/* -*- C++ -*- */
/**
* @file DSRT_Dispatcher_Impl_T.h
*
* $Id$
*
*/
#ifndef DSRT_DISPATCHER_IMPL_H
#define DSRT_DISPATCHER_IMPL_H
#include /**/ "ace/pre.h"
#include "ace/Synch_Traits.h"
#if defined (ACE_HAS_THREADS)
# include "ace/Recursive_Thread_Mutex.h"
#else
# include "ace/Null_Mutex.h"
#endif /* ACE_HAS_THREADS */
#include "Kokyu_dsrt.h"
#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */
namespace Kokyu
{
/**
* @class Comparator_Adapter_Generator
*
* @brief Generates function object adapter that adapts the
* QoSComparator function object to compare between two schedulable
* items instead of QoSDescriptors.
*
* The QoSComparator function object that gets passed through the
* DSRT_Scheduler_Traits
takes two qos values and
* determines the more eligible one. Since the INT_ID (key) for
* RB_Tree needs to be of type DSRT_Dispatch_Item_var
*
, the QoSComparator needs to be adapted using an adapter
* to compare two schedulable items. This adapter compares the two
* using their qos values. Ties are resolved by giving preference to
* items which arrived earlier. Note that this class serves the
* purpose of a generator class, since it generates the adapter
* class for a given qos comparator function object.
*/
template
class Comparator_Adapter_Generator
{
public:
typedef typename
DSRT_Scheduler_Traits::QoSComparator_t QoSComparator_t;
/**
* @class More_Eligible
*
* @brief Actual function object that gets generated.
*/
class MoreEligible
{
public:
/**
* Function call operator to do comparison between two
* schedulable items. Returns 1 if item1 is more eligible than
* item2, otherwise 0.
*/
int operator ()
(const DSRT_Dispatch_Item_var& item1,
const DSRT_Dispatch_Item_var& item2)
{
int rc = qos_comparator_ (item1->qos (), item2->qos ());
#ifdef KOKYU_DSRT_LOGGING
ACE_DEBUG ((LM_DEBUG,
"(%t|%T): MoreEligible:: qos_comparator returned %d\n",
rc));
#endif
//more eligible
if (rc == 1)
return rc;
//if equally eligible, then resolve tie with the creation time of
//the item
if (rc == 0 && item1->insertion_time () < item2->insertion_time ())
return 1;
return 0;
}
private:
QoSComparator_t qos_comparator_;
};
/**
* Facilitates return of the generated function object adapter.
*/
typedef MoreEligible RET;
};
/**
* @class DSRT_Dispatcher
*
* @brief Base class for DSRT dispatcher implementations
*
* The responsibility of this class is to act as a common base class
* for different DSRT dispatcher implementations. This is an
* abstract base class and cannot be instantiated.
*/
template
class DSRT_Dispatcher_Impl
{
public:
typedef typename DSRT_Scheduler_Traits::Guid_t Guid_t;
typedef typename DSRT_Scheduler_Traits::QoSDescriptor_t DSRT_QoSDescriptor;
DSRT_Dispatcher_Impl (ACE_Sched_Params::Policy sched_policy,
int sched_scope);
/// Configure the DSRT dispatcher.
int init (const DSRT_ConfigInfo&);
/// Schedule a thread dynamically based on the qos info supplied.
int schedule (Guid_t guid,
const DSRT_QoSDescriptor&);
/// Update the schedule for a thread. This could alter the current
/// schedule.
int update_schedule (Guid_t guid,
const DSRT_QoSDescriptor&);
/// Inform the scheduler that the caller thread is about to
/// block. This could alter the current schedule.
int update_schedule (Guid_t guid, Block_Flag_t flag);
/// Cancel the schedule for a thread. This could alter the current
/// schedule.
int cancel_schedule (Guid_t guid);
/// Shut down the dispatcher. The dispatcher will stop processing
/// requests.
int shutdown ();
virtual ~DSRT_Dispatcher_Impl ();
private:
//following an idiom to avoid public virtual functions.
//instead make them private and use the template method
//pattern - "Virtually Yours" article in CUJ Experts Forum
virtual int init_i (const DSRT_ConfigInfo&)=0;
virtual int schedule_i (Guid_t guid,
const DSRT_QoSDescriptor&)=0;
virtual int update_schedule_i (Guid_t guid,
const DSRT_QoSDescriptor&)=0;
virtual int update_schedule_i (Guid_t guid, Block_Flag_t flag)=0;
virtual int cancel_schedule_i (Guid_t guid)=0;
virtual int shutdown_i ()=0;
protected:
/// Generate the QoSComparator adapter.
typedef typename
Comparator_Adapter_Generator::RET
Queue_Item_Comparator_t;
typedef Sched_Ready_Queue
DSRT_Sched_Queue_t;
ACE_Sched_Params::Policy sched_policy_;
int sched_scope_;
Priority_t min_prio_;
Priority_t max_prio_;
Priority_t executive_prio_;
Priority_t blocked_prio_;
Priority_t inactive_prio_;
Priority_t active_prio_;
DSRT_Sched_Queue_t ready_queue_;
int shutdown_flagged_;
long non_rt_thr_flags_;
long rt_thr_flags_;
ACE_SYNCH_RECURSIVE_MUTEX synch_lock_;
ACE_hthread_t curr_scheduled_thr_handle_;
Guid_t curr_scheduled_guid_;
};
} //end of namespace
#if defined (__ACE_INLINE__)
#include "DSRT_Dispatcher_Impl_T.i"
#endif /* __ACE_INLINE__ */
#if defined (ACE_TEMPLATES_REQUIRE_SOURCE)
#include "DSRT_Dispatcher_Impl_T.cpp"
#endif /* ACE_TEMPLATES_REQUIRE_SOURCE */
#if defined (ACE_TEMPLATES_REQUIRE_PRAGMA)
#pragma implementation ("DSRT_Dispatcher_Impl_T.cpp")
#endif /* ACE_TEMPLATES_REQUIRE_PRAGMA */
#include /**/ "ace/post.h"
#endif /* DSRT_DISPATCHER_IMPL_H */