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) 1992-2011, 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 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.
43 with System.Task_Info;
44 with System.Tasking.Debug;
45 with System.Interrupt_Management;
46 with System.OS_Primitives;
47 with System.Stack_Checking.Operations;
48 with System.Multiprocessors;
50 with System.Soft_Links;
51 -- We use System.Soft_Links instead of System.Tasking.Initialization
52 -- because the later is a higher level package that we shouldn't depend on.
53 -- For example when using the restricted run time, it is replaced by
54 -- System.Tasking.Restricted.Stages.
56 package body System.Task_Primitives.Operations is
58 package SSL renames System.Soft_Links;
59 package SC renames System.Stack_Checking.Operations;
61 use System.Tasking.Debug;
64 use System.OS_Interface;
65 use System.Parameters;
66 use System.OS_Primitives;
73 -- The followings are logically constants, but need to be initialized
76 Single_RTS_Lock : aliased RTS_Lock;
77 -- This is a lock to allow only one thread of control in the RTS at
78 -- a time; it is used to execute in mutual exclusion from all other tasks.
79 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
81 Environment_Task_Id : Task_Id;
82 -- A variable to hold Task_Id for the environment task
84 Unblocked_Signal_Mask : aliased sigset_t;
85 -- The set of signals that should be unblocked in all tasks
87 -- The followings are internal configuration constants needed
89 Next_Serial_Number : Task_Serial_Number := 100;
90 -- We start at 100 (reserve some special values for using in error checks)
92 Time_Slice_Val : Integer;
93 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
95 Dispatching_Policy : Character;
96 pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
98 Locking_Policy : Character;
99 pragma Import (C, Locking_Policy, "__gl_locking_policy");
101 Foreign_Task_Elaborated : aliased Boolean := True;
102 -- Used to identified fake tasks (i.e., non-Ada Threads)
104 Use_Alternate_Stack : constant Boolean := Alternate_Stack_Size /= 0;
105 -- Whether to use an alternate signal stack for stack overflows
107 Abort_Handler_Installed : Boolean := False;
108 -- True if a handler for the abort signal is installed
110 Null_Thread_Id : constant pthread_t := pthread_t'Last;
111 -- Constant to indicate that the thread identifier has not yet been
120 procedure Initialize (Environment_Task : Task_Id);
121 pragma Inline (Initialize);
122 -- Initialize various data needed by this package
124 function Is_Valid_Task return Boolean;
125 pragma Inline (Is_Valid_Task);
126 -- Does executing thread have a TCB?
128 procedure Set (Self_Id : Task_Id);
130 -- Set the self id for the current task
132 function Self return Task_Id;
133 pragma Inline (Self);
134 -- Return a pointer to the Ada Task Control Block of the calling task
138 package body Specific is separate;
139 -- The body of this package is target specific
141 ----------------------------------
142 -- ATCB allocation/deallocation --
143 ----------------------------------
145 package body ATCB_Allocation is separate;
146 -- The body of this package is shared across several targets
148 ---------------------------------
149 -- Support for foreign threads --
150 ---------------------------------
152 function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
153 -- Allocate and Initialize a new ATCB for the current Thread
155 function Register_Foreign_Thread
156 (Thread : Thread_Id) return Task_Id is separate;
158 -----------------------
159 -- Local Subprograms --
160 -----------------------
162 procedure Abort_Handler (signo : Signal);
168 procedure Abort_Handler (signo : Signal) is
169 pragma Unreferenced (signo);
171 Self_Id : constant Task_Id := Self;
172 Result : Interfaces.C.int;
173 Old_Set : aliased sigset_t;
176 -- It's not safe to raise an exception when using GCC ZCX mechanism.
177 -- Note that we still need to install a signal handler, since in some
178 -- cases (e.g. shutdown of the Server_Task in System.Interrupts) we
179 -- need to send the Abort signal to a task.
181 if ZCX_By_Default then
185 if Self_Id.Deferral_Level = 0
186 and then Self_Id.Pending_ATC_Level < Self_Id.ATC_Nesting_Level
187 and then not Self_Id.Aborting
189 Self_Id.Aborting := True;
191 -- Make sure signals used for RTS internal purpose are unmasked
196 Unblocked_Signal_Mask'Access,
198 pragma Assert (Result = 0);
200 raise Standard'Abort_Signal;
208 procedure Lock_RTS is
210 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
217 procedure Unlock_RTS is
219 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
226 -- The underlying thread system extends the memory (up to 2MB) when needed
228 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
229 pragma Unreferenced (T);
230 pragma Unreferenced (On);
239 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
241 return T.Common.LL.Thread;
248 function Self return Task_Id renames Specific.Self;
250 ---------------------
251 -- Initialize_Lock --
252 ---------------------
254 -- Note: mutexes and cond_variables needed per-task basis are initialized
255 -- in Initialize_TCB and the Storage_Error is handled. Other mutexes (such
256 -- as RTS_Lock, Memory_Lock...) used in RTS is initialized before any
257 -- status change of RTS. Therefore raising Storage_Error in the following
258 -- routines should be able to be handled safely.
260 procedure Initialize_Lock
261 (Prio : System.Any_Priority;
262 L : not null access Lock)
264 pragma Unreferenced (Prio);
267 if Locking_Policy = 'R' then
269 RWlock_Attr : aliased pthread_rwlockattr_t;
270 Result : Interfaces.C.int;
273 -- Set the rwlock to prefer writer to avoid writers starvation
275 Result := pthread_rwlockattr_init (RWlock_Attr'Access);
276 pragma Assert (Result = 0);
278 Result := pthread_rwlockattr_setkind_np
280 PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP);
281 pragma Assert (Result = 0);
283 Result := pthread_rwlock_init (L.RW'Access, RWlock_Attr'Access);
285 pragma Assert (Result = 0 or else Result = ENOMEM);
287 if Result = ENOMEM then
288 raise Storage_Error with "Failed to allocate a lock";
294 Result : Interfaces.C.int;
297 Result := pthread_mutex_init (L.WO'Access, null);
299 pragma Assert (Result = 0 or else Result = ENOMEM);
301 if Result = ENOMEM then
302 raise Storage_Error with "Failed to allocate a lock";
308 procedure Initialize_Lock
309 (L : not null access RTS_Lock;
312 pragma Unreferenced (Level);
314 Result : Interfaces.C.int;
317 Result := pthread_mutex_init (L, null);
319 pragma Assert (Result = 0 or else Result = ENOMEM);
321 if Result = ENOMEM then
330 procedure Finalize_Lock (L : not null access Lock) is
331 Result : Interfaces.C.int;
333 if Locking_Policy = 'R' then
334 Result := pthread_rwlock_destroy (L.RW'Access);
336 Result := pthread_mutex_destroy (L.WO'Access);
338 pragma Assert (Result = 0);
341 procedure Finalize_Lock (L : not null access RTS_Lock) is
342 Result : Interfaces.C.int;
344 Result := pthread_mutex_destroy (L);
345 pragma Assert (Result = 0);
353 (L : not null access Lock;
354 Ceiling_Violation : out Boolean)
356 Result : Interfaces.C.int;
358 if Locking_Policy = 'R' then
359 Result := pthread_rwlock_wrlock (L.RW'Access);
361 Result := pthread_mutex_lock (L.WO'Access);
364 Ceiling_Violation := Result = EINVAL;
366 -- Assume the cause of EINVAL is a priority ceiling violation
368 pragma Assert (Result = 0 or else Result = EINVAL);
372 (L : not null access RTS_Lock;
373 Global_Lock : Boolean := False)
375 Result : Interfaces.C.int;
377 if not Single_Lock or else Global_Lock then
378 Result := pthread_mutex_lock (L);
379 pragma Assert (Result = 0);
383 procedure Write_Lock (T : Task_Id) is
384 Result : Interfaces.C.int;
386 if not Single_Lock then
387 Result := pthread_mutex_lock (T.Common.LL.L'Access);
388 pragma Assert (Result = 0);
397 (L : not null access Lock;
398 Ceiling_Violation : out Boolean)
400 Result : Interfaces.C.int;
402 if Locking_Policy = 'R' then
403 Result := pthread_rwlock_rdlock (L.RW'Access);
405 Result := pthread_mutex_lock (L.WO'Access);
408 Ceiling_Violation := Result = EINVAL;
410 -- Assume the cause of EINVAL is a priority ceiling violation
412 pragma Assert (Result = 0 or else Result = EINVAL);
419 procedure Unlock (L : not null access Lock) is
420 Result : Interfaces.C.int;
422 if Locking_Policy = 'R' then
423 Result := pthread_rwlock_unlock (L.RW'Access);
425 Result := pthread_mutex_unlock (L.WO'Access);
427 pragma Assert (Result = 0);
431 (L : not null access RTS_Lock;
432 Global_Lock : Boolean := False)
434 Result : Interfaces.C.int;
436 if not Single_Lock or else Global_Lock then
437 Result := pthread_mutex_unlock (L);
438 pragma Assert (Result = 0);
442 procedure Unlock (T : Task_Id) is
443 Result : Interfaces.C.int;
445 if not Single_Lock then
446 Result := pthread_mutex_unlock (T.Common.LL.L'Access);
447 pragma Assert (Result = 0);
455 -- Dynamic priority ceilings are not supported by the underlying system
457 procedure Set_Ceiling
458 (L : not null access Lock;
459 Prio : System.Any_Priority)
461 pragma Unreferenced (L, Prio);
472 Reason : System.Tasking.Task_States)
474 pragma Unreferenced (Reason);
476 Result : Interfaces.C.int;
479 pragma Assert (Self_ID = Self);
483 (cond => Self_ID.Common.LL.CV'Access,
484 mutex => (if Single_Lock
485 then Single_RTS_Lock'Access
486 else Self_ID.Common.LL.L'Access));
488 -- EINTR is not considered a failure
490 pragma Assert (Result = 0 or else Result = EINTR);
497 -- This is for use within the run-time system, so abort is
498 -- assumed to be already deferred, and the caller should be
499 -- holding its own ATCB lock.
501 procedure Timed_Sleep
504 Mode : ST.Delay_Modes;
505 Reason : System.Tasking.Task_States;
506 Timedout : out Boolean;
507 Yielded : out Boolean)
509 pragma Unreferenced (Reason);
511 Base_Time : constant Duration := Monotonic_Clock;
512 Check_Time : Duration := Base_Time;
514 Request : aliased timespec;
515 Result : Interfaces.C.int;
523 then Duration'Min (Time, Max_Sensible_Delay) + Check_Time
524 else Duration'Min (Check_Time + Max_Sensible_Delay, Time));
526 if Abs_Time > Check_Time then
527 Request := To_Timespec (Abs_Time);
530 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
533 pthread_cond_timedwait
534 (cond => Self_ID.Common.LL.CV'Access,
535 mutex => (if Single_Lock
536 then Single_RTS_Lock'Access
537 else Self_ID.Common.LL.L'Access),
538 abstime => Request'Access);
540 Check_Time := Monotonic_Clock;
541 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
543 if Result = 0 or else Result = EINTR then
545 -- Somebody may have called Wakeup for us
551 pragma Assert (Result = ETIMEDOUT);
560 -- This is for use in implementing delay statements, so we assume the
561 -- caller is abort-deferred but is holding no locks.
563 procedure Timed_Delay
566 Mode : ST.Delay_Modes)
568 Base_Time : constant Duration := Monotonic_Clock;
569 Check_Time : Duration := Base_Time;
571 Request : aliased timespec;
573 Result : Interfaces.C.int;
574 pragma Warnings (Off, Result);
581 Write_Lock (Self_ID);
585 then Time + Check_Time
586 else Duration'Min (Check_Time + Max_Sensible_Delay, Time));
588 if Abs_Time > Check_Time then
589 Request := To_Timespec (Abs_Time);
590 Self_ID.Common.State := Delay_Sleep;
593 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
596 pthread_cond_timedwait
597 (cond => Self_ID.Common.LL.CV'Access,
598 mutex => (if Single_Lock
599 then Single_RTS_Lock'Access
600 else Self_ID.Common.LL.L'Access),
601 abstime => Request'Access);
603 Check_Time := Monotonic_Clock;
604 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
606 pragma Assert (Result = 0 or else
607 Result = ETIMEDOUT or else
611 Self_ID.Common.State := Runnable;
620 Result := sched_yield;
623 ---------------------
624 -- Monotonic_Clock --
625 ---------------------
627 function Monotonic_Clock return Duration is
630 type timeval is array (1 .. 2) of C.long;
632 procedure timeval_to_duration
633 (T : not null access timeval;
634 sec : not null access C.long;
635 usec : not null access C.long);
636 pragma Import (C, timeval_to_duration, "__gnat_timeval_to_duration");
638 Micro : constant := 10**6;
639 sec : aliased C.long;
640 usec : aliased C.long;
641 TV : aliased timeval;
644 function gettimeofday
645 (Tv : access timeval;
646 Tz : System.Address := System.Null_Address) return int;
647 pragma Import (C, gettimeofday, "gettimeofday");
650 Result := gettimeofday (TV'Access, System.Null_Address);
651 pragma Assert (Result = 0);
652 timeval_to_duration (TV'Access, sec'Access, usec'Access);
653 return Duration (sec) + Duration (usec) / Micro;
660 function RT_Resolution return Duration is
669 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
670 pragma Unreferenced (Reason);
671 Result : Interfaces.C.int;
673 Result := pthread_cond_signal (T.Common.LL.CV'Access);
674 pragma Assert (Result = 0);
681 procedure Yield (Do_Yield : Boolean := True) is
682 Result : Interfaces.C.int;
683 pragma Unreferenced (Result);
686 Result := sched_yield;
694 procedure Set_Priority
696 Prio : System.Any_Priority;
697 Loss_Of_Inheritance : Boolean := False)
699 pragma Unreferenced (Loss_Of_Inheritance);
701 Result : Interfaces.C.int;
702 Param : aliased struct_sched_param;
704 function Get_Policy (Prio : System.Any_Priority) return Character;
705 pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
706 -- Get priority specific dispatching policy
708 Priority_Specific_Policy : constant Character := Get_Policy (Prio);
709 -- Upper case first character of the policy name corresponding to the
710 -- task as set by a Priority_Specific_Dispatching pragma.
713 T.Common.Current_Priority := Prio;
715 -- Priorities are 1 .. 99 on GNU/Linux, so we map 0 .. 98 to 1 .. 99
717 Param.sched_priority := Interfaces.C.int (Prio) + 1;
719 if Dispatching_Policy = 'R'
720 or else Priority_Specific_Policy = 'R'
721 or else Time_Slice_Val > 0
724 pthread_setschedparam
725 (T.Common.LL.Thread, SCHED_RR, Param'Access);
727 elsif Dispatching_Policy = 'F'
728 or else Priority_Specific_Policy = 'F'
729 or else Time_Slice_Val = 0
732 pthread_setschedparam
733 (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
736 Param.sched_priority := 0;
738 pthread_setschedparam
740 SCHED_OTHER, Param'Access);
743 pragma Assert (Result = 0 or else Result = EPERM);
750 function Get_Priority (T : Task_Id) return System.Any_Priority is
752 return T.Common.Current_Priority;
759 procedure Enter_Task (Self_ID : Task_Id) is
761 if Self_ID.Common.Task_Info /= null
762 and then Self_ID.Common.Task_Info.CPU_Affinity = No_CPU
764 raise Invalid_CPU_Number;
767 Self_ID.Common.LL.Thread := pthread_self;
768 Self_ID.Common.LL.LWP := lwp_self;
770 Specific.Set (Self_ID);
772 if Use_Alternate_Stack
773 and then Self_ID.Common.Task_Alternate_Stack /= Null_Address
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 Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
794 -----------------------------
795 -- Register_Foreign_Thread --
796 -----------------------------
798 function Register_Foreign_Thread return Task_Id is
800 if Is_Valid_Task then
803 return Register_Foreign_Thread (pthread_self);
805 end Register_Foreign_Thread;
811 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
812 Cond_Attr : aliased pthread_condattr_t;
813 Result : Interfaces.C.int;
816 -- Give the task a unique serial number
818 Self_ID.Serial_Number := Next_Serial_Number;
819 Next_Serial_Number := Next_Serial_Number + 1;
820 pragma Assert (Next_Serial_Number /= 0);
822 Self_ID.Common.LL.Thread := Null_Thread_Id;
824 if not Single_Lock then
826 pthread_mutex_init (Self_ID.Common.LL.L'Access, null);
827 pragma Assert (Result = 0 or else Result = ENOMEM);
835 Result := pthread_condattr_init (Cond_Attr'Access);
836 pragma Assert (Result = 0);
839 pthread_cond_init (Self_ID.Common.LL.CV'Access, Cond_Attr'Access);
840 pragma Assert (Result = 0 or else Result = ENOMEM);
845 if not Single_Lock then
846 Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
847 pragma Assert (Result = 0);
858 procedure Create_Task
860 Wrapper : System.Address;
861 Stack_Size : System.Parameters.Size_Type;
862 Priority : System.Any_Priority;
863 Succeeded : out Boolean)
865 Attributes : aliased pthread_attr_t;
866 Adjusted_Stack_Size : Interfaces.C.size_t;
867 Result : Interfaces.C.int;
869 use type System.Multiprocessors.CPU_Range;
872 -- Check whether both Dispatching_Domain and CPU are specified for
873 -- the task, and the CPU value is not contained within the range of
874 -- processors for the domain.
876 if T.Common.Domain /= null
877 and then T.Common.Base_CPU /= System.Multiprocessors.Not_A_Specific_CPU
879 (T.Common.Base_CPU not in T.Common.Domain'Range
880 or else not T.Common.Domain (T.Common.Base_CPU))
886 Adjusted_Stack_Size :=
887 Interfaces.C.size_t (Stack_Size + Alternate_Stack_Size);
889 Result := pthread_attr_init (Attributes'Access);
890 pragma Assert (Result = 0 or else Result = ENOMEM);
898 pthread_attr_setstacksize (Attributes'Access, Adjusted_Stack_Size);
899 pragma Assert (Result = 0);
902 pthread_attr_setdetachstate
903 (Attributes'Access, PTHREAD_CREATE_DETACHED);
904 pragma Assert (Result = 0);
906 -- Set the required attributes for the creation of the thread
908 -- Note: Previously, we called pthread_setaffinity_np (after thread
909 -- creation but before thread activation) to set the affinity but it was
910 -- not behaving as expected. Setting the required attributes for the
911 -- creation of the thread works correctly and it is more appropriate.
913 -- Do nothing if required support not provided by the operating system
915 if pthread_attr_setaffinity_np'Address = System.Null_Address then
918 -- Support is available
920 elsif T.Common.Base_CPU /= System.Multiprocessors.Not_A_Specific_CPU then
922 CPUs : constant size_t :=
924 (System.Multiprocessors.Number_Of_CPUs);
925 CPU_Set : constant cpu_set_t_ptr := CPU_ALLOC (CPUs);
926 Size : constant size_t := CPU_ALLOC_SIZE (CPUs);
929 CPU_ZERO (Size, CPU_Set);
930 System.OS_Interface.CPU_SET
931 (int (T.Common.Base_CPU), Size, CPU_Set);
933 pthread_attr_setaffinity_np (Attributes'Access, Size, CPU_Set);
934 pragma Assert (Result = 0);
941 elsif T.Common.Task_Info /= null then
943 pthread_attr_setaffinity_np
946 T.Common.Task_Info.CPU_Affinity'Access);
947 pragma Assert (Result = 0);
949 -- Handle dispatching domains
951 -- To avoid changing CPU affinities when not needed, we set the
952 -- affinity only when assigning to a domain other than the default
953 -- one, or when the default one has been modified.
955 elsif T.Common.Domain /= null and then
956 (T.Common.Domain /= ST.System_Domain
957 or else T.Common.Domain.all /=
958 (Multiprocessors.CPU'First ..
959 Multiprocessors.Number_Of_CPUs => True))
962 CPUs : constant size_t :=
964 (System.Multiprocessors.Number_Of_CPUs);
965 CPU_Set : constant cpu_set_t_ptr := CPU_ALLOC (CPUs);
966 Size : constant size_t := CPU_ALLOC_SIZE (CPUs);
969 CPU_ZERO (Size, CPU_Set);
971 -- Set the affinity to all the processors belonging to the
972 -- dispatching domain.
974 for Proc in T.Common.Domain'Range loop
975 if T.Common.Domain (Proc) then
976 System.OS_Interface.CPU_SET (int (Proc), Size, CPU_Set);
981 pthread_attr_setaffinity_np (Attributes'Access, Size, CPU_Set);
982 pragma Assert (Result = 0);
988 -- Since the initial signal mask of a thread is inherited from the
989 -- creator, and the Environment task has all its signals masked, we
990 -- do not need to manipulate caller's signal mask at this point.
991 -- All tasks in RTS will have All_Tasks_Mask initially.
993 -- Note: the use of Unrestricted_Access in the following call is needed
994 -- because otherwise we have an error of getting a access-to-volatile
995 -- value which points to a non-volatile object. But in this case it is
996 -- safe to do this, since we know we have no problems with aliasing and
997 -- Unrestricted_Access bypasses this check.
1001 (T.Common.LL.Thread'Unrestricted_Access,
1003 Thread_Body_Access (Wrapper),
1007 (Result = 0 or else Result = EAGAIN or else Result = ENOMEM);
1011 Result := pthread_attr_destroy (Attributes'Access);
1012 pragma Assert (Result = 0);
1018 Result := pthread_attr_destroy (Attributes'Access);
1019 pragma Assert (Result = 0);
1021 Set_Priority (T, Priority);
1028 procedure Finalize_TCB (T : Task_Id) is
1029 Result : Interfaces.C.int;
1032 if not Single_Lock then
1033 Result := pthread_mutex_destroy (T.Common.LL.L'Access);
1034 pragma Assert (Result = 0);
1037 Result := pthread_cond_destroy (T.Common.LL.CV'Access);
1038 pragma Assert (Result = 0);
1040 if T.Known_Tasks_Index /= -1 then
1041 Known_Tasks (T.Known_Tasks_Index) := null;
1044 SC.Invalidate_Stack_Cache (T.Common.Compiler_Data.Pri_Stack_Info'Access);
1046 ATCB_Allocation.Free_ATCB (T);
1053 procedure Exit_Task is
1055 Specific.Set (null);
1062 procedure Abort_Task (T : Task_Id) is
1063 Result : Interfaces.C.int;
1065 if Abort_Handler_Installed then
1068 (T.Common.LL.Thread,
1069 Signal (System.Interrupt_Management.Abort_Task_Interrupt));
1070 pragma Assert (Result = 0);
1078 procedure Initialize (S : in out Suspension_Object) is
1079 Result : Interfaces.C.int;
1082 -- Initialize internal state (always to False (RM D.10(6)))
1087 -- Initialize internal mutex
1089 Result := pthread_mutex_init (S.L'Access, null);
1091 pragma Assert (Result = 0 or else Result = ENOMEM);
1093 if Result = ENOMEM then
1094 raise Storage_Error;
1097 -- Initialize internal condition variable
1099 Result := pthread_cond_init (S.CV'Access, null);
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;
1117 procedure Finalize (S : in out Suspension_Object) is
1118 Result : Interfaces.C.int;
1121 -- Destroy internal mutex
1123 Result := pthread_mutex_destroy (S.L'Access);
1124 pragma Assert (Result = 0);
1126 -- Destroy internal condition variable
1128 Result := pthread_cond_destroy (S.CV'Access);
1129 pragma Assert (Result = 0);
1136 function Current_State (S : Suspension_Object) return Boolean is
1138 -- We do not want to use lock on this read operation. State is marked
1139 -- as Atomic so that we ensure that the value retrieved is correct.
1148 procedure Set_False (S : in out Suspension_Object) is
1149 Result : Interfaces.C.int;
1152 SSL.Abort_Defer.all;
1154 Result := pthread_mutex_lock (S.L'Access);
1155 pragma Assert (Result = 0);
1159 Result := pthread_mutex_unlock (S.L'Access);
1160 pragma Assert (Result = 0);
1162 SSL.Abort_Undefer.all;
1169 procedure Set_True (S : in out Suspension_Object) is
1170 Result : Interfaces.C.int;
1173 SSL.Abort_Defer.all;
1175 Result := pthread_mutex_lock (S.L'Access);
1176 pragma Assert (Result = 0);
1178 -- If there is already a task waiting on this suspension object then
1179 -- we resume it, leaving the state of the suspension object to False,
1180 -- as it is specified in ARM D.10 par. 9. Otherwise, it just leaves
1181 -- the state to True.
1187 Result := pthread_cond_signal (S.CV'Access);
1188 pragma Assert (Result = 0);
1194 Result := pthread_mutex_unlock (S.L'Access);
1195 pragma Assert (Result = 0);
1197 SSL.Abort_Undefer.all;
1200 ------------------------
1201 -- Suspend_Until_True --
1202 ------------------------
1204 procedure Suspend_Until_True (S : in out Suspension_Object) is
1205 Result : Interfaces.C.int;
1208 SSL.Abort_Defer.all;
1210 Result := pthread_mutex_lock (S.L'Access);
1211 pragma Assert (Result = 0);
1215 -- Program_Error must be raised upon calling Suspend_Until_True
1216 -- if another task is already waiting on that suspension object
1219 Result := pthread_mutex_unlock (S.L'Access);
1220 pragma Assert (Result = 0);
1222 SSL.Abort_Undefer.all;
1224 raise Program_Error;
1227 -- Suspend the task if the state is False. Otherwise, the task
1228 -- continues its execution, and the state of the suspension object
1229 -- is set to False (ARM D.10 par. 9).
1237 -- Loop in case pthread_cond_wait returns earlier than expected
1238 -- (e.g. in case of EINTR caused by a signal). This should not
1239 -- happen with the current Linux implementation of pthread, but
1240 -- POSIX does not guarantee it so this may change in future.
1242 Result := pthread_cond_wait (S.CV'Access, S.L'Access);
1243 pragma Assert (Result = 0 or else Result = EINTR);
1245 exit when not S.Waiting;
1249 Result := pthread_mutex_unlock (S.L'Access);
1250 pragma Assert (Result = 0);
1252 SSL.Abort_Undefer.all;
1254 end Suspend_Until_True;
1262 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1263 pragma Unreferenced (Self_ID);
1268 --------------------
1269 -- Check_No_Locks --
1270 --------------------
1272 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1273 pragma Unreferenced (Self_ID);
1278 ----------------------
1279 -- Environment_Task --
1280 ----------------------
1282 function Environment_Task return Task_Id is
1284 return Environment_Task_Id;
1285 end Environment_Task;
1291 function Suspend_Task
1293 Thread_Self : Thread_Id) return Boolean
1296 if T.Common.LL.Thread /= Thread_Self then
1297 return pthread_kill (T.Common.LL.Thread, SIGSTOP) = 0;
1307 function Resume_Task
1309 Thread_Self : Thread_Id) return Boolean
1312 if T.Common.LL.Thread /= Thread_Self then
1313 return pthread_kill (T.Common.LL.Thread, SIGCONT) = 0;
1319 --------------------
1320 -- Stop_All_Tasks --
1321 --------------------
1323 procedure Stop_All_Tasks is
1332 function Stop_Task (T : ST.Task_Id) return Boolean is
1333 pragma Unreferenced (T);
1342 function Continue_Task (T : ST.Task_Id) return Boolean is
1343 pragma Unreferenced (T);
1352 procedure Initialize (Environment_Task : Task_Id) is
1353 act : aliased struct_sigaction;
1354 old_act : aliased struct_sigaction;
1355 Tmp_Set : aliased sigset_t;
1356 Result : Interfaces.C.int;
1357 -- Whether to use an alternate signal stack for stack overflows
1360 (Int : System.Interrupt_Management.Interrupt_ID) return Character;
1361 pragma Import (C, State, "__gnat_get_interrupt_state");
1362 -- Get interrupt state. Defined in a-init.c
1363 -- The input argument is the interrupt number,
1364 -- and the result is one of the following:
1366 Default : constant Character := 's';
1367 -- 'n' this interrupt not set by any Interrupt_State pragma
1368 -- 'u' Interrupt_State pragma set state to User
1369 -- 'r' Interrupt_State pragma set state to Runtime
1370 -- 's' Interrupt_State pragma set state to System (use "default"
1373 use type System.Multiprocessors.CPU_Range;
1376 Environment_Task_Id := Environment_Task;
1378 Interrupt_Management.Initialize;
1380 -- Prepare the set of signals that should be unblocked in all tasks
1382 Result := sigemptyset (Unblocked_Signal_Mask'Access);
1383 pragma Assert (Result = 0);
1385 for J in Interrupt_Management.Interrupt_ID loop
1386 if System.Interrupt_Management.Keep_Unmasked (J) then
1387 Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
1388 pragma Assert (Result = 0);
1392 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1394 -- Initialize the global RTS lock
1396 Specific.Initialize (Environment_Task);
1398 if Use_Alternate_Stack then
1399 Environment_Task.Common.Task_Alternate_Stack :=
1400 Alternate_Stack'Address;
1403 -- Make environment task known here because it doesn't go through
1404 -- Activate_Tasks, which does it for all other tasks.
1406 Known_Tasks (Known_Tasks'First) := Environment_Task;
1407 Environment_Task.Known_Tasks_Index := Known_Tasks'First;
1409 Enter_Task (Environment_Task);
1412 (System.Interrupt_Management.Abort_Task_Interrupt) /= Default
1415 act.sa_handler := Abort_Handler'Address;
1417 Result := sigemptyset (Tmp_Set'Access);
1418 pragma Assert (Result = 0);
1419 act.sa_mask := Tmp_Set;
1423 (Signal (Interrupt_Management.Abort_Task_Interrupt),
1424 act'Unchecked_Access,
1425 old_act'Unchecked_Access);
1426 pragma Assert (Result = 0);
1427 Abort_Handler_Installed := True;
1430 -- pragma CPU and dispatching domains for the environment task
1432 Set_Task_Affinity (Environment_Task);
1435 -----------------------
1436 -- Set_Task_Affinity --
1437 -----------------------
1439 procedure Set_Task_Affinity (T : ST.Task_Id) is
1440 use type System.Multiprocessors.CPU_Range;
1443 -- Do nothing if there is no support for setting affinities or the
1444 -- underlying thread has not yet been created. If the thread has not
1445 -- yet been created then the proper affinity will be set during its
1448 if pthread_setaffinity_np'Address /= System.Null_Address
1449 and then T.Common.LL.Thread /= Null_Thread_Id
1452 CPUs : constant size_t :=
1454 (System.Multiprocessors.Number_Of_CPUs);
1455 CPU_Set : cpu_set_t_ptr := null;
1456 Size : constant size_t := CPU_ALLOC_SIZE (CPUs);
1458 Result : Interfaces.C.int;
1461 -- We look at the specific CPU (Base_CPU) first, then at the
1462 -- Task_Info field, and finally at the assigned dispatching
1465 if T.Common.Base_CPU /= Multiprocessors.Not_A_Specific_CPU then
1467 -- Set the affinity to an unique CPU
1469 CPU_Set := CPU_ALLOC (CPUs);
1470 System.OS_Interface.CPU_ZERO (Size, CPU_Set);
1471 System.OS_Interface.CPU_SET
1472 (int (T.Common.Base_CPU), Size, CPU_Set);
1476 elsif T.Common.Task_Info /= null then
1477 CPU_Set := T.Common.Task_Info.CPU_Affinity'Access;
1479 -- Handle dispatching domains
1481 elsif T.Common.Domain /= null and then
1482 (T.Common.Domain /= ST.System_Domain
1483 or else T.Common.Domain.all /=
1484 (Multiprocessors.CPU'First ..
1485 Multiprocessors.Number_Of_CPUs => True))
1487 -- Set the affinity to all the processors belonging to the
1488 -- dispatching domain. To avoid changing CPU affinities when
1489 -- not needed, we set the affinity only when assigning to a
1490 -- domain other than the default one, or when the default one
1491 -- has been modified.
1493 CPU_Set := CPU_ALLOC (CPUs);
1494 System.OS_Interface.CPU_ZERO (Size, CPU_Set);
1496 for Proc in T.Common.Domain'Range loop
1497 System.OS_Interface.CPU_SET (int (Proc), Size, CPU_Set);
1501 -- We set the new affinity if needed. Otherwise, the new task
1502 -- will inherit its creator's CPU affinity mask (according to
1503 -- the documentation of pthread_setaffinity_np), which is
1504 -- consistent with Ada's required semantics.
1506 if CPU_Set /= null then
1508 pthread_setaffinity_np (T.Common.LL.Thread, Size, CPU_Set);
1509 pragma Assert (Result = 0);
1515 end Set_Task_Affinity;
1517 end System.Task_Primitives.Operations;