timers: optimize `setImmediate()`

Save the setImmediate() callback arguments into an array instead of a
closure, and invoke the callback on the arguments from an optimizable
function.

  60% faster setImmediate with 0 args (15% if self-recursive)
  4x faster setImmediate with 1-3 args, 2x with > 3
  seems to be faster with less memory pressure when memory is tight

Changes:
- use L.create() to build faster lists
- use runCallback() from within tryOnImmediate()
- save the arguments and do not build closures for the callbacks

PR-URL: https://github.com/nodejs/node/pull/6436
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>

2 files changed, 8 insertions, 2 deletions

diff --git a/test/parallel/test-timers-immediate.js b/test/parallel/test-timers-immediate.js
index cd0a423f4d..d160adc998 100644
--- a/test/parallel/test-timers-immediate.js
+++ b/test/parallel/test-timers-immediate.js
@@ -5,6 +5,7 @@ var assert = require('assert');
 let immediateA = false;
 let immediateB = false;
 let immediateC = [];
+let immediateD = [];
 
 setImmediate(function() {
   try {
@@ -25,8 +26,13 @@ setImmediate(function(x, y, z) {
   immediateC = [x, y, z];
 }, 1, 2, 3);
 
+setImmediate(function(x, y, z, a, b) {
+  immediateD = [x, y, z, a, b];
+}, 1, 2, 3, 4, 5);
+
 process.on('exit', function() {
   assert.ok(immediateA, 'Immediate should happen after normal execution');
   assert.notStrictEqual(immediateB, true, 'immediateB should not fire');
   assert.deepStrictEqual(immediateC, [1, 2, 3], 'immediateC args should match');
+  assert.deepStrictEqual(immediateD, [1, 2, 3, 4, 5], '5 args should match');
 });
diff --git a/test/parallel/test-timers-linked-list.js b/test/parallel/test-timers-linked-list.js
index cdae64d344..4ec7770cfa 100644
--- a/test/parallel/test-timers-linked-list.js
+++ b/test/parallel/test-timers-linked-list.js
@@ -103,8 +103,8 @@ assert.equal(C, L.shift(list));
 // list
 assert.ok(L.isEmpty(list));
 
-var list2 = L.create();
-var list3 = L.create();
+const list2 = L.create();
+const list3 = L.create();
 assert.ok(L.isEmpty(list2));
 assert.ok(L.isEmpty(list3));
 assert.ok(list2 != list3);