Timer: minor revisions

* C++11-ify a little.
* Make it copy/move constructible.

Author: kjbracey

drivers/Timer.h

@@ -22,6 +22,9 @@
 #include "platform/NonCopyable.h"
 
 namespace mbed {
+
+class CriticalSectionLock;
+
 /**
  * \defgroup drivers_Timer Timer class
  * \ingroup drivers-public-api-ticker
@@ -51,7 +54,7 @@ namespace mbed {
  * }
  * @endcode
  */
-class TimerBase : private NonCopyable<TimerBase> {
+class TimerBase {
 
 public:
     /** Start the timer
@@ -109,13 +112,24 @@ class TimerBase : private NonCopyable<TimerBase> {
 protected:
     TimerBase(const ticker_data_t *data);
     TimerBase(const ticker_data_t *data, bool lock_deepsleep);
+    TimerBase(const TimerBase &t);
+    TimerBase(TimerBase &&t);
     ~TimerBase();
+
+    const TimerBase &operator=(const TimerBase &) = delete;
+
     std::chrono::microseconds slicetime() const;
     TickerDataClock::time_point _start{};   // the start time of the latest slice
     std::chrono::microseconds _time{};    // any accumulated time from previous slices
     TickerDataClock _ticker_data;
     bool _lock_deepsleep;    // flag that indicates if deep sleep should be disabled
     bool _running = false;   // whether the timer is running
+
+private:
+    // Copy storage while a lock is held
+    TimerBase(const TimerBase &t, const CriticalSectionLock &) : TimerBase(t, false) {}
+    // Copy storage only - used by delegating constructors
+    TimerBase(const TimerBase &t, bool) : _start(t._start), _time(t._time), _ticker_data(t._ticker_data), _lock_deepsleep(t._lock_deepsleep), _running(t._running) {}
 };
 #endif
 

drivers/source/Timer.cpp

@@ -38,6 +38,26 @@ TimerBase::TimerBase(const ticker_data_t *data, bool lock_deepsleep) : _ticker_d
     reset();
 }
 
+// This creates a temporary CriticalSectionLock while we delegate to the
+// constructor that does the copy, thus holding critical section during the copy,
+// ensuring locking on the source. Then continue our own initialization
+// outside the critical section
+TimerBase::TimerBase(const TimerBase &t) : TimerBase(t, CriticalSectionLock{})
+{
+    // If running, new copy needs an extra lock
+    if (_running && _lock_deepsleep) {
+        sleep_manager_lock_deep_sleep();
+    }
+}
+
+// Unlike copy constructor, no need for lock on move - we must be only person
+// accessing source.
+TimerBase::TimerBase(TimerBase &&t) : TimerBase(t, false)
+{
+    // Original is marked as no longer running - we adopt any lock it had
+    t._running = false;
+}
+
 TimerBase::~TimerBase()
 {
     if (_running) {