libos: Add Timer::reset, restart and stop

libos/include/os/Timer.h

@@ -22,15 +22,21 @@ namespace os
         static Result<OwnedPtr<Timer>> create_singleshot(unsigned int milliseconds, Action&& action);
         static Result<OwnedPtr<Timer>> create_repeating(unsigned int milliseconds, Action&& action);
 
+        void restart();
+        void reset(unsigned int milliseconds);
+        void stop();
+
         ~Timer();
 
       private:
         timer_t m_timerid { -1 };
         bool m_repeating;
+        bool m_stopped { false };
         struct timespec m_interval;
         Action m_action;
 
         void check_if_should_invoke_action();
+        void readd_if_necessary();
 
         Timer() = default;
 

libos/src/Timer.cpp

@@ -54,21 +54,45 @@ namespace os
         return timer;
     }
 
+    void Timer::restart()
+    {
+        struct itimerspec itimer = { .it_interval = { .tv_sec = 0, .tv_nsec = 0 }, .it_value = m_interval };
+
+        timer_settime(m_timerid, 0, &itimer, nullptr);
+
+        readd_if_necessary();
+    }
+
+    void Timer::reset(unsigned int milliseconds)
+    {
+        m_interval = { .tv_sec = milliseconds / 1000, .tv_nsec = (milliseconds % 1000) * 1'000'000 };
+        restart();
+    }
+
+    void Timer::stop()
+    {
+        EventLoop::the().m_timer_list.remove(this);
+        m_stopped = true;
+
+        struct itimerspec itimer;
+        memset(&itimer, 0, sizeof(itimer));
+        timer_settime(m_timerid, 0, &itimer, nullptr);
+    }
+
     void Timer::check_if_should_invoke_action()
     {
         struct itimerspec remaining;
         if (timer_gettime(m_timerid, &remaining) < 0) return;
 
-        if (!remaining.it_value.tv_sec && !remaining.it_value.tv_nsec)
+        if (!remaining.it_value.tv_sec && !remaining.it_value.tv_nsec && !m_stopped)
         {
             // Timer expired!
             m_action();
 
             if (!m_repeating)
             {
-                timer_delete(m_timerid);
                 EventLoop::the().m_timer_list.remove(this);
-                m_timerid = -1;
+                m_stopped = true;
             }
             else
             {
@@ -79,6 +103,15 @@ namespace os
         }
     }
 
+    void Timer::readd_if_necessary()
+    {
+        if (m_stopped)
+        {
+            m_stopped = false;
+            EventLoop::the().m_timer_list.append(this);
+        }
+    }
+
     Timer::~Timer()
     {
         if (m_timerid >= 0) timer_delete(m_timerid);