src: add tracing controller

This commit adds support for trace-event tracing to Node.js. It provides
a mechanism to centralize tracing information generated by V8, Node
core, and userspace code. It includes:

 - A trace writer responsible for serializing traces and cycling the
   output files so that no individual file becomes to large.
 - A buffer for aggregating traces to allow for batched flushes.
 - An agent which initializes the tracing controller and ensures that
   trace serialization is done on a separate thread.
 - A set of macros for generating trace events.
 - Tests and documentation.

Author: Raymond Kang <raymondksi@gmail.com>
Author: Kelvin Jin <kelvinjin@google.com>
Author: Matthew Loring <mattloring@google.com>
Author: Jason Ginchereau <jasongin@microsoft.com>

PR-URL: https://github.com/nodejs/node/pull/11106
Reviewed-By: Josh Gavant <josh.gavant@outlook.com>

1 files changed, 35 insertions, 0 deletions

diff --git a/test/parallel/test-trace-event.js b/test/parallel/test-trace-event.js
new file mode 100644
index 00000000000..18734705834
--- /dev/null
+++ b/test/parallel/test-trace-event.js
@@ -0,0 +1,35 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const cp = require('child_process');
+const fs = require('fs');
+
+const CODE = 'for (var i = 0; i < 100000; i++) { "test" + i }';
+const FILE_NAME = 'node_trace.1.log';
+
+common.refreshTmpDir();
+process.chdir(common.tmpDir);
+
+const proc_no_categories = cp.spawn(process.execPath,
+  [ '--trace-events-enabled', '--trace-event-categories', '""', '-e', CODE ]);
+
+proc_no_categories.once('exit', common.mustCall(() => {
+  assert(!common.fileExists(FILE_NAME));
+
+  const proc = cp.spawn(process.execPath,
+  [ '--trace-events-enabled', '-e', CODE ]);
+
+  proc.once('exit', common.mustCall(() => {
+    assert(common.fileExists(FILE_NAME));
+    fs.readFile(FILE_NAME, (err, data) => {
+      const traces = JSON.parse(data.toString()).traceEvents;
+      assert(traces.length > 0);
+      // Values that should be present on all runs to approximate correctness.
+      assert(traces.some((trace) => { return trace.pid === proc.pid; }));
+      assert(traces.some((trace) => { return trace.cat === 'v8'; }));
+      assert(traces.some((trace) => {
+        return trace.name === 'V8.ScriptCompiler';
+      }));
+    });
+  }));
+}));