Added interval and count options to setKeepAlive.

The OS defaults for these are too extreme if you want to run a
chat server and know if someone disconnects. Changes go along
with libuv changes.

doc/api/net.markdown

@@ -388,16 +388,19 @@ algorithm, they buffer data before sending it off. Setting `true` for
 `noDelay` will immediately fire off data each time `socket.write()` is called.
 `noDelay` defaults to `true`.
 
-### socket.setKeepAlive([enable], [initialDelay])
+### socket.setKeepAlive([enable], [initialDelay], [probeInterval], [failureCount])
 
-Enable/disable keep-alive functionality, and optionally set the initial
-delay before the first keepalive probe is sent on an idle socket.
+Enable/disable keep-alive functionality, and optionally set keep-alive options.
+Options default to `0`, which leaves the value unchanged from the default
+(or previous) setting.
 `enable` defaults to `false`.
 
 Set `initialDelay` (in milliseconds) to set the delay between the last
-data packet received and the first keepalive probe. Setting 0 for
-initialDelay will leave the value unchanged from the default
-(or previous) setting. Defaults to `0`.
+data packet received and the first keepalive probe.
+Set `probeInterval` (in milliseconds) to set the interval between the
+keep-alive probes sent after the initial probe.
+Set `failureCount` to set the maximum number of probes that can fail before
+the OS closes the connection. Ignored on Windows.
 
 ### socket.address()
 

lib/net.js

@@ -294,9 +294,9 @@ Socket.prototype.setNoDelay = function(enable) {
 };
 
 
-Socket.prototype.setKeepAlive = function(setting, msecs) {
+Socket.prototype.setKeepAlive = function(setting, msecs, interval, count) {
   if (this._handle && this._handle.setKeepAlive)
-    this._handle.setKeepAlive(setting, ~~(msecs / 1000));
+    this._handle.setKeepAlive(setting, ~~(msecs / 1000), ~~(interval / 1000), ~~count);
 };
 
 

src/tcp_wrap.cc

@@ -230,8 +230,10 @@ Handle<Value> TCPWrap::SetKeepAlive(const Arguments& args) {
 
   int enable = args[0]->Int32Value();
   unsigned int delay = args[1]->Uint32Value();
+  unsigned int interval = args[2]->Uint32Value();
+  unsigned int count = args[3]->Uint32Value();
 
-  int r = uv_tcp_keepalive(&wrap->handle_, enable, delay);
+  int r = uv_tcp_keepalive(&wrap->handle_, enable, delay, interval, count);
   if (r)
     SetErrno(uv_last_error(uv_default_loop()));