------------------------------------------------------------------------------
-- --
--- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
+-- 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 --
-- --
-- S p e c --
-- --
-- Copyright (C) 1991-1994, Florida State University --
--- Copyright (C) 1995-2003, Ada Core Technologies --
+-- Copyright (C) 1995-2005, AdaCore --
-- --
-- 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- --
-- 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. --
+-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
+-- Boston, MA 02110-1301, 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 is a POSIX-like version of this package.
--- Note: this file can only be used for POSIX compliant systems.
+-- This is a POSIX-like version of this package
+
+-- Note: this file can only be used for POSIX compliant systems
pragma Polling (Off);
-- Turn off polling, we do not want ATC polling to take place during
-- pthread_t
package System.Task_Primitives is
+ pragma Preelaborate;
type Lock is limited private;
- -- Should be used for implementation of protected objects.
+ -- Should be used for implementation of protected objects
type RTS_Lock is limited private;
- -- Should be used inside the runtime system.
- -- The difference between Lock and the RTS_Lock is that the later
- -- one serves only as a semaphore so that do not check for
- -- ceiling violations.
+ -- Should be used inside the runtime system. The difference between Lock
+ -- and the RTS_Lock is that the later one serves only as a semaphore so
+ -- that do not check for ceiling violations.
+
+ type Suspension_Object is limited private;
+ -- Should be used for the implementation of Ada.Synchronous_Task_Control
type Task_Body_Access is access procedure;
- -- Pointer to the task body's entry point (or possibly a wrapper
- -- declared local to the GNARL).
+ -- Pointer to the task body's entry point (or possibly a wrapper declared
+ -- local to the GNARL).
type Private_Data is limited private;
- -- Any information that the GNULLI needs maintained on a per-task
- -- basis. A component of this type is guaranteed to be included
- -- in the Ada_Task_Control_Block.
+ -- Any information that the GNULLI needs maintained on a per-task basis.
+ -- A component of this type is guaranteed to be included in the
+ -- Ada_Task_Control_Block.
private
type Lock is new System.OS_Interface.pthread_mutex_t;
type RTS_Lock is new System.OS_Interface.pthread_mutex_t;
+ type Suspension_Object is record
+ State : Boolean;
+ pragma Atomic (State);
+ -- Boolean that indicates whether the object is open. This field is
+ -- marked Atomic to ensure that we can read its value without locking
+ -- the access to the Suspension_Object.
+
+ Waiting : Boolean;
+ -- Flag showing if there is a task already suspended on this object
+
+ L : aliased System.OS_Interface.pthread_mutex_t;
+ -- Protection for ensuring mutual exclusion on the Suspension_Object
+
+ CV : aliased System.OS_Interface.pthread_cond_t;
+ -- Condition variable used to queue threads until condition is signaled
+ end record;
+
type Private_Data is record
Thread : aliased System.OS_Interface.pthread_t;
pragma Atomic (Thread);
-- Thread field may be updated by two different threads of control.
- -- (See, Enter_Task and Create_Task in s-taprop.adb).
- -- They put the same value (thr_self value). We do not want to
- -- use lock on those operations and the only thing we have to
- -- make sure is that they are updated in atomic fashion.
+ -- (See, Enter_Task and Create_Task in s-taprop.adb). They put the same
+ -- value (thr_self value). We do not want to use lock on those
+ -- operations and the only thing we have to make sure is that they are
+ -- updated in atomic fashion.
LWP : aliased System.Address;
-- The purpose of this field is to provide a better tasking support on
-- On targets where lwp is not relevant, this is equivalent to Thread.
CV : aliased System.OS_Interface.pthread_cond_t;
+ -- Should be commented ??? (in all versions of taspri)
- L : aliased RTS_Lock;
+ L : aliased RTS_Lock;
-- Protection for all components is lock L
end record;
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