Improves minimum RTT probing, adds packet pacing and refactors the code.

tcp_roccet.h

@@ -7,6 +7,16 @@
 
 #include <linux/math64.h>
 
+/* State in which roccet currently opperates */
+enum roccet_state {
+  LAUNCH,
+  ORBITER,
+  RTT_PROBE,
+  RTT_PROBE_REFILL,
+  DRAIN
+};
+
+/* TCP ROCCET helper type, storing data related to ack counting */
 struct ack_rate {
 	u32 last_rate;	/* Last ACK-rate */
 	u32 last_rate_time;	/* Timestamp of the last ACK-rate */
@@ -14,8 +24,8 @@ struct ack_rate {
 	u32 cnt;	/* Used for counting acks */
 };
 
-/* Based on the BICTCP struct with additions specific
- * for the ROCCET-Algorithm
+/* TCP ROCCET struct based on the original BICTCP struct with
+ * additions specific to the ROCCET-Algorithm.
  */
 struct roccettcp {
 	u32 cnt;		/* increase cwnd by 1 after ACKs */
@@ -30,7 +40,7 @@ struct roccettcp {
 	u32 epoch_start;	/* beginning of an epoch */
 	u32 ack_cnt;		/* number of acks */
 	u32 tcp_cwnd;		/* estimated tcp cwnd */
-	u32 curr_rtt;		/* the minimum rtt of current round */
+	u32 curr_rtt;		/* last sample rtt of current round */
 
 	u32 roccet_last_event_time_us;	/* The last time ROCCET was
 					 * triggered
@@ -39,11 +49,15 @@ struct roccettcp {
 	u32 curr_min_rtt;	/* The current observed minRTT */
 	u32 next_min_rtt_probe; /* Next time to probe the minRTT */
 	u32 probe_min_rtt_until;	/* End of minRTT probing period */
-	u32 cwnd_before_min_rtt_probe; /* cwnd before min RTT probeing */
+	u32 refill_until;       /* End of pipe refill after minRTT probe */
+	u32 cwnd_before_min_rtt_probe;	/* cwnd before min RTT probeing */
 	u32 curr_srrtt;		/* srRTT calculated based on the latest ACK */
 	u32 next_srrtt_check;	/* Next check for srRTT */
 	struct ack_rate ack_rate;	/* The last and the current ACK rate */
-	u32 last_rtt;			/* Used for jitter calculation */
+	u32 last_rtt;			/* sample rtt of previous round.
+					 * Used for jitter calculation
+					 */
+    enum roccet_state state; /* State in which roccet currently opperates */
 };
 
 #endif /* __TCP_ROCCET_H */