From 42480b63be8416785771f0b68aa5d2abf4e87b54 Mon Sep 17 00:00:00 2001
From: Sasan Golchin <ahmad.golchin@mail.polimi.it>
Date: Thu, 13 Oct 2016 14:49:13 +0200
Subject: [PATCH] Control Scheduler modified to work with CSTimer instead of
AuxTimer
---
.../common/interfaces-impl/portability.cpp | 85 -------------------
.../scheduler/control/control_scheduler.cpp | 47 ++++++++--
.../scheduler/control/control_scheduler.h | 2 +-
miosix/kernel/scheduler/control/parameters.h | 8 +-
4 files changed, 44 insertions(+), 98 deletions(-)
diff --git a/miosix/arch/cortexM4_stm32f4/common/interfaces-impl/portability.cpp b/miosix/arch/cortexM4_stm32f4/common/interfaces-impl/portability.cpp
index 9b27e6ce..4776adab 100644
--- a/miosix/arch/cortexM4_stm32f4/common/interfaces-impl/portability.cpp
+++ b/miosix/arch/cortexM4_stm32f4/common/interfaces-impl/portability.cpp
@@ -56,25 +56,6 @@ void SVC_Handler()
restoreContext();
}
-#ifdef SCHED_TYPE_CONTROL_BASED
-/**
- * \internal
- * Auxiliary timer interupt routine.
- * Used for variable lenght bursts in control based scheduler.
- * Since inside naked functions only assembler code is allowed, this function
- * only calls the ctxsave/ctxrestore macros (which are in assembler), and calls
- * the implementation code in ISR_yield()
- */
-void TIM3_IRQHandler() __attribute__((naked));
-void TIM3_IRQHandler()
-{
- saveContext();
- //Call ISR_auxTimer(). Name is a C++ mangled name.
- asm volatile("bl _ZN14miosix_private12ISR_auxTimerEv");
- restoreContext();
-}
-#endif //SCHED_TYPE_CONTROL_BASED
-
namespace miosix_private {
/**
@@ -132,22 +113,6 @@ void ISR_yield()
#endif //WITH_PROCESSES
}
-#ifdef SCHED_TYPE_CONTROL_BASED
-/**
- * \internal
- * Auxiliary timer interupt routine.
- * Used for variable lenght bursts in control based scheduler.
- */
-void ISR_auxTimer() __attribute__((noinline));
-void ISR_auxTimer()
-{
- IRQstackOverflowCheck();
- miosix::Scheduler::IRQfindNextThread();//If the kernel is running, preempt
- if(miosix::kernel_running!=0) miosix::tick_skew=true;
- TIM3->SR=0;
-}
-#endif //SCHED_TYPE_CONTROL_BASED
-
void IRQstackOverflowCheck()
{
const unsigned int watermarkSize=miosix::WATERMARK_LEN/sizeof(unsigned int);
@@ -278,9 +243,6 @@ void IRQportableStartKernel()
#ifdef WITH_PROCESSES
miosix::IRQenableMPUatBoot();
#endif //WITH_PROCESSES
- #ifdef SCHED_TYPE_CONTROL_BASED
- AuxiliaryTimer::IRQinit();
- #endif //SCHED_TYPE_CONTROL_BASED
//create a temporary space to save current registers. This data is useless
//since there's no way to stop the sheduler, but we need to save it anyway.
@@ -303,51 +265,4 @@ void sleepCpu()
__WFI();
}
-#ifdef SCHED_TYPE_CONTROL_BASED
-void AuxiliaryTimer::IRQinit()
-{
- RCC->APB1ENR|=RCC_APB1ENR_TIM3EN;
- RCC_SYNC();
- DBGMCU->APB1FZ|=DBGMCU_APB1_FZ_DBG_TIM3_STOP; //Tim3 stops while debugging
- TIM3->CR1=0; //Upcounter, not started, no special options
- TIM3->CR2=0; //No special options
- TIM3->SMCR=0; //No external trigger
- TIM3->CNT=0; //Clear timer
- //get timer frequency considering APB1 prescaler
- //consider that timer clock is twice APB1 clock when the APB1 prescaler has
- //a division factor greater than 2
- int timerClock=SystemCoreClock;
- int apb1prescaler=(RCC->CFGR>>10) & 7;
- if(apb1prescaler>4) timerClock>>=(apb1prescaler-4);
- TIM3->PSC=(timerClock/miosix::AUX_TIMER_CLOCK)-1;
- TIM3->ARR=0xffff; //Count from zero to 0xffff
- TIM3->DIER=TIM_DIER_CC1IE; //Enable interrupt on compare
- TIM3->CCR1=0xffff; //This will be initialized later with setValue
- NVIC_SetPriority(TIM3_IRQn,3);//High priority for TIM3 (Max=0, min=15)
- NVIC_EnableIRQ(TIM3_IRQn);
- TIM3->CR1=TIM_CR1_CEN; //Start timer
- //This is very important: without this the prescaler shadow register may
- //not be updated
- TIM3->EGR=TIM_EGR_UG;
-}
-
-int AuxiliaryTimer::IRQgetValue()
-{
- return static_cast<int>(TIM3->CNT);
-}
-
-void AuxiliaryTimer::IRQsetValue(int x)
-{
- TIM3->CR1=0; //Stop timer since changing CNT or CCR1 while running fails
- TIM3->CNT=0;
- TIM3->CCR1=static_cast<unsigned short>(std::min(x,0xffff));
- TIM3->CR1=TIM_CR1_CEN; //Start timer again
- //The above instructions cause a spurious if not called within the
- //timer 2 IRQ (This happens if called from an SVC).
- //Clearing the pending bit prevents this spurious interrupt
- TIM3->SR=0;
- NVIC_ClearPendingIRQ(TIM3_IRQn);
-}
-#endif //SCHED_TYPE_CONTROL_BASED
-
} //namespace miosix_private
diff --git a/miosix/kernel/scheduler/control/control_scheduler.cpp b/miosix/kernel/scheduler/control/control_scheduler.cpp
index 09a1ea38..b131273d 100644
--- a/miosix/kernel/scheduler/control/control_scheduler.cpp
+++ b/miosix/kernel/scheduler/control/control_scheduler.cpp
@@ -29,6 +29,7 @@
#include "kernel/error.h"
#include "kernel/process.h"
#include <limits>
+#include "interfaces/cstimer.h"
using namespace std;
@@ -39,6 +40,9 @@ namespace miosix {
//These are defined in kernel.cpp
extern volatile Thread *cur;
extern volatile int kernel_running;
+static ContextSwitchTimer& timer = ContextSwitchTimer::instance();
+extern IntrusiveList<SleepData> *sleepingList;
+static long long burstStart = 0;
//
// class ControlScheduler
@@ -145,20 +149,45 @@ Thread *ControlScheduler::IRQgetIdleThread()
return idle;
}
-void ControlScheduler::IRQfindNextThread()
+// Should be called when the current thread is the idle thread
+static inline void IRQsetNextPreemptionForIdle(){
+ if (sleepingList->empty())
+ timer.IRQsetNextInterrupt(numeric_limits<long long>::max());
+ else
+ timer.IRQsetNextInterrupt(sleepingList->front()->wakeup_time);
+}
+
+// Should be called for threads other than idle thread
+static inline void IRQsetNextPreemption(long long burst){
+ long long firstWakeupInList;
+ long long nextPreemption;
+ if (sleepingList->empty())
+ firstWakeupInList = numeric_limits<long long>::max();
+ else
+ firstWakeupInList = sleepingList->front()->wakeup_time;
+ burstStart = timer.IRQgetCurrentTick();
+ nextPreemption = burstStart + burst;
+ if (firstWakeupInList < nextPreemption)
+ timer.IRQsetNextInterrupt(firstWakeupInList);
+ else
+ timer.IRQsetNextInterrupt(nextPreemption);
+}
+
+unsigned int ControlScheduler::IRQfindNextThread()
{
// Warning: since this function is called within interrupt routines, it
//is not possible to add/remove elements to threadList, since that would
//require dynamic memory allocation/deallocation which is forbidden within
//interrupts. Iterating the list is safe, though
- if(kernel_running!=0) return;//If kernel is paused, do nothing
+ if(kernel_running!=0) return 0;//If kernel is paused, do nothing
if(cur!=idle)
{
//Not preempting from the idle thread, store actual burst time of
//the preempted thread
- int Tp=miosix_private::AuxiliaryTimer::IRQgetValue();
+ //int Tp=miosix_private::AuxiliaryTimer::IRQgetValue(); //CurTime - LastTime = real burst
+ int Tp = static_cast<int>(timer.IRQgetCurrentTick() - burstStart);
cur->schedData.Tp=Tp;
Tr+=Tp;
}
@@ -204,8 +233,9 @@ void ControlScheduler::IRQfindNextThread()
#ifdef WITH_PROCESSES
MPUConfiguration::IRQdisable();
#endif
- miosix_private::AuxiliaryTimer::IRQsetValue(bIdle);
- return;
+ //miosix_private::AuxiliaryTimer::IRQsetValue(bIdle); //curTime + burst
+ IRQsetNextPreemptionForIdle();
+ return 0;
}
//End of round reached, run scheduling algorithm
@@ -230,9 +260,10 @@ void ControlScheduler::IRQfindNextThread()
#else //WITH_PROCESSES
ctxsave=cur->ctxsave;
#endif //WITH_PROCESSES
- miosix_private::AuxiliaryTimer::IRQsetValue(
- curInRound->schedData.bo/multFactor);
- return;
+ //miosix_private::AuxiliaryTimer::IRQsetValue(
+ // curInRound->schedData.bo/multFactor);
+ IRQsetNextPreemption(curInRound->schedData.bo/multFactor);
+ return 0;
} else {
//If we get here we have a non ready thread that cannot run,
//so regardless of the burst calculated by the scheduler
diff --git a/miosix/kernel/scheduler/control/control_scheduler.h b/miosix/kernel/scheduler/control/control_scheduler.h
index a52db3bd..851ccd87 100644
--- a/miosix/kernel/scheduler/control/control_scheduler.h
+++ b/miosix/kernel/scheduler/control/control_scheduler.h
@@ -150,7 +150,7 @@ public:
* It's behaviour is to modify the global variable miosix::cur which always
* points to the currently running thread.
*/
- static void IRQfindNextThread();
+ static unsigned int IRQfindNextThread();
private:
diff --git a/miosix/kernel/scheduler/control/parameters.h b/miosix/kernel/scheduler/control/parameters.h
index c6586139..db1f144d 100644
--- a/miosix/kernel/scheduler/control/parameters.h
+++ b/miosix/kernel/scheduler/control/parameters.h
@@ -76,19 +76,19 @@ const int multFactor=static_cast<int>(1.0f/kpi);
///Instead of fixing a round time the current policy is to have
///roundTime=bNominal * numThreads, where bNominal is the nominal thread burst
-static const int bNominal=static_cast<int>(AUX_TIMER_CLOCK*0.004);// 4ms
+static const int bNominal=static_cast<int>(4000000);// 4ms
///minimum burst time (to avoid inefficiency caused by context switch
///time longer than burst time)
-static const int bMin=static_cast<int>(AUX_TIMER_CLOCK*0.0002);// 200us
+static const int bMin=static_cast<int>(200000);// 200us
///maximum burst time (to avoid losing responsiveness/timer overflow)
-static const int bMax=static_cast<int>(AUX_TIMER_CLOCK*0.02);// 20ms
+static const int bMax=static_cast<int>(20000000);// 20ms
///idle thread has a fixed burst length that can be modified here
///it is recomended to leave it to a high value, but that does not cause
///overflow of the auxiliary timer
-static const int bIdle=static_cast<int>(AUX_TIMER_CLOCK*0.5);// 500ms
+static const int bIdle=static_cast<int>(500000000);// 500ms
}
--
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