lib: simplify nextTick() usage

This commit removes unnecessary nextTick() closures and adds some
shared nextTick() callbacks for better re-use.

PR-URL: https://github.com/nodejs/io.js/pull/1612
Reviewed-By: Yosuke Furukawa <yosuke.furukawa@gmail.com>
Reviewed-By: Brendan Ashworth <brendan.ashworth@me.com>

lib/_stream_writable.js

@@ -292,22 +292,16 @@ function doWrite(stream, state, writev, len, chunk, encoding, cb) {
 }
 
 function onwriteError(stream, state, sync, er, cb) {
+  --state.pendingcb;
   if (sync)
-    process.nextTick(onwriteErrorNT, state, cb, er);
+    process.nextTick(cb, er);
-  else {
+  else
-    state.pendingcb--;
     cb(er);
-  }
 
   stream._writableState.errorEmitted = true;
   stream.emit('error', er);
 }
 
-function onwriteErrorNT(state, cb, er) {
-  state.pendingcb--;
-  cb(er);
-}
-
 function onwriteStateUpdate(state) {
   state.writing = false;
   state.writecb = null;

lib/_tls_legacy.js

@@ -448,16 +448,16 @@ CryptoStream.prototype.destroy = function(err) {
   }
   this._opposite.destroy();
 
-  process.nextTick(destroyNT, this, err);
+  process.nextTick(destroyNT, this, err ? true : false);
 };
 
 
-function destroyNT(self, err) {
+function destroyNT(self, hadErr) {
   // Force EOF
   self.push(null);
 
   // Emit 'close' event
-  self.emit('close', err ? true : false);
+  self.emit('close', hadErr);
 }
 
 

lib/_tls_wrap.js

@@ -444,9 +444,7 @@ TLSSocket.prototype.renegotiate = function(options, callback) {
   }
   if (!this._handle.renegotiate()) {
     if (callback) {
-      process.nextTick(function() {
+      process.nextTick(callback, new Error('Failed to renegotiate'));
-        callback(new Error('Failed to renegotiate'));
-      });
     }
     return false;
   }

lib/dgram.js

@@ -320,19 +320,14 @@ Socket.prototype.send = function(buffer,
                                   !!callback);
       if (err && callback) {
         // don't emit as error, dgram_legacy.js compatibility
-        process.nextTick(sendEmitErrorNT, err, address, port, callback);
+        var ex = exceptionWithHostPort(err, 'send', address, port);
+        process.nextTick(callback, ex);
       }
     }
   });
 };
 
 
-function sendEmitErrorNT(err, address, port, callback) {
-  var ex = exceptionWithHostPort(err, 'send', address, port);
-  callback(ex);
-}
-
-
 function afterSend(err) {
   if (err) {
     err = exceptionWithHostPort(err, 'send', this.address, this.port);

lib/dns.js

@@ -61,17 +61,16 @@ function makeAsync(callback) {
       // The API already returned, we can invoke the callback immediately.
       callback.apply(null, arguments);
     } else {
-      process.nextTick(callMakeAsyncCbNT, callback, arguments);
+      var args = new Array(arguments.length + 1);
+      args[0] = callback;
+      for (var i = 1, a = 0; a < arguments.length; ++i, ++a)
+        args[i] = arguments[a];
+      process.nextTick.apply(null, args);
     }
   };
 }
 
 
-function callMakeAsyncCbNT(callback, args) {
-  callback.apply(null, args);
-}
-
-
 function onlookup(err, addresses) {
   if (err) {
     return this.callback(errnoException(err, 'getaddrinfo', this.hostname));

lib/net.js

@@ -268,14 +268,10 @@ function writeAfterFIN(chunk, encoding, cb) {
   // TODO: defer error events consistently everywhere, not just the cb
   self.emit('error', er);
   if (typeof cb === 'function') {
-    process.nextTick(writeAfterFINNT, cb, er);
+    process.nextTick(cb, er);
   }
 }
 
-function writeAfterFINNT(cb, er) {
-  cb(er);
-}
-
 exports.Socket = Socket;
 exports.Stream = Socket; // Legacy naming.
 
@@ -442,9 +438,7 @@ Socket.prototype._destroy = function(exception, cb) {
   function fireErrorCallbacks() {
     if (cb) cb(exception);
     if (exception && !self._writableState.errorEmitted) {
-      process.nextTick(function() {
+      process.nextTick(emitErrorNT, self, exception);
-        self.emit('error', exception);
-      });
       self._writableState.errorEmitted = true;
     }
   }
@@ -962,7 +956,10 @@ function lookupAndConnect(self, options) {
       // immediately calls net.Socket.connect() on it (that's us).
       // There are no event listeners registered yet so defer the
       // error event to the next tick.
-      process.nextTick(connectErrorNT, self, err, options);
+      err.host = options.host;
+      err.port = options.port;
+      err.message = err.message + ' ' + options.host + ':' + options.port;
+      process.nextTick(connectErrorNT, self, err);
     } else {
       self._unrefTimer();
       connect(self,
@@ -976,10 +973,7 @@ function lookupAndConnect(self, options) {
 }
 
 
-function connectErrorNT(self, err, options) {
+function connectErrorNT(self, err) {
-  err.host = options.host;
-  err.port = options.port;
-  err.message = err.message + ' ' + options.host + ':' + options.port;
   self.emit('error', err);
   self._destroy();
 }
@@ -1205,9 +1199,7 @@ Server.prototype._listen2 = function(address, port, addressType, backlog, fd) {
 
     if (typeof rval === 'number') {
       var error = exceptionWithHostPort(rval, 'listen', address, port);
-      process.nextTick(function() {
+      process.nextTick(emitErrorNT, self, error);
-        self.emit('error', error);
-      });
       return;
     }
     self._handle = rval;
@@ -1222,9 +1214,7 @@ Server.prototype._listen2 = function(address, port, addressType, backlog, fd) {
     var ex = exceptionWithHostPort(err, 'listen', address, port);
     self._handle.close();
     self._handle = null;
-    process.nextTick(function() {
+    process.nextTick(emitErrorNT, self, ex);
-      self.emit('error', ex);
-    });
     return;
   }
 
@@ -1239,6 +1229,11 @@ Server.prototype._listen2 = function(address, port, addressType, backlog, fd) {
 };
 
 
+function emitErrorNT(self, err) {
+  self.emit('error', err);
+}
+
+
 function emitListeningNT(self) {
   // ensure handle hasn't closed
   if (self._handle)
@@ -1412,9 +1407,7 @@ function onconnection(err, clientHandle) {
 
 Server.prototype.getConnections = function(cb) {
   function end(err, connections) {
-    process.nextTick(function() {
+    process.nextTick(cb, err, connections);
-      cb(err, connections);
-    });
   }
 
   if (!this._usingSlaves) {
@@ -1493,11 +1486,14 @@ Server.prototype._emitCloseIfDrained = function() {
     return;
   }
 
-  process.nextTick(function() {
+  process.nextTick(emitCloseNT, self);
+};
+
+
+function emitCloseNT(self) {
   debug('SERVER: emit close');
   self.emit('close');
-  });
+}
-};
 
 
 Server.prototype.listenFD = util.deprecate(function(fd, type) {

lib/timers.js

@@ -97,9 +97,7 @@ function listOnTimeout() {
           // when the timeout threw its exception.
           var oldDomain = process.domain;
           process.domain = null;
-          process.nextTick(function() {
+          process.nextTick(listOnTimeoutNT, list);
-            list[kOnTimeout]();
-          });
           process.domain = oldDomain;
         }
       }
@@ -113,6 +111,11 @@ function listOnTimeout() {
 }
 
 
+function listOnTimeoutNT(list) {
+  list[kOnTimeout]();
+}
+
+
 const unenroll = exports.unenroll = function(item) {
   L.remove(item);