From fe79ac593cfc7b6cbda38db74a8e5f5be3d6cbd7 Mon Sep 17 00:00:00 2001
From: crs <cschoeneman@gmail.com>
Date: Sun, 13 May 2001 12:43:16 +0000
Subject: [PATCH] more fixes to reduce latency.  nagle agorithm doesn't seem to
 stay off on a socket on linux because a connection clearly doesn't send data
 as often as possible.  will have to implement a UDP socket to reduce overhead
 and avoid these delays.  wanted to do that anyway.

---
 CUnixTCPSocket.cpp | 20 ++++++++++++++------
 CUnixTCPSocket.h   |  3 +++
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/CUnixTCPSocket.cpp b/CUnixTCPSocket.cpp
index 99cd1ecd..ed5d2202 100644
--- a/CUnixTCPSocket.cpp
+++ b/CUnixTCPSocket.cpp
@@ -31,12 +31,8 @@ CUnixTCPSocket::CUnixTCPSocket() : m_fd(-1),
 		throw XSocketCreate(::strerror(errno));
 	}
 
-	// turn off Nagle algorithm.  we send lots of really short messages.
-	struct protoent* p = getprotobyname("tcp");
-	if (p) {
-		int on = 1;
-		setsockopt(m_fd, p->p_proto, TCP_NODELAY, &on, sizeof(on));
-	}
+	// always send immediately
+	setNoDelay();
 }
 
 CUnixTCPSocket::CUnixTCPSocket(int fd) : m_fd(fd),
@@ -44,6 +40,7 @@ CUnixTCPSocket::CUnixTCPSocket(int fd) : m_fd(fd),
 								m_addedJobs(false)
 {
 	assert(m_fd != -1);
+	setNoDelay();
 }
 
 CUnixTCPSocket::~CUnixTCPSocket()
@@ -268,3 +265,14 @@ void					CUnixTCPSocket::write(
 		numBytes -= n;
 	}
 }
+
+void					CUnixTCPSocket::setNoDelay()
+{
+	// turn off Nagle algorithm.  we send lots of really short messages
+	// so we'll accept the (much) larger overhead to reduce latency.
+	struct protoent* p = getprotobyname("tcp");
+	if (p) {
+		int on = 1;
+		setsockopt(m_fd, p->p_proto, TCP_NODELAY, &on, sizeof(on));
+	}
+}
diff --git a/CUnixTCPSocket.h b/CUnixTCPSocket.h
index ac8d0a34..0a04c5c4 100644
--- a/CUnixTCPSocket.h
+++ b/CUnixTCPSocket.h
@@ -23,6 +23,9 @@ class CUnixTCPSocket : public CSocket {
   private:
 	CUnixTCPSocket(int);
 
+	// disable Nagle algorithm
+	void				setNoDelay();
+
 	// callbacks for read/write events
 	void				readCB();
 	void				writeCB();