+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNAT RUNTIME COMPONENTS --
--- --
--- A D A . S Y N C H R O N O U S _ T A S K _ C O N T R O L --
--- --
--- B o d y --
--- --
--- $Revision: 1.1.16.1 $
--- --
--- Copyright (C) 1992-2001 Free Software Foundation, Inc. --
--- --
--- GNAT 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. 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. See the GNU General Public License --
--- for more details. You should have received a copy of the GNU General --
--- Public License distributed with GNAT; 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. --
--- --
--- GNAT was originally developed by the GNAT team at New York University. --
--- Extensive contributions were provided by Ada Core Technologies Inc. --
--- --
-------------------------------------------------------------------------------
-
-with Interfaces.C;
-package body Ada.Synchronous_Task_Control is
- use System.OS_Interface;
- use type Interfaces.C.int;
-
- -------------------
- -- Current_State --
- -------------------
-
- function Current_State (S : Suspension_Object) return Boolean is
- St : STATUS;
- Result : Boolean := False;
-
- begin
- -- Determine state by attempting to take the semaphore with
- -- a 0 timeout value. Status = OK indicates the semaphore was
- -- full, so reset it to the full state.
-
- St := semTake (S.Sema, NO_WAIT);
-
- if St = OK then
- -- Took the semaphore. Reset semaphore state to FULL
- Result := True;
- St := semGive (S.Sema);
- end if;
-
- return Result;
- end Current_State;
-
- ---------------
- -- Set_False --
- ---------------
-
- procedure Set_False (S : in out Suspension_Object) is
- St : STATUS;
- begin
- -- Need to get the semaphore into the "empty" state.
- -- On return, this task will have made the semaphore
- -- empty (St = OK) or have left it empty.
- St := semTake (S.Sema, NO_WAIT);
- end Set_False;
-
- --------------
- -- Set_True --
- --------------
-
- procedure Set_True (S : in out Suspension_Object) is
- St : STATUS;
- begin
- St := semGive (S.Sema);
- end Set_True;
-
- ------------------------
- -- Suspend_Until_True --
- ------------------------
-
- procedure Suspend_Until_True (S : in out Suspension_Object) is
- St : STATUS;
-
- -- Declare local exception so the mutex can still be reset
- -- to full if Program_Error is raised
-
- Task_Already_Pending : exception;
- begin
- -- Determine whether another task is pending on the suspension
- -- object. Should never be called from an ISR. Therefore semTake can
- -- be called on the mutex
- St := semTake (S.Mutex, NO_WAIT);
-
- if St = OK then
- -- Wait for suspension object
-
- St := semTake (S.Sema, WAIT_FOREVER);
- St := semGive (S.Mutex);
-
- else
- -- Another task is pending on the suspension object
-
- raise Task_Already_Pending;
- end if;
- exception
- when Task_Already_Pending =>
- raise Program_Error;
- when others =>
- St := semGive (S.Mutex);
- raise;
- end Suspend_Until_True;
-
- procedure Initialize (S : in out Suspension_Object) is
- begin
- S.Sema := semBCreate (SEM_Q_FIFO, SEM_EMPTY);
-
- -- Use simpler binary semaphore instead of VxWorks
- -- mutual exclusion semaphore, because we don't need
- -- the fancier semantics and their overhead.
-
- S.Mutex := semBCreate (SEM_Q_FIFO, SEM_FULL);
- end Initialize;
-
- procedure Finalize (S : in out Suspension_Object) is
- St : STATUS;
- begin
- St := semDelete (S.Sema);
- St := semDelete (S.Mutex);
- end Finalize;
-
-end Ada.Synchronous_Task_Control;
projects / msp430-gcc.git / blobdiff