diff options
Diffstat (limited to 'gcc/ada/s-tarest.ads')
| -rw-r--r-- | gcc/ada/s-tarest.ads | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/gcc/ada/s-tarest.ads b/gcc/ada/s-tarest.ads new file mode 100644 index 00000000000..7846fbc3233 --- /dev/null +++ b/gcc/ada/s-tarest.ads @@ -0,0 +1,211 @@ +------------------------------------------------------------------------------ +-- -- +-- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS -- +-- -- +-- S Y S T E M . T A S K I N G . R E S T R I C T E D . S T A G E S -- +-- -- +-- S p e c -- +-- -- +-- $Revision: 1.5 $ +-- -- +-- Copyright (C) 1992-1999, 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 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 simplified version of the System.Tasking.Stages package, +-- intended to be used in a restricted run time. + +-- This package represents the high level tasking interface used by the +-- compiler to expand Ada 95 tasking constructs into simpler run time calls +-- (aka GNARLI, GNU Ada Run-time Library Interface) + +-- Note: the compiler generates direct calls to this interface, via Rtsfind. +-- Any changes to this interface may require corresponding compiler changes +-- in exp_ch9.adb and possibly exp_ch7.adb + +-- The restricted GNARLI is also composed of System.Protected_Objects and +-- System.Protected_Objects.Single_Entry + +with System.Task_Info; +-- used for Task_Info_Type + +with System.Parameters; +-- used for Size_Type + +package System.Tasking.Restricted.Stages is + pragma Elaborate_Body; + + --------------------------------- + -- Compiler Interface (GNARLI) -- + --------------------------------- + + -- The compiler will expand in the GNAT tree the following construct: + -- + -- task type T (Discr : Integer); + -- + -- task body T is + -- ...declarations, possibly some controlled... + -- begin + -- ...B...; + -- end T; + -- + -- T1 : T (1); + -- + -- as follows: + -- + -- task type t (discr : integer); + -- tE : aliased boolean := false; + -- tZ : size_type := unspecified_size; + -- type tV (discr : integer) is limited record + -- _task_id : task_id; + -- end record; + -- procedure tB (_task : access tV); + -- freeze tV [ + -- procedure _init_proc (_init : in out tV; _master : master_id; + -- _chain : in out activation_chain; _task_id : in task_image_type; + -- discr : integer) is + -- begin + -- _init.discr := discr; + -- _init._task_id := null; + -- create_restricted_task (unspecified_priority, tZ, + -- unspecified_task_info, task_procedure_access!(tB'address), + -- _init'address, tE'unchecked_access, _chain, _task_id, _init. + -- _task_id); + -- return; + -- end _init_proc; + -- ] + -- + -- _chain : aliased activation_chain; + -- _init_proc (_chain); + -- + -- procedure tB (_task : access tV) is + -- discr : integer renames _task.discr; + -- + -- procedure _clean is + -- begin + -- complete_restricted_task; + -- finalize_list (F14b); + -- return; + -- end _clean; + -- begin + -- ...declarations... + -- complete_restricted_activation; + -- ...B...; + -- return; + -- at end + -- _clean; + -- end tB; + -- + -- tE := true; + -- t1 : t (1); + -- t1I : task_image_type := new string'"t1"; + -- _init_proc (t1, 3, _chain, t1I, 1); + -- + -- activate_restricted_tasks (_chain'unchecked_access); + + procedure Create_Restricted_Task + (Priority : Integer; + Size : System.Parameters.Size_Type; + Task_Info : System.Task_Info.Task_Info_Type; + State : Task_Procedure_Access; + Discriminants : System.Address; + Elaborated : Access_Boolean; + Chain : in out Activation_Chain; + Task_Image : System.Task_Info.Task_Image_Type; + Created_Task : out Task_ID); + -- Compiler interface only. Do not call from within the RTS. + -- This must be called to create a new task. + -- + -- Priority is the task's priority (assumed to be in the + -- System.Any_Priority'Range) + -- Size is the stack size of the task to create + -- Task_Info is the task info associated with the created task, or + -- Unspecified_Task_Info if none. + -- State is the compiler generated task's procedure body + -- Discriminants is a pointer to a limited record whose discriminants + -- are those of the task to create. This parameter should be passed as + -- the single argument to State. + -- Elaborated is a pointer to a Boolean that must be set to true on exit + -- if the task could be sucessfully elaborated. + -- Chain is a linked list of task that needs to be created. On exit, + -- Created_Task.Activation_Link will be Chain.T_ID, and Chain.T_ID + -- will be Created_Task (e.g the created task will be linked at the front + -- of Chain). + -- Task_Image is a pointer to a string created by the compiler that the + -- run time can store to ease the debugging and the + -- Ada.Task_Identification facility. + -- Created_Task is the resulting task. + -- + -- This procedure can raise Storage_Error if the task creation failed. + + procedure Activate_Restricted_Tasks + (Chain_Access : Activation_Chain_Access); + -- Compiler interface only. Do not call from within the RTS. + -- This must be called by the creator of a chain of one or more new tasks, + -- to activate them. The chain is a linked list that up to this point is + -- only known to the task that created them, though the individual tasks + -- are already in the All_Tasks_List. + -- + -- The compiler builds the chain in LIFO order (as a stack). Another + -- version of this procedure had code to reverse the chain, so as to + -- activate the tasks in the order of declaration. This might be nice, but + -- it is not needed if priority-based scheduling is supported, since all + -- the activated tasks synchronize on the activators lock before they + -- start activating and so they should start activating in priority order. + + procedure Complete_Restricted_Activation; + -- Compiler interface only. Do not call from within the RTS. + -- This should be called from the task body at the end of + -- the elaboration code for its declarative part. + -- Decrement the count of tasks to be activated by the activator and + -- wake it up so it can check to see if all tasks have been activated. + -- Except for the environment task, which should never call this procedure, + -- T.Activator should only be null iff T has completed activation. + + procedure Complete_Restricted_Task; + -- Compiler interface only. Do not call from within the RTS. + -- This should be called from an implicit at-end handler + -- associated with the task body, when it completes. + -- From this point, the current task will become not callable. + -- If the current task have not completed activation, this should be done + -- now in order to wake up the activator (the environment task). + + function Restricted_Terminated (T : Task_ID) return Boolean; + -- Compiler interface only. Do not call from within the RTS. + -- This is called by the compiler to implement the 'Terminated attribute. + -- + -- source code: + -- T1'Terminated + -- + -- code expansion: + -- restricted_terminated (t1._task_id) + + procedure Finalize_Global_Tasks; + -- This is needed to support the compiler interface; it will only be called + -- by the Environment task in the binder generated file (by adafinal). + -- Instead, it will cause the Environment to block forever, since none of + -- the dependent tasks are expected to terminate + +end System.Tasking.Restricted.Stages; |