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) 1992-2005, 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 2, or (at your option) any later ver- --
14 -- sion. GNARL 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. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNARL; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNARL was developed by the GNARL team at Florida State University. --
30 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
32 ------------------------------------------------------------------------------
34 -- This is the VxWorks version of this package
36 -- This package contains all the GNULL primitives that interface directly
37 -- with the underlying OS.
40 -- Turn off polling, we do not want ATC polling to take place during
41 -- tasking operations. It causes infinite loops and other problems.
43 with System.Tasking.Debug;
44 -- used for Known_Tasks
46 with System.Interrupt_Management;
47 -- used for Keep_Unmasked
50 -- Initialize_Interrupts
52 with System.Soft_Links;
53 -- used for Defer/Undefer_Abort
55 -- Note that we do not use System.Tasking.Initialization directly since
56 -- this is a higher level package that we shouldn't depend on. For example
57 -- when using the restricted run time, it is replaced by
58 -- System.Tasking.Restricted.Stages.
60 with System.OS_Interface;
61 -- used for various type, constant, and operations
63 with System.Parameters;
67 -- used for Ada_Task_Control_Block
69 -- ATCB components and types
73 with Unchecked_Conversion;
74 with Unchecked_Deallocation;
76 package body System.Task_Primitives.Operations is
78 use System.Tasking.Debug;
80 use System.OS_Interface;
81 use System.Parameters;
82 use type Interfaces.C.int;
84 package SSL renames System.Soft_Links;
86 subtype int is System.OS_Interface.int;
88 Relative : constant := 0;
94 -- The followings are logically constants, but need to be initialized at
97 Single_RTS_Lock : aliased RTS_Lock;
98 -- This is a lock to allow only one thread of control in the RTS at a
99 -- time; it is used to execute in mutual exclusion from all other tasks.
100 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
102 ATCB_Key : aliased System.Address := System.Null_Address;
103 -- Key used to find the Ada Task_Id associated with a thread
105 ATCB_Key_Addr : System.Address := ATCB_Key'Address;
106 pragma Export (Ada, ATCB_Key_Addr, "__gnat_ATCB_key_addr");
107 -- Exported to support the temporary AE653 task registration
108 -- implementation. This mechanism is used to minimize impact on other
111 Environment_Task_Id : Task_Id;
112 -- A variable to hold Task_Id for the environment task
114 Unblocked_Signal_Mask : aliased sigset_t;
115 -- The set of signals that should unblocked in all tasks
117 -- The followings are internal configuration constants needed
119 Time_Slice_Val : Integer;
120 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
122 Locking_Policy : Character;
123 pragma Import (C, Locking_Policy, "__gl_locking_policy");
125 Dispatching_Policy : Character;
126 pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
128 FIFO_Within_Priorities : constant Boolean := Dispatching_Policy = 'F';
129 -- Indicates whether FIFO_Within_Priorities is set
131 Mutex_Protocol : Priority_Type;
133 Foreign_Task_Elaborated : aliased Boolean := True;
134 -- Used to identified fake tasks (i.e., non-Ada Threads)
142 function Is_Valid_Task return Boolean;
143 pragma Inline (Is_Valid_Task);
144 -- Does executing thread have a TCB?
146 procedure Set (Self_Id : Task_Id);
148 -- Set the self id for the current task
150 function Self return Task_Id;
151 pragma Inline (Self);
152 -- Return a pointer to the Ada Task Control Block of the calling task
156 package body Specific is separate;
157 -- The body of this package is target specific
159 ---------------------------------
160 -- Support for foreign threads --
161 ---------------------------------
163 function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
164 -- Allocate and Initialize a new ATCB for the current Thread
166 function Register_Foreign_Thread
167 (Thread : Thread_Id) return Task_Id is separate;
169 -----------------------
170 -- Local Subprograms --
171 -----------------------
173 procedure Abort_Handler (signo : Signal);
174 -- Handler for the abort (SIGABRT) signal to handle asynchronous abort
176 procedure Install_Signal_Handlers;
177 -- Install the default signal handlers for the current task
179 function To_Address is new Unchecked_Conversion (Task_Id, System.Address);
185 procedure Abort_Handler (signo : Signal) is
186 pragma Unreferenced (signo);
188 Self_ID : constant Task_Id := Self;
190 Old_Set : aliased sigset_t;
193 -- It is not safe to raise an exception when using ZCX and the GCC
194 -- exception handling mechanism.
196 if ZCX_By_Default and then GCC_ZCX_Support then
200 if Self_ID.Deferral_Level = 0
201 and then Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
202 and then not Self_ID.Aborting
204 Self_ID.Aborting := True;
206 -- Make sure signals used for RTS internal purpose are unmasked
208 Result := pthread_sigmask (SIG_UNBLOCK,
209 Unblocked_Signal_Mask'Unchecked_Access, Old_Set'Unchecked_Access);
210 pragma Assert (Result = 0);
212 raise Standard'Abort_Signal;
220 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
221 pragma Unreferenced (T);
222 pragma Unreferenced (On);
225 -- Nothing needed (why not???)
234 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
236 return T.Common.LL.Thread;
243 function Self return Task_Id renames Specific.Self;
245 -----------------------------
246 -- Install_Signal_Handlers --
247 -----------------------------
249 procedure Install_Signal_Handlers is
250 act : aliased struct_sigaction;
251 old_act : aliased struct_sigaction;
252 Tmp_Set : aliased sigset_t;
257 act.sa_handler := Abort_Handler'Address;
259 Result := sigemptyset (Tmp_Set'Access);
260 pragma Assert (Result = 0);
261 act.sa_mask := Tmp_Set;
265 (Signal (Interrupt_Management.Abort_Task_Signal),
266 act'Unchecked_Access,
267 old_act'Unchecked_Access);
268 pragma Assert (Result = 0);
270 Interrupt_Management.Initialize_Interrupts;
271 end Install_Signal_Handlers;
273 ---------------------
274 -- Initialize_Lock --
275 ---------------------
277 procedure Initialize_Lock (Prio : System.Any_Priority; L : access Lock) is
279 L.Mutex := semMCreate (SEM_Q_PRIORITY + SEM_INVERSION_SAFE);
280 L.Prio_Ceiling := int (Prio);
281 L.Protocol := Mutex_Protocol;
282 pragma Assert (L.Mutex /= 0);
285 procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level) is
286 pragma Unreferenced (Level);
289 L.Mutex := semMCreate (SEM_Q_PRIORITY + SEM_INVERSION_SAFE);
290 L.Prio_Ceiling := int (System.Any_Priority'Last);
291 L.Protocol := Mutex_Protocol;
292 pragma Assert (L.Mutex /= 0);
299 procedure Finalize_Lock (L : access Lock) is
303 Result := semDelete (L.Mutex);
304 pragma Assert (Result = 0);
307 procedure Finalize_Lock (L : access RTS_Lock) is
311 Result := semDelete (L.Mutex);
312 pragma Assert (Result = 0);
319 procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
323 if L.Protocol = Prio_Protect
324 and then int (Self.Common.Current_Priority) > L.Prio_Ceiling
326 Ceiling_Violation := True;
329 Ceiling_Violation := False;
332 Result := semTake (L.Mutex, WAIT_FOREVER);
333 pragma Assert (Result = 0);
337 (L : access RTS_Lock;
338 Global_Lock : Boolean := False)
343 if not Single_Lock or else Global_Lock then
344 Result := semTake (L.Mutex, WAIT_FOREVER);
345 pragma Assert (Result = 0);
349 procedure Write_Lock (T : Task_Id) is
353 if not Single_Lock then
354 Result := semTake (T.Common.LL.L.Mutex, WAIT_FOREVER);
355 pragma Assert (Result = 0);
363 procedure Read_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
365 Write_Lock (L, Ceiling_Violation);
372 procedure Unlock (L : access Lock) is
376 Result := semGive (L.Mutex);
377 pragma Assert (Result = 0);
380 procedure Unlock (L : access RTS_Lock; Global_Lock : Boolean := False) is
384 if not Single_Lock or else Global_Lock then
385 Result := semGive (L.Mutex);
386 pragma Assert (Result = 0);
390 procedure Unlock (T : Task_Id) is
394 if not Single_Lock then
395 Result := semGive (T.Common.LL.L.Mutex);
396 pragma Assert (Result = 0);
404 procedure Sleep (Self_ID : Task_Id; Reason : System.Tasking.Task_States) is
405 pragma Unreferenced (Reason);
410 pragma Assert (Self_ID = Self);
412 -- Release the mutex before sleeping
415 Result := semGive (Single_RTS_Lock.Mutex);
417 Result := semGive (Self_ID.Common.LL.L.Mutex);
420 pragma Assert (Result = 0);
422 -- Perform a blocking operation to take the CV semaphore. Note that a
423 -- blocking operation in VxWorks will reenable task scheduling. When we
424 -- are no longer blocked and control is returned, task scheduling will
425 -- again be disabled.
427 Result := semTake (Self_ID.Common.LL.CV, WAIT_FOREVER);
428 pragma Assert (Result = 0);
430 -- Take the mutex back
433 Result := semTake (Single_RTS_Lock.Mutex, WAIT_FOREVER);
435 Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER);
438 pragma Assert (Result = 0);
445 -- This is for use within the run-time system, so abort is assumed to be
446 -- already deferred, and the caller should be holding its own ATCB lock.
448 procedure Timed_Sleep
451 Mode : ST.Delay_Modes;
452 Reason : System.Tasking.Task_States;
453 Timedout : out Boolean;
454 Yielded : out Boolean)
456 pragma Unreferenced (Reason);
458 Orig : constant Duration := Monotonic_Clock;
462 Wakeup : Boolean := False;
468 if Mode = Relative then
469 Absolute := Orig + Time;
471 -- Systematically add one since the first tick will delay *at most*
472 -- 1 / Rate_Duration seconds, so we need to add one to be on the
475 Ticks := To_Clock_Ticks (Time);
477 if Ticks > 0 and then Ticks < int'Last then
483 Ticks := To_Clock_Ticks (Time - Monotonic_Clock);
488 -- Release the mutex before sleeping
491 Result := semGive (Single_RTS_Lock.Mutex);
493 Result := semGive (Self_ID.Common.LL.L.Mutex);
496 pragma Assert (Result = 0);
498 -- Perform a blocking operation to take the CV semaphore. Note
499 -- that a blocking operation in VxWorks will reenable task
500 -- scheduling. When we are no longer blocked and control is
501 -- returned, task scheduling will again be disabled.
503 Result := semTake (Self_ID.Common.LL.CV, Ticks);
507 -- Somebody may have called Wakeup for us
512 if errno /= S_objLib_OBJ_TIMEOUT then
516 -- If Ticks = int'last, it was most probably truncated so
517 -- let's make another round after recomputing Ticks from
518 -- the the absolute time.
520 if Ticks /= int'Last then
523 Ticks := To_Clock_Ticks (Absolute - Monotonic_Clock);
532 -- Take the mutex back
535 Result := semTake (Single_RTS_Lock.Mutex, WAIT_FOREVER);
537 Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER);
540 pragma Assert (Result = 0);
542 exit when Timedout or Wakeup;
548 -- Should never hold a lock while yielding
551 Result := semGive (Single_RTS_Lock.Mutex);
553 Result := semTake (Single_RTS_Lock.Mutex, WAIT_FOREVER);
556 Result := semGive (Self_ID.Common.LL.L.Mutex);
558 Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER);
567 -- This is for use in implementing delay statements, so we assume the
568 -- caller is holding no locks.
570 procedure Timed_Delay
573 Mode : ST.Delay_Modes)
575 Orig : constant Duration := Monotonic_Clock;
580 Aborted : Boolean := False;
585 if Mode = Relative then
586 Absolute := Orig + Time;
587 Ticks := To_Clock_Ticks (Time);
589 if Ticks > 0 and then Ticks < int'Last then
591 -- First tick will delay anytime between 0 and 1 / sysClkRateGet
592 -- seconds, so we need to add one to be on the safe side.
599 Ticks := To_Clock_Ticks (Time - Orig);
604 -- Modifying State and Pending_Priority_Change, locking the TCB
607 Result := semTake (Single_RTS_Lock.Mutex, WAIT_FOREVER);
609 Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER);
612 pragma Assert (Result = 0);
614 Self_ID.Common.State := Delay_Sleep;
618 if Self_ID.Pending_Priority_Change then
619 Self_ID.Pending_Priority_Change := False;
620 Self_ID.Common.Base_Priority := Self_ID.New_Base_Priority;
621 Set_Priority (Self_ID, Self_ID.Common.Base_Priority);
624 Aborted := Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
626 -- Release the TCB before sleeping
629 Result := semGive (Single_RTS_Lock.Mutex);
631 Result := semGive (Self_ID.Common.LL.L.Mutex);
633 pragma Assert (Result = 0);
637 Result := semTake (Self_ID.Common.LL.CV, Ticks);
641 -- If Ticks = int'last, it was most probably truncated
642 -- so let's make another round after recomputing Ticks
643 -- from the the absolute time.
645 if errno = S_objLib_OBJ_TIMEOUT and then Ticks /= int'Last then
648 Ticks := To_Clock_Ticks (Absolute - Monotonic_Clock);
656 -- Take back the lock after having slept, to protect further
660 Result := semTake (Single_RTS_Lock.Mutex, WAIT_FOREVER);
662 Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER);
665 pragma Assert (Result = 0);
670 Self_ID.Common.State := Runnable;
673 Result := semGive (Single_RTS_Lock.Mutex);
675 Result := semGive (Self_ID.Common.LL.L.Mutex);
682 SSL.Abort_Undefer.all;
685 ---------------------
686 -- Monotonic_Clock --
687 ---------------------
689 function Monotonic_Clock return Duration is
690 TS : aliased timespec;
693 Result := clock_gettime (CLOCK_REALTIME, TS'Unchecked_Access);
694 pragma Assert (Result = 0);
695 return To_Duration (TS);
702 function RT_Resolution return Duration is
704 return 1.0 / Duration (sysClkRateGet);
711 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
712 pragma Unreferenced (Reason);
715 Result := semGive (T.Common.LL.CV);
716 pragma Assert (Result = 0);
723 procedure Yield (Do_Yield : Boolean := True) is
724 pragma Unreferenced (Do_Yield);
726 pragma Unreferenced (Result);
728 Result := taskDelay (0);
735 type Prio_Array_Type is array (System.Any_Priority) of Integer;
736 pragma Atomic_Components (Prio_Array_Type);
738 Prio_Array : Prio_Array_Type;
739 -- Global array containing the id of the currently running task for
740 -- each priority. Note that we assume that we are on a single processor
741 -- with run-till-blocked scheduling.
743 procedure Set_Priority
745 Prio : System.Any_Priority;
746 Loss_Of_Inheritance : Boolean := False)
748 Array_Item : Integer;
754 (T.Common.LL.Thread, To_VxWorks_Priority (int (Prio)));
755 pragma Assert (Result = 0);
757 if FIFO_Within_Priorities then
759 -- Annex D requirement [RM D.2.2 par. 9]:
761 -- If the task drops its priority due to the loss of inherited
762 -- priority, it is added at the head of the ready queue for its
763 -- new active priority.
765 if Loss_Of_Inheritance
766 and then Prio < T.Common.Current_Priority
768 Array_Item := Prio_Array (T.Common.Base_Priority) + 1;
769 Prio_Array (T.Common.Base_Priority) := Array_Item;
772 -- Give some processes a chance to arrive
776 -- Then wait for our turn to proceed
778 exit when Array_Item = Prio_Array (T.Common.Base_Priority)
779 or else Prio_Array (T.Common.Base_Priority) = 1;
782 Prio_Array (T.Common.Base_Priority) :=
783 Prio_Array (T.Common.Base_Priority) - 1;
787 T.Common.Current_Priority := Prio;
794 function Get_Priority (T : Task_Id) return System.Any_Priority is
796 return T.Common.Current_Priority;
803 procedure Enter_Task (Self_ID : Task_Id) is
804 procedure Init_Float;
805 pragma Import (C, Init_Float, "__gnat_init_float");
806 -- Properly initializes the FPU for PPC/MIPS systems
809 Self_ID.Common.LL.Thread := taskIdSelf;
810 Specific.Set (Self_ID);
814 -- Install the signal handlers
816 -- This is called for each task since there is no signal inheritance
817 -- between VxWorks tasks.
819 Install_Signal_Handlers;
823 for J in Known_Tasks'Range loop
824 if Known_Tasks (J) = null then
825 Known_Tasks (J) := Self_ID;
826 Self_ID.Known_Tasks_Index := J;
838 function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
840 return new Ada_Task_Control_Block (Entry_Num);
847 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
849 -----------------------------
850 -- Register_Foreign_Thread --
851 -----------------------------
853 function Register_Foreign_Thread return Task_Id is
855 if Is_Valid_Task then
858 return Register_Foreign_Thread (taskIdSelf);
860 end Register_Foreign_Thread;
866 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
868 Self_ID.Common.LL.CV := semBCreate (SEM_Q_PRIORITY, SEM_EMPTY);
869 Self_ID.Common.LL.Thread := 0;
871 if Self_ID.Common.LL.CV = 0 then
876 if not Single_Lock then
877 Initialize_Lock (Self_ID.Common.LL.L'Access, ATCB_Level);
886 procedure Create_Task
888 Wrapper : System.Address;
889 Stack_Size : System.Parameters.Size_Type;
890 Priority : System.Any_Priority;
891 Succeeded : out Boolean)
893 Adjusted_Stack_Size : size_t;
895 if Stack_Size = Unspecified_Size then
896 Adjusted_Stack_Size := size_t (Default_Stack_Size);
898 elsif Stack_Size < Minimum_Stack_Size then
899 Adjusted_Stack_Size := size_t (Minimum_Stack_Size);
902 Adjusted_Stack_Size := size_t (Stack_Size);
905 -- Ask for four extra bytes of stack space so that the ATCB pointer can
906 -- be stored below the stack limit, plus extra space for the frame of
907 -- Task_Wrapper. This is so the user gets the amount of stack requested
908 -- exclusive of the needs
910 -- We also have to allocate n more bytes for the task name storage and
911 -- enough space for the Wind Task Control Block which is around 0x778
912 -- bytes. VxWorks also seems to carve out additional space, so use 2048
913 -- as a nice round number. We might want to increment to the nearest
914 -- page size in case we ever support VxVMI.
916 -- XXX - we should come back and visit this so we can set the task name
917 -- to something appropriate.
919 Adjusted_Stack_Size := Adjusted_Stack_Size + 2048;
921 -- Since the initial signal mask of a thread is inherited from the
922 -- creator, and the Environment task has all its signals masked, we do
923 -- not need to manipulate caller's signal mask at this point. All tasks
924 -- in RTS will have All_Tasks_Mask initially.
926 if T.Common.Task_Image_Len = 0 then
927 T.Common.LL.Thread := taskSpawn
928 (System.Null_Address,
929 To_VxWorks_Priority (int (Priority)),
936 Name : aliased String (1 .. T.Common.Task_Image_Len + 1);
939 Name (1 .. Name'Last - 1) :=
940 T.Common.Task_Image (1 .. T.Common.Task_Image_Len);
941 Name (Name'Last) := ASCII.NUL;
943 T.Common.LL.Thread := taskSpawn
945 To_VxWorks_Priority (int (Priority)),
953 if T.Common.LL.Thread = -1 then
959 Task_Creation_Hook (T.Common.LL.Thread);
960 Set_Priority (T, Priority);
967 procedure Finalize_TCB (T : Task_Id) is
970 Is_Self : constant Boolean := (T = Self);
972 procedure Free is new
973 Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
976 if not Single_Lock then
977 Result := semDelete (T.Common.LL.L.Mutex);
978 pragma Assert (Result = 0);
981 T.Common.LL.Thread := 0;
983 Result := semDelete (T.Common.LL.CV);
984 pragma Assert (Result = 0);
986 if T.Known_Tasks_Index /= -1 then
987 Known_Tasks (T.Known_Tasks_Index) := null;
993 Result := taskVarDelete (taskIdSelf, ATCB_Key'Access);
994 pragma Assert (Result /= ERROR);
1002 procedure Exit_Task is
1004 Specific.Set (null);
1011 procedure Abort_Task (T : Task_Id) is
1014 Result := kill (T.Common.LL.Thread,
1015 Signal (Interrupt_Management.Abort_Task_Signal));
1016 pragma Assert (Result = 0);
1023 procedure Initialize (S : in out Suspension_Object) is
1025 -- Initialize internal state. It is always initialized to False (ARM
1031 -- Initialize internal mutex
1033 -- Use simpler binary semaphore instead of VxWorks
1034 -- mutual exclusion semaphore, because we don't need
1035 -- the fancier semantics and their overhead.
1037 S.L := semBCreate (SEM_Q_FIFO, SEM_FULL);
1039 -- Initialize internal condition variable
1041 S.CV := semBCreate (SEM_Q_FIFO, SEM_EMPTY);
1048 procedure Finalize (S : in out Suspension_Object) is
1051 -- Destroy internal mutex
1053 Result := semDelete (S.L);
1054 pragma Assert (Result = OK);
1056 -- Destroy internal condition variable
1058 Result := semDelete (S.CV);
1059 pragma Assert (Result = OK);
1066 function Current_State (S : Suspension_Object) return Boolean is
1068 -- We do not want to use lock on this read operation. State is marked
1069 -- as Atomic so that we ensure that the value retrieved is correct.
1078 procedure Set_False (S : in out Suspension_Object) is
1081 Result := semTake (S.L, WAIT_FOREVER);
1082 pragma Assert (Result = OK);
1086 Result := semGive (S.L);
1087 pragma Assert (Result = OK);
1094 procedure Set_True (S : in out Suspension_Object) is
1097 Result := semTake (S.L, WAIT_FOREVER);
1098 pragma Assert (Result = OK);
1100 -- If there is already a task waiting on this suspension object then
1101 -- we resume it, leaving the state of the suspension object to False,
1102 -- as it is specified in ARM D.10 par. 9. Otherwise, it just leaves
1103 -- the state to True.
1109 Result := semGive (S.CV);
1110 pragma Assert (Result = OK);
1115 Result := semGive (S.L);
1116 pragma Assert (Result = OK);
1119 ------------------------
1120 -- Suspend_Until_True --
1121 ------------------------
1123 procedure Suspend_Until_True (S : in out Suspension_Object) is
1126 Result := semTake (S.L, WAIT_FOREVER);
1129 -- Program_Error must be raised upon calling Suspend_Until_True
1130 -- if another task is already waiting on that suspension object
1131 -- (ARM D.10 par. 10).
1133 Result := semGive (S.L);
1134 pragma Assert (Result = OK);
1136 raise Program_Error;
1138 -- Suspend the task if the state is False. Otherwise, the task
1139 -- continues its execution, and the state of the suspension object
1140 -- is set to False (ARM D.10 par. 9).
1145 Result := semGive (S.L);
1146 pragma Assert (Result = 0);
1150 -- Release the mutex before sleeping
1152 Result := semGive (S.L);
1153 pragma Assert (Result = OK);
1155 Result := semTake (S.CV, WAIT_FOREVER);
1156 pragma Assert (Result = 0);
1159 end Suspend_Until_True;
1167 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1168 pragma Unreferenced (Self_ID);
1173 --------------------
1174 -- Check_No_Locks --
1175 --------------------
1177 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1178 pragma Unreferenced (Self_ID);
1183 ----------------------
1184 -- Environment_Task --
1185 ----------------------
1187 function Environment_Task return Task_Id is
1189 return Environment_Task_Id;
1190 end Environment_Task;
1196 procedure Lock_RTS is
1198 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
1205 procedure Unlock_RTS is
1207 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
1214 function Suspend_Task
1216 Thread_Self : Thread_Id) return Boolean
1219 if T.Common.LL.Thread /= 0
1220 and then T.Common.LL.Thread /= Thread_Self
1222 return taskSuspend (T.Common.LL.Thread) = 0;
1232 function Resume_Task
1234 Thread_Self : Thread_Id) return Boolean
1237 if T.Common.LL.Thread /= 0
1238 and then T.Common.LL.Thread /= Thread_Self
1240 return taskResume (T.Common.LL.Thread) = 0;
1250 procedure Initialize (Environment_Task : Task_Id) is
1254 if Locking_Policy = 'C' then
1255 Mutex_Protocol := Prio_Protect;
1256 elsif Locking_Policy = 'I' then
1257 Mutex_Protocol := Prio_Inherit;
1259 Mutex_Protocol := Prio_None;
1262 if Time_Slice_Val > 0 then
1263 Result := kernelTimeSlice
1265 (Duration (Time_Slice_Val) / Duration (1_000_000.0)));
1268 Result := sigemptyset (Unblocked_Signal_Mask'Access);
1269 pragma Assert (Result = 0);
1271 for J in Interrupt_Management.Signal_ID loop
1272 if System.Interrupt_Management.Keep_Unmasked (J) then
1273 Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
1274 pragma Assert (Result = 0);
1278 Environment_Task_Id := Environment_Task;
1280 -- Initialize the lock used to synchronize chain of all ATCBs
1282 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1284 Enter_Task (Environment_Task);
1287 end System.Task_Primitives.Operations;