[GRC] Process Coordination Unit support for Global Resource Controller

services/resource_coordinator/coordination_unit/process_coordination_unit_impl.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 "services/resource_coordinator/coordination_unit/process_coordination_unit_impl.h"
+#include "base/process/process_handle.h"
+#include "base/process/process_metrics.h"
+#include "base/time/time.h"
+#include "services/resource_coordinator/public/cpp/coordination_unit_id.h"
+#include "services/service_manager/public/cpp/service_context_ref.h"
+
+#if defined(OS_MACOSX)
+#include "services/service_manager/public/cpp/standalone_service/mach_broker.h"
+#endif
+
+namespace resource_coordinator {
+
+namespace {
+
+const int kCPUProfilingIntervalInSeconds = 5;
+
+}  // namespace
+
+ProcessCoordinationUnitImpl::ProcessCoordinationUnitImpl(
+    const CoordinationUnitID& id,
+    std::unique_ptr<service_manager::ServiceContextRef> service_ref)
+    : CoordinationUnitImpl(id, std::move(service_ref)), cpu_usage_(-1.0) {
+  // ProcessCoordinationUnit ids should correspond to its pid
+  base::ProcessHandle pid = id.id;
+
+#if defined(OS_MACOSX)
+  process_metrics_ = base::ProcessMetrics::CreateProcessMetrics(
+      pid, service_manager::MachBroker::GetInstance()->port_provider());
+#else
+  process_metrics_ = base::ProcessMetrics::CreateProcessMetrics(pid);
+#endif
+
+  ScheduleProcessCPUProfiling(base::TimeDelta());
+}
+
+ProcessCoordinationUnitImpl::~ProcessCoordinationUnitImpl() {}
+
+void ProcessCoordinationUnitImpl::ScheduleProcessCPUProfiling(
+    base::TimeDelta delay) {
+  repeating_timer_.Start(FROM_HERE, delay, this,
+                         &ProcessCoordinationUnitImpl::MeasureProcessCPUUsage);
+}
+
+void ProcessCoordinationUnitImpl::MeasureProcessCPUUsage() {
+  cpu_usage_ = process_metrics_->GetPlatformIndependentCPUUsage();
+
+  ScheduleProcessCPUProfiling(
+      base::TimeDelta::FromSeconds(kCPUProfilingIntervalInSeconds));
+}
+
+double ProcessCoordinationUnitImpl::GetCPUUsageForTesting() {
+  return cpu_usage_;
+}
+
+}  // namespace resource_coordinator