started polling the gpu usage

ci/licenses_golden/licenses_flutter

@@ -903,6 +903,7 @@ FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterView.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterViewController.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterViewControllerTest.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/FlutterViewController_Internal.h
+FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/IOKit.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/SemanticsObject.h
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/SemanticsObject.mm
 FILE: ../../../flutter/shell/platform/darwin/ios/framework/Source/SemanticsObjectTest.mm

shell/platform/darwin/ios/BUILD.gn

@@ -141,13 +141,18 @@ source_set("flutter_framework_source") {
   public_configs = [ "//flutter:config" ]
 
   libs = [
+    "AudioToolbox.framework",
     "CoreMedia.framework",
     "CoreVideo.framework",
-    "UIKit.framework",
     "OpenGLES.framework",
-    "AudioToolbox.framework",
     "QuartzCore.framework",
+    "UIKit.framework",
   ]
+  if (flutter_runtime_mode == "profile" || flutter_runtime_mode == "debug") {
+    # This is required by the profiler_metrics_ios.mm to get GPU statistics.
+    # Usage in release builds will cause rejection from the App Store.
+    libs += [ "IOKit.framework" ]
+  }
 }
 
 ios_test_flutter_path = rebase_path("$root_out_dir/libios_test_flutter.dylib")

shell/platform/darwin/ios/framework/Source/IOKit.h

@@ -0,0 +1,108 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// These declarations are an amalgamation of different headers whose
+// symbols exist in IOKit.framework.  The headers have been removed
+// from the iOS SDKs but all the functions are documented here:
+//  * https://developer.apple.com/documentation/iokit/iokitlib_h?language=objc
+//  * https://developer.apple.com/documentation/iokit/iokit_functions?language=objc
+//  * file:///Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/IOKit.framework/Versions/A/Headers/IOKitLib.h
+
+#if FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_DEBUG || \
+    FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_PROFILE
+#ifndef FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_IOKIT_H_
+#define FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_IOKIT_H_
+
+#if __cplusplus
+extern "C" {
+#endif  // __cplusplus
+
+#include <CoreFoundation/CoreFoundation.h>
+#include <mach/mach.h>
+#include <stdint.h>
+
+#define IOKIT
+#include <device/device_types.h>
+
+static const char* kIOServicePlane = "IOService";
+
+typedef io_object_t io_registry_entry_t;
+typedef io_object_t io_service_t;
+typedef io_object_t io_connect_t;
+typedef io_object_t io_iterator_t;
+
+enum {
+  kIOReturnSuccess = 0,
+};
+
+extern const mach_port_t kIOMasterPortDefault;
+
+kern_return_t IOObjectRetain(io_object_t object);
+kern_return_t IOObjectRelease(io_object_t object);
+boolean_t IOObjectConformsTo(io_object_t object, const io_name_t name);
+uint32_t IOObjectGetKernelRetainCount(io_object_t object);
+kern_return_t IOObjectGetClass(io_object_t object, io_name_t name);
+CFStringRef IOObjectCopyClass(io_object_t object);
+CFStringRef IOObjectCopySuperclassForClass(CFStringRef name);
+CFStringRef IOObjectCopyBundleIdentifierForClass(CFStringRef name);
+
+io_registry_entry_t IORegistryGetRootEntry(mach_port_t master);
+kern_return_t IORegistryEntryGetName(io_registry_entry_t entry, io_name_t name);
+kern_return_t IORegistryEntryGetRegistryEntryID(io_registry_entry_t entry,
+                                                uint64_t* entryID);
+kern_return_t IORegistryEntryGetPath(io_registry_entry_t entry,
+                                     const io_name_t plane,
+                                     io_string_t path);
+kern_return_t IORegistryEntryGetProperty(io_registry_entry_t entry,
+                                         const io_name_t name,
+                                         io_struct_inband_t buffer,
+                                         uint32_t* size);
+kern_return_t IORegistryEntryCreateCFProperties(
+    io_registry_entry_t entry,
+    CFMutableDictionaryRef* properties,
+    CFAllocatorRef allocator,
+    uint32_t options);
+CFTypeRef IORegistryEntryCreateCFProperty(io_registry_entry_t entry,
+                                          CFStringRef key,
+                                          CFAllocatorRef allocator,
+                                          uint32_t options);
+kern_return_t IORegistryEntrySetCFProperties(io_registry_entry_t entry,
+                                             CFTypeRef properties);
+
+kern_return_t IORegistryCreateIterator(mach_port_t master,
+                                       const io_name_t plane,
+                                       uint32_t options,
+                                       io_iterator_t* it);
+kern_return_t IORegistryEntryCreateIterator(io_registry_entry_t entry,
+                                            const io_name_t plane,
+                                            uint32_t options,
+                                            io_iterator_t* it);
+kern_return_t IORegistryEntryGetChildIterator(io_registry_entry_t entry,
+                                              const io_name_t plane,
+                                              io_iterator_t* it);
+kern_return_t IORegistryEntryGetParentIterator(io_registry_entry_t entry,
+                                               const io_name_t plane,
+                                               io_iterator_t* it);
+io_object_t IOIteratorNext(io_iterator_t it);
+boolean_t IOIteratorIsValid(io_iterator_t it);
+void IOIteratorReset(io_iterator_t it);
+
+CFMutableDictionaryRef IOServiceMatching(const char* name) CF_RETURNS_RETAINED;
+CFMutableDictionaryRef IOServiceNameMatching(const char* name)
+    CF_RETURNS_RETAINED;
+io_service_t IOServiceGetMatchingService(mach_port_t master,
+                                         CFDictionaryRef matching
+                                             CF_RELEASES_ARGUMENT);
+kern_return_t IOServiceGetMatchingServices(mach_port_t master,
+                                           CFDictionaryRef matching
+                                               CF_RELEASES_ARGUMENT,
+                                           io_iterator_t* it);
+
+#if __cplusplus
+}
+#endif  // __cplusplus
+
+#endif  // FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_IOKIT_H_
+#endif  // defined(FLUTTER_RUNTIME_MODE_DEBUG) ||
+        // defined(FLUTTER_RUNTIME_MODE_PROFILE)

shell/platform/darwin/ios/framework/Source/profiler_metrics_ios.mm

@@ -3,6 +3,8 @@
 // found in the LICENSE file.
 
 #include "flutter/shell/platform/darwin/ios/framework/Source/profiler_metrics_ios.h"
+#import <Foundation/Foundation.h>
+#import "IOKit.h"
 
 namespace {
 
@@ -28,9 +30,126 @@
 }
 
 namespace flutter {
+namespace {
+
+#if FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_DEBUG || \
+    FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_PROFILE
+
+template <typename T>
+T ClearValue() {
+  return nullptr;
+}
+
+template <>
+io_object_t ClearValue<io_object_t>() {
+  return 0;
+}
+
+template <typename T>
+/// Generic RAII wrapper like unique_ptr but gives access to its handle.
+class Scoped {
+ public:
+  typedef void (*Deleter)(T);
+  explicit Scoped(Deleter deleter) : object_(ClearValue<T>()), deleter_(deleter) {}
+  Scoped(T object, Deleter deleter) : object_(object), deleter_(deleter) {}
+  ~Scoped() {
+    if (object_) {
+      deleter_(object_);
+    }
+  }
+  T* handle() {
+    if (object_) {
+      deleter_(object_);
+      object_ = ClearValue<T>();
+    }
+    return &object_;
+  }
+  T get() { return object_; }
+  void reset(T new_value) {
+    if (object_) {
+      deleter_(object_);
+    }
+    object_ = new_value;
+  }
+
+ private:
+  FML_DISALLOW_COPY_ASSIGN_AND_MOVE(Scoped);
+  T object_;
+  Deleter deleter_;
+};
+
+void DeleteCF(CFMutableDictionaryRef value) {
+  CFRelease(value);
+}
+
+void DeleteIO(io_object_t value) {
+  IOObjectRelease(value);
+}
+
+std::optional<GpuUsageInfo> FindGpuUsageInfo(io_iterator_t iterator) {
+  for (Scoped<io_registry_entry_t> regEntry(IOIteratorNext(iterator), DeleteIO); regEntry.get();
+       regEntry.reset(IOIteratorNext(iterator))) {
+    Scoped<CFMutableDictionaryRef> serviceDictionary(DeleteCF);
+    if (IORegistryEntryCreateCFProperties(regEntry.get(), serviceDictionary.handle(),
+                                          kCFAllocatorDefault, kNilOptions) != kIOReturnSuccess) {
+      continue;
+    }
+
+    NSDictionary* dictionary =
+        ((__bridge NSDictionary*)serviceDictionary.get())[@"PerformanceStatistics"];
+    NSNumber* utilization = dictionary[@"Device Utilization %"];
+    if (utilization) {
+      return (GpuUsageInfo){.percent_usage = [utilization doubleValue]};
+    }
+  }
+  return std::nullopt;
+}
+
+[[maybe_unused]] std::optional<GpuUsageInfo> FindSimulatorGpuUsageInfo() {
+  Scoped<io_iterator_t> iterator(DeleteIO);
+  if (IOServiceGetMatchingServices(kIOMasterPortDefault, IOServiceNameMatching("IntelAccelerator"),
+                                   iterator.handle()) == kIOReturnSuccess) {
+    return FindGpuUsageInfo(iterator.get());
+  }
+  return std::nullopt;
+}
+
+[[maybe_unused]] std::optional<GpuUsageInfo> FindDeviceGpuUsageInfo() {
+  Scoped<io_iterator_t> iterator(DeleteIO);
+  if (IOServiceGetMatchingServices(kIOMasterPortDefault, IOServiceNameMatching("sgx"),
+                                   iterator.handle()) == kIOReturnSuccess) {
+    for (Scoped<io_registry_entry_t> regEntry(IOIteratorNext(iterator.get()), DeleteIO);
+         regEntry.get(); regEntry.reset(IOIteratorNext(iterator.get()))) {
+      Scoped<io_iterator_t> innerIterator(DeleteIO);
+      if (IORegistryEntryGetChildIterator(regEntry.get(), kIOServicePlane,
+                                          innerIterator.handle()) == kIOReturnSuccess) {
+        std::optional<GpuUsageInfo> result = FindGpuUsageInfo(innerIterator.get());
+        if (result.has_value()) {
+          return result;
+        }
+      }
+    }
+  }
+  return std::nullopt;
+}
+
+#endif  // FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_DEBUG ||
+        // FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_PROFILE
+
+std::optional<GpuUsageInfo> PollGpuUsage() {
+#if (FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_RELEASE || \
+     FLUTTER_RUNTIME_MODE == FLUTTER_RUNTIME_MODE_JIT_RELEASE)
+  return std::nullopt;
+#elif TARGET_IPHONE_SIMULATOR
+  return FindSimulatorGpuUsageInfo();
+#elif TARGET_OS_IOS
+  return FindDeviceGpuUsageInfo();
+#endif  // TARGET_IPHONE_SIMULATOR
+}
+}  // namespace
 
 ProfileSample ProfilerMetricsIOS::GenerateSample() {
-  return {.cpu_usage = CpuUsage(), .memory_usage = MemoryUsage()};
+  return {.cpu_usage = CpuUsage(), .memory_usage = MemoryUsage(), .gpu_usage = PollGpuUsage()};
 }
 
 std::optional<CpuUsageInfo> ProfilerMetricsIOS::CpuUsage() {

shell/profiling/sampling_profiler.cc

@@ -54,6 +54,12 @@ void SamplingProfiler::SampleRepeatedly(fml::TimeDelta task_delay) const {
                                "owned_shared_memory_usage",
                                owned_shared_memory_usage.c_str());
         }
+        if (usage.gpu_usage) {
+          std::string gpu_usage =
+              std::to_string(usage.gpu_usage->percent_usage);
+          TRACE_EVENT_INSTANT1("flutter::profiling", "GpuUsage", "gpu_usage",
+                               gpu_usage.c_str());
+        }
         profiler->SampleRepeatedly(task_delay);
       },
       task_delay);

shell/profiling/sampling_profiler.h

@@ -42,6 +42,13 @@ struct MemoryUsageInfo {
   double owned_shared_memory_usage;
 };
 
+/**
+ * @brief Polled information related to the usage of the GPU.
+ */
+struct GpuUsageInfo {
+  double percent_usage;
+};
+
 /**
  * @brief Container for the metrics we collect during each run of `Sampler`.
  * This currently holds `CpuUsageInfo` and `MemoryUsageInfo` but the intent
@@ -52,6 +59,7 @@ struct MemoryUsageInfo {
 struct ProfileSample {
   std::optional<CpuUsageInfo> cpu_usage;
   std::optional<MemoryUsageInfo> memory_usage;
+  std::optional<GpuUsageInfo> gpu_usage;
 };
 
 /**