Clean up some memory management issues

- TimerEvent destructor should cancel timer.
- Fix memory leak.

src/test/test_basic.cc

@@ -94,6 +94,13 @@ bool test_single_timer_no_hierarchy() {
     timers.advance(10);
     EXPECT_INTEQ(count, 4);
 
+    {
+        TimerEvent<Callback> timer2([&count] () { ++count; });
+        timers.schedule(&timer2, 5);
+    }
+    timers.advance(10);
+    EXPECT_INTEQ(count, 4);
+
     return true;
 }
 

src/timer-wheel.h

@@ -11,6 +11,7 @@
 #include <cstdint>
 #include <cstdio>
 #include <limits>
+#include <memory>
 
 typedef uint64_t Tick;
 
@@ -22,6 +23,10 @@ public:
     TimerEventInterface() {
     }
 
+    virtual ~TimerEventInterface() {
+        cancel();
+    }
+
     void cancel();
 
     virtual void execute() = 0;
@@ -212,7 +217,7 @@ private:
         : now_(0),
           down_(down) {
         if (offset + WIDTH_BITS < 64) {
-            up_ = new TimerWheel(offset + WIDTH_BITS, down);
+            up_.reset(new TimerWheel(offset + WIDTH_BITS, down));
         }
      }
 
@@ -222,7 +227,7 @@ private:
     static const int NUM_SLOTS = 1 << WIDTH_BITS;
     static const int MASK = (NUM_SLOTS - 1);
     TimerWheelSlot slots_[NUM_SLOTS];
-    TimerWheel* up_;
+    std::unique_ptr<TimerWheel> up_;
     TimerWheel* down_;
 };