pactch to fix selective_ack

RESENDS_MAX_COUNT_v2.diff

--- J:/!/svn-uTP/utp.cpp.org	Fri Nov 30 20:12:44 2012
+++ J:/!/svn-uTP/utp.cpp	Mon Dec  3 22:09:56 2012
@@ -60,6 +60,11 @@
 // that hasn't been acked yet
 #define DUPLICATE_ACKS_BEFORE_RESEND 3
 
+// maximum number of resends SRS 11-30-2012
+// per BEP29 calculations limit is 2040 if so desired
+// RESENDS_MAX_COUNT never allowed to be 0
+#define RESENDS_MAX_COUNT 32
+
 #define DELAYED_ACK_BYTE_THRESHOLD 2400 // bytes
 #define DELAYED_ACK_TIME_THRESHOLD 100 // milliseconds
 
@@ -1499,8 +1504,10 @@
 	// resends is a stack of sequence numbers we need to resend. Since we
 	// iterate in reverse over the acked packets, at the end, the top packets
 	// are the ones we want to resend
-	int resends[32];
+	// RESENDS_MAX_COUNT SRS 11-30-2012
+	int resends[RESENDS_MAX_COUNT];
 	int nr = 0;
+	bool filled = false;
 
 	LOG_UTPV("0x%08x: Got EACK [%032b] base:%u", this, *(uint32*)mask, base);
 	do {
@@ -1573,6 +1580,12 @@
 			count >= DUPLICATE_ACKS_BEFORE_RESEND &&
 			duplicate_ack < DUPLICATE_ACKS_BEFORE_RESEND) {
 			resends[nr++] = v;
+			if (nr >= RESENDS_MAX_COUNT) {
+				// we have filled AT LEAST ONCE so start dumpimg the oldest, one at a time
+				// maybe again, as we re-fill
+				filled = true;
+				nr = 0;
+			}
 			LOG_UTPV("0x%08x: no ack for %u", this, v);
 		} else {
 			LOG_UTPV("0x%08x: not resending %u count:%d dup_ack:%u fast_resend_seq_nr:%u",
@@ -1580,22 +1593,43 @@
 		}
 	} while (--bits >= -1);
 
-	if (((base - 1 - fast_resend_seq_nr) & ACK_NR_MASK) < 256 &&
-		count >= DUPLICATE_ACKS_BEFORE_RESEND &&
-		duplicate_ack < DUPLICATE_ACKS_BEFORE_RESEND) {
+	if (((base - 1 - fast_resend_seq_nr) & ACK_NR_MASK) <= OUTGOING_BUFFER_MAX_SIZE &&
+		count >= DUPLICATE_ACKS_BEFORE_RESEND) {
 		// if we get enough duplicate acks to start
 		// resending, the first packet we should resend
 		// is base-1
-		resends[nr++] = base - 1;
+		resends[nr++] = (base - 1) & ACK_NR_MASK;
+		if (nr >= RESENDS_MAX_COUNT) {
+			// we have totally filled on the very last
+			// no need to reset
+			// no more new can come in, all previous over-fill gone
+			filled = false;
+		}
 	} else {
-		LOG_UTPV("0x%08x: not resending %u count:%d dup_ack:%u fast_resend_seq_nr:%u",
-				 this, base - 1, count, duplicate_ack, fast_resend_seq_nr);
+		LOG_UTPV("0x%08x: not resending %u count:%d dup_ack:%u fast_resend_seq_nr:%u nr:%d",
+				 this, base - 1, count, duplicate_ack, fast_resend_seq_nr, nr);
 	}
 
 	bool back_off = false;
 	int i = 0;
-	while (nr > 0) {
-		uint v = resends[--nr];
+	int bottom = 0;
+	int top = nr;
+	if ((top == 0) && filled) {
+		// exactly completely filled, but nothing pushed into over-fill
+		top = RESENDS_MAX_COUNT;
+		filled = false;
+	}
+	while (top > bottom) {
+		uint v = resends[--top];
+
+		// maybe next iteration begin to utilize what is left over before the last refill
+		if ((top == bottom) && filled) {
+		top = RESENDS_MAX_COUNT;
+		bottom = nr;
+		filled = false;
+		// iterate overfill only once at most
+		}
+
 		// don't consider the tail of 0:es to be lost packets
 		// only unacked packets with acked packets after should
 		// be considered lost

either revision will work.