+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- 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: 1.3 $
--- --
--- Copyright (C) 1991-2001, 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 a GNU/Linux (GNU/LinuxThreads) version of this package
-
--- This package contains all the GNULL primitives that interface directly
--- with the underlying OS.
-
-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 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 Ada.Exceptions;
--- used for Raise_Exception
--- Raise_From_Signal_Handler
--- Exception_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 System.Soft_Links;
--- used for Get_Machine_State_Addr
-
-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;
-
- ------------------
- -- Local Data --
- ------------------
-
- Max_Stack_Size : constant := 2000 * 1024;
- -- GNU/LinuxThreads does not return an error value when requesting
- -- a task stack size which is too large, so we have to check this
- -- ourselves.
-
- -- The followings are logically constants, but need to be initialized
- -- at run time.
-
- ATCB_Key : aliased pthread_key_t;
- -- Key used to find the Ada Task_ID associated with a thread
-
- All_Tasks_L : aliased System.Task_Primitives.RTS_Lock;
- -- See comments on locking rules in System.Tasking (spec).
-
- Environment_Task_ID : Task_ID;
- -- A variable to hold Task_ID for the environment task.
-
- Unblocked_Signal_Mask : aliased sigset_t;
- -- The set of signals that should unblocked in all tasks
-
- -- The followings are internal configuration constants needed.
- Priority_Ceiling_Emulation : constant Boolean := True;
-
- Next_Serial_Number : Task_Serial_Number := 100;
- -- We start at 100, to reserve some special values for
- -- using in error checking.
- -- The following are internal configuration constants needed.
-
- 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.
-
- -- The following are effectively constants, but they need to
- -- be initialized by calling a pthread_ function.
-
- Mutex_Attr : aliased pthread_mutexattr_t;
- Cond_Attr : aliased pthread_condattr_t;
-
- -----------------------
- -- Local Subprograms --
- -----------------------
-
- subtype unsigned_short is Interfaces.C.unsigned_short;
- subtype unsigned_long is Interfaces.C.unsigned_long;
-
- procedure Abort_Handler
- (signo : Signal;
- gs : unsigned_short;
- fs : unsigned_short;
- es : unsigned_short;
- ds : unsigned_short;
- edi : unsigned_long;
- esi : unsigned_long;
- ebp : unsigned_long;
- esp : unsigned_long;
- ebx : unsigned_long;
- edx : unsigned_long;
- ecx : unsigned_long;
- eax : unsigned_long;
- trapno : unsigned_long;
- err : unsigned_long;
- eip : unsigned_long;
- cs : unsigned_short;
- eflags : unsigned_long;
- esp_at_signal : unsigned_long;
- ss : unsigned_short;
- fpstate : System.Address;
- oldmask : unsigned_long;
- cr2 : unsigned_long);
-
- function To_Task_ID is new Unchecked_Conversion (System.Address, Task_ID);
-
- function To_Address is new Unchecked_Conversion (Task_ID, System.Address);
-
- function To_pthread_t is new Unchecked_Conversion
- (Integer, System.OS_Interface.pthread_t);
-
- -------------------
- -- 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).
-
- -- Note that with the new exception mechanism, it is not correct to
- -- simply "raise" an exception from a signal handler, that's why we
- -- use Raise_From_Signal_Handler
-
- procedure Abort_Handler
- (signo : Signal;
- gs : unsigned_short;
- fs : unsigned_short;
- es : unsigned_short;
- ds : unsigned_short;
- edi : unsigned_long;
- esi : unsigned_long;
- ebp : unsigned_long;
- esp : unsigned_long;
- ebx : unsigned_long;
- edx : unsigned_long;
- ecx : unsigned_long;
- eax : unsigned_long;
- trapno : unsigned_long;
- err : unsigned_long;
- eip : unsigned_long;
- cs : unsigned_short;
- eflags : unsigned_long;
- esp_at_signal : unsigned_long;
- ss : unsigned_short;
- fpstate : System.Address;
- oldmask : unsigned_long;
- cr2 : unsigned_long)
- is
- Self_Id : Task_ID := Self;
- Result : Interfaces.C.int;
- Old_Set : aliased sigset_t;
-
- function To_Machine_State_Ptr is new
- Unchecked_Conversion (Address, Machine_State_Ptr);
-
- -- These are not directly visible
-
- procedure Raise_From_Signal_Handler
- (E : Ada.Exceptions.Exception_Id;
- M : System.Address);
- pragma Import
- (Ada, Raise_From_Signal_Handler,
- "ada__exceptions__raise_from_signal_handler");
- pragma No_Return (Raise_From_Signal_Handler);
-
- mstate : Machine_State_Ptr;
- message : aliased constant String := "" & ASCII.Nul;
- -- a null terminated String.
-
- begin
- 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 purpose are unmasked
-
- Result := pthread_sigmask (SIG_UNBLOCK,
- Unblocked_Signal_Mask'Unchecked_Access, Old_Set'Unchecked_Access);
- pragma Assert (Result = 0);
-
- mstate := To_Machine_State_Ptr (SSL.Get_Machine_State_Addr.all);
- mstate.eip := eip;
- mstate.ebx := ebx;
- mstate.esp := esp_at_signal;
- mstate.ebp := ebp;
- mstate.esi := esi;
- mstate.edi := edi;
-
- Raise_From_Signal_Handler
- (Standard'Abort_Signal'Identity, message'Address);
- end if;
- end Abort_Handler;
-
- -------------------
- -- Stack_Guard --
- -------------------
-
- -- The underlying thread system extends the memory (up to 2MB) when
- -- needed.
-
- procedure Stack_Guard (T : ST.Task_ID; On : Boolean) is
- begin
- 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 is
- Result : System.Address;
-
- begin
- Result := pthread_getspecific (ATCB_Key);
- pragma Assert (Result /= System.Null_Address);
- return To_Task_ID (Result);
- end Self;
-
- ---------------------
- -- 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 All_Tasks_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
- Result : Interfaces.C.int;
- begin
- if Priority_Ceiling_Emulation then
- L.Ceiling := Prio;
- end if;
-
- Result := pthread_mutex_init (L.L'Access, Mutex_Attr'Access);
-
- pragma Assert (Result = 0 or else Result = ENOMEM);
-
- if Result = ENOMEM then
- Ada.Exceptions.Raise_Exception (Storage_Error'Identity,
- "Failed to allocate a lock");
- end if;
- end Initialize_Lock;
-
- procedure Initialize_Lock (L : access RTS_Lock; Level : Lock_Level) is
- Result : Interfaces.C.int;
-
- begin
- Result := pthread_mutex_init (L, Mutex_Attr'Access);
-
- pragma Assert (Result = 0 or else Result = ENOMEM);
-
- if Result = ENOMEM then
- raise Storage_Error;
- end if;
- end Initialize_Lock;
-
- -------------------
- -- Finalize_Lock --
- -------------------
-
- procedure Finalize_Lock (L : access Lock) is
- Result : Interfaces.C.int;
-
- begin
- Result := pthread_mutex_destroy (L.L'Access);
- 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
- if Priority_Ceiling_Emulation then
- declare
- Self_ID : constant Task_ID := Self;
- begin
- if Self_ID.Common.LL.Active_Priority > L.Ceiling then
- Ceiling_Violation := True;
- return;
- end if;
- L.Saved_Priority := Self_ID.Common.LL.Active_Priority;
- if Self_ID.Common.LL.Active_Priority < L.Ceiling then
- Self_ID.Common.LL.Active_Priority := L.Ceiling;
- end if;
- Result := pthread_mutex_lock (L.L'Access);
- pragma Assert (Result = 0);
- Ceiling_Violation := False;
- end;
- else
- Result := pthread_mutex_lock (L.L'Access);
- Ceiling_Violation := Result = EINVAL;
- -- assumes the cause of EINVAL is a priority ceiling violation
- pragma Assert (Result = 0 or else Result = EINVAL);
- end if;
- end Write_Lock;
-
- procedure Write_Lock (L : 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 : 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
- if Priority_Ceiling_Emulation then
- declare
- Self_ID : constant Task_ID := Self;
- begin
- Result := pthread_mutex_unlock (L.L'Access);
- pragma Assert (Result = 0);
- if Self_ID.Common.LL.Active_Priority > L.Saved_Priority then
- Self_ID.Common.LL.Active_Priority := L.Saved_Priority;
- end if;
- end;
- else
- Result := pthread_mutex_unlock (L.L'Access);
- pragma Assert (Result = 0);
- end if;
- end Unlock;
-
- procedure Unlock (L : access RTS_Lock) is
- Result : Interfaces.C.int;
- -- Beware of any changes to this that might
- -- require access to the ATCB after the mutex is unlocked.
- -- This is the last operation performed by a task
- -- before it allows its ATCB to be deallocated, so it
- -- MUST NOT refer to the ATCB.
-
- 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;
-
- -------------
- -- Sleep --
- -------------
-
- procedure Sleep (Self_ID : Task_ID;
- Reason : System.Tasking.Task_States) is
- Result : Interfaces.C.int;
-
- begin
- pragma Assert (Self_ID = Self);
- Result := pthread_cond_wait (Self_ID.Common.LL.CV'Access,
- 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 : System.Tasking.Task_States;
- Timedout : out Boolean;
- Yielded : out Boolean)
- is
- Check_Time : constant Duration := Monotonic_Clock;
- 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;
- else
- Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
- end if;
-
- if Abs_Time > Check_Time then
- Request := To_Timespec (Abs_Time);
-
- loop
- exit when Self_ID.Pending_ATC_Level < Self_ID.ATC_Nesting_Level
- or else Self_ID.Pending_Priority_Change;
-
- Result := pthread_cond_timedwait
- (Self_ID.Common.LL.CV'Access, Self_ID.Common.LL.L'Access,
- Request'Access);
-
- 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;
- 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;
- Write_Lock (Self_ID);
-
- if Mode = Relative then
- Abs_Time := Time + Check_Time;
- else
- Abs_Time := Duration'Min (Check_Time + Max_Sensible_Delay, Time);
- end if;
-
- if Abs_Time > Check_Time then
- Request := To_Timespec (Abs_Time);
- 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;
-
- Result := pthread_cond_timedwait (Self_ID.Common.LL.CV'Access,
- Self_ID.Common.LL.L'Access, Request'Access);
-
- 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);
- Result := sched_yield;
- SSL.Abort_Undefer.all;
- end Timed_Delay;
-
- ---------------------
- -- Monotonic_Clock --
- ---------------------
-
- function Monotonic_Clock return Duration is
- TV : aliased struct_timeval;
- Result : Interfaces.C.int;
-
- begin
- Result := gettimeofday (TV'Access, System.Null_Address);
- pragma Assert (Result = 0);
- return To_Duration (TV);
- 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;
-
- if Priority_Ceiling_Emulation then
- if T.Common.LL.Active_Priority < Prio then
- T.Common.LL.Active_Priority := Prio;
- end if;
- end if;
-
- -- Priorities are in range 1 .. 99 on GNU/Linux, so we map
- -- map 0 .. 31 to 1 .. 32
-
- Param.sched_priority := Interfaces.C.int (Prio) + 1;
-
- if 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 or else Result = EPERM);
- 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
- Result : Interfaces.C.int;
-
- begin
- Self_ID.Common.LL.Thread := pthread_self;
-
- Result := pthread_setspecific (ATCB_Key, To_Address (Self_ID));
- pragma Assert (Result = 0);
-
- Lock_All_Tasks_List;
- for I in Known_Tasks'Range loop
- if Known_Tasks (I) = null then
- Known_Tasks (I) := Self_ID;
- Self_ID.Known_Tasks_Index := I;
- exit;
- end if;
- end loop;
- Unlock_All_Tasks_List;
- 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
- Result : Interfaces.C.int;
-
- 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);
-
- Self_ID.Common.LL.Thread := To_pthread_t (-1);
-
- Result := pthread_mutex_init (Self_ID.Common.LL.L'Access,
- Mutex_Attr'Access);
- pragma Assert (Result = 0 or else Result = ENOMEM);
-
- if Result /= 0 then
- Succeeded := False;
- return;
- end if;
-
- Result := pthread_cond_init (Self_ID.Common.LL.CV'Access,
- Cond_Attr'Access);
- pragma Assert (Result = 0 or else Result = ENOMEM);
-
- 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;
- Result : Interfaces.C.int;
-
- function Thread_Body_Access is new
- Unchecked_Conversion (System.Address, Thread_Body);
-
- begin
- Result := pthread_attr_init (Attributes'Access);
- pragma Assert (Result = 0 or else Result = ENOMEM);
-
- if Result /= 0 or else Stack_Size > Max_Stack_Size then
- Succeeded := False;
- return;
- end if;
-
- Result := pthread_attr_setdetachstate
- (Attributes'Access, PTHREAD_CREATE_DETACHED);
- 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.
-
- 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;
-
- 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
- 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;
- 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_All_Tasks_List --
- -------------------------
-
- procedure Lock_All_Tasks_List is
- begin
- Write_Lock (All_Tasks_L'Access);
- end Lock_All_Tasks_List;
-
- ---------------------------
- -- Unlock_All_Tasks_List --
- ---------------------------
-
- procedure Unlock_All_Tasks_List is
- begin
- Unlock (All_Tasks_L'Access);
- end Unlock_All_Tasks_List;
-
- ------------------
- -- Suspend_Task --
- ------------------
-
- function Suspend_Task
- (T : ST.Task_ID;
- Thread_Self : Thread_Id) return Boolean is
- begin
- if T.Common.LL.Thread /= Thread_Self then
- return pthread_kill (T.Common.LL.Thread, SIGSTOP) = 0;
- 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 /= Thread_Self then
- return pthread_kill (T.Common.LL.Thread, SIGCONT) = 0;
- else
- return True;
- end if;
- 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;
-
- Result := pthread_mutexattr_init (Mutex_Attr'Access);
- pragma Assert (Result = 0 or else Result = ENOMEM);
-
- Result := pthread_condattr_init (Cond_Attr'Access);
- pragma Assert (Result = 0 or else Result = ENOMEM);
-
- Initialize_Lock (All_Tasks_L'Access, All_Tasks_Level);
- -- Initialize the lock used to synchronize chain of all ATCBs.
-
- 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 (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;
-
- Result := pthread_key_create (ATCB_Key'Access, null);
- pragma Assert (Result = 0);
- end;
-
-end System.Task_Primitives.Operations;
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