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ubuntu-buildroot/output/build/host-gcc-initial-11.4.0/gcc/ada/libgnarl/s-taprop__qnx.adb

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2024-04-01 15:19:46 +00:00
------------------------------------------------------------------------------
-- --
-- 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) 1992-2020, 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 a POSIX-like version of this package
-- 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.
-- For configurations where SCHED_FIFO and priority ceiling are not a
-- requirement, this file can also be used (e.g AiX threads)
with Ada.Unchecked_Conversion;
with Interfaces.C;
with System.Tasking.Debug;
with System.Interrupt_Management;
with System.OS_Constants;
with System.OS_Primitives;
with System.Task_Info;
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.
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 Interfaces.C;
use System.OS_Interface;
use System.Parameters;
use System.OS_Primitives;
----------------
-- 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 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");
Foreign_Task_Elaborated : aliased Boolean := True;
-- Used to identified fake tasks (i.e., non-Ada Threads)
Use_Alternate_Stack : constant Boolean := Alternate_Stack_Size /= 0;
-- Whether to use an alternate signal stack for stack overflows
Abort_Handler_Installed : Boolean := False;
-- True if a handler for the abort signal is installed
type RTS_Lock_Ptr is not null access all RTS_Lock;
function Init_Mutex (L : RTS_Lock_Ptr; Prio : Any_Priority) return int;
-- Initialize the mutex L. If Ceiling_Support is True, then set the ceiling
-- to Prio. Returns 0 for success, or ENOMEM for out-of-memory.
function Get_Policy (Prio : System.Any_Priority) return Character;
pragma Import (C, Get_Policy, "__gnat_get_specific_dispatching");
-- Get priority specific dispatching policy
--------------------
-- Local Packages --
--------------------
package Specific is
procedure Initialize (Environment_Task : Task_Id);
pragma Inline (Initialize);
-- Initialize various data needed by this package
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
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
package Monotonic is
function Monotonic_Clock return Duration;
pragma Inline (Monotonic_Clock);
-- Returns an absolute time, represented as an offset relative to some
-- unspecified starting point, typically system boot time. This clock
-- is not affected by discontinuous jumps in the system time.
function RT_Resolution return Duration;
pragma Inline (RT_Resolution);
-- Returns resolution of the underlying clock used to implement RT_Clock
procedure Timed_Sleep
(Self_ID : ST.Task_Id;
Time : Duration;
Mode : ST.Delay_Modes;
Reason : System.Tasking.Task_States;
Timedout : out Boolean;
Yielded : out Boolean);
-- Combination of Sleep (above) and Timed_Delay
procedure Timed_Delay
(Self_ID : ST.Task_Id;
Time : Duration;
Mode : ST.Delay_Modes);
-- Implement the semantics of the delay statement.
-- The caller should be abort-deferred and should not hold any locks.
end Monotonic;
package body Monotonic is separate;
----------------------------------
-- 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 (Sig : Signal);
-- Signal handler used to implement asynchronous abort.
-- See also comment before body, below.
function To_Address is
new Ada.Unchecked_Conversion (Task_Id, System.Address);
function GNAT_pthread_condattr_setup
(attr : access pthread_condattr_t) return int;
pragma Import (C,
GNAT_pthread_condattr_setup, "__gnat_pthread_condattr_setup");
-------------------
-- 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.
procedure Abort_Handler (Sig : Signal) is
pragma Unreferenced (Sig);
T : constant Task_Id := Self;
Old_Set : aliased sigset_t;
Result : Interfaces.C.int;
pragma Warnings (Off, Result);
begin
-- It's not safe to raise an exception when using GCC ZCX mechanism.
-- Note that we still need to install a signal handler, since in some
-- cases (e.g. shutdown of the Server_Task in System.Interrupts) we
-- need to send the Abort signal to a task.
if ZCX_By_Default then
return;
end if;
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'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
Stack_Base : constant Address := Get_Stack_Base (T.Common.LL.Thread);
Page_Size : Address;
Res : Interfaces.C.int;
begin
if Stack_Base_Available then
-- Compute the guard page address
Page_Size := Address (Get_Page_Size);
Res :=
mprotect
(Stack_Base - (Stack_Base mod Page_Size) + Page_Size,
size_t (Page_Size),
prot => (if On then PROT_ON else PROT_OFF));
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;
----------------
-- Init_Mutex --
----------------
function Init_Mutex (L : RTS_Lock_Ptr; Prio : Any_Priority) return int
is
Attributes : aliased pthread_mutexattr_t;
Result : int;
Result_2 : aliased int;
begin
Result := pthread_mutexattr_init (Attributes'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = ENOMEM then
return Result;
end if;
if Locking_Policy = 'C' then
Result := pthread_mutexattr_setprotocol
(Attributes'Access, PTHREAD_PRIO_PROTECT);
pragma Assert (Result = 0);
Result := pthread_mutexattr_getprotocol
(Attributes'Access, Result_2'Access);
if Result_2 /= PTHREAD_PRIO_PROTECT then
raise Program_Error with "setprotocol failed";
end if;
Result := pthread_mutexattr_setprioceiling
(Attributes'Access, To_Target_Priority (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);
Result_2 := pthread_mutexattr_destroy (Attributes'Access);
pragma Assert (Result_2 = 0);
return Result;
end Init_Mutex;
---------------------
-- Initialize_Lock --
---------------------
-- Note: mutexes and cond_variables needed per-task basis are initialized
-- in Initialize_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 raising Storage_Error in the following
-- routines should be able to be handled safely.
procedure Initialize_Lock
(Prio : System.Any_Priority;
L : not null access Lock)
is
begin
if Init_Mutex (L.WO'Access, Prio) = ENOMEM then
raise Storage_Error with "Failed to allocate a lock";
end if;
end Initialize_Lock;
procedure Initialize_Lock
(L : not null access RTS_Lock; Level : Lock_Level)
is
pragma Unreferenced (Level);
begin
if Init_Mutex (L.all'Access, Any_Priority'Last) = ENOMEM then
raise Storage_Error with "Failed to allocate a lock";
end if;
end Initialize_Lock;
-------------------
-- Finalize_Lock --
-------------------
procedure Finalize_Lock (L : not null access Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_destroy (L.WO'Access);
pragma Assert (Result = 0);
end Finalize_Lock;
procedure Finalize_Lock (L : not null 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 : not null access Lock; Ceiling_Violation : out Boolean)
is
Self : constant pthread_t := pthread_self;
Result : int;
Policy : aliased int;
Ceiling : aliased int;
Sched : aliased struct_sched_param;
begin
Result := pthread_mutex_lock (L.WO'Access);
-- The cause of EINVAL is a priority ceiling violation
Ceiling_Violation := Result = EINVAL;
pragma Assert (Result = 0 or else Ceiling_Violation);
-- Workaround bug in QNX on ceiling locks: tasks with priority higher
-- than the ceiling priority don't receive EINVAL upon trying to lock.
if Result = 0 and then Locking_Policy = 'C' then
Result := pthread_getschedparam (Self, Policy'Access, Sched'Access);
pragma Assert (Result = 0);
Result := pthread_mutex_getprioceiling (L.WO'Access, Ceiling'Access);
pragma Assert (Result = 0);
-- Ceiling < current priority means Ceiling violation
-- (otherwise the current priority == ceiling)
if Ceiling < Sched.sched_curpriority then
Ceiling_Violation := True;
Result := pthread_mutex_unlock (L.WO'Access);
pragma Assert (Result = 0);
end if;
end if;
end Write_Lock;
procedure Write_Lock (L : not null access RTS_Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_lock (L);
pragma Assert (Result = 0);
end Write_Lock;
procedure Write_Lock (T : Task_Id) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_lock (T.Common.LL.L'Access);
pragma Assert (Result = 0);
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 : Interfaces.C.int;
begin
Result := pthread_mutex_unlock (L.WO'Access);
pragma Assert (Result = 0);
end Unlock;
procedure Unlock (L : not null access RTS_Lock) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_unlock (L);
pragma Assert (Result = 0);
end Unlock;
procedure Unlock (T : Task_Id) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_unlock (T.Common.LL.L'Access);
pragma Assert (Result = 0);
end Unlock;
-----------------
-- Set_Ceiling --
-----------------
procedure Set_Ceiling
(L : not null access Lock;
Prio : System.Any_Priority)
is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_setprioceiling
(L.WO'Access, To_Target_Priority (Prio), null);
pragma Assert (Result = 0);
end Set_Ceiling;
-----------
-- Sleep --
-----------
procedure Sleep
(Self_ID : Task_Id;
Reason : System.Tasking.Task_States)
is
pragma Unreferenced (Reason);
Result : Interfaces.C.int;
begin
Result :=
pthread_cond_wait
(cond => Self_ID.Common.LL.CV'Access,
mutex => Self_ID.Common.LL.L'Access);
-- 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) renames Monotonic.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) renames Monotonic.Timed_Delay;
---------------------
-- Monotonic_Clock --
---------------------
function Monotonic_Clock return Duration renames Monotonic.Monotonic_Clock;
-------------------
-- RT_Resolution --
-------------------
function RT_Resolution return Duration renames Monotonic.RT_Resolution;
------------
-- Wakeup --
------------
procedure Wakeup (T : Task_Id; Reason : System.Tasking.Task_States) is
pragma Unreferenced (Reason);
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;
pragma Unreferenced (Result);
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
pragma Unreferenced (Loss_Of_Inheritance);
Result : Interfaces.C.int;
Old : constant System.Any_Priority := T.Common.Current_Priority;
begin
T.Common.Current_Priority := Prio;
Result := pthread_setschedprio
(T.Common.LL.Thread, To_Target_Priority (Prio));
pragma Assert (Result = 0);
if T.Common.LL.Thread = pthread_self
and then Old > Prio
then
-- When lowering the priority via a pthread_setschedprio, QNX ensures
-- that the running thread remains in the head of the FIFO for tne
-- new priority. Annex D expects the thread to be requeued so let's
-- yield to the other threads of the same priority.
Result := sched_yield;
pragma Assert (Result = 0);
end if;
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);
if Use_Alternate_Stack then
declare
Stack : aliased stack_t;
Result : Interfaces.C.int;
begin
Stack.ss_sp := Self_ID.Common.Task_Alternate_Stack;
Stack.ss_size := Alternate_Stack_Size;
Stack.ss_flags := 0;
Result := sigaltstack (Stack'Access, null);
pragma Assert (Result = 0);
end;
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 (pthread_self);
end if;
end Register_Foreign_Thread;
--------------------
-- Initialize_TCB --
--------------------
procedure Initialize_TCB (Self_ID : Task_Id; Succeeded : out Boolean) is
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);
Result := Init_Mutex (Self_ID.Common.LL.L'Access, Any_Priority'Last);
pragma Assert (Result = 0);
if Result /= 0 then
Succeeded := False;
return;
end if;
Result := pthread_condattr_init (Cond_Attr'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = 0 then
Result := GNAT_pthread_condattr_setup (Cond_Attr'Access);
pragma Assert (Result = 0);
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
Result := pthread_mutex_destroy (Self_ID.Common.LL.L'Access);
pragma Assert (Result = 0);
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;
Page_Size : constant Interfaces.C.size_t :=
Interfaces.C.size_t (Get_Page_Size);
Sched_Param : aliased struct_sched_param;
Result : Interfaces.C.int;
Priority_Specific_Policy : constant Character := Get_Policy (Priority);
-- Upper case first character of the policy name corresponding to the
-- task as set by a Priority_Specific_Dispatching pragma.
function Thread_Body_Access is new
Ada.Unchecked_Conversion (System.Address, Thread_Body);
begin
Adjusted_Stack_Size :=
Interfaces.C.size_t (Stack_Size + Alternate_Stack_Size);
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 * Page_Size;
end if;
-- Round stack size as this is required by some OSes (Darwin)
Adjusted_Stack_Size := Adjusted_Stack_Size + Page_Size - 1;
Adjusted_Stack_Size :=
Adjusted_Stack_Size - Adjusted_Stack_Size mod Page_Size;
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);
-- Set thread priority
T.Common.Current_Priority := Priority;
Sched_Param.sched_priority := To_Target_Priority (Priority);
Result := pthread_attr_setinheritsched
(Attributes'Access, PTHREAD_EXPLICIT_SCHED);
pragma Assert (Result = 0);
Result := pthread_attr_setschedparam
(Attributes'Access, Sched_Param'Access);
pragma Assert (Result = 0);
if Time_Slice_Supported
and then (Dispatching_Policy = 'R'
or else Priority_Specific_Policy = 'R'
or else Time_Slice_Val > 0)
then
Result := pthread_attr_setschedpolicy
(Attributes'Access, SCHED_RR);
elsif Dispatching_Policy = 'F'
or else Priority_Specific_Policy = 'F'
or else Time_Slice_Val = 0
then
Result := pthread_attr_setschedpolicy
(Attributes'Access, SCHED_FIFO);
else
Result := pthread_attr_setschedpolicy
(Attributes'Access, SCHED_OTHER);
end if;
pragma Assert (Result = 0);
-- 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.
-- Note: the use of Unrestricted_Access in the following call is needed
-- because otherwise we have an error of getting a access-to-volatile
-- value which points to a non-volatile object. But in this case it is
-- safe to do this, since we know we have no problems with aliasing and
-- Unrestricted_Access bypasses this check.
Result := pthread_create
(T.Common.LL.Thread'Unrestricted_Access,
Attributes'Access,
Thread_Body_Access (Wrapper),
To_Address (T));
pragma Assert (Result = 0 or else Result = EAGAIN);
Succeeded := Result = 0;
Result := pthread_attr_destroy (Attributes'Access);
pragma Assert (Result = 0);
end Create_Task;
------------------
-- Finalize_TCB --
------------------
procedure Finalize_TCB (T : Task_Id) is
Result : Interfaces.C.int;
begin
Result := pthread_mutex_destroy (T.Common.LL.L'Access);
pragma Assert (Result = 0);
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;
ATCB_Allocation.Free_ATCB (T);
end Finalize_TCB;
---------------
-- Exit_Task --
---------------
procedure Exit_Task is
begin
-- Mark this task as unknown, so that if Self is called, it won't
-- return a dangling pointer.
Specific.Set (null);
end Exit_Task;
----------------
-- Abort_Task --
----------------
procedure Abort_Task (T : Task_Id) is
Result : Interfaces.C.int;
begin
if Abort_Handler_Installed then
Result :=
pthread_kill
(T.Common.LL.Thread,
Signal (System.Interrupt_Management.Abort_Task_Interrupt));
pragma Assert (Result = 0);
end if;
end Abort_Task;
----------------
-- Initialize --
----------------
procedure Initialize (S : in out Suspension_Object) is
Mutex_Attr : aliased pthread_mutexattr_t;
Cond_Attr : aliased pthread_condattr_t;
Result : Interfaces.C.int;
begin
-- Initialize internal state (always to False (RM D.10 (6)))
S.State := False;
S.Waiting := False;
-- Initialize internal mutex
Result := pthread_mutexattr_init (Mutex_Attr'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = ENOMEM then
raise Storage_Error;
end if;
Result := pthread_mutex_init (S.L'Access, Mutex_Attr'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result = ENOMEM then
Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
pragma Assert (Result = 0);
raise Storage_Error;
end if;
Result := pthread_mutexattr_destroy (Mutex_Attr'Access);
pragma Assert (Result = 0);
-- Initialize internal condition variable
Result := pthread_condattr_init (Cond_Attr'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result /= 0 then
Result := pthread_mutex_destroy (S.L'Access);
pragma Assert (Result = 0);
-- Storage_Error is propagated as intended if the allocation of the
-- underlying OS entities fails.
raise Storage_Error;
else
Result := GNAT_pthread_condattr_setup (Cond_Attr'Access);
pragma Assert (Result = 0);
end if;
Result := pthread_cond_init (S.CV'Access, Cond_Attr'Access);
pragma Assert (Result = 0 or else Result = ENOMEM);
if Result /= 0 then
Result := pthread_mutex_destroy (S.L'Access);
pragma Assert (Result = 0);
Result := pthread_condattr_destroy (Cond_Attr'Access);
pragma Assert (Result = 0);
-- Storage_Error is propagated as intended if the allocation of the
-- underlying OS entities fails.
raise Storage_Error;
end if;
Result := pthread_condattr_destroy (Cond_Attr'Access);
pragma Assert (Result = 0);
end Initialize;
--------------
-- Finalize --
--------------
procedure Finalize (S : in out Suspension_Object) is
Result : Interfaces.C.int;
begin
-- Destroy internal mutex
Result := pthread_mutex_destroy (S.L'Access);
pragma Assert (Result = 0);
-- Destroy internal condition variable
Result := pthread_cond_destroy (S.CV'Access);
pragma Assert (Result = 0);
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 : Interfaces.C.int;
begin
SSL.Abort_Defer.all;
Result := pthread_mutex_lock (S.L'Access);
pragma Assert (Result = 0);
S.State := False;
Result := pthread_mutex_unlock (S.L'Access);
pragma Assert (Result = 0);
SSL.Abort_Undefer.all;
end Set_False;
--------------
-- Set_True --
--------------
procedure Set_True (S : in out Suspension_Object) is
Result : Interfaces.C.int;
begin
SSL.Abort_Defer.all;
Result := pthread_mutex_lock (S.L'Access);
pragma Assert (Result = 0);
-- 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 := pthread_cond_signal (S.CV'Access);
pragma Assert (Result = 0);
else
S.State := True;
end if;
Result := pthread_mutex_unlock (S.L'Access);
pragma Assert (Result = 0);
SSL.Abort_Undefer.all;
end Set_True;
------------------------
-- Suspend_Until_True --
------------------------
procedure Suspend_Until_True (S : in out Suspension_Object) is
Result : Interfaces.C.int;
begin
SSL.Abort_Defer.all;
Result := pthread_mutex_lock (S.L'Access);
pragma Assert (Result = 0);
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 := pthread_mutex_unlock (S.L'Access);
pragma Assert (Result = 0);
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 (ARM D.10 par. 9).
if S.State then
S.State := False;
else
S.Waiting := True;
loop
-- Loop in case pthread_cond_wait returns earlier than expected
-- (e.g. in case of EINTR caused by a signal).
Result := pthread_cond_wait (S.CV'Access, S.L'Access);
pragma Assert (Result = 0 or else Result = EINTR);
exit when not S.Waiting;
end loop;
end if;
Result := pthread_mutex_unlock (S.L'Access);
pragma Assert (Result = 0);
SSL.Abort_Undefer.all;
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
pragma Unreferenced (T, Thread_Self);
begin
return False;
end Suspend_Task;
-----------------
-- Resume_Task --
-----------------
function Resume_Task
(T : ST.Task_Id;
Thread_Self : Thread_Id) return Boolean
is
pragma Unreferenced (T, Thread_Self);
begin
return False;
end Resume_Task;
--------------------
-- Stop_All_Tasks --
--------------------
procedure Stop_All_Tasks is
begin
null;
end Stop_All_Tasks;
---------------
-- Stop_Task --
---------------
function Stop_Task (T : ST.Task_Id) return Boolean is
pragma Unreferenced (T);
begin
return False;
end Stop_Task;
-------------------
-- Continue_Task --
-------------------
function Continue_Task (T : ST.Task_Id) return Boolean is
pragma Unreferenced (T);
begin
return False;
end Continue_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;
function State
(Int : System.Interrupt_Management.Interrupt_ID) return Character;
pragma Import (C, State, "__gnat_get_interrupt_state");
-- Get interrupt state. Defined in a-init.c
-- The input argument is the interrupt number,
-- and the result is one of the following:
Default : constant Character := 's';
-- 'n' this interrupt not set by any Interrupt_State pragma
-- 'u' Interrupt_State pragma set state to User
-- 'r' Interrupt_State pragma set state to Runtime
-- 's' Interrupt_State pragma set state to System (use "default"
-- system handler)
begin
Environment_Task_Id := Environment_Task;
Interrupt_Management.Initialize;
-- 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;
-- Initialize the lock used to synchronize chain of all ATCBs
Initialize_Lock (Single_RTS_Lock'Access, RTS_Lock_Level);
Specific.Initialize (Environment_Task);
if Use_Alternate_Stack then
Environment_Task.Common.Task_Alternate_Stack :=
Alternate_Stack'Address;
end if;
-- 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);
if State
(System.Interrupt_Management.Abort_Task_Interrupt) /= Default
then
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);
Abort_Handler_Installed := True;
end if;
end Initialize;
-----------------------
-- Set_Task_Affinity --
-----------------------
procedure Set_Task_Affinity (T : ST.Task_Id) is
pragma Unreferenced (T);
begin
-- Setting task affinity is not supported by the underlying system
null;
end Set_Task_Affinity;
end System.Task_Primitives.Operations;