Refactored cstimer.h, removed getNextInterrupt() and destructor

miosix/arch/cortexM3_efm32gg/efm32gg332f1024_wandstem/interfaces-impl/cstimer.cpp

@@ -45,25 +45,28 @@ namespace miosix {
     return instance;
 }
 
-    void ContextSwitchTimer::IRQsetNextInterrupt(long long ns){
+void ContextSwitchTimer::IRQsetNextInterrupt(long long ns)
+{
     pImpl->b.IRQsetNextInterruptCS(pImpl->b.removeBasicCorrection(vht->corrected2uncorrected(vt->corrected2uncorrected(tc->ns2tick(ns)))));
 }
 
-    long long ContextSwitchTimer::getNextInterrupt() const{
-        return tc->tick2ns(vt->uncorrected2corrected(vht->uncorrected2corrected(pImpl->b.addBasicCorrection(pImpl->b.IRQgetSetTimeCS()))));
-    }
+// long long ContextSwitchTimer::getNextInterrupt() const
+// {
+//     return tc->tick2ns(vt->uncorrected2corrected(vht->uncorrected2corrected(pImpl->b.addBasicCorrection(pImpl->b.IRQgetSetTimeCS()))));
+// }
 
-    long long ContextSwitchTimer::getCurrentTime() const{
+long long ContextSwitchTimer::getCurrentTime() const
+{
     return tc->tick2ns(vt->uncorrected2corrected(vht->uncorrected2corrected(pImpl->b.addBasicCorrection(pImpl->b.getCurrentTick()))));
 }
 
-    long long ContextSwitchTimer::IRQgetCurrentTime() const{
+long long ContextSwitchTimer::IRQgetCurrentTime() const
+{
     return tc->tick2ns(vt->uncorrected2corrected(vht->uncorrected2corrected(pImpl->b.addBasicCorrection(pImpl->b.IRQgetCurrentTick()))));
 }
 
-    ContextSwitchTimer::~ContextSwitchTimer(){}
-    
-    ContextSwitchTimer::ContextSwitchTimer(){
+ContextSwitchTimer::ContextSwitchTimer()
+{
     pImpl=new ContextSwitchTimerImpl();
     timerFreq=pImpl->b.getTimerFrequency();
     tc = new TimeConversion(timerFreq);
@@ -71,4 +74,5 @@ namespace miosix {
     vt=&VirtualClock::instance();
     
 }
-}
+
+} //namespace miosix

miosix/arch/cortexM3_stm32/common/interfaces-impl/cstimer.cpp

@@ -105,11 +105,6 @@ void ContextSwitchTimer::IRQsetNextInterrupt(long long ns)
     }
 }
 
-long long ContextSwitchTimer::getNextInterrupt() const
-{
-    return tc->tick2ns(nextInterrupt());
-}
-
 long long ContextSwitchTimer::getCurrentTime() const
 {
     bool interrupts=areInterruptsEnabled();
@@ -127,8 +122,6 @@ long long ContextSwitchTimer::IRQgetCurrentTime() const
     return tc->tick2ns(IRQgetTick());
 }
 
-ContextSwitchTimer::~ContextSwitchTimer() {}
-
 ContextSwitchTimer::ContextSwitchTimer()
 {
     // TIM2 Source Clock (from APB1) Enable

miosix/arch/cortexM3_stm32f2/common/interfaces-impl/cstimer.cpp

@@ -105,11 +105,6 @@ void ContextSwitchTimer::IRQsetNextInterrupt(long long ns)
     }
 }
 
-long long ContextSwitchTimer::getNextInterrupt() const
-{
-    return tc->tick2ns(nextInterrupt());
-}
-
 long long ContextSwitchTimer::getCurrentTime() const
 {
     bool interrupts=areInterruptsEnabled();
@@ -127,8 +122,6 @@ long long ContextSwitchTimer::IRQgetCurrentTime() const
     return tc->tick2ns(IRQgetTick());
 }
 
-ContextSwitchTimer::~ContextSwitchTimer() {}
-
 ContextSwitchTimer::ContextSwitchTimer()
 {
     // TIM2 Source Clock (from APB1) Enable
@@ -176,4 +169,5 @@ ContextSwitchTimer::ContextSwitchTimer()
     static TimeConversion stc(timerFreq);
     tc = &stc;
 }
+
 } //namespace miosix

miosix/arch/cortexM4_stm32f4/common/interfaces-impl/cstimer.cpp

@@ -112,11 +112,6 @@ void ContextSwitchTimer::IRQsetNextInterrupt(long long ns)
     }
 }
 
-long long ContextSwitchTimer::getNextInterrupt() const
-{
-    return tc->tick2ns(nextInterrupt()) + set_offset; 
-}
-
 long long ContextSwitchTimer::getCurrentTime() const
 {
     bool interrupts=areInterruptsEnabled();
@@ -136,7 +131,7 @@ long long ContextSwitchTimer::IRQgetCurrentTime() const
   
 void ContextSwitchTimer::IRQsetCurrentTime(long long ns)
 {
-    long long nextInterrupt = getNextInterrupt();
+    long long nextInterrupt = tc->tick2ns(nextInterrupt()) + set_offset;
     long long currentTime = tc->tick2ns(IRQgetTick());
     //NOTE: can only move time forward, the OS can't tolerate a backward jump
     set_offset = std::max(ns - currentTime, 0LL);
@@ -144,8 +139,6 @@ void ContextSwitchTimer::IRQsetCurrentTime(long long ns)
     IRQsetNextInterrupt(nextInterrupt);
 }
 
-ContextSwitchTimer::~ContextSwitchTimer() {}
-
 ContextSwitchTimer::ContextSwitchTimer()
 {
     // TIM2 Source Clock (from APB1) Enable

miosix/interfaces/cstimer.h

-#ifndef CSTIMER_H
-#define	CSTIMER_H
+/***************************************************************************
+ *   Copyright (C) 2015-2021 by Terraneo Federico, Sasan Golchin           *
+ *                                                                         *
+ *   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/>   *
+ ***************************************************************************/
+
+#pragma once
 
 namespace miosix {
 
 class ContextSwitchTimerImpl;
 
 /**
- * This class is a low level interface to a hardware timer, that is used as
- * the basis for the Miosix timing infrastructure. In detail, it allows to
- * set interrupts used both for thread wakeup from sleep, and for preemption.
- * Please note that although the HW timer may operate in ticks, the class should
- * provide the user (which is kernel/scheduler codes) with a timing scheme
- * in nanoseconds. It is highly recommended to use TimeConversion class for
- * this purpose.
+ * \internal
+ * This class is meant to be used only by the kernel, not by application code!
+ * 
+ * This class is a low level interface to a hardware timer, that is used to:
+ * - measure time durations
+ * - set interrupts used both preemption and to handle sleeping threads wakeup
+ * 
+ * Please note that this class should provide the kernel with time information
+ * in nanoseconds. It is highly recommended to use TimeConversion class
+ * to convert the underlying hardware timer ticks to nanoseconds.
  */
 class ContextSwitchTimer
 {
@@ -25,18 +54,19 @@ public:
     /**
      * Set the next interrupt.
      * Can be called with interrupts disabled or within an interrupt.
-     * \param ns the time when the interrupt will be fired, in nanoseconds
+     * The hardware timer handles only one outstading interrupt request at a
+     * time, so a new call before the interrupt expires cancels the previous one.
+     * \param ns the time when the interrupt will be fired, in nanoseconds.
+     * When the interrupt fires, it shall call the
+     * \code
+     * void IRQtimerInterrupt(long long currentTime);
+     * \endcode
+     * function defined in kernel/scheduler/timer_interrupt.h
      */
     void IRQsetNextInterrupt(long long ns);
     
     /**
-     * \return the time in nanoseconds when the next interrupt will be fired.
-     * That is, the last value passed to setNextInterrupt().
-     */
-    long long getNextInterrupt() const;
-    
-    /**
-     * Could be call both when the interrupts are enabled/disabled!
+     * Can be called both when the interrupts are enabled/disabled!
      * TODO: investigate if it's possible to remove the possibility to call
      * this with IRQ disabled and use IRQgetCurrentTime() instead
      * \return the current time in nanoseconds as read from the timer
@@ -50,12 +80,15 @@ public:
     long long IRQgetCurrentTime() const;
     
     /**
-     * Set the current system time.
+     * Set the current system time. Used to adjust the time for example if the
+     * system clock was stopped due to entering deep sleep.
      * Can be called with interrupts disabled or within an interrupt.
-     * Used to adjust the time for example if the system clock was stopped
-     * due to entering deep sleep.
-     * FIXME: specify what should happen to an already set interrupt when time
-     * is changed
+     * \param ns value to set the hardware timer to. Note that the timer can
+     * only be set to a higher value, never to a lower one, as the OS timer
+     * needs to be monotonic.
+     * If an interrupt has been set with IRQsetNextInterrupt, it needs to be
+     * moved accordingly or fired immediately if the timer advance causes it
+     * to be in the past.
      */ 
     void IRQsetCurrentTime(long long ns);
     
@@ -70,11 +103,6 @@ public:
         return timerFreq;
     }
 
-    /**
-     * Destructor
-     */
-    virtual ~ContextSwitchTimer();
-
     ContextSwitchTimer(const ContextSwitchTimer&) = delete;
     ContextSwitchTimer& operator=(const ContextSwitchTimer&) = delete;
 private:
@@ -87,5 +115,3 @@ private:
 };
 
 } //namespace miosix
-
-#endif //CSTIMER_H