node: improve nextTick performance

This commit uses separate functions to isolate deopts caused by
try-catches and avoids fn.apply() for callbacks with small numbers
of arguments.

These changes improve performance by ~1-40% in the various
nextTick benchmarks.

PR-URL: https://github.com/iojs/io.js/pull/1571
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>

2 files changed, 85 insertions, 0 deletions

diff --git a/benchmark/misc/next-tick-breadth-args.js b/benchmark/misc/next-tick-breadth-args.js
new file mode 100644
index 0000000000..e617fcfc82
--- /dev/null
+++ b/benchmark/misc/next-tick-breadth-args.js
@@ -0,0 +1,37 @@
+'use strict';
+
+var common = require('../common.js');
+var bench = common.createBenchmark(main, {
+  millions: [2]
+});
+
+function main(conf) {
+  var N = +conf.millions * 1e6;
+  var n = 0;
+
+  function cb1(arg1) {
+    n++;
+    if (n === N)
+      bench.end(n / 1e6);
+  }
+  function cb2(arg1, arg2) {
+    n++;
+    if (n === N)
+      bench.end(n / 1e6);
+  }
+  function cb3(arg1, arg2, arg3) {
+    n++;
+    if (n === N)
+      bench.end(n / 1e6);
+  }
+
+  bench.start();
+  for (var i = 0; i < N; i++) {
+    if (i % 3 === 0)
+      process.nextTick(cb3, 512, true, null);
+    else if (i % 2 === 0)
+      process.nextTick(cb2, false, 5.1);
+    else
+      process.nextTick(cb1, 0);
+  }
+}
diff --git a/benchmark/misc/next-tick-depth-args.js b/benchmark/misc/next-tick-depth-args.js
new file mode 100644
index 0000000000..066b483785
--- /dev/null
+++ b/benchmark/misc/next-tick-depth-args.js
@@ -0,0 +1,48 @@
+'use strict';
+
+var common = require('../common.js');
+var bench = common.createBenchmark(main, {
+  millions: [2]
+});
+
+process.maxTickDepth = Infinity;
+
+function main(conf) {
+  var n = +conf.millions * 1e6;
+
+  function cb3(arg1, arg2, arg3) {
+    if (--n) {
+      if (n % 3 === 0)
+        process.nextTick(cb3, 512, true, null);
+      else if (n % 2 === 0)
+        process.nextTick(cb2, false, 5.1);
+      else
+        process.nextTick(cb1, 0);
+    } else
+      bench.end(+conf.millions);
+  }
+  function cb2(arg1, arg2) {
+    if (--n) {
+      if (n % 3 === 0)
+        process.nextTick(cb3, 512, true, null);
+      else if (n % 2 === 0)
+        process.nextTick(cb2, false, 5.1);
+      else
+        process.nextTick(cb1, 0);
+    } else
+      bench.end(+conf.millions);
+  }
+  function cb1(arg1) {
+    if (--n) {
+      if (n % 3 === 0)
+        process.nextTick(cb3, 512, true, null);
+      else if (n % 2 === 0)
+        process.nextTick(cb2, false, 5.1);
+      else
+        process.nextTick(cb1, 0);
+    } else
+      bench.end(+conf.millions);
+  }
+  bench.start();
+  process.nextTick(cb1, true);
+}