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) 1992-2009, 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 NT (native) 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_Deallocation;
44 with Interfaces.C.Strings;
46 with System.Tasking.Debug;
47 with System.OS_Primitives;
48 with System.Task_Info;
49 with System.Interrupt_Management;
50 with System.Win32.Ext;
52 with System.Soft_Links;
53 -- We use System.Soft_Links instead of System.Tasking.Initialization because
54 -- the later is a higher level package that we shouldn't depend on. For
55 -- 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;
62 use System.Tasking.Debug;
65 use Interfaces.C.Strings;
66 use System.OS_Interface;
67 use System.Parameters;
68 use System.OS_Primitives;
73 pragma Link_With ("-Xlinker --stack=0x200000,0x1000");
74 -- Change the default stack size (2 MB) for tasking programs on Windows.
75 -- This allows about 1000 tasks running at the same time. Note that
76 -- we set the stack size for non tasking programs on System unit.
77 -- Also note that under Windows XP, we use a Windows XP extension to
78 -- specify the stack size on a per task basis, as done under other OSes.
84 procedure InitializeCriticalSection (pCriticalSection : access RTS_Lock);
85 procedure InitializeCriticalSection
86 (pCriticalSection : access CRITICAL_SECTION);
88 (Stdcall, InitializeCriticalSection, "InitializeCriticalSection");
90 procedure EnterCriticalSection (pCriticalSection : access RTS_Lock);
91 procedure EnterCriticalSection
92 (pCriticalSection : access CRITICAL_SECTION);
93 pragma Import (Stdcall, EnterCriticalSection, "EnterCriticalSection");
95 procedure LeaveCriticalSection (pCriticalSection : access RTS_Lock);
96 procedure LeaveCriticalSection (pCriticalSection : access CRITICAL_SECTION);
97 pragma Import (Stdcall, LeaveCriticalSection, "LeaveCriticalSection");
99 procedure DeleteCriticalSection (pCriticalSection : access RTS_Lock);
100 procedure DeleteCriticalSection
101 (pCriticalSection : access CRITICAL_SECTION);
102 pragma Import (Stdcall, DeleteCriticalSection, "DeleteCriticalSection");
108 Environment_Task_Id : Task_Id;
109 -- A variable to hold Task_Id for the environment task
111 Single_RTS_Lock : aliased RTS_Lock;
112 -- This is a lock to allow only one thread of control in the RTS at
113 -- a time; it is used to execute in mutual exclusion from all other tasks.
114 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
116 Time_Slice_Val : Integer;
117 pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
119 Dispatching_Policy : Character;
120 pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
122 function Get_Policy (Prio : System.Any_Priority) return Character;
123 pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
124 -- Get priority specific dispatching policy
126 Foreign_Task_Elaborated : aliased Boolean := True;
127 -- Used to identified fake tasks (i.e., non-Ada Threads)
129 Annex_D : Boolean := False;
130 -- Set to True if running with Annex-D semantics
132 ------------------------------------
133 -- The thread local storage index --
134 ------------------------------------
137 pragma Export (Ada, TlsIndex);
138 -- To ensure that this variable won't be local to this package, since
139 -- in some cases, inlining forces this variable to be global anyway.
147 function Is_Valid_Task return Boolean;
148 pragma Inline (Is_Valid_Task);
149 -- Does executing thread have a TCB?
151 procedure Set (Self_Id : Task_Id);
153 -- Set the self id for the current task
157 package body Specific is
159 function Is_Valid_Task return Boolean is
161 return TlsGetValue (TlsIndex) /= System.Null_Address;
164 procedure Set (Self_Id : Task_Id) is
167 Succeeded := TlsSetValue (TlsIndex, To_Address (Self_Id));
168 pragma Assert (Succeeded = Win32.TRUE);
173 ---------------------------------
174 -- Support for foreign threads --
175 ---------------------------------
177 function Register_Foreign_Thread (Thread : Thread_Id) return Task_Id;
178 -- Allocate and Initialize a new ATCB for the current Thread
180 function Register_Foreign_Thread
181 (Thread : Thread_Id) return Task_Id is separate;
183 ----------------------------------
184 -- Condition Variable Functions --
185 ----------------------------------
187 procedure Initialize_Cond (Cond : not null access Condition_Variable);
188 -- Initialize given condition variable Cond
190 procedure Finalize_Cond (Cond : not null access Condition_Variable);
191 -- Finalize given condition variable Cond
193 procedure Cond_Signal (Cond : not null access Condition_Variable);
194 -- Signal condition variable Cond
197 (Cond : not null access Condition_Variable;
198 L : not null access RTS_Lock);
199 -- Wait on conditional variable Cond, using lock L
201 procedure Cond_Timed_Wait
202 (Cond : not null access Condition_Variable;
203 L : not null access RTS_Lock;
205 Timed_Out : out Boolean;
206 Status : out Integer);
207 -- Do timed wait on condition variable Cond using lock L. The duration
208 -- of the timed wait is given by Rel_Time. When the condition is
209 -- signalled, Timed_Out shows whether or not a time out occurred.
210 -- Status is only valid if Timed_Out is False, in which case it
211 -- shows whether Cond_Timed_Wait completed successfully.
213 ---------------------
214 -- Initialize_Cond --
215 ---------------------
217 procedure Initialize_Cond (Cond : not null access Condition_Variable) is
220 hEvent := CreateEvent (null, Win32.TRUE, Win32.FALSE, Null_Ptr);
221 pragma Assert (hEvent /= 0);
222 Cond.all := Condition_Variable (hEvent);
229 -- No such problem here, DosCloseEventSem has been derived.
230 -- What does such refer to in above comment???
232 procedure Finalize_Cond (Cond : not null access Condition_Variable) is
235 Result := CloseHandle (HANDLE (Cond.all));
236 pragma Assert (Result = Win32.TRUE);
243 procedure Cond_Signal (Cond : not null access Condition_Variable) is
246 Result := SetEvent (HANDLE (Cond.all));
247 pragma Assert (Result = Win32.TRUE);
254 -- Pre-condition: Cond is posted
257 -- Post-condition: Cond is posted
261 (Cond : not null access Condition_Variable;
262 L : not null access RTS_Lock)
268 -- Must reset Cond BEFORE L is unlocked
270 Result_Bool := ResetEvent (HANDLE (Cond.all));
271 pragma Assert (Result_Bool = Win32.TRUE);
272 Unlock (L, Global_Lock => True);
274 -- No problem if we are interrupted here: if the condition is signaled,
275 -- WaitForSingleObject will simply not block
277 Result := WaitForSingleObject (HANDLE (Cond.all), Wait_Infinite);
278 pragma Assert (Result = 0);
280 Write_Lock (L, Global_Lock => True);
283 ---------------------
284 -- Cond_Timed_Wait --
285 ---------------------
287 -- Pre-condition: Cond is posted
290 -- Post-condition: Cond is posted
293 procedure Cond_Timed_Wait
294 (Cond : not null access Condition_Variable;
295 L : not null access RTS_Lock;
297 Timed_Out : out Boolean;
298 Status : out Integer)
300 Time_Out_Max : constant DWORD := 16#FFFF0000#;
301 -- NT 4 can't handle excessive timeout values (e.g. DWORD'Last - 1)
308 -- Must reset Cond BEFORE L is unlocked
310 Result := ResetEvent (HANDLE (Cond.all));
311 pragma Assert (Result = Win32.TRUE);
312 Unlock (L, Global_Lock => True);
314 -- No problem if we are interrupted here: if the condition is signaled,
315 -- WaitForSingleObject will simply not block.
317 if Rel_Time <= 0.0 then
323 (if Rel_Time >= Duration (Time_Out_Max) / 1000
325 else DWORD (Rel_Time * 1000));
327 Wait_Result := WaitForSingleObject (HANDLE (Cond.all), Time_Out);
329 if Wait_Result = WAIT_TIMEOUT then
337 Write_Lock (L, Global_Lock => True);
339 -- Ensure post-condition
342 Result := SetEvent (HANDLE (Cond.all));
343 pragma Assert (Result = Win32.TRUE);
346 Status := Integer (Wait_Result);
353 -- The underlying thread system sets a guard page at the bottom of a thread
354 -- stack, so nothing is needed.
355 -- ??? Check the comment above
357 procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
358 pragma Unreferenced (T, On);
367 function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
369 return T.Common.LL.Thread;
376 function Self return Task_Id is
377 Self_Id : constant Task_Id := To_Task_Id (TlsGetValue (TlsIndex));
379 if Self_Id = null then
380 return Register_Foreign_Thread (GetCurrentThread);
386 ---------------------
387 -- Initialize_Lock --
388 ---------------------
390 -- Note: mutexes and cond_variables needed per-task basis are initialized
391 -- in Initialize_TCB and the Storage_Error is handled. Other mutexes (such
392 -- as RTS_Lock, Memory_Lock...) used in the RTS is initialized before any
393 -- status change of RTS. Therefore raising Storage_Error in the following
394 -- routines should be able to be handled safely.
396 procedure Initialize_Lock
397 (Prio : System.Any_Priority;
398 L : not null access Lock)
401 InitializeCriticalSection (L.Mutex'Access);
402 L.Owner_Priority := 0;
406 procedure Initialize_Lock
407 (L : not null access RTS_Lock; Level : Lock_Level)
409 pragma Unreferenced (Level);
411 InitializeCriticalSection (L);
418 procedure Finalize_Lock (L : not null access Lock) is
420 DeleteCriticalSection (L.Mutex'Access);
423 procedure Finalize_Lock (L : not null access RTS_Lock) is
425 DeleteCriticalSection (L);
433 (L : not null access Lock; Ceiling_Violation : out Boolean) is
435 L.Owner_Priority := Get_Priority (Self);
437 if L.Priority < L.Owner_Priority then
438 Ceiling_Violation := True;
442 EnterCriticalSection (L.Mutex'Access);
444 Ceiling_Violation := False;
448 (L : not null access RTS_Lock;
449 Global_Lock : Boolean := False)
452 if not Single_Lock or else Global_Lock then
453 EnterCriticalSection (L);
457 procedure Write_Lock (T : Task_Id) is
459 if not Single_Lock then
460 EnterCriticalSection (T.Common.LL.L'Access);
469 (L : not null access Lock; Ceiling_Violation : out Boolean) is
471 Write_Lock (L, Ceiling_Violation);
478 procedure Unlock (L : not null access Lock) is
480 LeaveCriticalSection (L.Mutex'Access);
484 (L : not null access RTS_Lock; Global_Lock : Boolean := False) is
486 if not Single_Lock or else Global_Lock then
487 LeaveCriticalSection (L);
491 procedure Unlock (T : Task_Id) is
493 if not Single_Lock then
494 LeaveCriticalSection (T.Common.LL.L'Access);
502 -- Dynamic priority ceilings are not supported by the underlying system
504 procedure Set_Ceiling
505 (L : not null access Lock;
506 Prio : System.Any_Priority)
508 pragma Unreferenced (L, Prio);
519 Reason : System.Tasking.Task_States)
521 pragma Unreferenced (Reason);
524 pragma Assert (Self_ID = Self);
527 Cond_Wait (Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access);
529 Cond_Wait (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access);
532 if Self_ID.Deferral_Level = 0
533 and then Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
536 raise Standard'Abort_Signal;
544 -- This is for use within the run-time system, so abort is assumed to be
545 -- already deferred, and the caller should be holding its own ATCB lock.
547 procedure Timed_Sleep
550 Mode : ST.Delay_Modes;
551 Reason : System.Tasking.Task_States;
552 Timedout : out Boolean;
553 Yielded : out Boolean)
555 pragma Unreferenced (Reason);
556 Check_Time : Duration := Monotonic_Clock;
561 pragma Unreferenced (Result);
563 Local_Timedout : Boolean;
569 if Mode = Relative then
571 Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
573 Rel_Time := Time - Check_Time;
577 if Rel_Time > 0.0 then
579 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
583 (Self_ID.Common.LL.CV'Access,
584 Single_RTS_Lock'Access,
585 Rel_Time, Local_Timedout, Result);
588 (Self_ID.Common.LL.CV'Access,
589 Self_ID.Common.LL.L'Access,
590 Rel_Time, Local_Timedout, Result);
593 Check_Time := Monotonic_Clock;
594 exit when Abs_Time <= Check_Time;
596 if not Local_Timedout then
598 -- Somebody may have called Wakeup for us
604 Rel_Time := Abs_Time - Check_Time;
613 procedure Timed_Delay
616 Mode : ST.Delay_Modes)
618 Check_Time : Duration := Monotonic_Clock;
624 pragma Unreferenced (Timedout, Result);
631 Write_Lock (Self_ID);
633 if Mode = Relative then
635 Abs_Time := Time + Check_Time;
637 Rel_Time := Time - Check_Time;
641 if Rel_Time > 0.0 then
642 Self_ID.Common.State := Delay_Sleep;
645 exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
649 (Self_ID.Common.LL.CV'Access,
650 Single_RTS_Lock'Access,
651 Rel_Time, Timedout, Result);
654 (Self_ID.Common.LL.CV'Access,
655 Self_ID.Common.LL.L'Access,
656 Rel_Time, Timedout, Result);
659 Check_Time := Monotonic_Clock;
660 exit when Abs_Time <= Check_Time;
662 Rel_Time := Abs_Time - Check_Time;
665 Self_ID.Common.State := Runnable;
681 procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
682 pragma Unreferenced (Reason);
684 Cond_Signal (T.Common.LL.CV'Access);
691 procedure Yield (Do_Yield : Boolean := True) is
697 -- If running with Annex-D semantics we need a delay
698 -- above 0 milliseconds here otherwise processes give
699 -- enough time to the other tasks to have a chance to
702 -- This makes cxd8002 ACATS pass on Windows.
712 type Prio_Array_Type is array (System.Any_Priority) of Integer;
713 pragma Atomic_Components (Prio_Array_Type);
715 Prio_Array : Prio_Array_Type;
716 -- Global array containing the id of the currently running task for
719 -- Note: we assume that we are on a single processor with run-til-blocked
722 procedure Set_Priority
724 Prio : System.Any_Priority;
725 Loss_Of_Inheritance : Boolean := False)
728 Array_Item : Integer;
731 Res := SetThreadPriority
732 (T.Common.LL.Thread, Interfaces.C.int (Underlying_Priorities (Prio)));
733 pragma Assert (Res = Win32.TRUE);
735 if Dispatching_Policy = 'F' or else Get_Policy (Prio) = 'F' then
737 -- Annex D requirement [RM D.2.2 par. 9]:
738 -- If the task drops its priority due to the loss of inherited
739 -- priority, it is added at the head of the ready queue for its
740 -- new active priority.
742 if Loss_Of_Inheritance
743 and then Prio < T.Common.Current_Priority
745 Array_Item := Prio_Array (T.Common.Base_Priority) + 1;
746 Prio_Array (T.Common.Base_Priority) := Array_Item;
749 -- Let some processes a chance to arrive
753 -- Then wait for our turn to proceed
755 exit when Array_Item = Prio_Array (T.Common.Base_Priority)
756 or else Prio_Array (T.Common.Base_Priority) = 1;
759 Prio_Array (T.Common.Base_Priority) :=
760 Prio_Array (T.Common.Base_Priority) - 1;
764 T.Common.Current_Priority := Prio;
771 function Get_Priority (T : Task_Id) return System.Any_Priority is
773 return T.Common.Current_Priority;
780 -- There were two paths were we needed to call Enter_Task :
781 -- 1) from System.Task_Primitives.Operations.Initialize
782 -- 2) from System.Tasking.Stages.Task_Wrapper
784 -- The thread initialisation has to be done only for the first case
786 -- This is because the GetCurrentThread NT call does not return the real
787 -- thread handler but only a "pseudo" one. It is not possible to release
788 -- the thread handle and free the system resources from this "pseudo"
789 -- handle. So we really want to keep the real thread handle set in
790 -- System.Task_Primitives.Operations.Create_Task during thread creation.
792 procedure Enter_Task (Self_ID : Task_Id) is
793 procedure Init_Float;
794 pragma Import (C, Init_Float, "__gnat_init_float");
795 -- Properly initializes the FPU for x86 systems
798 Specific.Set (Self_ID);
801 if Self_ID.Common.Task_Info /= null
803 Self_ID.Common.Task_Info.CPU >= CPU_Number (Number_Of_Processors)
805 raise Invalid_CPU_Number;
808 Self_ID.Common.LL.Thread_Id := GetCurrentThreadId;
815 function New_ATCB (Entry_Num : Task_Entry_Index) return Task_Id is
817 return new Ada_Task_Control_Block (Entry_Num);
824 function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
826 -----------------------------
827 -- Register_Foreign_Thread --
828 -----------------------------
830 function Register_Foreign_Thread return Task_Id is
832 if Is_Valid_Task then
835 return Register_Foreign_Thread (GetCurrentThread);
837 end Register_Foreign_Thread;
843 procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
845 -- Initialize thread ID to 0, this is needed to detect threads that
846 -- are not yet activated.
848 Self_ID.Common.LL.Thread := 0;
850 Initialize_Cond (Self_ID.Common.LL.CV'Access);
852 if not Single_Lock then
853 Initialize_Lock (Self_ID.Common.LL.L'Access, ATCB_Level);
863 procedure Create_Task
865 Wrapper : System.Address;
866 Stack_Size : System.Parameters.Size_Type;
867 Priority : System.Any_Priority;
868 Succeeded : out Boolean)
870 Initial_Stack_Size : constant := 1024;
871 -- We set the initial stack size to 1024. On Windows version prior to XP
872 -- there is no way to fix a task stack size. Only the initial stack size
873 -- can be set, the operating system will raise the task stack size if
876 function Is_Windows_XP return Integer;
877 pragma Import (C, Is_Windows_XP, "__gnat_is_windows_xp");
878 -- Returns 1 if running on Windows XP
881 TaskId : aliased DWORD;
882 pTaskParameter : Win32.PVOID;
884 Entry_Point : PTHREAD_START_ROUTINE;
887 pTaskParameter := To_Address (T);
889 Entry_Point := To_PTHREAD_START_ROUTINE (Wrapper);
891 if Is_Windows_XP = 1 then
892 hTask := CreateThread
897 DWORD (Create_Suspended) or
898 DWORD (Stack_Size_Param_Is_A_Reservation),
899 TaskId'Unchecked_Access);
901 hTask := CreateThread
906 DWORD (Create_Suspended),
907 TaskId'Unchecked_Access);
910 -- Step 1: Create the thread in blocked mode
917 -- Step 2: set its TCB
919 T.Common.LL.Thread := hTask;
921 -- Step 3: set its priority (child has inherited priority from parent)
923 Set_Priority (T, Priority);
925 if Time_Slice_Val = 0
926 or else Dispatching_Policy = 'F'
927 or else Get_Policy (Priority) = 'F'
929 -- Here we need Annex D semantics so we disable the NT priority
930 -- boost. A priority boost is temporarily given by the system to a
931 -- thread when it is taken out of a wait state.
933 SetThreadPriorityBoost (hTask, DisablePriorityBoost => Win32.TRUE);
936 -- Step 4: Handle Task_Info
938 if T.Common.Task_Info /= null then
939 if T.Common.Task_Info.CPU /= Task_Info.Any_CPU then
940 Result := SetThreadIdealProcessor (hTask, T.Common.Task_Info.CPU);
941 pragma Assert (Result = 1);
945 -- Step 5: Now, start it for good:
947 Result := ResumeThread (hTask);
948 pragma Assert (Result = 1);
950 Succeeded := Result = 1;
957 procedure Finalize_TCB (T : Task_Id) is
958 Self_ID : Task_Id := T;
961 Is_Self : constant Boolean := T = Self;
963 procedure Free is new
964 Ada.Unchecked_Deallocation (Ada_Task_Control_Block, Task_Id);
967 if not Single_Lock then
968 Finalize_Lock (T.Common.LL.L'Access);
971 Finalize_Cond (T.Common.LL.CV'Access);
973 if T.Known_Tasks_Index /= -1 then
974 Known_Tasks (T.Known_Tasks_Index) := null;
977 if Self_ID.Common.LL.Thread /= 0 then
979 -- This task has been activated. Wait for the thread to terminate
980 -- then close it. This is needed to release system resources.
982 Result := WaitForSingleObject (T.Common.LL.Thread, Wait_Infinite);
983 pragma Assert (Result /= WAIT_FAILED);
984 Succeeded := CloseHandle (T.Common.LL.Thread);
985 pragma Assert (Succeeded = Win32.TRUE);
999 procedure Exit_Task is
1001 Specific.Set (null);
1008 procedure Abort_Task (T : Task_Id) is
1009 pragma Unreferenced (T);
1014 ----------------------
1015 -- Environment_Task --
1016 ----------------------
1018 function Environment_Task return Task_Id is
1020 return Environment_Task_Id;
1021 end Environment_Task;
1027 procedure Lock_RTS is
1029 Write_Lock (Single_RTS_Lock'Access, Global_Lock => True);
1036 procedure Unlock_RTS is
1038 Unlock (Single_RTS_Lock'Access, Global_Lock => True);
1045 procedure Initialize (Environment_Task : Task_Id) is
1047 pragma Unreferenced (Discard);
1050 Environment_Task_Id := Environment_Task;
1051 OS_Primitives.Initialize;
1052 Interrupt_Management.Initialize;
1054 if Time_Slice_Val = 0 or else Dispatching_Policy = 'F' then
1055 -- Here we need Annex D semantics, switch the current process to the
1056 -- Realtime_Priority_Class.
1058 Discard := OS_Interface.SetPriorityClass
1059 (GetCurrentProcess, Realtime_Priority_Class);
1064 TlsIndex := TlsAlloc;
1066 -- Initialize the lock used to synchronize chain of all ATCBs
1068 Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
1070 Environment_Task.Common.LL.Thread := GetCurrentThread;
1072 -- Make environment task known here because it doesn't go through
1073 -- Activate_Tasks, which does it for all other tasks.
1075 Known_Tasks (Known_Tasks'First) := Environment_Task;
1076 Environment_Task.Known_Tasks_Index := Known_Tasks'First;
1078 Enter_Task (Environment_Task);
1081 ---------------------
1082 -- Monotonic_Clock --
1083 ---------------------
1085 function Monotonic_Clock return Duration
1086 renames System.OS_Primitives.Monotonic_Clock;
1092 function RT_Resolution return Duration is
1094 return 0.000_001; -- 1 micro-second
1101 procedure Initialize (S : in out Suspension_Object) is
1103 -- Initialize internal state. It is always initialized to False (ARM
1109 -- Initialize internal mutex
1111 InitializeCriticalSection (S.L'Access);
1113 -- Initialize internal condition variable
1115 S.CV := CreateEvent (null, Win32.TRUE, Win32.FALSE, Null_Ptr);
1116 pragma Assert (S.CV /= 0);
1123 procedure Finalize (S : in out Suspension_Object) is
1126 -- Destroy internal mutex
1128 DeleteCriticalSection (S.L'Access);
1130 -- Destroy internal condition variable
1132 Result := CloseHandle (S.CV);
1133 pragma Assert (Result = Win32.TRUE);
1140 function Current_State (S : Suspension_Object) return Boolean is
1142 -- We do not want to use lock on this read operation. State is marked
1143 -- as Atomic so that we ensure that the value retrieved is correct.
1152 procedure Set_False (S : in out Suspension_Object) is
1154 SSL.Abort_Defer.all;
1156 EnterCriticalSection (S.L'Access);
1160 LeaveCriticalSection (S.L'Access);
1162 SSL.Abort_Undefer.all;
1169 procedure Set_True (S : in out Suspension_Object) is
1172 SSL.Abort_Defer.all;
1174 EnterCriticalSection (S.L'Access);
1176 -- If there is already a task waiting on this suspension object then
1177 -- we resume it, leaving the state of the suspension object to False,
1178 -- as it is specified in ARM D.10 par. 9. Otherwise, it just leaves
1179 -- the state to True.
1185 Result := SetEvent (S.CV);
1186 pragma Assert (Result = Win32.TRUE);
1191 LeaveCriticalSection (S.L'Access);
1193 SSL.Abort_Undefer.all;
1196 ------------------------
1197 -- Suspend_Until_True --
1198 ------------------------
1200 procedure Suspend_Until_True (S : in out Suspension_Object) is
1204 SSL.Abort_Defer.all;
1206 EnterCriticalSection (S.L'Access);
1209 -- Program_Error must be raised upon calling Suspend_Until_True
1210 -- if another task is already waiting on that suspension object
1211 -- (ARM D.10 par. 10).
1213 LeaveCriticalSection (S.L'Access);
1215 SSL.Abort_Undefer.all;
1217 raise Program_Error;
1219 -- Suspend the task if the state is False. Otherwise, the task
1220 -- continues its execution, and the state of the suspension object
1221 -- is set to False (ARM D.10 par. 9).
1226 LeaveCriticalSection (S.L'Access);
1228 SSL.Abort_Undefer.all;
1232 -- Must reset CV BEFORE L is unlocked
1234 Result_Bool := ResetEvent (S.CV);
1235 pragma Assert (Result_Bool = Win32.TRUE);
1237 LeaveCriticalSection (S.L'Access);
1239 SSL.Abort_Undefer.all;
1241 Result := WaitForSingleObject (S.CV, Wait_Infinite);
1242 pragma Assert (Result = 0);
1245 end Suspend_Until_True;
1251 -- Dummy versions. The only currently working versions is for solaris
1254 function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
1255 pragma Unreferenced (Self_ID);
1260 --------------------
1261 -- Check_No_Locks --
1262 --------------------
1264 function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
1265 pragma Unreferenced (Self_ID);
1274 function Suspend_Task
1276 Thread_Self : Thread_Id) return Boolean
1279 if T.Common.LL.Thread /= Thread_Self then
1280 return SuspendThread (T.Common.LL.Thread) = NO_ERROR;
1290 function Resume_Task
1292 Thread_Self : Thread_Id) return Boolean
1295 if T.Common.LL.Thread /= Thread_Self then
1296 return ResumeThread (T.Common.LL.Thread) = NO_ERROR;
1302 --------------------
1303 -- Stop_All_Tasks --
1304 --------------------
1306 procedure Stop_All_Tasks is
1315 function Stop_Task (T : ST.Task_Id) return Boolean is
1316 pragma Unreferenced (T);
1325 function Continue_Task (T : ST.Task_Id) return Boolean is
1326 pragma Unreferenced (T);
1331 end System.Task_Primitives.Operations;