OpenRTX/lib/miosix-kernel/miosix/kernel/scheduler/control/control_scheduler.h

283 lines
10 KiB
C++

/***************************************************************************
* Copyright (C) 2010, 2011 by Terraneo Federico *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* As a special exception, if other files instantiate templates or use *
* macros or inline functions from this file, or you compile this file *
* and link it with other works to produce a work based on this file, *
* this file does not by itself cause the resulting work to be covered *
* by the GNU General Public License. However the source code for this *
* file must still be made available in accordance with the GNU General *
* Public License. This exception does not invalidate any other reasons *
* why a work based on this file might be covered by the GNU General *
* Public License. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, see <http://www.gnu.org/licenses/> *
***************************************************************************/
#ifndef CONTROL_SCHEDULER_H
#define CONTROL_SCHEDULER_H
#include "config/miosix_settings.h"
#include "control_scheduler_types.h"
#include "parameters.h"
#include "kernel/kernel.h"
#include <algorithm>
#ifdef SCHED_TYPE_CONTROL_BASED
namespace miosix {
/**
* \internal
* Control based scheduler.
*/
class ControlScheduler
{
public:
/**
* \internal
* Add a new thread to the scheduler.
* This is called when a thread is created.
* \param thread a pointer to a valid thread instance.
* The behaviour is undefined if a thread is added multiple timed to the
* scheduler, or if thread is NULL.
* \param priority the priority of the new thread.
* Priority must be a positive value.
* Note that the meaning of priority is scheduler specific.
*/
static bool PKaddThread(Thread *thread, ControlSchedulerPriority priority);
/**
* \internal
* \return true if thread exists, false if does not exist or has been
* deleted. A joinable thread is considered existing until it has been
* joined, even if it returns from its entry point (unless it is detached
* and terminates).
*
* Can be called both with the kernel paused and with interrupts disabled.
*/
static bool PKexists(Thread *thread);
/**
* \internal
* Called when there is at least one dead thread to be removed from the
* scheduler
*/
static void PKremoveDeadThreads();
/**
* \internal
* Set the priority of a thread.
* Note that the meaning of priority is scheduler specific.
* \param thread thread whose priority needs to be changed.
* \param newPriority new thread priority.
* Priority must be a positive value.
*/
static void PKsetPriority(Thread *thread,
ControlSchedulerPriority newPriority);
/**
* \internal
* Get the priority of a thread.
* Note that the meaning of priority is scheduler specific.
* \param thread thread whose priority needs to be queried.
* \return the priority of thread.
*/
static ControlSchedulerPriority getPriority(Thread *thread)
{
return thread->schedData.priority;
}
/**
* \internal
* Same as getPriority, but meant to be called with interrupts disabled.
* \param thread thread whose priority needs to be queried.
* \return the priority of thread.
*/
static ControlSchedulerPriority IRQgetPriority(Thread *thread)
{
return thread->schedData.priority;
}
/**
* \internal
* This is called before the kernel is started to by the kernel. The given
* thread is the idle thread, to be run all the times where no other thread
* can run.
*/
static void IRQsetIdleThread(Thread *idleThread);
/**
* \internal
* \return the idle thread.
*/
static Thread *IRQgetIdleThread();
/**
* \internal
* This member function is called by the kernel every time a thread changes
* its running status. For example when a thread become sleeping, waiting,
* deleted or if it exits the sleeping or waiting status
*/
static void IRQwaitStatusHook()
{
#ifdef ENABLE_FEEDFORWARD
IRQrecalculateAlfa();
#endif //ENABLE_FEEDFORWARD
}
/**
* \internal
* This function is used to develop interrupt driven peripheral drivers.<br>
* Can be used ONLY inside an IRQ (and not when interrupts are disabled) to
* find next thread in READY status. If the kernel is paused, does nothing.
* Can be used for example if an IRQ causes a higher priority thread to be
* woken, to change context. Note that to use this function the IRQ must
* use the macros to save/restore context defined in portability.h
*
* If the kernel is paused does nothing.
* It's behaviour is to modify the global variable miosix::cur which always
* points to the currently running thread.
*/
static void IRQfindNextThread();
private:
/**
* \internal
* When priorities are modified, this function recalculates alfa for each
* thread. Must be called with kernel paused
*/
static void IRQrecalculateAlfa();
/**
* Called by IRQfindNextThread(), this function is where the control based
* scheduling algorithm is run. It is called once per round.
*/
static void IRQrunRegulator(bool allReadyThreadsSaturated)
{
using namespace std;
#ifdef SCHED_CONTROL_FIXED_POINT
//The fixed point scheduler may overflow if Tr is higher than this
Tr=min(Tr,524287);
#endif //FIXED_POINT_MATH
#ifdef ENABLE_REGULATOR_REINIT
if(reinitRegulator==false)
{
#endif //ENABLE_REGULATOR_REINIT
int eTr=SP_Tr-Tr;
#ifndef SCHED_CONTROL_FIXED_POINT
int bc=bco+static_cast<int>(krr*eTr-krr*zrr*eTro);
#else //FIXED_POINT_MATH
//Tr is clamped to 524287, so eTr uses at most 19bits. Considering
//the 31bits of a signed int, we have 12bits free.
const int fixedKrr=static_cast<int>(krr*2048);
const int fixedKrrZrr=static_cast<int>(krr*zrr*1024);
int bc=bco+(fixedKrr*eTr)/2048-(fixedKrrZrr*eTro)/1024;
#endif //FIXED_POINT_MATH
if(allReadyThreadsSaturated)
{
//If all inner regulators reached upper saturation,
//allow only a decrease in the burst correction.
if(bc<bco) bco=bc;
} else bco=bc;
bco=min<int>(max(bco,-Tr),bMax*threadListSize);
#ifndef SCHED_CONTROL_FIXED_POINT
float nextRoundTime=static_cast<float>(Tr+bco);
#else //FIXED_POINT_MATH
unsigned int nextRoundTime=Tr+bco; //Bounded to 20bits
#endif //FIXED_POINT_MATH
eTro=eTr;
Tr=0;//Reset round time
for(Thread *it=threadList;it!=0;it=it->schedData.next)
{
//Recalculate per thread set point
#ifndef SCHED_CONTROL_FIXED_POINT
it->schedData.SP_Tp=static_cast<int>(
it->schedData.alfa*nextRoundTime);
#else //FIXED_POINT_MATH
//nextRoundTime is bounded to 20bits, alfa to 12bits,
//so the multiplication fits in 32bits
it->schedData.SP_Tp=(it->schedData.alfa*nextRoundTime)/4096;
#endif //FIXED_POINT_MATH
//Run each thread internal regulator
int eTp=it->schedData.SP_Tp - it->schedData.Tp;
//note: since b and bo contain the real value multiplied by
//multFactor, this equals b=bo+eTp/multFactor.
int b=it->schedData.bo + eTp;
//saturation
it->schedData.bo=min(max(b,bMin*multFactor),bMax*multFactor);
}
#ifdef ENABLE_REGULATOR_REINIT
} else {
reinitRegulator=false;
Tr=0;//Reset round time
//Reset state of the external regulator
eTro=0;
bco=0;
for(Thread *it=threadList;it!=0;it=it->schedData.next)
{
//Recalculate per thread set point
#ifndef SCHED_CONTROL_FIXED_POINT
it->schedData.SP_Tp=static_cast<int>(it->schedData.alfa*SP_Tr);
#else //FIXED_POINT_MATH
//SP_Tr is bounded to 20bits, alfa to 12bits,
//so the multiplication fits in 32bits
it->schedData.SP_Tp=(it->schedData.alfa*SP_Tr)/4096;
#endif //FIXED_POINT_MATH
int b=it->schedData.SP_Tp*multFactor;
it->schedData.bo=min(max(b,bMin*multFactor),bMax*multFactor);
}
}
#endif //ENABLE_REGULATOR_REINIT
}
///\internal Threads (except idle thread) are stored here
static Thread *threadList;
static unsigned int threadListSize;
///\internal current thread in the round
static Thread *curInRound;
///\internal idle thread
static Thread *idle;
///\internal Set point of round time
///Current policy = bNominal * actual # of threads
static int SP_Tr;
///\internal Round time.
static int Tr;
///\internal old burst correction
static int bco;
///\internal old round tome error
static int eTro;
///\internal set to true by IRQrecalculateAlfa() to signal that
///due to a change in alfa the regulator needs to be reinitialized
static bool reinitRegulator;
};
} //namespace miosix
#endif //SCHED_TYPE_CONTROL_BASED
#endif //CONTROL_SCHEDULER_H