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freebsd-ports/lang/gnat/files/5ftaprop.adb
Daniel Eischen f12ee9219b Update to the latest released version of GNAT (3.15p). Also use a 
new bootstrap compiler and fix so that it builds under -current.

Approved by:	portmgr
2002-12-01 19:10:48 +00:00

1155 lines
34 KiB
Ada
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------------------------------------------------------------------------------
-- --
-- GNU ADA 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 --
-- --
-- $Revision: 1.33 $
-- --
-- Copyright (C) 1991-2000, Florida State University --
-- --
-- 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 2, or (at your option) any later ver- --
-- sion. GNARL 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. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNARL; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. It is --
-- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
-- State University (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
-- This is the FreeBSD PTHREADS version of this package. Contributed
-- by Daniel M. Eischen (eischen@vigrid.com).
-- This package contains all the GNULL primitives that interface directly
-- with the underlying OS.
-- Note: this file can only be used for POSIX compliant systems that
-- implement SCHED_FIFO and Ceiling Locking correctly (that is, for now:
-- FSU Threads, RTEMS Threads, and FreeBSD Threads).
-- For configurations where SCHED_FIFO and priority ceiling are not a
-- requirement, this file can also be used (e.g AiX threads)
pragma Polling (Off);
-- Turn off polling, we do not want ATC polling to take place during
-- tasking operations. It causes infinite loops and other problems.
with System.Tasking.Debug;
-- used for Known_Tasks
with System.Task_Info;
-- used for Task_Info_Type
with Interfaces.C;
-- used for int
-- size_t
with System.Interrupt_Management;
-- used for Keep_Unmasked
-- Abort_Task_Interrupt
-- Interrupt_ID
with System.Interrupt_Management.Operations;
-- used for Set_Interrupt_Mask
-- All_Tasks_Mask
pragma Elaborate_All (System.Interrupt_Management.Operations);
with System.Parameters;
-- used for Size_Type
with System.Tasking;
-- used for Ada_Task_Control_Block
-- Task_ID
with System.Soft_Links;
-- used for Defer/Undefer_Abort
-- Note that we do not use System.Tasking.Initialization directly since
-- this 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.Initialization
with System.OS_Primitives;
-- used for Delay_Modes
with Unchecked_Conversion;
with Unchecked_Deallocation;
package body System.Task_Primitives.Operations is
use System.Tasking.Debug;
use System.Tasking;
use Interfaces.C;
use System.OS_Interface;
use System.Parameters;
use System.OS_Primitives;
package SSL renames System.Soft_Links;
pragma Linker_Options ("-pthread");
----------------
-- Local Data --
----------------
-- The followings are logically constants, but need to be initialized
-- at run time.
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 mainly in Single_Lock mode, but also to protect All_Tasks_List
Environment_Task_ID : Task_ID;
-- A variable to hold Task_ID for the environment task.
Locking_Policy : Character;
pragma Import (C, Locking_Policy, "__gl_locking_policy");
-- Value of the pragma Locking_Policy:
-- 'C' for Ceiling_Locking
-- 'I' for Inherit_Locking
-- ' ' for none.
Unblocked_Signal_Mask : aliased sigset_t;
-- The set of signals that should unblocked in all tasks
-- The followings are internal configuration constants needed.
Next_Serial_Number : Task_Serial_Number := 100;
-- We start at 100, to reserve some special values for
-- using in error checking.
Time_Slice_Val : Integer;
pragma Import (C, Time_Slice_Val, "__gl_time_slice_val");
Dispatching_Policy : Character;
pragma Import (C, Dispatching_Policy, "__gl_task_dispatching_policy");
FIFO_Within_Priorities : constant Boolean := Dispatching_Policy = 'F';
-- Indicates whether FIFO_Within_Priorities is set.
-----------------------
-- Local Subprograms --
-----------------------
procedure Abort_Handler (Sig : Signal);
function To_Task_ID is new Unchecked_Conversion (System.Address, Task_ID);
function To_Address is new Unchecked_Conversion (Task_ID, System.Address);
--------------------
-- Local Packages --
--------------------
package Specific is
procedure Initialize (Environment_Task : Task_ID);
pragma Inline (Initialize);
-- Initialize various data needed by this package.
procedure Set (Self_Id : Task_ID);
pragma Inline (Set);
-- Set the self id for the current task.
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.
-------------------
-- Abort_Handler --
-------------------
-- Target-dependent binding of inter-thread Abort signal to
-- the raising of the Abort_Signal exception.
-- The technical issues and alternatives here are essentially
-- the same as for raising exceptions in response to other
-- signals (e.g. Storage_Error). See code and comments in
-- the package body System.Interrupt_Management.
-- Some implementations may not allow an exception to be propagated
-- out of a handler, and others might leave the signal or
-- interrupt that invoked this handler masked after the exceptional
-- return to the application code.
-- GNAT exceptions are originally implemented using setjmp()/longjmp().
-- On most UNIX systems, this will allow transfer out of a signal handler,
-- which is usually the only mechanism available for implementing
-- asynchronous handlers of this kind. However, some
-- systems do not restore the signal mask on longjmp(), leaving the
-- abort signal masked.
-- Alternative solutions include:
-- 1. Change the PC saved in the system-dependent Context
-- parameter to point to code that raises the exception.
-- Normal return from this handler will then raise
-- the exception after the mask and other system state has
-- been restored (see example below).
-- 2. Use siglongjmp()/sigsetjmp() to implement exceptions.
-- 3. Unmask the signal in the Abortion_Signal exception handler
-- (in the RTS).
-- The following procedure would be needed if we can't lonjmp out of
-- a signal handler (See below)
-- procedure Raise_Abort_Signal is
-- begin
-- raise Standard'Abort_Signal;
-- end if;
procedure Abort_Handler
(Sig : Signal) is
T : Task_ID := Self;
Result : Interfaces.C.int;
Old_Set : aliased sigset_t;
begin
-- Assuming it is safe to longjmp out of a signal handler, the
-- following code can be used:
if T.Deferral_Level = 0
and then T.Pending_ATC_Level < T.ATC_Nesting_Level and then
not T.Aborting
then
T.Aborting := True;
-- Make sure signals used for RTS internal purpose are unmasked
Result := pthread_sigmask (SIG_UNBLOCK,
Unblocked_Signal_Mask'Unchecked_Access, Old_Set'Unchecked_Access);
pragma Assert (Result = 0);
raise Standard'Abort_Signal;
end if;
-- Otherwise, something like this is required:
-- if not Abort_Is_Deferred.all then
-- -- Overwrite the return PC address with the address of the
-- -- special raise routine, and "return" to that routine's
-- -- starting address.
-- Context.PC := Raise_Abort_Signal'Address;
-- return;
-- end if;
end Abort_Handler;
-----------------
-- Stack_Guard --
-----------------
procedure Stack_Guard (T : ST.Task_ID; On : Boolean) is
Stack_Base : constant Address := Get_Stack_Base (T.Common.LL.Thread);
Guard_Page_Address : Address;
Res : Interfaces.C.int;
begin
if Stack_Base_Available then
-- Compute the guard page address
Guard_Page_Address :=
Stack_Base - (Stack_Base mod Get_Page_Size) + Get_Page_Size;
if On then
Res := mprotect (Guard_Page_Address, Get_Page_Size, PROT_ON);
else
Res := mprotect (Guard_Page_Address, Get_Page_Size, PROT_OFF);
end if;
pragma Assert (Res = 0);
end if;
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;
---------------------
-- Initialize_Lock --
---------------------
-- Note: mutexes and cond_variables needed per-task basis are
-- initialized in Intialize_TCB and the Storage_Error is
-- handled. Other mutexes (such as RTS_Lock, Memory_Lock...)
-- used in RTS is initialized before any status change of RTS.
-- Therefore rasing Storage_Error in the following routines
-- should be able to be handled safely.
procedure Initialize_Lock
(Prio : System.Any_Priority;
L : access Lock)
is
Attributes : aliased pthread_mutexattr_t;
Result : Interfaces.C.int;
begin
Result := pthread_mutexattr_init (Attributes'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = ENOMEM then
raise Storage_Error;
end if;
if Locking_Policy = 'C' then
Result := pthread_mutexattr_setprotocol
(Attributes'Access, PTHREAD_PRIO_PROTECT);
pragma Assert (Result = 0);
Result := pthread_mutexattr_setprioceiling
(Attributes'Access, Interfaces.C.int (Prio));
pragma Assert (Result = 0);
elsif Locking_Policy = 'I' then
Result := pthread_mutexattr_setprotocol
(Attributes'Access, PTHREAD_PRIO_INHERIT);
pragma Assert (Result = 0);
end if;
Result := pthread_mutex_init (L, Attributes'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = ENOMEM then
raise Storage_Error;
end if;
Result := pthread_mutexattr_destroy (Attributes'Access);
pragma Assert (Result = 0);
end Initialize_Lock;
procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level) is
Attributes : aliased pthread_mutexattr_t;
Result : Interfaces.C.int;
begin
Result := pthread_mutexattr_init (Attributes'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = ENOMEM then
raise Storage_Error;
end if;
if Locking_Policy = 'C' then
Result := pthread_mutexattr_setprotocol
(Attributes'Access, PTHREAD_PRIO_PROTECT);
pragma Assert (Result = 0);
Result := pthread_mutexattr_setprioceiling
(Attributes'Access, Interfaces.C.int (System.Any_Priority'Last));
pragma Assert (Result = 0);
elsif Locking_Policy = 'I' then
Result := pthread_mutexattr_setprotocol
(Attributes'Access, PTHREAD_PRIO_INHERIT);
pragma Assert (Result = 0);
end if;
Result := pthread_mutex_init (L, Attributes'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = ENOMEM then
Result := pthread_mutexattr_destroy (Attributes'Access);
raise Storage_Error;
end if;
Result := pthread_mutexattr_destroy (Attributes'Access);
pragma Assert (Result = 0);
end Initialize_Lock;
-------------------
-- Finalize_Lock --
-------------------
procedure Finalize_Lock (L : access Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_destroy (L);
pragma Assert (Result = 0);
end Finalize_Lock;
procedure Finalize_Lock (L : access RTS_Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_destroy (L);
pragma Assert (Result = 0);
end Finalize_Lock;
----------------
-- Write_Lock --
----------------
procedure Write_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_lock (L);
-- Assume that the cause of EINVAL is a priority ceiling violation
Ceiling_Violation := (Result = EINVAL);
pragma Assert (Result = 0 or else Result = EINVAL);
end Write_Lock;
procedure Write_Lock
(L : access RTS_Lock; Global_Lock : Boolean := False)
is
Result : Interfaces.C.int;
begin
if not Single_Lock or else Global_Lock then
Result := pthread_mutex_lock (L);
pragma Assert (Result = 0);
end if;
end Write_Lock;
procedure Write_Lock (T : Task_ID) is
Result : Interfaces.C.int;
begin
if not Single_Lock then
Result := pthread_mutex_lock (T.Common.LL.L'Access);
pragma Assert (Result = 0);
end if;
end Write_Lock;
---------------
-- Read_Lock --
---------------
procedure Read_Lock (L : access Lock; Ceiling_Violation : out Boolean) is
begin
Write_Lock (L, Ceiling_Violation);
end Read_Lock;
------------
-- Unlock --
------------
procedure Unlock (L : access Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_unlock (L);
pragma Assert (Result = 0);
end Unlock;
procedure Unlock (L : access RTS_Lock; Global_Lock : Boolean := False) is
Result : Interfaces.C.int;
begin
if not Single_Lock or else Global_Lock then
Result := pthread_mutex_unlock (L);
pragma Assert (Result = 0);
end if;
end Unlock;
procedure Unlock (T : Task_ID) is
Result : Interfaces.C.int;
begin
if not Single_Lock then
Result := pthread_mutex_unlock (T.Common.LL.L'Access);
pragma Assert (Result = 0);
end if;
end Unlock;
-----------
-- Sleep --
-----------
procedure Sleep
(Self_ID : Task_ID;
Reason : System.Tasking.Task_States)
is
Result : Interfaces.C.int;
begin
if Single_Lock then
Result := pthread_cond_wait
(Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access);
else
Result := pthread_cond_wait
(Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access);
end if;
-- EINTR is not considered a failure.
pragma Assert (Result = 0 or else Result = EINTR);
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 : Task_States;
Timedout : out Boolean;
Yielded : out Boolean)
is
Check_Time : constant Duration := Monotonic_Clock;
Rel_Time : Duration;
Abs_Time : Duration;
Request : aliased timespec;
Result : Interfaces.C.int;
begin
Timedout := True;
Yielded := False;
if Mode = Relative then
Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
if Relative_Timed_Wait then
Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
end if;
else
Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
if Relative_Timed_Wait then
Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
end if;
end if;
if Abs_Time > Check_Time then
if Relative_Timed_Wait then
Request := To_Timespec (Rel_Time);
else
Request := To_Timespec (Abs_Time);
end if;
loop
exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
or else Self_ID.Pending_Priority_Change;
if Single_Lock then
Result := pthread_cond_timedwait
(Self_ID.Common.LL.CV'Access, Single_RTS_Lock'Access,
Request'Access);
else
Result := pthread_cond_timedwait
(Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access,
Request'Access);
end if;
exit when Abs_Time <= Monotonic_Clock;
if Result = 0 or Result = EINTR then
-- Somebody may have called Wakeup for us
Timedout := False;
exit;
end if;
pragma Assert (Result = ETIMEDOUT);
end loop;
end if;
end Timed_Sleep;
-----------------
-- Timed_Delay --
-----------------
-- This is for use in implementing delay statements, so
-- we assume the caller is abort-deferred but is holding
-- no locks.
procedure Timed_Delay
(Self_ID : Task_ID;
Time : Duration;
Mode : ST.Delay_Modes)
is
Check_Time : constant Duration := Monotonic_Clock;
Abs_Time : Duration;
Rel_Time : Duration;
Request : aliased timespec;
Result : Interfaces.C.int;
begin
-- Only the little window between deferring abort and
-- locking Self_ID is the reason we need to
-- check for pending abort and priority change below! :(
SSL.Abort_Defer.all;
if Single_Lock then
Lock_RTS;
end if;
Write_Lock (Self_ID);
if Mode = Relative then
Abs_Time := Duration'Min (Time, Max_Sensible_Delay) + Check_Time;
if Relative_Timed_Wait then
Rel_Time := Duration'Min (Max_Sensible_Delay, Time);
end if;
else
Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
if Relative_Timed_Wait then
Rel_Time := Duration'Min (Max_Sensible_Delay, Time - Check_Time);
end if;
end if;
if Abs_Time > Check_Time then
if Relative_Timed_Wait then
Request := To_Timespec (Rel_Time);
else
Request := To_Timespec (Abs_Time);
end if;
Self_ID.Common.State := Delay_Sleep;
loop
if Self_ID.Pending_Priority_Change then
Self_ID.Pending_Priority_Change := False;
Self_ID.Common.Base_Priority := Self_ID.New_Base_Priority;
Set_Priority (Self_ID, Self_ID.Common.Base_Priority);
end if;
exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level;
if Single_Lock then
Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access,
Single_RTS_Lock'Access, Request'Access);
else
Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access,
Self_ID.Common.LL.L'Access, Request'Access);
end if;
exit when Abs_Time <= Monotonic_Clock;
pragma Assert (Result = 0
or else Result = ETIMEDOUT
or else Result = EINTR);
end loop;
Self_ID.Common.State := Runnable;
end if;
Unlock (Self_ID);
if Single_Lock then
Unlock_RTS;
end if;
Result := sched_yield;
SSL.Abort_Undefer.all;
end Timed_Delay;
---------------------
-- Monotonic_Clock --
---------------------
function Monotonic_Clock return Duration is
TS : aliased timespec;
Result : Interfaces.C.int;
begin
Result := clock_gettime
(clock_id => CLOCK_REALTIME, tp => TS'Unchecked_Access);
pragma Assert (Result = 0);
return To_Duration (TS);
end Monotonic_Clock;
-------------------
-- RT_Resolution --
-------------------
function RT_Resolution return Duration is
begin
return 10#1.0#E-6;
end RT_Resolution;
------------
-- Wakeup --
------------
procedure Wakeup (T : Task_ID; Reason : System.Tasking.Task_States) is
Result : Interfaces.C.int;
begin
Result := pthread_cond_signal (T.Common.LL.CV'Access);
pragma Assert (Result = 0);
end Wakeup;
-----------
-- Yield --
-----------
procedure Yield (Do_Yield : Boolean := True) is
Result : Interfaces.C.int;
begin
if Do_Yield then
Result := sched_yield;
end if;
end Yield;
------------------
-- Set_Priority --
------------------
procedure Set_Priority
(T : Task_ID;
Prio : System.Any_Priority;
Loss_Of_Inheritance : Boolean := False)
is
Result : Interfaces.C.int;
Param : aliased struct_sched_param;
begin
T.Common.Current_Priority := Prio;
Param.sched_priority := Interfaces.C.int (Prio);
if Time_Slice_Supported and then Time_Slice_Val > 0 then
Result := pthread_setschedparam
(T.Common.LL.Thread, SCHED_RR, Param'Access);
elsif FIFO_Within_Priorities or else Time_Slice_Val = 0 then
Result := pthread_setschedparam
(T.Common.LL.Thread, SCHED_FIFO, Param'Access);
else
Result := pthread_setschedparam
(T.Common.LL.Thread, SCHED_OTHER, Param'Access);
end if;
pragma Assert (Result = 0);
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
Self_ID.Common.LL.Thread := pthread_self;
Self_ID.Common.LL.LWP := lwp_self;
Specific.Set (Self_ID);
Lock_RTS;
for J in Known_Tasks'Range loop
if Known_Tasks (J) = null then
Known_Tasks (J) := Self_ID;
Self_ID.Known_Tasks_Index := J;
exit;
end if;
end loop;
Unlock_RTS;
end Enter_Task;
--------------
-- New_ATCB --
--------------
function New_ATCB (Entry_Num : Task_Entry_Index) return Task_ID is
begin
return new Ada_Task_Control_Block (Entry_Num);
end New_ATCB;
----------------------
-- Initialize_TCB --
----------------------
procedure Initialize_TCB (Self_ID : Task_ID; Succeeded : out Boolean) is
Mutex_Attr : aliased pthread_mutexattr_t;
Result : Interfaces.C.int;
Cond_Attr : aliased pthread_condattr_t;
begin
-- Give the task a unique serial number.
Self_ID.Serial_Number := Next_Serial_Number;
Next_Serial_Number := Next_Serial_Number + 1;
pragma Assert (Next_Serial_Number /= 0);
if not Single_Lock then
Result := pthread_mutexattr_init (Mutex_Attr'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = 0 then
if Locking_Policy = 'C' then
Result := pthread_mutexattr_setprotocol
(Mutex_Attr'Access, PTHREAD_PRIO_PROTECT);
pragma Assert (Result = 0);
Result := pthread_mutexattr_setprioceiling
(Mutex_Attr'Access,
Interfaces.C.int (System.Any_Priority'Last));
pragma Assert (Result = 0);
elsif Locking_Policy = 'I' then
Result := pthread_mutexattr_setprotocol
(Mutex_Attr'Access, PTHREAD_PRIO_INHERIT);
pragma Assert (Result = 0);
end if;
Result := pthread_mutex_init (Self_ID.Common.LL.L'Access,
Mutex_Attr'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
end if;
if Result /= 0 then
Succeeded := False;
return;
end if;
Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
pragma Assert (Result = 0);
end if;
Result := pthread_condattr_init (Cond_Attr'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = 0 then
Result := pthread_cond_init (Self_ID.Common.LL.CV'Access,
Cond_Attr'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
end if;
if Result = 0 then
Succeeded := True;
else
if not Single_Lock then
Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
pragma Assert (Result = 0);
end if;
Succeeded := False;
end if;
Result := pthread_condattr_destroy (Cond_Attr'Access);
pragma Assert (Result = 0);
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
Attributes : aliased pthread_attr_t;
Adjusted_Stack_Size : Interfaces.C.size_t;
Result : Interfaces.C.int;
function Thread_Body_Access is new
Unchecked_Conversion (System.Address, Thread_Body);
use System.Task_Info;
begin
if Stack_Size = Unspecified_Size then
Adjusted_Stack_Size := Interfaces.C.size_t (Default_Stack_Size);
elsif Stack_Size < Minimum_Stack_Size then
Adjusted_Stack_Size := Interfaces.C.size_t (Minimum_Stack_Size);
else
Adjusted_Stack_Size := Interfaces.C.size_t (Stack_Size);
end if;
if Stack_Base_Available then
-- If Stack Checking is supported then allocate 2 additional pages:
--
-- In the worst case, stack is allocated at something like
-- N * Get_Page_Size - epsilon, we need to add the size for 2 pages
-- to be sure the effective stack size is greater than what
-- has been asked.
Adjusted_Stack_Size := Adjusted_Stack_Size + 2 * Get_Page_Size;
end if;
Result := pthread_attr_init (Attributes'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result /= 0 then
Succeeded := False;
return;
end if;
Result := pthread_attr_setdetachstate
(Attributes'Access, PTHREAD_CREATE_DETACHED);
pragma Assert (Result = 0);
Result := pthread_attr_setstacksize
(Attributes'Access, Adjusted_Stack_Size);
pragma Assert (Result = 0);
if T.Common.Task_Info /= Default_Scope then
-- We are assuming that Scope_Type has the same values than the
-- corresponding C macros
Result := pthread_attr_setscope
(Attributes'Access, Task_Info_Type'Pos (T.Common.Task_Info));
pragma Assert (Result = 0);
end if;
-- 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.
Result := pthread_create
(T.Common.LL.Thread'Access,
Attributes'Access,
Thread_Body_Access (Wrapper),
To_Address (T));
pragma Assert (Result = 0 or else Result = EAGAIN);
Succeeded := Result = 0;
if T.Common.Task_Image /= null then
declare
Name : aliased String (1 .. T.Common.Task_Image.all'Length + 1);
begin
Name := T.Common.Task_Image.all & ASCII.Nul;
Result := pthread_set_name_np (T.Common.LL.Thread, Name'Address);
end;
end if;
Result := pthread_attr_destroy (Attributes'Access);
pragma Assert (Result = 0);
Set_Priority (T, Priority);
end Create_Task;
------------------
-- Finalize_TCB --
------------------
procedure Finalize_TCB (T : Task_ID) is
Result : Interfaces.C.int;
Tmp : Task_ID := T;
procedure Free is new
Unchecked_Deallocation (Ada_Task_Control_Block, Task_ID);
begin
if not Single_Lock then
Result := pthread_mutex_destroy (T.Common.LL.L'Access);
pragma Assert (Result = 0);
end if;
Result := pthread_cond_destroy (T.Common.LL.CV'Access);
pragma Assert (Result = 0);
if T.Known_Tasks_Index /= -1 then
Known_Tasks (T.Known_Tasks_Index) := null;
end if;
Free (Tmp);
end Finalize_TCB;
---------------
-- Exit_Task --
---------------
procedure Exit_Task is
begin
pthread_exit (System.Null_Address);
end Exit_Task;
----------------
-- Abort_Task --
----------------
procedure Abort_Task (T : Task_ID) is
Result : Interfaces.C.int;
begin
Result := pthread_kill (T.Common.LL.Thread,
Signal (System.Interrupt_Management.Abort_Task_Interrupt));
pragma Assert (Result = 0);
end Abort_Task;
----------------
-- Check_Exit --
----------------
-- Dummy versions. The only currently working versions is for solaris
-- (native).
function Check_Exit (Self_ID : ST.Task_ID) return Boolean is
begin
return True;
end Check_Exit;
--------------------
-- Check_No_Locks --
--------------------
function Check_No_Locks (Self_ID : ST.Task_ID) return Boolean is
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, Global_Lock => True);
end Lock_RTS;
----------------
-- Unlock_RTS --
----------------
procedure Unlock_RTS is
begin
Unlock (Single_RTS_Lock'Access, Global_Lock => True);
end Unlock_RTS;
------------------
-- Suspend_Task --
------------------
function Suspend_Task
(T : ST.Task_ID;
Thread_Self : Thread_Id) return Boolean is
begin
return False;
end Suspend_Task;
-----------------
-- Resume_Task --
-----------------
function Resume_Task
(T : ST.Task_ID;
Thread_Self : Thread_Id) return Boolean is
begin
return False;
end Resume_Task;
----------------
-- Initialize --
----------------
procedure Initialize (Environment_Task : Task_ID) is
act : aliased struct_sigaction;
old_act : aliased struct_sigaction;
Tmp_Set : aliased sigset_t;
Result : Interfaces.C.int;
begin
Environment_Task_ID := Environment_Task;
-- Initialize the lock used to synchronize chain of all ATCBs.
Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
Specific.Initialize (Environment_Task);
Enter_Task (Environment_Task);
-- Install the abort-signal handler
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 (System.Interrupt_Management.Abort_Task_Interrupt),
act'Unchecked_Access,
old_act'Unchecked_Access);
pragma Assert (Result = 0);
end Initialize;
begin
declare
Result : Interfaces.C.int;
begin
-- Mask Environment task for all signals. The original mask of the
-- Environment task will be recovered by Interrupt_Server task
-- during the elaboration of s-interr.adb.
System.Interrupt_Management.Operations.Set_Interrupt_Mask
(System.Interrupt_Management.Operations.All_Tasks_Mask'Access);
-- Prepare the set of signals that should unblocked in all tasks
Result := sigemptyset (Unblocked_Signal_Mask'Access);
pragma Assert (Result = 0);
for J in Interrupt_Management.Interrupt_ID loop
if System.Interrupt_Management.Keep_Unmasked (J) then
Result := sigaddset (Unblocked_Signal_Mask'Access, Signal (J));
pragma Assert (Result = 0);
end if;
end loop;
end;
end System.Task_Primitives.Operations;
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