Add SwapMetricsObserverMac

content/browser/memory/swap_metrics_observer_mac.cc

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "content/browser/memory/swap_metrics_observer.h"
+#include "content/browser/memory/swap_metrics_observer_mac.h"
+
+#include <mach/mach.h>
+#include <mach/mach_vm.h>
+
+#include "base/mac/mach_logging.h"
+#include "base/metrics/histogram_macros.h"
 
 namespace content {
 
 // static
 SwapMetricsObserver* SwapMetricsObserver::GetInstance() {
-  // TODO(bashi): Implement SwapMetricsObserver for macOS.
-  return nullptr;
+  static SwapMetricsObserverMac* instance = new SwapMetricsObserverMac();
+  return instance;
+}
+
+SwapMetricsObserverMac::SwapMetricsObserverMac() : host_(mach_host_self()) {}
+
+SwapMetricsObserverMac::~SwapMetricsObserverMac() {}
+
+void SwapMetricsObserverMac::UpdateMetricsInternal(base::TimeDelta interval) {
+  vm_statistics64_data_t statistics;
+  mach_msg_type_number_t count = HOST_VM_INFO64_COUNT;
+  kern_return_t result =
+      host_statistics64(host_.get(), HOST_VM_INFO64,
+                        reinterpret_cast<host_info64_t>(&statistics), &count);
+  if (result != KERN_SUCCESS) {
+    MACH_DLOG(WARNING, result) << "host_statistics64";
+    Stop();
+    return;
+  }
+  DCHECK_EQ(HOST_VM_INFO64_COUNT, count);
+
+  double swapins = statistics.swapins - last_swapins_;
+  double swapouts = statistics.swapouts - last_swapouts_;
+  double decompressions = statistics.decompressions - last_decompressions_;
+  double compressions = statistics.compressions - last_compressions_;
+  last_swapins_ = statistics.swapins;
+  last_swapouts_ = statistics.swapouts;
+  last_decompressions_ = statistics.decompressions;
+  last_compressions_ = statistics.compressions;
+
+  if (interval.is_zero())
+    return;
+
+  UMA_HISTOGRAM_COUNTS_10000("Memory.Experimental.SwapInPerSecond",
+                             swapins / interval.InSecondsF());
+  UMA_HISTOGRAM_COUNTS_10000("Memory.Experimental.SwapOutPerSecond",
+                             swapouts / interval.InSecondsF());
+  UMA_HISTOGRAM_COUNTS_10000("Memory.Experimental.DecompressedPagesPerSecond",
+                             decompressions / interval.InSecondsF());
+  UMA_HISTOGRAM_COUNTS_10000("Memory.Experimental.CompressedPagesPerSecond",
+                             compressions / interval.InSecondsF());
 }
 
 }  // namespace content