Implement nativePerformanceNow to improve Profiler API results

Libraries/Core/InitializeCore.js

@@ -29,6 +29,7 @@
 const start = Date.now();
 
 require('./setUpGlobals');
+require('./setUpPerformance');
 require('./setUpSystrace');
 require('./setUpErrorHandling');
 require('./polyfillPromise');

Libraries/Core/setUpPerformance.js

@@ -0,0 +1,26 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+'use strict';
+
+if (!global.performance) {
+  global.performance = {};
+}
+
+/**
+ * Returns a double, measured in milliseconds.
+ * https://developer.mozilla.org/en-US/docs/Web/API/Performance/now
+ */
+if (typeof global.performance.now !== 'function') {
+  global.performance.now = function() {
+    const performanceNow = global.nativePerformanceNow || Date.now;
+    return performanceNow();
+  };
+}

Libraries/Performance/Systrace.js

@@ -87,11 +87,25 @@ const userTimingPolyfill = __DEV__
     }
   : null;
 
+function installPerformanceHooks(polyfill) {
+  if (polyfill) {
+    if (global.performance === undefined) {
+      global.performance = {};
+    }
+
+    Object.keys(polyfill).forEach(methodName => {
+      if (typeof global.performance[methodName] !== 'function') {
+        global.performance[methodName] = polyfill[methodName];
+      }
+    });
+  }
+}
+
 const Systrace = {
   installReactHook() {
     if (_enabled) {
       if (__DEV__) {
-        global.performance = userTimingPolyfill;
+        installPerformanceHooks(userTimingPolyfill);
       }
     }
     _canInstallReactHook = true;
@@ -107,10 +121,8 @@ const Systrace = {
           global.nativeTraceEndLegacy &&
             global.nativeTraceEndLegacy(TRACE_TAG_JS_VM_CALLS);
         }
-        if (_canInstallReactHook) {
-          if (enabled && global.performance === undefined) {
-            global.performance = userTimingPolyfill;
-          }
+        if (_canInstallReactHook && enabled) {
+          installPerformanceHooks(userTimingPolyfill);
         }
       }
       _enabled = enabled;

React/CxxBridge/JSCExecutorFactory.mm

@@ -25,6 +25,13 @@
         [NSString stringWithUTF8String:message.c_str()]);
     };
     react::bindNativeLogger(runtime, iosLoggingBinder);
+
+    react::PerformanceNow iosPerformanceNowBinder =[]() {
+        // CACurrentMediaTime() returns the current absolute time, in seconds
+        return CACurrentMediaTime() * 1000;
+    };
+    react::bindNativePerformanceNow(runtime, iosPerformanceNowBinder);
+
     // Wrap over the original runtimeInstaller
     if (runtimeInstaller) {
       runtimeInstaller(runtime);

ReactAndroid/src/main/java/com/facebook/hermes/reactexecutor/OnLoad.cpp

@@ -14,6 +14,7 @@
 #include <react/jni/JReactMarker.h>
 #include <react/jni/JSLogging.h>
 #include <react/jni/JavaScriptExecutorHolder.h>
+#include <react/jni/NativeTime.h>
 
 #include <memory>
 
@@ -47,6 +48,11 @@ static void installBindings(jsi::Runtime &runtime) {
       static_cast<void (*)(const std::string &, unsigned int)>(
           &reactAndroidLoggingHook);
   react::bindNativeLogger(runtime, androidLogger);
+
+  react::PerformanceNow androidNativePerformanceNow =
+       static_cast<double (*)()>(
+          &reactAndroidNativePerformanceNowHook);
+  react::bindNativePerformanceNow(runtime, androidNativePerformanceNow);
 }
 
 class HermesExecutorHolder

ReactAndroid/src/main/java/com/facebook/react/jscexecutor/OnLoad.cpp

@@ -12,6 +12,7 @@
 #include <react/jni/JSLogging.h>
 #include <react/jni/JavaScriptExecutorHolder.h>
 #include <react/jni/ReadableNativeMap.h>
+#include <react/jni/NativeTime.h>
 
 #include <memory>
 
@@ -30,6 +31,11 @@ class JSCExecutorFactory : public JSExecutorFactory {
           static_cast<void (*)(const std::string &, unsigned int)>(
               &reactAndroidLoggingHook);
       react::bindNativeLogger(runtime, androidLogger);
+
+      react::PerformanceNow androidNativePerformanceNow =
+          static_cast<double (*)()>(
+              &reactAndroidNativePerformanceNowHook);
+      react::bindNativePerformanceNow(runtime, androidNativePerformanceNow);
     };
     return std::make_unique<JSIExecutor>(
         jsc::makeJSCRuntime(),

ReactAndroid/src/main/jni/react/jni/NativeTime.cpp

@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <chrono>
+#include "NativeTime.h"
+
+namespace facebook {
+namespace react {
+
+double reactAndroidNativePerformanceNowHook() {
+  auto time = std::chrono::steady_clock::now();
+  auto duration = std::chrono::duration_cast<std::chrono::nanoseconds>(time.time_since_epoch()).count();
+
+  constexpr double NANOSECONDS_IN_MILLISECOND = 1000000.0;
+
+  return duration / NANOSECONDS_IN_MILLISECOND;
+}
+
+} // namespace react
+} // namespace facebook

ReactAndroid/src/main/jni/react/jni/NativeTime.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+namespace facebook {
+namespace react {
+
+double reactAndroidNativePerformanceNowHook();
+
+} // namespace react
+} // namespace facebook

ReactCommon/jsiexecutor/jsireact/JSIExecutor.cpp

@@ -417,5 +417,22 @@ void bindNativeLogger(Runtime &runtime, Logger logger) {
           }));
 }
 
+void bindNativePerformanceNow(Runtime &runtime, PerformanceNow performanceNow) {
+  runtime.global().setProperty(
+        runtime,
+        "nativePerformanceNow",
+        Function::createFromHostFunction(
+            runtime,
+            PropNameID::forAscii(runtime, "nativePerformanceNow"),
+            0,
+            [performanceNow = std::move(performanceNow)](
+                jsi::Runtime &runtime,
+                const jsi::Value &,
+                const jsi::Value *args,
+                size_t count) {
+                return Value(performanceNow());
+            }));
+}
+
 } // namespace react
 } // namespace facebook

ReactCommon/jsiexecutor/jsireact/JSIExecutor.h

@@ -135,5 +135,8 @@ class JSIExecutor : public JSExecutor {
 using Logger =
     std::function<void(const std::string &message, unsigned int logLevel)>;
 void bindNativeLogger(jsi::Runtime &runtime, Logger logger);
+
+using PerformanceNow = std::function<double()>;
+void bindNativePerformanceNow(jsi::Runtime &runtime, PerformanceNow performanceNow);
 } // namespace react
 } // namespace facebook