Time: Remove serverside getter, and use atomic operations

It isn't possible to use atomic operations for floats, so don't use them there.

Having a lock is good out of other reasons too, because this way the float time
and the integer time both match, and can't get different values in a race,
e.g. when two setTimeofDay() get executed simultaneously.

1 files changed, 16 insertions, 14 deletions

diff --git a/src/environment.h b/src/environment.h
index cb8be71b2..7100bc5d3 100644
--- a/src/environment.h
+++ b/src/environment.h
@@ -40,6 +40,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapnode.h"
 #include "mapblock.h"
 #include "threading/mutex.h"
+#include "threading/atomic.h"
 #include "network/networkprotocol.h" // for AccessDeniedCode
 
 class ServerEnvironment;
@@ -94,8 +95,7 @@ public:
 
 	void setDayNightRatioOverride(bool enable, u32 value)
 	{
-		m_enable_day_night_ratio_override = enable;
-		m_day_night_ratio_override = value;
+		m_day_night_ratio_override_storage = value | ((u64)enable << 63);
 	}
 
 	// counter used internally when triggering ABMs
@@ -105,23 +105,25 @@ protected:
 	// peer_ids in here should be unique, except that there may be many 0s
 	std::vector<Player*> m_players;
 
+	// Time of day in milli-hours (0-23999); determines day and night
+	Atomic<u32> m_time_of_day;
 
 	/*
-	 *  Below: values under m_time_lock
-	 */
-	// Time of day in milli-hours (0-23999); determines day and night
-	u32 m_time_of_day;
+	 * Below: values managed by m_time_floats_lock
+	*/
 	// Time of day in 0...1
 	float m_time_of_day_f;
 	float m_time_of_day_speed;
-	// Used to buffer dtime for adding to m_time_of_day
-	float m_time_counter;
-	// Overriding the day-night ratio is useful for custom sky visuals
-	bool m_enable_day_night_ratio_override;
-	u32 m_day_night_ratio_override;
+	// Stores the skew created by the float -> u32 conversion
+	// to be applied at next conversion, so that there is no real skew.
+	float m_time_conversion_skew;
 	/*
-	 * Above: values under m_time_lock
-	 */
+	 * Above: values managed by m_time_floats_lock
+	*/
+
+	// Overriding the day-night ratio is useful for custom sky visuals
+	// lowest 32 bits store the overriden ratio, highest bit stores whether its enabled
+	Atomic<u64> m_day_night_ratio_override_storage;
 
 	/* TODO: Add a callback function so these can be updated when a setting
 	 *       changes.  At this point in time it doesn't matter (e.g. /set
@@ -135,7 +137,7 @@ protected:
 	bool m_cache_enable_shaders;
 
 private:
-	Mutex m_time_lock;
+	Mutex m_time_floats_lock;
 
 	DISABLE_CLASS_COPY(Environment);
 };