Add virtual timer

src/application/blinky/main.cc

@@ -42,10 +42,10 @@ int main(void)
 {
     cm4::InterruptGuardian::enable_interrupts();
     while(true) {
-        for(auto it = std::begin(leds); it != std::end(leds); ++it) {
-            nrf52::Gpio * tmp = *it;
-            tmp->toggle();
-            delay.delay(200);
+        for(auto it = leds.begin(); it != leds.end(); ++it) {
+            nrf52::Gpio * led = *it;
+            led->toggle();
+            delay.ms(200);
         }
     }
     return 0;

src/delay.cc

@@ -9,7 +9,7 @@ Delay::Delay()
 {
 }
 
-void Delay::delay(uint64_t time_ms)
+void Delay::ms(uint64_t time_ms)
 {
     this->pause = true;
     this->timer_set_period_ms(time_ms);

src/delay.h

@@ -12,7 +12,7 @@ class Delay
 
 public:
     Delay();
-    void delay(uint64_t);
+    void ms(uint64_t);
 
     void notification();
 

src/virtual_timer/VirtualTimerDistributor.cc

@@ -33,6 +33,7 @@ void VirtualTimerDistributor::register_timer(VirtualTimerInterface *timer)
     }
     for(auto it = this->virtual_timer_list.begin(); it != this->virtual_timer_list.end(); ++it) {
         if(*it == nullptr) {
+            // FIXME: We might need an interrupt lock here?
             *it = timer;
             num_registered_timers++;
             break;
@@ -45,8 +46,13 @@ void VirtualTimerDistributor::register_timer(VirtualTimerInterface *timer)
 
 void VirtualTimerDistributor::unregister_timer(VirtualTimerInterface *timer)
 {
+    if(num_registered_timers == 0) {
+        // FIXME: Error notification
+        return;
+    }
     for(auto it = this->virtual_timer_list.begin(); it != this->virtual_timer_list.end(); ++it) {
         if(*it == timer) {
+            // FIXME: We might need an interrupt lock here?
             *it = nullptr;
             num_registered_timers--;
             break;
@@ -59,6 +65,7 @@ void VirtualTimerDistributor::unregister_timer(VirtualTimerInterface *timer)
 
 void VirtualTimerDistributor::notify(uint64_t time_ms)
 {
+    // FIXME: We're still in interrupt context of hw timer interrupt.
     for(auto it = this->virtual_timer_list.begin(); it != this->virtual_timer_list.end(); ++it) {
         if(*it != nullptr) {
             VirtualTimerInterface *vt = *it;