public static class CodeTimer
{
public static void Initialize()
{
Process.GetCurrentProcess().PriorityClass = ProcessPriorityClass.High;
Thread.CurrentThread.Priority = ThreadPriority.Highest;
Time("", 1, () => { });
}
public static void Time(string name, int iteration, Action action) { if (String.IsNullOrEmpty(name)) return; // 1. ConsoleColor currentForeColor = Console.ForegroundColor; Console.ForegroundColor = ConsoleColor.Yellow; Console.WriteLine(name); // 2. GC.Collect(GC.MaxGeneration, GCCollectionMode.Forced); int[] gcCounts = new int[GC.MaxGeneration + 1]; for (int i = 0; i <= GC.MaxGeneration; i++) { gcCounts[i] = GC.CollectionCount(i); } // 3. Stopwatch watch = new Stopwatch(); watch.Start(); ulong cycleCount = GetCycleCount(); for (int i = 0; i < iteration; i++) action(); ulong cpuCycles = GetCycleCount() - cycleCount; watch.Stop(); // 4. Console.ForegroundColor = currentForeColor; Console.WriteLine("/tTime Elapsed:/t" + watch.ElapsedMilliseconds.ToString("N0") + "ms"); Console.WriteLine("/tCPU Cycles:/t" + cpuCycles.ToString("N0")); // 5. for (int i = 0; i <= GC.MaxGeneration; i++) { int count = GC.CollectionCount(i) - gcCounts[i]; Console.WriteLine("/tGen " + i + ": /t/t" + count); } Console.WriteLine(); } private static ulong GetCycleCount() { ulong cycleCount = 0; QueryThreadCycleTime(GetCurrentThread(), ref cycleCount); return cycleCount; } [DllImport("kernel32.dll")] [return: MarshalAs(UnmanagedType.Bool)] static extern bool QueryThreadCycleTime(IntPtr threadHandle, ref ulong cycleTime); [DllImport("kernel32.dll")] static extern IntPtr GetCurrentThread();
}
Time方法接受三个参数,名称,循环次数以及需要执行的方法体。打印出花费时间,消耗的CPU时钟周期,以及各代垃圾收集的回收次数。具体实现分几个步骤,如下:
- 保留当前控制台前景色,并使用黄色输出名称参数。
- 强制GC进行收集,并记录目前各代已经收集的次数。
- 执行代码,记录下消耗的时间及CPU时钟周期1。
- 恢复控制台默认前景色,并打印出消耗时间及CPU时钟周期。
- 打印执行过程中各代垃圾收集回收次数。
与传统计数方法相比,这段代码还输出了更多信息:CPU时钟周期及各代垃圾收集回收次数。CPU时钟周期是性能计数中的辅助参考,说明CPU分配了多少时间片给这段方法来执行,它和消耗时间并没有必然联系。例如Thread.Sleep方法会让CPU暂时停止对当前线程的“供给”,这样虽然消耗了时间,但是节省了CPU时钟周期:
CodeTimer.Time("Thread Sleep", 1, () => { Thread.Sleep(3000); }); CodeTimer.Time("Empty Method", 10000000, () => { });
结果如下: