src: fix negative nodeTiming milestone values

src/env.cc

@@ -670,8 +670,9 @@ Environment::Environment(IsolateData* isolate_data,
       stream_base_state_(isolate_,
                          StreamBase::kNumStreamBaseStateFields,
                          MAYBE_FIELD_PTR(env_info, stream_base_state)),
-      time_origin_(PERFORMANCE_NOW()),
-      time_origin_timestamp_(GetCurrentTimeInMicroseconds()),
+      time_origin_(performance::performance_process_start),
+      time_origin_timestamp_(performance::performance_process_start_timestamp),
+      environment_start_(PERFORMANCE_NOW()),
       flags_(flags),
       thread_id_(thread_id.id == static_cast<uint64_t>(-1)
                      ? AllocateEnvironmentThreadId().id
@@ -777,7 +778,7 @@ void Environment::InitializeMainContext(Local<Context> context,
   set_exiting(false);
 
   performance_state_->Mark(performance::NODE_PERFORMANCE_MILESTONE_ENVIRONMENT,
-                           time_origin_);
+                           environment_start_);
   performance_state_->Mark(performance::NODE_PERFORMANCE_MILESTONE_NODE_START,
                            per_process::node_start_time);
 

src/env.h

@@ -863,9 +863,11 @@ class Environment : public MemoryRetainer {
   inline HandleWrapQueue* handle_wrap_queue() { return &handle_wrap_queue_; }
   inline ReqWrapQueue* req_wrap_queue() { return &req_wrap_queue_; }
 
+  // https://w3c.github.io/hr-time/#dfn-time-origin
   inline uint64_t time_origin() {
     return time_origin_;
   }
+  // https://w3c.github.io/hr-time/#dfn-get-time-origin-timestamp
   inline double time_origin_timestamp() {
     return time_origin_timestamp_;
   }
@@ -1071,10 +1073,17 @@ class Environment : public MemoryRetainer {
 
   AliasedInt32Array stream_base_state_;
 
-  // https://w3c.github.io/hr-time/#dfn-time-origin
-  uint64_t time_origin_;
-  // https://w3c.github.io/hr-time/#dfn-get-time-origin-timestamp
-  double time_origin_timestamp_;
+  // As PerformanceNodeTiming is exposed in worker_threads, the per_process
+  // time origin is exposed in the worker threads. This is an intentional
+  // diverge from the HTML spec of web workers.
+  // Process start time from the monotonic clock. This should not be used as an
+  // absolute time, but only as a time relative to another monotonic clock time.
+  const uint64_t time_origin_;
+  // Process start timestamp from the wall clock. This is an absolute time
+  // exposed as `performance.timeOrigin`.
+  const double time_origin_timestamp_;
+  // This is the time when the environment is created.
+  const uint64_t environment_start_;
   std::unique_ptr<performance::PerformanceState> performance_state_;
 
   bool has_serialized_options_ = false;

src/node_perf.cc

@@ -38,6 +38,9 @@ using v8::Value;
 // Nanoseconds in a millisecond, as a float.
 #define NANOS_PER_MILLIS 1e6
 
+const uint64_t performance_process_start = PERFORMANCE_NOW();
+const double performance_process_start_timestamp =
+    GetCurrentTimeInMicroseconds();
 uint64_t performance_v8_start;
 
 PerformanceState::PerformanceState(Isolate* isolate,
@@ -271,7 +274,7 @@ void CreateELDHistogram(const FunctionCallbackInfo<Value>& args) {
 void GetTimeOrigin(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
   args.GetReturnValue().Set(
-      Number::New(args.GetIsolate(), env->time_origin() / 1e6));
+      Number::New(args.GetIsolate(), env->time_origin() / NANOS_PER_MILLIS));
 }
 
 void GetTimeOriginTimeStamp(const FunctionCallbackInfo<Value>& args) {

src/node_perf_common.h

@@ -20,6 +20,8 @@ namespace performance {
 
 // These occur before the environment is created. Cache them
 // here and add them to the milestones when the env is init'd.
+extern const uint64_t performance_process_start;
+extern const double performance_process_start_timestamp;
 extern uint64_t performance_v8_start;
 
 #define NODE_PERFORMANCE_MILESTONES(V)                                        \

test/parallel/test-perf-hooks-worker-timeorigin.js

@@ -9,10 +9,10 @@ require('worker_threads').parentPort.postMessage(performance.timeOrigin);
 `, { eval: true });
 
 w.on('message', common.mustCall((timeOrigin) => {
-  // Worker is created after this main context, it's
-  // `performance.timeOrigin` must be greater than this
-  // main context's.
-  assert.ok(timeOrigin > performance.timeOrigin);
+  // PerformanceNodeTiming exposes process milestones so the
+  // `performance.timeOrigin` in the `worker_threads.Worker` must be the start
+  // time of the process.
+  assert.strictEqual(timeOrigin, performance.timeOrigin);
 }));
 
 w.on('exit', common.mustCall((code) => {

test/parallel/test-performance-nodetiming.js

@@ -0,0 +1,39 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const { performance } = require('perf_hooks');
+
+const { nodeTiming } = performance;
+assert.strictEqual(nodeTiming.name, 'node');
+assert.strictEqual(nodeTiming.entryType, 'node');
+
+assert.strictEqual(nodeTiming.startTime, 0);
+const now = performance.now();
+assert.ok(nodeTiming.duration >= now);
+
+// Check that the nodeTiming milestone values are in the correct order and greater than 0.
+const keys = ['nodeStart', 'v8Start', 'environment', 'bootstrapComplete'];
+for (let idx = 0; idx < keys.length; idx++) {
+  if (idx === 0) {
+    assert.ok(nodeTiming[keys[idx]] >= 0);
+    continue;
+  }
+  assert.ok(nodeTiming[keys[idx]] > nodeTiming[keys[idx - 1]], `expect nodeTiming['${keys[idx]}'] > nodeTiming['${keys[idx - 1]}']`);
+}
+
+// loop milestones.
+assert.strictEqual(nodeTiming.idleTime, 0);
+assert.strictEqual(nodeTiming.loopStart, -1);
+assert.strictEqual(nodeTiming.loopExit, -1);
+
+setTimeout(common.mustCall(() => {
+  assert.ok(nodeTiming.idleTime >= 0);
+  assert.ok(nodeTiming.idleTime + nodeTiming.loopExit <= nodeTiming.duration);
+  assert.ok(nodeTiming.loopStart >= nodeTiming.bootstrapComplete);
+}, 1), 1);
+
+// Can not be wrapped in common.mustCall().
+process.on('exit', () => {
+  assert.ok(nodeTiming.loopExit > 0);
+});