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) 1992-2010, 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;
51 with System.Multiprocessors;
53 with System.Soft_Links;
54 -- We use System.Soft_Links instead of System.Tasking.Initialization
55 -- because the later is a higher level package that we shouldn't depend on.
56 -- For example when using the restricted run time, it is replaced by
57 -- System.Tasking.Restricted.Stages.
59 package body System.Task_Primitives.Operations is
61 package SSL renames System.Soft_Links;
62 package SC renames System.Stack_Checking.Operations;
64 use System.Tasking.Debug;
67 use System.OS_Interface;
68 use System.Parameters;
69 use System.OS_Primitives;
76 -- The followings are logically constants, but need to be initialized
79 Single_RTS_Lock : aliased RTS_Lock;
80 -- This is a lock to allow only one thread of control in the RTS at
81 -- a time; it is used to execute in mutual exclusion from all other tasks.
82 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
84 ATCB_Key : aliased pthread_key_t;
85 -- Key used to find the Ada Task_Id associated with a thread
87 Environment_Task_Id : Task_Id;
88 -- A variable to hold Task_Id for the environment task
90 Unblocked_Signal_Mask : aliased sigset_t;
91 -- The set of signals that should be unblocked in all tasks
93 -- The followings are internal configuration constants needed
95 Next_Serial_Number : Task_Serial_Number := 100;
96 -- We start at 100 (reserve some special values for using in error checks)
98 Time_Slice_Val : Integer;
99 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
101 Dispatching_Policy : Character;
102 pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
104 -- The following are effectively constants, but they need to be initialized
105 -- by calling a pthread_ function.
107 Mutex_Attr : aliased pthread_mutexattr_t;
108 Cond_Attr : aliased pthread_condattr_t;
110 Foreign_Task_Elaborated : aliased Boolean := True;
111 -- Used to identified fake tasks (i.e., non-Ada Threads)
113 Use_Alternate_Stack : constant Boolean := Alternate_Stack_Size /= 0;
114 -- Whether to use an alternate signal stack for stack overflows
116 Abort_Handler_Installed : Boolean := False;
117 -- True if a handler for the abort signal is installed
125 procedure Initialize (Environment_Task : Task_Id);
126 pragma Inline (Initialize);
127 -- Initialize various data needed by this package
129 function Is_Valid_Task return Boolean;
130 pragma Inline (Is_Valid_Task);
131 -- Does executing thread have a TCB?
133 procedure Set (Self_Id : Task_Id);
135 -- Set the self id for the current task
137 function Self return Task_Id;
138 pragma Inline (Self);
139 -- Return a pointer to the Ada Task Control Block of the calling task
143 package body Specific is separate;
144 -- The body of this package is target specific
146 ---------------------------------
147 -- Support for foreign threads --
148 ---------------------------------
150 function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
151 -- Allocate and Initialize a new ATCB for the current Thread
153 function Register_Foreign_Thread
154 (Thread : Thread_Id) return Task_Id is separate;
156 -----------------------
157 -- Local Subprograms --
158 -----------------------
160 subtype unsigned_long is Interfaces.C.unsigned_long;
162 procedure Abort_Handler (signo : Signal);
164 function To_pthread_t is new Ada.Unchecked_Conversion
165 (unsigned_long, System.OS_Interface.pthread_t);
171 procedure Abort_Handler (signo : Signal) is
172 pragma Unreferenced (signo);
174 Self_Id : constant Task_Id := Self;
175 Result : Interfaces.C.int;
176 Old_Set : aliased sigset_t;
179 -- It's not safe to raise an exception when using GCC ZCX mechanism.
180 -- Note that we still need to install a signal handler, since in some
181 -- cases (e.g. shutdown of the Server_Task in System.Interrupts) we
182 -- need to send the Abort signal to a task.
184 if ZCX_By_Default and then GCC_ZCX_Support then
188 if Self_Id.Deferral_Level = 0
189 and then Self_Id.Pending_ATC_Level < Self_Id.ATC_Nesting_Level
190 and then not Self_Id.Aborting
192 Self_Id.Aborting := True;
194 -- Make sure signals used for RTS internal purpose are unmasked
199 Unblocked_Signal_Mask'Access,
201 pragma Assert (Result = 0);
203 raise Standard'Abort_Signal;
211 procedure Lock_RTS is
213 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
220 procedure Unlock_RTS is
222 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
229 -- The underlying thread system extends the memory (up to 2MB) when needed
231 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
232 pragma Unreferenced (T);
233 pragma Unreferenced (On);
242 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
244 return T.Common.LL.Thread;
251 function Self return Task_Id renames Specific.Self;
253 ---------------------
254 -- Initialize_Lock --
255 ---------------------
257 -- Note: mutexes and cond_variables needed per-task basis are initialized
258 -- in Initialize_TCB and the Storage_Error is handled. Other mutexes (such
259 -- as RTS_Lock, Memory_Lock...) used in RTS is initialized before any
260 -- status change of RTS. Therefore raising Storage_Error in the following
261 -- routines should be able to be handled safely.
263 procedure Initialize_Lock
264 (Prio : System.Any_Priority;
265 L : not null access Lock)
267 pragma Unreferenced (Prio);
269 Result : Interfaces.C.int;
272 Result := pthread_mutex_init (L, Mutex_Attr'Access);
274 pragma Assert (Result = 0 or else Result = ENOMEM);
276 if Result = ENOMEM then
277 raise Storage_Error with "Failed to allocate a lock";
281 procedure Initialize_Lock
282 (L : not null access RTS_Lock;
285 pragma Unreferenced (Level);
287 Result : Interfaces.C.int;
290 Result := pthread_mutex_init (L, Mutex_Attr'Access);
292 pragma Assert (Result = 0 or else Result = ENOMEM);
294 if Result = ENOMEM then
303 procedure Finalize_Lock (L : not null access Lock) is
304 Result : Interfaces.C.int;
306 Result := pthread_mutex_destroy (L);
307 pragma Assert (Result = 0);
310 procedure Finalize_Lock (L : not null access RTS_Lock) is
311 Result : Interfaces.C.int;
313 Result := pthread_mutex_destroy (L);
314 pragma Assert (Result = 0);
322 (L : not null access Lock;
323 Ceiling_Violation : out Boolean)
325 Result : Interfaces.C.int;
327 Result := pthread_mutex_lock (L);
328 Ceiling_Violation := Result = EINVAL;
330 -- Assume the cause of EINVAL is a priority ceiling violation
332 pragma Assert (Result = 0 or else Result = EINVAL);
336 (L : not null access RTS_Lock;
337 Global_Lock : Boolean := False)
339 Result : Interfaces.C.int;
341 if not Single_Lock or else Global_Lock then
342 Result := pthread_mutex_lock (L);
343 pragma Assert (Result = 0);
347 procedure Write_Lock (T : Task_Id) is
348 Result : Interfaces.C.int;
350 if not Single_Lock then
351 Result := pthread_mutex_lock (T.Common.LL.L'Access);
352 pragma Assert (Result = 0);
361 (L : not null access Lock;
362 Ceiling_Violation : out Boolean)
365 Write_Lock (L, Ceiling_Violation);
372 procedure Unlock (L : not null access Lock) is
373 Result : Interfaces.C.int;
375 Result := pthread_mutex_unlock (L);
376 pragma Assert (Result = 0);
380 (L : not null access RTS_Lock;
381 Global_Lock : Boolean := False)
383 Result : Interfaces.C.int;
385 if not Single_Lock or else Global_Lock then
386 Result := pthread_mutex_unlock (L);
387 pragma Assert (Result = 0);
391 procedure Unlock (T : Task_Id) is
392 Result : Interfaces.C.int;
394 if not Single_Lock then
395 Result := pthread_mutex_unlock (T.Common.LL.L'Access);
396 pragma Assert (Result = 0);
404 -- Dynamic priority ceilings are not supported by the underlying system
406 procedure Set_Ceiling
407 (L : not null access Lock;
408 Prio : System.Any_Priority)
410 pragma Unreferenced (L, Prio);
421 Reason : System.Tasking.Task_States)
423 pragma Unreferenced (Reason);
425 Result : Interfaces.C.int;
428 pragma Assert (Self_ID = Self);
432 (cond => Self_ID.Common.LL.CV'Access,
433 mutex => (if Single_Lock
434 then Single_RTS_Lock'Access
435 else Self_ID.Common.LL.L'Access));
437 -- EINTR is not considered a failure
439 pragma Assert (Result = 0 or else Result = EINTR);
446 -- This is for use within the run-time system, so abort is
447 -- assumed to be already deferred, and the caller should be
448 -- holding its own ATCB lock.
450 procedure Timed_Sleep
453 Mode : ST.Delay_Modes;
454 Reason : System.Tasking.Task_States;
455 Timedout : out Boolean;
456 Yielded : out Boolean)
458 pragma Unreferenced (Reason);
460 Base_Time : constant Duration := Monotonic_Clock;
461 Check_Time : Duration := Base_Time;
463 Request : aliased timespec;
464 Result : Interfaces.C.int;
472 then Duration'Min (Time, Max_Sensible_Delay) + Check_Time
473 else Duration'Min (Check_Time + Max_Sensible_Delay, Time));
475 if Abs_Time > Check_Time then
476 Request := To_Timespec (Abs_Time);
479 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
482 pthread_cond_timedwait
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),
487 abstime => Request'Access);
489 Check_Time := Monotonic_Clock;
490 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
492 if Result = 0 or else Result = EINTR then
494 -- Somebody may have called Wakeup for us
500 pragma Assert (Result = ETIMEDOUT);
509 -- This is for use in implementing delay statements, so we assume the
510 -- caller is abort-deferred but is holding no locks.
512 procedure Timed_Delay
515 Mode : ST.Delay_Modes)
517 Base_Time : constant Duration := Monotonic_Clock;
518 Check_Time : Duration := Base_Time;
520 Request : aliased timespec;
522 Result : Interfaces.C.int;
523 pragma Warnings (Off, Result);
530 Write_Lock (Self_ID);
534 then Time + Check_Time
535 else Duration'Min (Check_Time + Max_Sensible_Delay, Time));
537 if Abs_Time > Check_Time then
538 Request := To_Timespec (Abs_Time);
539 Self_ID.Common.State := Delay_Sleep;
542 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
545 pthread_cond_timedwait
546 (cond => Self_ID.Common.LL.CV'Access,
547 mutex => (if Single_Lock
548 then Single_RTS_Lock'Access
549 else Self_ID.Common.LL.L'Access),
550 abstime => Request'Access);
552 Check_Time := Monotonic_Clock;
553 exit when Abs_Time <= Check_Time or else Check_Time < Base_Time;
555 pragma Assert (Result = 0 or else
556 Result = ETIMEDOUT or else
560 Self_ID.Common.State := Runnable;
569 Result := sched_yield;
572 ---------------------
573 -- Monotonic_Clock --
574 ---------------------
576 function Monotonic_Clock return Duration is
579 type timeval is array (1 .. 2) of C.long;
581 procedure timeval_to_duration
582 (T : not null access timeval;
583 sec : not null access C.long;
584 usec : not null access C.long);
585 pragma Import (C, timeval_to_duration, "__gnat_timeval_to_duration");
587 Micro : constant := 10**6;
588 sec : aliased C.long;
589 usec : aliased C.long;
590 TV : aliased timeval;
593 function gettimeofday
594 (Tv : access timeval;
595 Tz : System.Address := System.Null_Address) return int;
596 pragma Import (C, gettimeofday, "gettimeofday");
599 Result := gettimeofday (TV'Access, System.Null_Address);
600 pragma Assert (Result = 0);
601 timeval_to_duration (TV'Access, sec'Access, usec'Access);
602 return Duration (sec) + Duration (usec) / Micro;
609 function RT_Resolution return Duration is
618 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
619 pragma Unreferenced (Reason);
620 Result : Interfaces.C.int;
622 Result := pthread_cond_signal (T.Common.LL.CV'Access);
623 pragma Assert (Result = 0);
630 procedure Yield (Do_Yield : Boolean := True) is
631 Result : Interfaces.C.int;
632 pragma Unreferenced (Result);
635 Result := sched_yield;
643 procedure Set_Priority
645 Prio : System.Any_Priority;
646 Loss_Of_Inheritance : Boolean := False)
648 pragma Unreferenced (Loss_Of_Inheritance);
650 Result : Interfaces.C.int;
651 Param : aliased struct_sched_param;
653 function Get_Policy (Prio : System.Any_Priority) return Character;
654 pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
655 -- Get priority specific dispatching policy
657 Priority_Specific_Policy : constant Character := Get_Policy (Prio);
658 -- Upper case first character of the policy name corresponding to the
659 -- task as set by a Priority_Specific_Dispatching pragma.
662 T.Common.Current_Priority := Prio;
664 -- Priorities are 1 .. 99 on GNU/Linux, so we map 0 .. 98 to 1 .. 99
666 Param.sched_priority := Interfaces.C.int (Prio) + 1;
668 if Dispatching_Policy = 'R'
669 or else Priority_Specific_Policy = 'R'
670 or else Time_Slice_Val > 0
673 pthread_setschedparam
674 (T.Common.LL.Thread, SCHED_RR, Param'Access);
676 elsif Dispatching_Policy = 'F'
677 or else Priority_Specific_Policy = 'F'
678 or else Time_Slice_Val = 0
681 pthread_setschedparam
682 (T.Common.LL.Thread, SCHED_FIFO, Param'Access);
685 Param.sched_priority := 0;
687 pthread_setschedparam
689 SCHED_OTHER, Param'Access);
692 pragma Assert (Result = 0 or else Result = EPERM);
699 function Get_Priority (T : Task_Id) return System.Any_Priority is
701 return T.Common.Current_Priority;
708 procedure Enter_Task (Self_ID : Task_Id) is
710 if Self_ID.Common.Task_Info /= null
711 and then Self_ID.Common.Task_Info.CPU_Affinity = No_CPU
713 raise Invalid_CPU_Number;
716 Self_ID.Common.LL.Thread := pthread_self;
717 Self_ID.Common.LL.LWP := lwp_self;
719 Specific.Set (Self_ID);
721 if Use_Alternate_Stack
722 and then Self_ID.Common.Task_Alternate_Stack /= Null_Address
725 Stack : aliased stack_t;
726 Result : Interfaces.C.int;
728 Stack.ss_sp := Self_ID.Common.Task_Alternate_Stack;
729 Stack.ss_size := Alternate_Stack_Size;
731 Result := sigaltstack (Stack'Access, null);
732 pragma Assert (Result = 0);
741 function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
743 return new Ada_Task_Control_Block (Entry_Num);
750 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
752 -----------------------------
753 -- Register_Foreign_Thread --
754 -----------------------------
756 function Register_Foreign_Thread return Task_Id is
758 if Is_Valid_Task then
761 return Register_Foreign_Thread (pthread_self);
763 end Register_Foreign_Thread;
769 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
770 Result : Interfaces.C.int;
773 -- Give the task a unique serial number
775 Self_ID.Serial_Number := Next_Serial_Number;
776 Next_Serial_Number := Next_Serial_Number + 1;
777 pragma Assert (Next_Serial_Number /= 0);
779 Self_ID.Common.LL.Thread := To_pthread_t (-1);
781 if not Single_Lock then
782 Result := pthread_mutex_init (Self_ID.Common.LL.L'Access,
784 pragma Assert (Result = 0 or else Result = ENOMEM);
792 Result := pthread_cond_init (Self_ID.Common.LL.CV'Access,
794 pragma Assert (Result = 0 or else Result = ENOMEM);
799 if not Single_Lock then
800 Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
801 pragma Assert (Result = 0);
812 procedure Create_Task
814 Wrapper : System.Address;
815 Stack_Size : System.Parameters.Size_Type;
816 Priority : System.Any_Priority;
817 Succeeded : out Boolean)
819 Attributes : aliased pthread_attr_t;
820 Adjusted_Stack_Size : Interfaces.C.size_t;
821 Result : Interfaces.C.int;
823 use type System.Multiprocessors.CPU_Range;
826 Adjusted_Stack_Size :=
827 Interfaces.C.size_t (Stack_Size + Alternate_Stack_Size);
829 Result := pthread_attr_init (Attributes'Access);
830 pragma Assert (Result = 0 or else Result = ENOMEM);
838 pthread_attr_setstacksize
839 (Attributes'Access, Adjusted_Stack_Size);
840 pragma Assert (Result = 0);
843 pthread_attr_setdetachstate
844 (Attributes'Access, PTHREAD_CREATE_DETACHED);
845 pragma Assert (Result = 0);
847 -- Set the required attributes for the creation of the thread
849 -- Note: Previously, we called pthread_setaffinity_np (after thread
850 -- creation but before thread activation) to set the affinity but it was
851 -- not behaving as expected. Setting the required attributes for the
852 -- creation of the thread works correctly and it is more appropriate.
854 -- Do nothing if required support not provided by the operating system
856 if pthread_attr_setaffinity_np'Address = System.Null_Address then
859 -- Support is available
861 elsif T.Common.Base_CPU /= System.Multiprocessors.Not_A_Specific_CPU then
863 CPU_Set : aliased cpu_set_t := (bits => (others => False));
865 CPU_Set.bits (Integer (T.Common.Base_CPU)) := True;
867 pthread_attr_setaffinity_np
871 pragma Assert (Result = 0);
876 elsif T.Common.Task_Info /= null
877 and then T.Common.Task_Info.CPU_Affinity /= Task_Info.Any_CPU
880 pthread_attr_setaffinity_np
883 T.Common.Task_Info.CPU_Affinity'Access);
884 pragma Assert (Result = 0);
887 -- Since the initial signal mask of a thread is inherited from the
888 -- creator, and the Environment task has all its signals masked, we
889 -- do not need to manipulate caller's signal mask at this point.
890 -- All tasks in RTS will have All_Tasks_Mask initially.
892 Result := pthread_create
893 (T.Common.LL.Thread'Access,
895 Thread_Body_Access (Wrapper),
898 (Result = 0 or else Result = EAGAIN or else Result = ENOMEM);
902 Result := pthread_attr_destroy (Attributes'Access);
903 pragma Assert (Result = 0);
909 Result := pthread_attr_destroy (Attributes'Access);
910 pragma Assert (Result = 0);
912 Set_Priority (T, Priority);
919 procedure Finalize_TCB (T : Task_Id) is
920 Result : Interfaces.C.int;
922 Is_Self : constant Boolean := T = Self;
924 procedure Free is new
925 Ada.Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
928 if not Single_Lock then
929 Result := pthread_mutex_destroy (T.Common.LL.L'Access);
930 pragma Assert (Result = 0);
933 Result := pthread_cond_destroy (T.Common.LL.CV'Access);
934 pragma Assert (Result = 0);
936 if T.Known_Tasks_Index /= -1 then
937 Known_Tasks (T.Known_Tasks_Index) := null;
939 SC.Invalidate_Stack_Cache (T.Common.Compiler_Data.Pri_Stack_Info'Access);
951 procedure Exit_Task is
960 procedure Abort_Task (T : Task_Id) is
961 Result : Interfaces.C.int;
963 if Abort_Handler_Installed then
967 Signal (System.Interrupt_Management.Abort_Task_Interrupt));
968 pragma Assert (Result = 0);
976 procedure Initialize (S : in out Suspension_Object) is
977 Result : Interfaces.C.int;
980 -- Initialize internal state (always to False (RM D.10(6)))
985 -- Initialize internal mutex
987 Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
989 pragma Assert (Result = 0 or else Result = ENOMEM);
991 if Result = ENOMEM then
995 -- Initialize internal condition variable
997 Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
999 pragma Assert (Result = 0 or else Result = ENOMEM);
1002 Result := pthread_mutex_destroy (S.L'Access);
1003 pragma Assert (Result = 0);
1005 if Result = ENOMEM then
1006 raise Storage_Error;
1015 procedure Finalize (S : in out Suspension_Object) is
1016 Result : Interfaces.C.int;
1019 -- Destroy internal mutex
1021 Result := pthread_mutex_destroy (S.L'Access);
1022 pragma Assert (Result = 0);
1024 -- Destroy internal condition variable
1026 Result := pthread_cond_destroy (S.CV'Access);
1027 pragma Assert (Result = 0);
1034 function Current_State (S : Suspension_Object) return Boolean is
1036 -- We do not want to use lock on this read operation. State is marked
1037 -- as Atomic so that we ensure that the value retrieved is correct.
1046 procedure Set_False (S : in out Suspension_Object) is
1047 Result : Interfaces.C.int;
1050 SSL.Abort_Defer.all;
1052 Result := pthread_mutex_lock (S.L'Access);
1053 pragma Assert (Result = 0);
1057 Result := pthread_mutex_unlock (S.L'Access);
1058 pragma Assert (Result = 0);
1060 SSL.Abort_Undefer.all;
1067 procedure Set_True (S : in out Suspension_Object) is
1068 Result : Interfaces.C.int;
1071 SSL.Abort_Defer.all;
1073 Result := pthread_mutex_lock (S.L'Access);
1074 pragma Assert (Result = 0);
1076 -- If there is already a task waiting on this suspension object then
1077 -- we resume it, leaving the state of the suspension object to False,
1078 -- as it is specified in ARM D.10 par. 9. Otherwise, it just leaves
1079 -- the state to True.
1085 Result := pthread_cond_signal (S.CV'Access);
1086 pragma Assert (Result = 0);
1092 Result := pthread_mutex_unlock (S.L'Access);
1093 pragma Assert (Result = 0);
1095 SSL.Abort_Undefer.all;
1098 ------------------------
1099 -- Suspend_Until_True --
1100 ------------------------
1102 procedure Suspend_Until_True (S : in out Suspension_Object) is
1103 Result : Interfaces.C.int;
1106 SSL.Abort_Defer.all;
1108 Result := pthread_mutex_lock (S.L'Access);
1109 pragma Assert (Result = 0);
1113 -- Program_Error must be raised upon calling Suspend_Until_True
1114 -- if another task is already waiting on that suspension object
1117 Result := pthread_mutex_unlock (S.L'Access);
1118 pragma Assert (Result = 0);
1120 SSL.Abort_Undefer.all;
1122 raise Program_Error;
1125 -- Suspend the task if the state is False. Otherwise, the task
1126 -- continues its execution, and the state of the suspension object
1127 -- is set to False (ARM D.10 par. 9).
1135 -- Loop in case pthread_cond_wait returns earlier than expected
1136 -- (e.g. in case of EINTR caused by a signal). This should not
1137 -- happen with the current Linux implementation of pthread, but
1138 -- POSIX does not guarantee it so this may change in future.
1140 Result := pthread_cond_wait (S.CV'Access, S.L'Access);
1141 pragma Assert (Result = 0 or else Result = EINTR);
1143 exit when not S.Waiting;
1147 Result := pthread_mutex_unlock (S.L'Access);
1148 pragma Assert (Result = 0);
1150 SSL.Abort_Undefer.all;
1152 end Suspend_Until_True;
1160 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1161 pragma Unreferenced (Self_ID);
1166 --------------------
1167 -- Check_No_Locks --
1168 --------------------
1170 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1171 pragma Unreferenced (Self_ID);
1176 ----------------------
1177 -- Environment_Task --
1178 ----------------------
1180 function Environment_Task return Task_Id is
1182 return Environment_Task_Id;
1183 end Environment_Task;
1189 function Suspend_Task
1191 Thread_Self : Thread_Id) return Boolean
1194 if T.Common.LL.Thread /= Thread_Self then
1195 return pthread_kill (T.Common.LL.Thread, SIGSTOP) = 0;
1205 function Resume_Task
1207 Thread_Self : Thread_Id) return Boolean
1210 if T.Common.LL.Thread /= Thread_Self then
1211 return pthread_kill (T.Common.LL.Thread, SIGCONT) = 0;
1217 --------------------
1218 -- Stop_All_Tasks --
1219 --------------------
1221 procedure Stop_All_Tasks is
1230 function Stop_Task (T : ST.Task_Id) return Boolean is
1231 pragma Unreferenced (T);
1240 function Continue_Task (T : ST.Task_Id) return Boolean is
1241 pragma Unreferenced (T);
1250 procedure Initialize (Environment_Task : Task_Id) is
1251 act : aliased struct_sigaction;
1252 old_act : aliased struct_sigaction;
1253 Tmp_Set : aliased sigset_t;
1254 Result : Interfaces.C.int;
1255 -- Whether to use an alternate signal stack for stack overflows
1258 (Int : System.Interrupt_Management.Interrupt_ID) return Character;
1259 pragma Import (C, State, "__gnat_get_interrupt_state");
1260 -- Get interrupt state. Defined in a-init.c
1261 -- The input argument is the interrupt number,
1262 -- and the result is one of the following:
1264 Default : constant Character := 's';
1265 -- 'n' this interrupt not set by any Interrupt_State pragma
1266 -- 'u' Interrupt_State pragma set state to User
1267 -- 'r' Interrupt_State pragma set state to Runtime
1268 -- 's' Interrupt_State pragma set state to System (use "default"
1271 use type System.Multiprocessors.CPU_Range;
1274 Environment_Task_Id := Environment_Task;
1276 Interrupt_Management.Initialize;
1278 -- Prepare the set of signals that should be unblocked in all tasks
1280 Result := sigemptyset (Unblocked_Signal_Mask'Access);
1281 pragma Assert (Result = 0);
1283 for J in Interrupt_Management.Interrupt_ID loop
1284 if System.Interrupt_Management.Keep_Unmasked (J) then
1285 Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
1286 pragma Assert (Result = 0);
1290 Result := pthread_mutexattr_init (Mutex_Attr'Access);
1291 pragma Assert (Result = 0);
1293 Result := pthread_condattr_init (Cond_Attr'Access);
1294 pragma Assert (Result = 0);
1296 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1298 -- Initialize the global RTS lock
1300 Specific.Initialize (Environment_Task);
1302 if Use_Alternate_Stack then
1303 Environment_Task.Common.Task_Alternate_Stack :=
1304 Alternate_Stack'Address;
1307 -- Make environment task known here because it doesn't go through
1308 -- Activate_Tasks, which does it for all other tasks.
1310 Known_Tasks (Known_Tasks'First) := Environment_Task;
1311 Environment_Task.Known_Tasks_Index := Known_Tasks'First;
1313 Enter_Task (Environment_Task);
1316 (System.Interrupt_Management.Abort_Task_Interrupt) /= Default
1319 act.sa_handler := Abort_Handler'Address;
1321 Result := sigemptyset (Tmp_Set'Access);
1322 pragma Assert (Result = 0);
1323 act.sa_mask := Tmp_Set;
1327 (Signal (Interrupt_Management.Abort_Task_Interrupt),
1328 act'Unchecked_Access,
1329 old_act'Unchecked_Access);
1330 pragma Assert (Result = 0);
1331 Abort_Handler_Installed := True;
1334 -- pragma CPU for the environment task
1336 if pthread_setaffinity_np'Address /= System.Null_Address
1337 and then Environment_Task.Common.Base_CPU /=
1338 System.Multiprocessors.Not_A_Specific_CPU
1341 CPU_Set : aliased cpu_set_t := (bits => (others => False));
1343 CPU_Set.bits (Integer (Environment_Task.Common.Base_CPU)) := True;
1345 pthread_setaffinity_np
1346 (Environment_Task.Common.LL.Thread,
1349 pragma Assert (Result = 0);
1354 end System.Task_Primitives.Operations;