IdleWakeups tool

tools/win/IdleWakeups/system_information_sampler.h

+// Copyright 2016 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.
+
+#ifndef TOOLS_WIN_IDLEWAKEUPS_SYSTEM_INFORMATION_SAMPLER_H_
+#define TOOLS_WIN_IDLEWAKEUPS_SYSTEM_INFORMATION_SAMPLER_H_
+
+#include <map>
+#include <memory>
+#include <vector>
+
+#include <windows.h>
+
+// SYSTEM_PROCESS_INFORMATION and SYSTEM_THREAD_INFORMATION structures
+// use HANDLE for the thread / process IDs.
+typedef HANDLE ThreadId;
+typedef HANDLE ProcessId;
+
+// Contains per thread data stored in each data snapshot.
+struct ThreadData {
+  ThreadId thread_id;
+  ULONG context_switches;
+};
+
+typedef std::vector<ThreadData> ThreadsVector;
+
+// Contains per process data stored in each data snapshot.
+struct ProcessData {
+  ULONGLONG cpu_time;
+  ULONGLONG working_set;
+  ThreadsVector threads;
+};
+
+typedef std::map<ProcessId, ProcessData> ProcessDataMap;
+
+struct ProcessDataSnapshot {
+  ProcessDataMap processes;
+  double timestamp;
+};
+
+class SystemInformationSampler {
+ public:
+  SystemInformationSampler(const wchar_t* process_name);
+  ~SystemInformationSampler();
+
+  std::unique_ptr<ProcessDataSnapshot> TakeSnapshot();
+
+  const wchar_t* target_process_name_filter() const {
+    return target_process_name_;
+  }
+
+ private:
+  wchar_t target_process_name_[256] = {};
+  LARGE_INTEGER perf_frequency_;
+  LARGE_INTEGER initial_counter_;
+  size_t previous_buffer_size_ = 0;
+
+  SystemInformationSampler& operator=(const SystemInformationSampler&) = delete;
+  SystemInformationSampler(const SystemInformationSampler&) = delete;
+};
+
+#endif  // TOOLS_WIN_IDLEWAKEUPS_SYSTEM_INFORMATION_SAMPLER_H_