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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- 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 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2022, Free Software Foundation, Inc. --
-- --
-- GNARL is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. --
-- Extensive contributions were provided by Ada Core Technologies, Inc. --
-- --
------------------------------------------------------------------------------
-- This is the VxWorks version of this package
-- This package contains all the GNULL primitives that interface directly with
-- the underlying OS.
with Ada.Unchecked_Conversion;
with Interfaces.C;
with System.Multiprocessors;
with System.Tasking.Debug;
with System.Interrupt_Management;
with System.Float_Control;
with System.OS_Constants;
with System.Soft_Links;
-- We use System.Soft_Links instead of System.Tasking.Initialization
-- because the later is a higher level package that we shouldn't depend
-- on. For example when using the restricted run time, it is replaced by
-- System.Tasking.Restricted.Stages.
with System.Task_Info;
with System.VxWorks.Ext;
package body System.Task_Primitives.Operations is
package OSC renames System.OS_Constants;
package SSL renames System.Soft_Links;
use System.Tasking.Debug;
use System.Tasking;
use System.OS_Interface;
use System.Parameters;
use type Interfaces.C.int;
use type System.OS_Interface.unsigned;
use type System.VxWorks.Ext.t_id;
use type System.VxWorks.Ext.STATUS;
use type System.VxWorks.Ext.BOOL;
subtype int is System.OS_Interface.int;
subtype unsigned is System.OS_Interface.unsigned;
subtype STATUS is System.VxWorks.Ext.STATUS;
OK : constant STATUS := System.VxWorks.Ext.OK;
Relative : constant := 0;
----------------
-- Local Data --
----------------
-- The followings are logically constants, but need to be initialized at
-- run time.
Environment_Task_Id : Task_Id;
-- A variable to hold Task_Id for the environment task
-- The followings are internal configuration constants needed
Dispatching_Policy : constant Character;
pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
Foreign_Task_Elaborated : aliased Boolean := True;
-- Used to identified fake tasks (i.e., non-Ada Threads)
Locking_Policy : constant Character;
pragma Import (C, Locking_Policy, "__gl_locking_policy");
Mutex_Protocol : Priority_Type;
Single_RTS_Lock : aliased RTS_Lock;
-- This is a lock to allow only one thread of control in the RTS at a
-- time; it is used to execute in mutual exclusion from all other tasks.
-- Used to protect All_Tasks_List
Time_Slice_Val : constant Integer;
pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
Null_Thread_Id : constant Thread_Id := 0;
-- Constant to indicate that the thread identifier has not yet been
-- initialized.
--------------------
-- Local Packages --
--------------------
package Specific is
procedure Initialize;
pragma Inline (Initialize);
-- Initialize task specific data
function Is_Valid_Task return Boolean;
pragma Inline (Is_Valid_Task);
-- Does executing thread have a TCB?
procedure Set (Self_Id : Task_Id);
pragma Inline (Set);
-- Set the self id for the current task, unless Self_Id is null, in
-- which case the task specific data is deleted.
function Self return Task_Id;
pragma Inline (Self);
-- Return a pointer to the Ada Task Control Block of the calling task
end Specific;
package body Specific is separate;
-- The body of this package is target specific
----------------------------------
-- ATCB allocation/deallocation --
----------------------------------
package body ATCB_Allocation is separate;
-- The body of this package is shared across several targets
---------------------------------
-- Support for foreign threads --
---------------------------------
function Register_Foreign_Thread
(Thread : Thread_Id;
Sec_Stack_Size : Size_Type := Unspecified_Size) return Task_Id;
-- Allocate and initialize a new ATCB for the current Thread. The size of
-- the secondary stack can be optionally specified.
function Register_Foreign_Thread
(Thread : Thread_Id;
Sec_Stack_Size : Size_Type := Unspecified_Size)
return Task_Id is separate;
-----------------------
-- Local Subprograms --
-----------------------
procedure Abort_Handler (signo : Signal);
-- Handler for the abort (SIGABRT) signal to handle asynchronous abort
procedure Install_Signal_Handlers;
-- Install the default signal handlers for the current task
function Is_Task_Context return Boolean;
-- This function returns True if the current execution is in the context of
-- a task, and False if it is an interrupt context.
type Set_Stack_Limit_Proc_Acc is access procedure;
pragma Convention (C, Set_Stack_Limit_Proc_Acc);
Set_Stack_Limit_Hook : Set_Stack_Limit_Proc_Acc;
pragma Import (C, Set_Stack_Limit_Hook, "__gnat_set_stack_limit_hook");
-- Procedure to be called when a task is created to set stack limit. Used
-- only for VxWorks 5 and VxWorks MILS guest OS.
function To_Address is
new Ada.Unchecked_Conversion (Task_Id, System.Address);
-------------------
-- Abort_Handler --
-------------------
procedure Abort_Handler (signo : Signal) is
pragma Unreferenced (signo);
-- Do not call Self at this point as we're in a signal handler
-- and it may not be available, in particular on targets where we
-- support ZCX and where we don't do anything here anyway.
Self_ID : Task_Id;
Old_Set : aliased sigset_t;
Unblocked_Mask : aliased sigset_t;
Result : int;
pragma Warnings (Off, Result);
use System.Interrupt_Management;
begin
-- It is not safe to raise an exception when using ZCX and the GCC
-- exception handling mechanism.
if ZCX_By_Default then
return;
end if;
Self_ID := Self;
if Self_ID.Deferral_Level = 0
and then Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
and then not Self_ID.Aborting
then
Self_ID.Aborting := True;
-- Make sure signals used for RTS internal purposes are unmasked
Result := sigemptyset (Unblocked_Mask'Access);
pragma Assert (Result = 0);
Result :=
sigaddset
(Unblocked_Mask'Access,
Signal (Abort_Task_Interrupt));
pragma Assert (Result = 0);
Result := sigaddset (Unblocked_Mask'Access, SIGBUS);
pragma Assert (Result = 0);
Result := sigaddset (Unblocked_Mask'Access, SIGFPE);
pragma Assert (Result = 0);
Result := sigaddset (Unblocked_Mask'Access, SIGILL);
pragma Assert (Result = 0);
Result := sigaddset (Unblocked_Mask'Access, SIGSEGV);
pragma Assert (Result = 0);
Result :=
pthread_sigmask
(SIG_UNBLOCK,
Unblocked_Mask'Access,
Old_Set'Access);
pragma Assert (Result = 0);
raise Standard'Abort_Signal;
end if;
end Abort_Handler;
-----------------
-- Stack_Guard --
-----------------
procedure Stack_Guard (T : ST.Task_Id; On : Boolean) is
pragma Unreferenced (T);
pragma Unreferenced (On);
begin
-- Nothing needed (why not???)
null;
end Stack_Guard;
-------------------
-- Get_Thread_Id --
-------------------
function Get_Thread_Id (T : ST.Task_Id) return OSI.Thread_Id is
begin
return T.Common.LL.Thread;
end Get_Thread_Id;
----------
-- Self --
----------
function Self return Task_Id renames Specific.Self;
-----------------------------
-- Install_Signal_Handlers --
-----------------------------
procedure Install_Signal_Handlers is
act : aliased struct_sigaction;
old_act : aliased struct_sigaction;
Tmp_Set : aliased sigset_t;
Result : int;
begin
act.sa_flags := 0;
act.sa_handler := Abort_Handler'Address;
Result := sigemptyset (Tmp_Set'Access);
pragma Assert (Result = 0);
act.sa_mask := Tmp_Set;
Result :=
sigaction
(Signal (Interrupt_Management.Abort_Task_Interrupt),
act'Unchecked_Access,
old_act'Unchecked_Access);
pragma Assert (Result = 0);
Interrupt_Management.Initialize_Interrupts;
end Install_Signal_Handlers;
---------------------
-- Initialize_Lock --
---------------------
procedure Initialize_Lock
(Prio : System.Any_Priority;
L : not null access Lock)
is
begin
L.Mutex := semMCreate (SEM_Q_PRIORITY + SEM_INVERSION_SAFE);
L.Prio_Ceiling := int (Prio);
L.Protocol := Mutex_Protocol;
pragma Assert (L.Mutex /= 0);
end Initialize_Lock;
procedure Initialize_Lock
(L : not null access RTS_Lock;
Level : Lock_Level)
is
pragma Unreferenced (Level);
begin
L.Mutex := semMCreate (SEM_Q_PRIORITY + SEM_INVERSION_SAFE);
L.Prio_Ceiling := int (System.Any_Priority'Last);
L.Protocol := Mutex_Protocol;
pragma Assert (L.Mutex /= 0);
end Initialize_Lock;
-------------------
-- Finalize_Lock --
-------------------
procedure Finalize_Lock (L : not null access Lock) is
Result : STATUS;
begin
Result := semDelete (L.Mutex);
pragma Assert (Result = OK);
end Finalize_Lock;
procedure Finalize_Lock (L : not null access RTS_Lock) is
Result : STATUS;
begin
Result := semDelete (L.Mutex);
pragma Assert (Result = OK);
end Finalize_Lock;
----------------
-- Write_Lock --
----------------
procedure Write_Lock
(L : not null access Lock;
Ceiling_Violation : out Boolean)
is
Result : STATUS;
begin
if L.Protocol = Prio_Protect
and then int (Self.Common.Current_Priority) > L.Prio_Ceiling
then
Ceiling_Violation := True;
return;
else
Ceiling_Violation := False;
end if;
Result := semTake (L.Mutex, WAIT_FOREVER);
pragma Assert (Result = OK);
end Write_Lock;
procedure Write_Lock (L : not null access RTS_Lock) is
Result : STATUS;
begin
Result := semTake (L.Mutex, WAIT_FOREVER);
pragma Assert (Result = OK);
end Write_Lock;
procedure Write_Lock (T : Task_Id) is
Result : STATUS;
begin
Result := semTake (T.Common.LL.L.Mutex, WAIT_FOREVER);
pragma Assert (Result = OK);
end Write_Lock;
---------------
-- Read_Lock --
---------------
procedure Read_Lock
(L : not null access Lock;
Ceiling_Violation : out Boolean) is
begin
Write_Lock (L, Ceiling_Violation);
end Read_Lock;
------------
-- Unlock --
------------
procedure Unlock (L : not null access Lock) is
Result : STATUS;
begin
Result := semGive (L.Mutex);
pragma Assert (Result = OK);
end Unlock;
procedure Unlock (L : not null access RTS_Lock) is
Result : STATUS;
begin
Result := semGive (L.Mutex);
pragma Assert (Result = OK);
end Unlock;
procedure Unlock (T : Task_Id) is
Result : STATUS;
begin
Result := semGive (T.Common.LL.L.Mutex);
pragma Assert (Result = OK);
end Unlock;
-----------------
-- Set_Ceiling --
-----------------
-- Dynamic priority ceilings are not supported by the underlying system
procedure Set_Ceiling
(L : not null access Lock;
Prio : System.Any_Priority)
is
pragma Unreferenced (L, Prio);
begin
null;
end Set_Ceiling;
-----------
-- Sleep --
-----------
procedure Sleep (Self_ID : Task_Id; Reason : System.Tasking.Task_States) is
pragma Unreferenced (Reason);
Result : STATUS;
begin
pragma Assert (Self_ID = Self);
-- Release the mutex before sleeping
Result := semGive (Self_ID.Common.LL.L.Mutex);
pragma Assert (Result = OK);
-- Perform a blocking operation to take the CV semaphore. Note that a
-- blocking operation in VxWorks will reenable task scheduling. When we
-- are no longer blocked and control is returned, task scheduling will
-- again be disabled.
Result := semTake (Self_ID.Common.LL.CV, WAIT_FOREVER);
pragma Assert (Result = OK);
-- Take the mutex back
Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER);
pragma Assert (Result = OK);
end Sleep;
-----------------
-- Timed_Sleep --
-----------------
-- This is for use within the run-time system, so abort is assumed to be
-- already deferred, and the caller should be holding its own ATCB lock.
procedure Timed_Sleep
(Self_ID : Task_Id;
Time : Duration;
Mode : ST.Delay_Modes;
Reason : System.Tasking.Task_States;
Timedout : out Boolean;
Yielded : out Boolean)
is
pragma Unreferenced (Reason);
Orig : constant Duration := Monotonic_Clock;
Absolute : Duration;
Ticks : int;
Result : STATUS;
Wakeup : Boolean := False;
begin
Timedout := False;
Yielded := True;
if Mode = Relative then
Absolute := Orig + Time;
-- Systematically add one since the first tick will delay *at most*
-- 1 / Rate_Duration seconds, so we need to add one to be on the
-- safe side.
Ticks := To_Clock_Ticks (Time);
if Ticks > 0 and then Ticks < int'Last then
Ticks := Ticks + 1;
end if;
else
Absolute := Time;
Ticks := To_Clock_Ticks (Time - Monotonic_Clock);
end if;
if Ticks > 0 then
loop
-- Release the mutex before sleeping
Result := semGive (Self_ID.Common.LL.L.Mutex);
pragma Assert (Result = OK);
-- Perform a blocking operation to take the CV semaphore. Note
-- that a blocking operation in VxWorks will reenable task
-- scheduling. When we are no longer blocked and control is
-- returned, task scheduling will again be disabled.
Result := semTake (Self_ID.Common.LL.CV, Ticks);
if Result = OK then
-- Somebody may have called Wakeup for us
Wakeup := True;
else
if errno /= S_objLib_OBJ_TIMEOUT then
Wakeup := True;
else
-- If Ticks = int'last, it was most probably truncated so
-- let's make another round after recomputing Ticks from
-- the absolute time.
if Ticks /= int'Last then
Timedout := True;
else
Ticks := To_Clock_Ticks (Absolute - Monotonic_Clock);
if Ticks < 0 then
Timedout := True;
end if;
end if;
end if;
end if;
-- Take the mutex back
Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER);
pragma Assert (Result = OK);
exit when Timedout or Wakeup;
end loop;
else
Timedout := True;
-- Should never hold a lock while yielding
Result := semGive (Self_ID.Common.LL.L.Mutex);
Result := taskDelay (0);
Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER);
end if;
end Timed_Sleep;
-----------------
-- Timed_Delay --
-----------------
-- This is for use in implementing delay statements, so we assume the
-- caller is holding no locks.
procedure Timed_Delay
(Self_ID : Task_Id;
Time : Duration;
Mode : ST.Delay_Modes)
is
Orig : constant Duration := Monotonic_Clock;
Absolute : Duration;
Ticks : int;
Timedout : Boolean;
Aborted : Boolean := False;
Result : STATUS;
pragma Warnings (Off, Result);
begin
if Mode = Relative then
Absolute := Orig + Time;
Ticks := To_Clock_Ticks (Time);
if Ticks > 0 and then Ticks < int'Last then
-- First tick will delay anytime between 0 and 1 / sysClkRateGet
-- seconds, so we need to add one to be on the safe side.
Ticks := Ticks + 1;
end if;
else
Absolute := Time;
Ticks := To_Clock_Ticks (Time - Orig);
end if;
if Ticks > 0 then
-- Modifying State, locking the TCB
Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER);
pragma Assert (Result = OK);
Self_ID.Common.State := Delay_Sleep;
Timedout := False;
loop
Aborted := Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
-- Release the TCB before sleeping
Result := semGive (Self_ID.Common.LL.L.Mutex);
pragma Assert (Result = OK);
exit when Aborted;
Result := semTake (Self_ID.Common.LL.CV, Ticks);
if Result /= OK then
-- If Ticks = int'last, it was most probably truncated, so make
-- another round after recomputing Ticks from absolute time.
if errno = S_objLib_OBJ_TIMEOUT and then Ticks /= int'Last then
Timedout := True;
else
Ticks := To_Clock_Ticks (Absolute - Monotonic_Clock);
if Ticks < 0 then
Timedout := True;
end if;
end if;
end if;
-- Take back the lock after having slept, to protect further
-- access to Self_ID.
Result := semTake (Self_ID.Common.LL.L.Mutex, WAIT_FOREVER);
pragma Assert (Result = OK);
exit when Timedout;
end loop;
Self_ID.Common.State := Runnable;
Result := semGive (Self_ID.Common.LL.L.Mutex);
else
Result := taskDelay (0);
end if;
end Timed_Delay;
---------------------
-- Monotonic_Clock --
---------------------
function Monotonic_Clock return Duration is
TS : aliased timespec;
Result : int;
begin
Result := clock_gettime (OSC.CLOCK_RT_Ada, TS'Unchecked_Access);
pragma Assert (Result = 0);
return To_Duration (TS);
end Monotonic_Clock;
-------------------
-- RT_Resolution --
-------------------
function RT_Resolution return Duration is
begin
return 1.0 / Duration (sysClkRateGet);
end RT_Resolution;
------------
-- Wakeup --
------------
procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
pragma Unreferenced (Reason);
Result : STATUS;
begin
Result := semGive (T.Common.LL.CV);
pragma Assert (Result = OK);
end Wakeup;
-----------
-- Yield --
-----------
procedure Yield (Do_Yield : Boolean := True) is
pragma Unreferenced (Do_Yield);
Result : STATUS;
pragma Unreferenced (Result);
begin
Result := taskDelay (0);
end Yield;
------------------
-- Set_Priority --
------------------
procedure Set_Priority
(T : Task_Id;
Prio : System.Any_Priority;
Loss_Of_Inheritance : Boolean := False)
is
pragma Unreferenced (Loss_Of_Inheritance);
Result : STATUS;
begin
Result :=
taskPrioritySet
(T.Common.LL.Thread, To_VxWorks_Priority (int (Prio)));
pragma Assert (Result = OK);
-- Note: in VxWorks 6.6 (or earlier), the task is placed at the end of
-- the priority queue instead of the head. This is not the behavior
-- required by Annex D (RM D.2.3(5/2)), but we consider it an acceptable
-- variation (RM 1.1.3(6)), given this is the built-in behavior of the
-- operating system. VxWorks versions starting from 6.7 implement the
-- required Annex D semantics.
-- In older versions we attempted to better approximate the Annex D
-- required behavior, but this simulation was not entirely accurate,
-- and it seems better to live with the standard VxWorks semantics.
T.Common.Current_Priority := Prio;
end Set_Priority;
------------------
-- Get_Priority --
------------------
function Get_Priority (T : Task_Id) return System.Any_Priority is
begin
return T.Common.Current_Priority;
end Get_Priority;
----------------
-- Enter_Task --
----------------
procedure Enter_Task (Self_ID : Task_Id) is
begin
-- Store the user-level task id in the Thread field (to be used
-- internally by the run-time system) and the kernel-level task id in
-- the LWP field (to be used by the debugger).
Self_ID.Common.LL.Thread := taskIdSelf;
Self_ID.Common.LL.LWP := getpid;
Specific.Set (Self_ID);
-- Properly initializes the FPU for PPC/MIPS systems
System.Float_Control.Reset;
-- Install the signal handlers
-- This is called for each task since there is no signal inheritance
-- between VxWorks tasks.
Install_Signal_Handlers;
-- If stack checking is enabled, set the stack limit for this task
if Set_Stack_Limit_Hook /= null then
Set_Stack_Limit_Hook.all;
end if;
end Enter_Task;
-------------------
-- Is_Valid_Task --
-------------------
function Is_Valid_Task return Boolean renames Specific.Is_Valid_Task;
-----------------------------
-- Register_Foreign_Thread --
-----------------------------
function Register_Foreign_Thread return Task_Id is
begin
if Is_Valid_Task then
return Self;
else
return Register_Foreign_Thread (taskIdSelf);
end if;
end Register_Foreign_Thread;
--------------------
-- Initialize_TCB --
--------------------
procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
begin
Self_ID.Common.LL.CV := semBCreate (SEM_Q_PRIORITY, SEM_EMPTY);
Self_ID.Common.LL.Thread := Null_Thread_Id;
if Self_ID.Common.LL.CV = 0 then
Succeeded := False;
else
Succeeded := True;
Initialize_Lock (Self_ID.Common.LL.L'Access, ATCB_Level);
end if;
end Initialize_TCB;
-----------------
-- Create_Task --
-----------------
procedure Create_Task
(T : Task_Id;
Wrapper : System.Address;
Stack_Size : System.Parameters.Size_Type;
Priority : System.Any_Priority;
Succeeded : out Boolean)
is
Adjusted_Stack_Size : size_t;
use type System.Multiprocessors.CPU_Range;
begin
-- Check whether both Dispatching_Domain and CPU are specified for
-- the task, and the CPU value is not contained within the range of
-- processors for the domain.
if T.Common.Domain /= null
and then T.Common.Base_CPU /= System.Multiprocessors.Not_A_Specific_CPU
and then
(T.Common.Base_CPU not in T.Common.Domain'Range
or else not T.Common.Domain (T.Common.Base_CPU))
then
Succeeded := False;
return;
end if;
-- Ask for four extra bytes of stack space so that the ATCB pointer can
-- be stored below the stack limit, plus extra space for the frame of
-- Task_Wrapper. This is so the user gets the amount of stack requested
-- exclusive of the needs.
-- We also have to allocate n more bytes for the task name storage and
-- enough space for the Wind Task Control Block which is around 0x778
-- bytes. VxWorks also seems to carve out additional space, so use 2048
-- as a nice round number. We might want to increment to the nearest
-- page size in case we ever support VxVMI.
-- ??? - we should come back and visit this so we can set the task name
-- to something appropriate.
Adjusted_Stack_Size := size_t (Stack_Size) + 2048;
-- Since the initial signal mask of a thread is inherited from the
-- creator, and the Environment task has all its signals masked, we do
-- not need to manipulate caller's signal mask at this point. All tasks
-- in RTS will have All_Tasks_Mask initially.
-- We now compute the VxWorks task name and options, then spawn ...
declare
Name : aliased String (1 .. T.Common.Task_Image_Len + 1);
Name_Address : System.Address;
-- Task name we are going to hand down to VxWorks
function Get_Task_Options return int;
pragma Import (C, Get_Task_Options, "__gnat_get_task_options");
-- Function that returns the options to be set for the task that we
-- are creating. We fetch the options assigned to the current task,
-- so offering some user level control over the options for a task
-- hierarchy, and force VX_FP_TASK because it is almost always
-- required.
begin
-- If there is no Ada task name handy, let VxWorks choose one.
-- Otherwise, tell VxWorks what the Ada task name is.
if T.Common.Task_Image_Len = 0 then
Name_Address := System.Null_Address;
else
Name (1 .. Name'Last - 1) :=
T.Common.Task_Image (1 .. T.Common.Task_Image_Len);
Name (Name'Last) := ASCII.NUL;
Name_Address := Name'Address;
end if;
-- Now spawn the VxWorks task for real
T.Common.LL.Thread :=
taskSpawn
(Name_Address,
To_VxWorks_Priority (int (Priority)),
Get_Task_Options,
Adjusted_Stack_Size,
Wrapper,
To_Address (T));
end;
-- Set processor affinity
Set_Task_Affinity (T);
-- Only case of failure is if taskSpawn returned 0 (aka Null_Thread_Id)
if T.Common.LL.Thread = Null_Thread_Id then
Succeeded := False;
else
Succeeded := True;
Task_Creation_Hook (T.Common.LL.Thread);
Set_Priority (T, Priority);
end if;
end Create_Task;
------------------
-- Finalize_TCB --
------------------
procedure Finalize_TCB (T : Task_Id) is
Result : STATUS;
begin
Result := semDelete (T.Common.LL.L.Mutex);
pragma Assert (Result = OK);
T.Common.LL.Thread := Null_Thread_Id;
Result := semDelete (T.Common.LL.CV);
pragma Assert (Result = OK);
if T.Known_Tasks_Index /= -1 then
Known_Tasks (T.Known_Tasks_Index) := null;
end if;
ATCB_Allocation.Free_ATCB (T);
end Finalize_TCB;
---------------
-- Exit_Task --
---------------
procedure Exit_Task is
begin
Specific.Set (null);
end Exit_Task;
----------------
-- Abort_Task --
----------------
procedure Abort_Task (T : Task_Id) is
Result : int;
begin
Result :=
kill
(T.Common.LL.Thread,
Signal (Interrupt_Management.Abort_Task_Interrupt));
pragma Assert (Result = 0);
end Abort_Task;
----------------
-- Initialize --
----------------
procedure Initialize (S : in out Suspension_Object) is
begin
-- Initialize internal state (always to False (RM D.10(6)))
S.State := False;
S.Waiting := False;
-- Initialize internal mutex
-- Use simpler binary semaphore instead of VxWorks mutual exclusion
-- semaphore, because we don't need the fancier semantics and their
-- overhead.
S.L := semBCreate (SEM_Q_FIFO, SEM_FULL);
-- Initialize internal condition variable
S.CV := semBCreate (SEM_Q_FIFO, SEM_EMPTY);
end Initialize;
--------------
-- Finalize --
--------------
procedure Finalize (S : in out Suspension_Object) is
pragma Unmodified (S);
-- S may be modified on other targets, but not on VxWorks
Result : STATUS;
begin
-- Destroy internal mutex
Result := semDelete (S.L);
pragma Assert (Result = OK);
-- Destroy internal condition variable
Result := semDelete (S.CV);
pragma Assert (Result = OK);
end Finalize;
-------------------
-- Current_State --
-------------------
function Current_State (S : Suspension_Object) return Boolean is
begin
-- We do not want to use lock on this read operation. State is marked
-- as Atomic so that we ensure that the value retrieved is correct.
return S.State;
end Current_State;
---------------
-- Set_False --
---------------
procedure Set_False (S : in out Suspension_Object) is
Result : STATUS;
begin
SSL.Abort_Defer.all;
Result := semTake (S.L, WAIT_FOREVER);
pragma Assert (Result = OK);
S.State := False;
Result := semGive (S.L);
pragma Assert (Result = OK);
SSL.Abort_Undefer.all;
end Set_False;
--------------
-- Set_True --
--------------
procedure Set_True (S : in out Suspension_Object) is
Result : STATUS;
begin
-- Set_True can be called from an interrupt context, in which case
-- Abort_Defer is undefined.
if Is_Task_Context then
SSL.Abort_Defer.all;
end if;
Result := semTake (S.L, WAIT_FOREVER);
pragma Assert (Result = OK);
-- If there is already a task waiting on this suspension object then we
-- resume it, leaving the state of the suspension object to False, as it
-- is specified in (RM D.10 (9)). Otherwise, it just leaves the state to
-- True.
if S.Waiting then
S.Waiting := False;
S.State := False;
Result := semGive (S.CV);
pragma Assert (Result = OK);
else
S.State := True;
end if;
Result := semGive (S.L);
pragma Assert (Result = OK);
-- Set_True can be called from an interrupt context, in which case
-- Abort_Undefer is undefined.
if Is_Task_Context then
SSL.Abort_Undefer.all;
end if;
end Set_True;
------------------------
-- Suspend_Until_True --
------------------------
procedure Suspend_Until_True (S : in out Suspension_Object) is
Result : STATUS;
begin
SSL.Abort_Defer.all;
Result := semTake (S.L, WAIT_FOREVER);
if S.Waiting then
-- Program_Error must be raised upon calling Suspend_Until_True
-- if another task is already waiting on that suspension object
-- (RM D.10(10)).
Result := semGive (S.L);
pragma Assert (Result = OK);
SSL.Abort_Undefer.all;
raise Program_Error;
else
-- Suspend the task if the state is False. Otherwise, the task
-- continues its execution, and the state of the suspension object
-- is set to False (RM D.10 (9)).
if S.State then
S.State := False;
Result := semGive (S.L);
pragma Assert (Result = OK);
SSL.Abort_Undefer.all;
else
S.Waiting := True;
-- Release the mutex before sleeping
Result := semGive (S.L);
pragma Assert (Result = OK);
SSL.Abort_Undefer.all;
Result := semTake (S.CV, WAIT_FOREVER);
pragma Assert (Result = 0);
end if;
end if;
end Suspend_Until_True;
----------------
-- Check_Exit --
----------------
-- Dummy version
function Check_Exit (Self_ID : ST.Task_Id) return Boolean is
pragma Unreferenced (Self_ID);
begin
return True;
end Check_Exit;
--------------------
-- Check_No_Locks --
--------------------
function Check_No_Locks (Self_ID : ST.Task_Id) return Boolean is
pragma Unreferenced (Self_ID);
begin
return True;
end Check_No_Locks;
----------------------
-- Environment_Task --
----------------------
function Environment_Task return Task_Id is
begin
return Environment_Task_Id;
end Environment_Task;
--------------
-- Lock_RTS --
--------------
procedure Lock_RTS is
begin
Write_Lock (Single_RTS_Lock'Access);
end Lock_RTS;
----------------
-- Unlock_RTS --
----------------
procedure Unlock_RTS is
begin
Unlock (Single_RTS_Lock'Access);
end Unlock_RTS;
------------------
-- Suspend_Task --
------------------
function Suspend_Task
(T : ST.Task_Id;
Thread_Self : Thread_Id) return Boolean
is
begin
if T.Common.LL.Thread /= Null_Thread_Id
and then T.Common.LL.Thread /= Thread_Self
then
return taskSuspend (T.Common.LL.Thread) = OK;
else
return True;
end if;
end Suspend_Task;
-----------------
-- Resume_Task --
-----------------
function Resume_Task
(T : ST.Task_Id;
Thread_Self : Thread_Id) return Boolean
is
begin
if T.Common.LL.Thread /= Null_Thread_Id
and then T.Common.LL.Thread /= Thread_Self
then
return taskResume (T.Common.LL.Thread) = OK;
else
return True;
end if;
end Resume_Task;
--------------------
-- Stop_All_Tasks --
--------------------
procedure Stop_All_Tasks
is
Thread_Self : constant Thread_Id := taskIdSelf;
C : Task_Id;
Dummy : STATUS;
Old : int;
begin
Old := Int_Lock;
C := All_Tasks_List;
while C /= null loop
if C.Common.LL.Thread /= Null_Thread_Id
and then C.Common.LL.Thread /= Thread_Self
then
Dummy := Task_Stop (C.Common.LL.Thread);
end if;
C := C.Common.All_Tasks_Link;
end loop;
Int_Unlock (Old);
end Stop_All_Tasks;
---------------
-- Stop_Task --
---------------
function Stop_Task (T : ST.Task_Id) return Boolean is
begin
if T.Common.LL.Thread /= Null_Thread_Id then
return Task_Stop (T.Common.LL.Thread) = OK;
else
return True;
end if;
end Stop_Task;
-------------------
-- Continue_Task --
-------------------
function Continue_Task (T : ST.Task_Id) return Boolean
is
begin
if T.Common.LL.Thread /= Null_Thread_Id then
return Task_Cont (T.Common.LL.Thread) = OK;
else
return True;
end if;
end Continue_Task;
---------------------
-- Is_Task_Context --
---------------------
function Is_Task_Context return Boolean is
begin
return OSI.Interrupt_Context = 0;
end Is_Task_Context;
----------------
-- Initialize --
----------------
procedure Initialize (Environment_Task : Task_Id) is
Result : STATUS;
pragma Unreferenced (Result);
begin
Environment_Task_Id := Environment_Task;
Interrupt_Management.Initialize;
Specific.Initialize;
if Locking_Policy = 'C' then
Mutex_Protocol := Prio_Protect;
elsif Locking_Policy = 'I' then
Mutex_Protocol := Prio_Inherit;
else
Mutex_Protocol := Prio_None;
end if;
if Time_Slice_Val > 0 then
Result :=
Set_Time_Slice
(To_Clock_Ticks
(Duration (Time_Slice_Val) / Duration (1_000_000.0)));
elsif Dispatching_Policy = 'R' then
Result := Set_Time_Slice (To_Clock_Ticks (0.01));
end if;
-- Initialize the lock used to synchronize chain of all ATCBs
Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
-- Make environment task known here because it doesn't go through
-- Activate_Tasks, which does it for all other tasks.
Known_Tasks (Known_Tasks'First) := Environment_Task;
Environment_Task.Known_Tasks_Index := Known_Tasks'First;
Enter_Task (Environment_Task);
-- Set processor affinity
Set_Task_Affinity (Environment_Task);
end Initialize;
-----------------------
-- Set_Task_Affinity --
-----------------------
procedure Set_Task_Affinity (T : ST.Task_Id) is
Result : int := 0;
pragma Unreferenced (Result);
use System.Task_Info;
use type System.Multiprocessors.CPU_Range;
begin
-- Do nothing if the underlying thread has not yet been created. If the
-- thread has not yet been created then the proper affinity will be set
-- during its creation.
if T.Common.LL.Thread = Null_Thread_Id then
null;
-- pragma CPU
elsif T.Common.Base_CPU /= Multiprocessors.Not_A_Specific_CPU then
-- Ada 2012 pragma CPU uses CPU numbers starting from 1, while on
-- VxWorks the first CPU is identified by a 0, so we need to adjust.
Result :=
taskCpuAffinitySet
(T.Common.LL.Thread, int (T.Common.Base_CPU) - 1);
-- Task_Info
elsif T.Common.Task_Info /= Unspecified_Task_Info then
Result := taskCpuAffinitySet (T.Common.LL.Thread, T.Common.Task_Info);
-- Handle dispatching domains
elsif T.Common.Domain /= null
and then (T.Common.Domain /= ST.System_Domain
or else T.Common.Domain.all /=
(Multiprocessors.CPU'First ..
Multiprocessors.Number_Of_CPUs => True))
then
declare
CPU_Set : unsigned := 0;
begin
-- Set the affinity to all the processors belonging to the
-- dispatching domain.
for Proc in T.Common.Domain'Range loop
if T.Common.Domain (Proc) then
-- The thread affinity mask is a bit vector in which each
-- bit represents a logical processor.
CPU_Set := CPU_Set + 2 ** (Integer (Proc) - 1);
end if;
end loop;
Result := taskMaskAffinitySet (T.Common.LL.Thread, CPU_Set);
end;
end if;
end Set_Task_Affinity;
end System.Task_Primitives.Operations;