Fix: wrong period operation without unit multiplicator

Possible divsion by 0. Don't know if it is good to keep different time unit
instead having one unit for project...

Change-Id: I73cfc1ab72d3420d337f10a9b79bdf305a3a2bc7
Signed-off-by: Romain Forlot <romain.forlot@iot.bzh>

2 files changed, 9 insertions, 7 deletions

diff --git a/src/utils/timer.cpp b/src/utils/timer.cpp
index 540cfe0d..a35a3e9f 100644
--- a/src/utils/timer.cpp
+++ b/src/utils/timer.cpp
@@ -51,19 +51,19 @@ long long int system_time_s()
 }
 
 frequency_clock_t::frequency_clock_t()
-	: frequency_{10.0}, last_tick_{0}, time_function_{nullptr}
+	: unit_{1000000}, frequency_{10.0}, last_tick_{0}, time_function_{nullptr}
 {}
 
 
 frequency_clock_t::frequency_clock_t(float frequency)
-	: frequency_{frequency}, last_tick_{0}, time_function_{nullptr}
+	: unit_{1000000}, frequency_{frequency}, last_tick_{0}, time_function_{nullptr}
 {}
 
 /// @brief Return the period in ms given the frequency in hertz.
-/// @param[in] frequency - Frequency to convert, in Hertz
-float frequency_clock_t::frequency_to_period(float frequency)
+/// @param[in] frequency - Frequency to convert, in hertz
+float frequency_clock_t::frequency_to_period()
 {
-	return 1 / frequency;
+	return 1 / frequency_ * unit_;
 }
 
 bool frequency_clock_t::started()
@@ -78,7 +78,7 @@ time_function_t frequency_clock_t::get_time_function()
 
 bool frequency_clock_t::elapsed(bool stagger)
 {
-	float period = frequency_to_period(frequency_);
+	float period = frequency_to_period();
 	float elapsed_time = 0;
 	if(!started() && stagger)
 		last_tick_ = get_time_function()() - (rand() % int(period));
diff --git a/src/utils/timer.hpp b/src/utils/timer.hpp
index 5be0e3cd..f5659044 100644
--- a/src/utils/timer.hpp
+++ b/src/utils/timer.hpp
@@ -32,6 +32,7 @@ long long int system_time_s();
 class frequency_clock_t
 {
 private:
+	float unit_; ///< unit_ - multiplicator to make operation to be in the right unit (milli, micro, nano, etc)
 	float frequency_; ///< the clock frequency in Hz.
 	unsigned long last_tick_; ///< the last time (in milliseconds since startup) that the clock ticked.
 	time_function_t time_function_; ///<  a function returning current time
@@ -42,7 +43,8 @@ public:
 	frequency_clock_t(float frequency, unsigned long last_tick, time_function_t time_function);
 
 	float get_frequency() const;
-	static float frequency_to_period(float frequency);
+
+	float frequency_to_period();
 	bool started();
 	time_function_t get_time_function();
 	bool elapsed(bool stagger);