ATC_Level < Self_Id.ATC_Nesting_Level
181 and then not Self_Id.Aborting
183 Self_Id.Aborting := True;
185 -- Make sure signals used for RTS internal purpose are unmasked
190 Unblocked_Signal_Mask'Access,
192 pragma Assert (Result = 0);
194 raise Standard'Abort_Signal;
202 procedure Lock_RTS is
204 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
211 procedure Unlock_RTS is
213 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
220 -- The underlying thread system extends the memory (up to 2MB) when needed
222 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
223 pragma Unreferenced (T);
224 pragma Unreferenced (On);
233 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
235 return T.Common.LL.Thread;
242 function Self return Task_Id renames Specific.Self;
244 ---------------------
245 -- Initialize_Lock --
246 ---------------------
248 -- Note: mutexes and cond_variables needed per-task basis are initialized
249 -- in Initialize_TCB and the Storage_Error is handled. Other mutexes (such
250 -- as RTS_Lock, Memory_Lock...) used in RTS is initialized before any
251 -- status change of RTS. Therefore raising Storage_Error in the following
252 -- routines should be able to be handled safely.
254 procedure Initialize_Lock
255 (Prio : System.Any_Priority;
256 L : not null access Lock)
258 pragma Unreferenced (Prio);
260 Result : Interfaces.C.int;
263 Result := pthread_mutex_init (L, Mutex_Attr'Access);
265 pragma Assert (Result = 0 or else Result = ENOMEM);
267 if Result = ENOMEM then
268 raise Storage_Error with "Failed to allocate a lock";
272 procedure Initialize_Lock
273 (L : not null access RTS_Lock;
276 pragma Unreferenced (Level);
278 Result : Interfaces.C.int;
281 Result := pthread_mutex_init (L, Mutex_Attr'Access);
283 pragma Assert (Result = 0 or else Result = ENOMEM);
285 if Result = ENOMEM then
294 procedure Finalize_Lock (L : not null access Lock) is
295 Result : Interfaces.C.int;
297 Result := pthread_mutex_destroy (L);
298 pragma Assert (Result = 0);
301 procedure Finalize_Lock (L : not null access RTS_Lock) is
302 Result : Interfaces.C.int;
304 Result := pthread_mutex_destroy (L);
305 pragma Assert (Result = 0);
313 (L : not null access Lock;
314 Ceiling_Violation : out Boolean)
316 Result : Interfaces.C.int;
318 Result := pthread_mutex_lock (L);
319 Ceiling_Violation := Result = EINVAL;
321 -- Assume the cause of EINVAL is a priority ceiling violation
323 pragma Assert (Result = 0 or else Result = EINVAL);
327 (L : not null access RTS_Lock;
328 Global_Lock : Boolean := False)
330 Result : Interfaces.C.int;
332 if not Single_Lock or else Global_Lock then
333 Result := pthread_mutex_lock (L);
334 pragma Assert (Result = 0);
338 procedure Write_Lock (T : Task_Id) is
339 Result : Interfaces.C.int;
341 if not Single_Lock then
342 Result := pthread_mutex_lock (T.Common.LL.L'Access);
343 pragma Assert (Result = 0);
352 (L : not null access Lock;
353 Ceiling_Violation : out Boolean)
356 Write_Lock (L, Ceiling_Violation);
363 procedure Unlock (L : not null access Lock) is
364 Result : Interfaces.C.int;
366 Result := pthread_mutex_unlock (L);
367 pragma Assert (Result = 0);
371 (L : not null access RTS_Lock;
372 Global_Lock : Boolean := False)
374 Result : Interfaces.C.int;
376 if not Single_Lock or else Global_Lock then
377 Result := pthread_mutex_unlock (L);
378 pragma Assert (Result = 0);
382 procedure Unlock (T : Task_Id) is
383 Result : Interfaces.C.int;
385 if not Single_Lock then
386 Result := pthread_mutex_unlock (T.Common.LL.L'Access);
387 pragma Assert (Result = 0);
395 -- Dynamic priority ceilings are not supported by the underlying system
397 procedure Set_Ceiling
398 (L : not null access Lock;
399 Prio : System.Any_Priority)
401 pragma Unreferenced (L, Prio);
412 Reason : System.Tasking.Task_States)
414 pragma Unreferenced (Reason);
416 Result : Interfaces.C.int;
419 pragma Assert (Self_ID = Self);
424 (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access);
428 (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access);
431 -- EINTR is not considered a failure
433 pragma Assert (Result = 0 or else Result = EINTR);
440 -- This is for use within the run-time system, so abort is
441 -- assumed to be already deferred, and the caller should be
442 -- holding its own ATCB lock.
444 procedure Timed_Sleep
447 Mode : ST.Delay_Modes;
448 Reason : System.Tasking.Task_States;
449 Timedout : out Boolean;
450 Yielded : out Boolean)
452 pragma Unreferenced (Reason);
454 Base_Time : constant Duration := Monotonic_Clock;
455 Check_Time : Duration := Base_Time;
457 Request : aliased timespec;
458 Result : Interfaces.C.int;
464 if Mode = Relative then
465 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
467 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
470 if Abs_Time > Check_Time then
471 Request := To_Timespec (Abs_Time);
474 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
478 pthread_cond_timedwait
479 (Self_ID.Common.LL.CV'Access,
480 Single_RTS_Lock'Access,
485 pthread_cond_timedwait
486 (Self_ID.Common.LL.CV'Access,
487 Self_ID.Common.LL.L'Access,
491 Check_Time := Monotonic_Clock;
492 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
494 if Result = 0 or else Result = EINTR then
496 -- Somebody may have called Wakeup for us
502 pragma Assert (Result = ETIMEDOUT);
511 -- This is for use in implementing delay statements, so we assume the
512 -- caller is abort-deferred but is holding no locks.
514 procedure Timed_Delay
517 Mode : ST.Delay_Modes)
519 Base_Time : constant Duration := Monotonic_Clock;
520 Check_Time : Duration := Base_Time;
522 Request : aliased timespec;
524 Result : Interfaces.C.int;
525 pragma Warnings (Off, Result);
532 Write_Lock (Self_ID);
534 if Mode = Relative then
535 Abs_Time := Time + Check_Time;
537 Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
540 if Abs_Time > Check_Time then
541 Request := To_Timespec (Abs_Time);
542 Self_ID.Common.State := Delay_Sleep;
545 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
548 Result := pthread_cond_timedwait
549 (Self_ID.Common.LL.CV'Access,
550 Single_RTS_Lock'Access,
553 Result := pthread_cond_timedwait
554 (Self_ID.Common.LL.CV'Access,
555 Self_ID.Common.LL.L'Access,
559 Check_Time := Monotonic_Clock;
560 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
562 pragma Assert (Result = 0 or else
563 Result = ETIMEDOUT or else
567 Self_ID.Common.State := Runnable;
576 Result := sched_yield;
579 ---------------------
580 -- Monotonic_Clock --
581 ---------------------
583 function Monotonic_Clock return Duration is
584 TV : aliased struct_timeval;
585 Result : Interfaces.C.int;
587 Result := gettimeofday (TV'Access, System.Null_Address);
588 pragma Assert (Result = 0);
589 return To_Duration (TV);
596 function RT_Resolution return Duration is
605 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
606 pragma Unreferenced (Reason);
607 Result : Interfaces.C.int;
609 Result := pthread_cond_signal (T.Common.LL.CV'Access);
610 pragma Assert (Result = 0);
617 procedure Yield (Do_Yield : Boolean := True) is
618 Result : Interfaces.C.int;
619 pragma Unreferenced (Result);
622 Result := sched_yield;
630 procedure Set_Priority
632 Prio : System.Any_Priority;
633 Loss_Of_Inheritance : Boolean := False)
635 pragma Unreferenced (Loss_Of_Inheritance);
637 Result : Interfaces.C.int;
638 Param : aliased struct_sched_param;
640 function Get_Policy (Prio : System.Any_Priority) return Character;
641 pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
642 -- Get priority specific dispatching policy
644 Priority_Specific_Policy : constant Character := Get_Policy (Prio);
645 -- Upper case first character of the policy name corresponding to the
646 -- task as set by a Priority_Specific_Dispatching pragma.
649 T.Common.Current_Priority := Prio;
651 -- Priorities are 1 .. 99 on GNU/Linux, so we map 0 .. 98 to 1 .. 99
653 Param.sched_priority := Interfaces.C.int (Prio) + 1;
655 if Dispatching_Policy = 'R'
656 or else Priority_Specific_Policy = 'R'
657 or else Time_Slice_Val > 0
660 pthread_setschedparam
661 (T.Common.LL.Thread, SCHED_RR, Param'Access);
663 elsif Dispatching_Policy = 'F'
664 or else Priority_Specific_Policy = 'F'
665 or else Time_Slice_Val = 0
668 pthread_setschedparam
669 (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
672 Param.sched_priority := 0;
674 pthread_setschedparam
676 SCHED_OTHER, Param'Access);
679 pragma Assert (Result = 0 or else Result = EPERM);
686 function Get_Priority (T : Task_Id) return System.Any_Priority is
688 return T.Common.Current_Priority;
695 procedure Enter_Task (Self_ID : Task_Id) is
697 if Self_ID.Common.Task_Info /= null
698 and then Self_ID.Common.Task_Info.CPU_Affinity = No_CPU
700 raise Invalid_CPU_Number;
703 Self_ID.Common.LL.Thread := pthread_self;
704 Self_ID.Common.LL.LWP := lwp_self;
706 Specific.Set (Self_ID);
708 if Use_Alternate_Stack then
710 Stack : aliased stack_t;
711 Result : Interfaces.C.int;
713 Stack.ss_sp := Self_ID.Common.Task_Alternate_Stack;
714 Stack.ss_size := Alternate_Stack_Size;
716 Result := sigaltstack (Stack'Access, null);
717 pragma Assert (Result = 0);
726 function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
728 return new Ada_Task_Control_Block (Entry_Num);
735 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
737 -----------------------------
738 -- Register_Foreign_Thread --
739 -----------------------------
741 function Register_Foreign_Thread return Task_Id is
743 if Is_Valid_Task then
746 return Register_Foreign_Thread (pthread_self);
748 end Register_Foreign_Thread;
754 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
755 Result : Interfaces.C.int;
758 -- Give the task a unique serial number
760 Self_ID.Serial_Number := Next_Serial_Number;
761 Next_Serial_Number := Next_Serial_Number + 1;
762 pragma Assert (Next_Serial_Number /= 0);
764 Self_ID.Common.LL.Thread := To_pthread_t (-1);
766 if not Single_Lock then
767 Result := pthread_mutex_init (Self_ID.Common.LL.L'Access,
769 pragma Assert (Result = 0 or else Result = ENOMEM);
777 Result := pthread_cond_init (Self_ID.Common.LL.CV'Access,
779 pragma Assert (Result = 0 or else Result = ENOMEM);
784 if not Single_Lock then
785 Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
786 pragma Assert (Result = 0);
797 procedure Create_Task
799 Wrapper : System.Address;
800 Stack_Size : System.Parameters.Size_Type;
801 Priority : System.Any_Priority;
802 Succeeded : out Boolean)
804 Attributes : aliased pthread_attr_t;
805 Adjusted_Stack_Size : Interfaces.C.size_t;
806 Result : Interfaces.C.int;
809 Adjusted_Stack_Size :=
810 Interfaces.C.size_t (Stack_Size + Alternate_Stack_Size);
812 Result := pthread_attr_init (Attributes'Access);
813 pragma Assert (Result = 0 or else Result = ENOMEM);
821 pthread_attr_setstacksize
822 (Attributes'Access, Adjusted_Stack_Size);
823 pragma Assert (Result = 0);
826 pthread_attr_setdetachstate
827 (Attributes'Access, PTHREAD_CREATE_DETACHED);
828 pragma Assert (Result = 0);
830 -- Since the initial signal mask of a thread is inherited from the
831 -- creator, and the Environment task has all its signals masked, we
832 -- do not need to manipulate caller's signal mask at this point.
833 -- All tasks in RTS will have All_Tasks_Mask initially.
835 Result := pthread_create
836 (T.Common.LL.Thread'Access,
838 Thread_Body_Access (Wrapper),
841 (Result = 0 or else Result = EAGAIN or else Result = ENOMEM);
845 Result := pthread_attr_destroy (Attributes'Access);
846 pragma Assert (Result = 0);
854 if T.Common.Task_Info /= null then
855 if T.Common.Task_Info.CPU_Affinity /= Task_Info.Any_CPU then
857 pthread_setaffinity_np
860 T.Common.Task_Info.CPU_Affinity'Access);
861 pragma Assert (Result = 0);
865 Result := pthread_attr_destroy (Attributes'Access);
866 pragma Assert (Result = 0);
868 Set_Priority (T, Priority);
875 procedure Finalize_TCB (T : Task_Id) is
876 Result : Interfaces.C.int;
878 Is_Self : constant Boolean := T = Self;
880 procedure Free is new
881 Ada.Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
884 if not Single_Lock then
885 Result := pthread_mutex_destroy (T.Common.LL.L'Access);
886 pragma Assert (Result = 0);
889 Result := pthread_cond_destroy (T.Common.LL.CV'Access);
890 pragma Assert (Result = 0);
892 if T.Known_Tasks_Index /= -1 then
893 Known_Tasks (T.Known_Tasks_Index) := null;
895 SC.Invalidate_Stack_Cache (T.Common.Compiler_Data.Pri_Stack_Info'Access);
907 procedure Exit_Task is
916 procedure Abort_Task (T : Task_Id) is
917 Result : Interfaces.C.int;
922 Signal (System.Interrupt_Management.Abort_Task_Interrupt));
923 pragma Assert (Result = 0);
930 procedure Initialize (S : in out Suspension_Object) is
931 Result : Interfaces.C.int;
934 -- Initialize internal state (always to False (RM D.10(6)))
939 -- Initialize internal mutex
941 Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
943 pragma Assert (Result = 0 or else Result = ENOMEM);
945 if Result = ENOMEM then
949 -- Initialize internal condition variable
951 Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
953 pragma Assert (Result = 0 or else Result = ENOMEM);
956 Result := pthread_mutex_destroy (S.L'Access);
957 pragma Assert (Result = 0);
959 if Result = ENOMEM then
969 procedure Finalize (S : in out Suspension_Object) is
970 Result : Interfaces.C.int;
973 -- Destroy internal mutex
975 Result := pthread_mutex_destroy (S.L'Access);
976 pragma Assert (Result = 0);
978 -- Destroy internal condition variable
980 Result := pthread_cond_destroy (S.CV'Access);
981 pragma Assert (Result = 0);
988 function Current_State (S : Suspension_Object) return Boolean is
990 -- We do not want to use lock on this read operation. State is marked
991 -- as Atomic so that we ensure that the value retrieved is correct.
1000 procedure Set_False (S : in out Suspension_Object) is
1001 Result : Interfaces.C.int;
1004 SSL.Abort_Defer.all;
1006 Result := pthread_mutex_lock (S.L'Access);
1007 pragma Assert (Result = 0);
1011 Result := pthread_mutex_unlock (S.L'Access);
1012 pragma Assert (Result = 0);
1014 SSL.Abort_Undefer.all;
1021 procedure Set_True (S : in out Suspension_Object) is
1022 Result : Interfaces.C.int;
1025 SSL.Abort_Defer.all;
1027 Result := pthread_mutex_lock (S.L'Access);
1028 pragma Assert (Result = 0);
1030 -- If there is already a task waiting on this suspension object then
1031 -- we resume it, leaving the state of the suspension object to False,
1032 -- as it is specified in ARM D.10 par. 9. Otherwise, it just leaves
1033 -- the state to True.
1039 Result := pthread_cond_signal (S.CV'Access);
1040 pragma Assert (Result = 0);
1046 Result := pthread_mutex_unlock (S.L'Access);
1047 pragma Assert (Result = 0);
1049 SSL.Abort_Undefer.all;
1052 ------------------------
1053 -- Suspend_Until_True --
1054 ------------------------
1056 procedure Suspend_Until_True (S : in out Suspension_Object) is
1057 Result : Interfaces.C.int;
1060 SSL.Abort_Defer.all;
1062 Result := pthread_mutex_lock (S.L'Access);
1063 pragma Assert (Result = 0);
1067 -- Program_Error must be raised upon calling Suspend_Until_True
1068 -- if another task is already waiting on that suspension object
1071 Result := pthread_mutex_unlock (S.L'Access);
1072 pragma Assert (Result = 0);
1074 SSL.Abort_Undefer.all;
1076 raise Program_Error;
1078 -- Suspend the task if the state is False. Otherwise, the task
1079 -- continues its execution, and the state of the suspension object
1080 -- is set to False (ARM D.10 par. 9).
1088 -- Loop in case pthread_cond_wait returns earlier than expected
1089 -- (e.g. in case of EINTR caused by a signal). This should not
1090 -- happen with the current Linux implementation of pthread, but
1091 -- POSIX does not guarantee it, so this may change in the
1094 Result := pthread_cond_wait (S.CV'Access, S.L'Access);
1095 pragma Assert (Result = 0 or else Result = EINTR);
1097 exit when not S.Waiting;
1101 Result := pthread_mutex_unlock (S.L'Access);
1102 pragma Assert (Result = 0);
1104 SSL.Abort_Undefer.all;
1106 end Suspend_Until_True;
1114 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1115 pragma Unreferenced (Self_ID);
1120 --------------------
1121 -- Check_No_Locks --
1122 --------------------
1124 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1125 pragma Unreferenced (Self_ID);
1130 ----------------------
1131 -- Environment_Task --
1132 ----------------------
1134 function Environment_Task return Task_Id is
1136 return Environment_Task_Id;
1137 end Environment_Task;
1143 function Suspend_Task
1145 Thread_Self : Thread_Id) return Boolean
1148 if T.Common.LL.Thread /= Thread_Self then
1149 return pthread_kill (T.Common.LL.Thread, SIGSTOP) = 0;
1159 function Resume_Task
1161 Thread_Self : Thread_Id) return Boolean
1164 if T.Common.LL.Thread /= Thread_Self then
1165 return pthread_kill (T.Common.LL.Thread, SIGCONT) = 0;
1171 --------------------
1172 -- Stop_All_Tasks --
1173 --------------------
1175 procedure Stop_All_Tasks is
1184 function Stop_Task (T : ST.Task_Id) return Boolean is
1185 pragma Unreferenced (T);
1194 function Continue_Task (T : ST.Task_Id) return Boolean is
1195 pragma Unreferenced (T);
1204 procedure Initialize (Environment_Task : Task_Id) is
1205 act : aliased struct_sigaction;
1206 old_act : aliased struct_sigaction;
1207 Tmp_Set : aliased sigset_t;
1208 Result : Interfaces.C.int;
1209 -- Whether to use an alternate signal stack for stack overflows
1212 (Int : System.Interrupt_Management.Interrupt_ID) return Character;
1213 pragma Import (C, State, "__gnat_get_interrupt_state");
1214 -- Get interrupt state. Defined in a-init.c
1215 -- The input argument is the interrupt number,
1216 -- and the result is one of the following:
1218 Default : constant Character := 's';
1219 -- 'n' this interrupt not set by any Interrupt_State pragma
1220 -- 'u' Interrupt_State pragma set state to User
1221 -- 'r' Interrupt_State pragma set state to Runtime
1222 -- 's' Interrupt_State pragma set state to System (use "default"
1226 Environment_Task_Id := Environment_Task;
1228 Interrupt_Management.Initialize;
1230 -- Prepare the set of signals that should be unblocked in all tasks
1232 Result := sigemptyset (Unblocked_Signal_Mask'Access);
1233 pragma Assert (Result = 0);
1235 for J in Interrupt_Management.Interrupt_ID loop
1236 if System.Interrupt_Management.Keep_Unmasked (J) then
1237 Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
1238 pragma Assert (Result = 0);
1242 Result := pthread_mutexattr_init (Mutex_Attr'Access);
1243 pragma Assert (Result = 0);
1245 Result := pthread_condattr_init (Cond_Attr'Access);
1246 pragma Assert (Result = 0);
1248 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1250 -- Initialize the global RTS lock
1252 Specific.Initialize (Environment_Task);
1254 if Use_Alternate_Stack then
1255 Environment_Task.Common.Task_Alternate_Stack :=
1256 Alternate_Stack'Address;
1259 -- Make environment task known here because it doesn't go through
1260 -- Activate_Tasks, which does it for all other tasks.
1262 Known_Tasks (Known_Tasks'First) := Environment_Task;
1263 Environment_Task.Known_Tasks_Index := Known_Tasks'First;
1265 Enter_Task (Environment_Task);
1267 -- Install the abort-signal handler
1270 (System.Interrupt_Management.Abort_Task_Interrupt) /= Default
1273 act.sa_handler := Abort_Handler'Address;
1275 Result := sigemptyset (Tmp_Set'Access);
1276 pragma Assert (Result = 0);
1277 act.sa_mask := Tmp_Set;
1281 (Signal (Interrupt_Management.Abort_Task_Interrupt),
1282 act'Unchecked_Access,
1283 old_act'Unchecked_Access);
1284 pragma Assert (Result = 0);
1288 end System.Task_Primitives.Operations;