我正在寻找一种方法来测量线程上函数调用所需的cpu周期。
伪代码示例:
void HostFunction()
{
var startTick = CurrentThread.CurrentTick; //does not exist
ChildFunction();
var endTick = CurrentThread.CurrentTick; //does not exist
var childFunctionCost = endTick - startTick;
}
void ChildFunction()
{
//Do whatever...
Thread.Sleep(3000);
//Do some more...
}
我不想使用秒表或其他一些时间测量,因为它会包含线程正在休眠的任何时间,我不想测量。我只想衡量实际工作。
这个测量需要在运行时工作,就像我的伪代码一样,因为结果用于确定是否应该允许子函数继续运行(我的实例是一个插件类型的体系结构),所以进行分析工具不会帮助我。
答案 0 :(得分:9)
你可以对QueryThreadCycleTime()进行转发。请查看链接以获取详细信息。
一些示例代码:
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
class Program {
static void Main(string[] args) {
ulong start, end;
start = NativeMethods.GetThreadCycles();
System.Threading.Thread.Sleep(1000);
end = NativeMethods.GetThreadCycles();
ulong cycles = end - start;
Debug.Assert(cycles < 200000);
}
static class NativeMethods {
public static ulong GetThreadCycles() {
ulong cycles;
if (!QueryThreadCycleTime(PseudoHandle, out cycles))
throw new System.ComponentModel.Win32Exception();
return cycles;
}
[DllImport("kernel32.dll", SetLastError = true)]
private static extern bool QueryThreadCycleTime(IntPtr hThread, out ulong cycles);
private static readonly IntPtr PseudoHandle = (IntPtr)(-2);
}
}
答案 1 :(得分:2)
根据我上面提供的评论,请考虑以下代码:
using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Threading;
namespace FunctionTiming
{
class Program
{
private static Thread _thread;
private static IntPtr _threadHandle;
static void Main(string[] args)
{
_thread = new Thread(new ThreadStart(Program.TargetFunction));
_thread.Start();
_thread.Join();
System.Runtime.InteropServices.ComTypes.FILETIME start, end, rawKernelTime, rawUserTime;
bool result = GetThreadTimes(_threadHandle, out start, out end, out rawKernelTime, out rawUserTime);
Debug.Assert(result);
ulong uLow = (ulong)rawKernelTime.dwLowDateTime;
ulong uHigh = (uint)rawKernelTime.dwHighDateTime;
uHigh = uHigh << 32;
long kernelTime = (long)(uHigh | uLow);
uLow = (ulong)rawUserTime.dwLowDateTime;
uHigh = (uint)rawUserTime.dwHighDateTime;
uHigh = uHigh << 32;
long userTime = (long)(uHigh | uLow);
Debug.WriteLine("Kernel time: " + kernelTime);
Debug.WriteLine("User time: " + userTime);
Debug.WriteLine("Combined raw execution time: " + (kernelTime + userTime));
long functionTime = (kernelTime + userTime) / 10000;
Debug.WriteLine("Funciton Time: " + functionTime + " milliseconds");
}
static void TargetFunction()
{
IntPtr processHandle = GetCurrentProcess();
bool result = DuplicateHandle(processHandle, GetCurrentThread(), processHandle, out _threadHandle, 0, false, (uint)DuplicateOptions.DUPLICATE_SAME_ACCESS);
double value = 9876543.0d;
for (int i = 0; i < 100000; ++i)
value = Math.Cos(value);
Thread.Sleep(3000);
value = 9876543.0d;
for (int i = 0; i < 100000; ++i)
value = Math.Cos(value);
}
[DllImport("kernel32.dll", SetLastError = true)]
static extern bool GetThreadTimes(IntPtr hThread,
out System.Runtime.InteropServices.ComTypes.FILETIME lpCreationTime, out System.Runtime.InteropServices.ComTypes.FILETIME lpExitTime,
out System.Runtime.InteropServices.ComTypes.FILETIME lpKernelTime, out System.Runtime.InteropServices.ComTypes.FILETIME lpUserTime);
[DllImport("kernel32.dll")]
private static extern IntPtr GetCurrentThread();
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool DuplicateHandle(IntPtr hSourceProcessHandle,
IntPtr hSourceHandle, IntPtr hTargetProcessHandle, out IntPtr lpTargetHandle,
uint dwDesiredAccess, [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle, uint dwOptions);
[Flags]
public enum DuplicateOptions : uint
{
DUPLICATE_CLOSE_SOURCE = (0x00000001),// Closes the source handle. This occurs regardless of any error status returned.
DUPLICATE_SAME_ACCESS = (0x00000002), //Ignores the dwDesiredAccess parameter. The duplicate handle has the same access as the source handle.
}
[DllImport("kernel32.dll")]
static extern IntPtr GetCurrentProcess();
}
}
产生以下结果(在我的旧机器上):
Kernel time: 0
User time: 156250
Combined raw execution time: 156250
Function time: 15 milliseconds
你可以清楚地看到没有包括3秒的睡眠时间。 希望这会有所帮助。