C# 对象创建比构造函数调用慢得多 [英] C# object creation much slower than constructor call

问题描述

在我的一生中，我无法弄清楚我的代码中的这种性能损失.我有一个容器对象，我测量运行构造函数(下面的对象)需要多长时间，公共构造函数中的计时代码

For the life of my, I can't figure out this performance hit in my code. I have a container object where I measure how long it takes to run the constructor (object below), timing code in the public constructor

 public class WorkUnit : IWorkUnit
{
    private JobInformation m_JobInfo;
    private MetaInfo m_MetaInfo;
    private IPreProcJobInfo m_PreprocDetails;


    readonly private Guid m_ID;
    private Guid m_ParentID;
    private Guid m_MasterJobID;


    private string m_ErrorLog = string.Empty;
    private PriorityKeeper m_Priority;
    private WorkUnitClassification m_Classification;

    private IJobPayload m_CachedPayload;
    private IJobLogger m_Logger;
    private EventHandler<JobEventArgs> m_IsFinished;
    private ReaderWriterLockSlim m_Lock;

    public WorkUnit(string InputXML, Guid JobID, IJobLogger Logger)
    {
        DateTime overstarttime = DateTime.Now;

        try
        {
        ....Do Stuff....
        }
        catch(XMLException e)
        {...}
        catch(Exception e)
        {
         ...
         throw;
        }

        double time = (DateTime.Now - overstarttime).TotalMilliseconds
        Console.WriteLine("{0}", time);
    }

    /// <summary>
    /// Private Constructor used to create children
    /// </summary>
    private WorkUnit(Guid MasterID, Guid ParentID, WorkUnitClassification Classification, PriorityKeeper Keeper)
    {...}

    [OnDeserializing()]
    private void OnDeserialize(StreamingContext s)
    {...}

    public PriorityKeeper PriorityKey
    {...}

    public bool HasError
    {...}

    public bool Processing
    {...}

    public bool Splittable
    {...}

    public IEnumerable<IWorkUnit> Split(int RequestedPieces, int Bonds)
    {...}

    public void Merge(IResponse finishedjob)
    {...}

    public ReadOnlyCollection<IWorkUnit> Children
    {...}

    public bool IsMasterJob
    {...}

    public Guid MasterJobID
    {...}

    public Guid ID
    {...}

    public Guid ParentID
    {...}

    public EnumPriority Priority
    {...}

    public void ChangePriority(EnumPriority priority)
    {...}

    public string ErrorLog
    {...}

    public IMetaInfo MetaData
    {...}

    public IJobPayload GetProcessingInfo()
    {... }

    public IResponseGenerator GetResponseGenerator()
    {... }

}

现在，我正在测量创建对象所需的总时间

Now, I'm measuring the total time it takes to create the object as

DateTime starttime = DateTime.Now;
var test = new WorkUnit(temp, JobID, m_JobLogger);
double finished = (DateTime.Now - starttime).TotalMilliseconds;

而且我一直得到以下性能数据 -

and I'm consistently getting the following performance numbers -

构造函数时间 - 47 毫秒

Constructor time - 47 ms

对象创建时间 - 387 毫秒

Object creation time - 387 ms

47 毫秒是可以接受的，387 真的很糟糕.取出日志可以忽略不计地改变这些数字.有谁知道为什么这需要这么长时间?我的系统是 VS 2008 SP1，目标是 Windows XP 上的 .NET 3.5 SP1.我将不胜感激任何解释.我很快就会打破分析器，但我觉得它无法深入到我需要解释这种行为的水平.感谢您的帮助.

47 ms is acceptable, 387 is really bad. Taking out the logging negligibly changes these numbers. Does anyone have any idea why this is taking so long? My system is VS 2008 SP1, targeting .NET 3.5 SP1 on Windows XP. I would appreciate any explanation. I'll be breaking out the profiler shortly, but I feel that it won't be able to delve into the level I need to explain this behavior. Thanks for any help.

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推荐答案

您确定您看到的是对象创建时间而不是 CLR 启动的影响吗?

Are you sure what you're seeing is the object creation time and not the effects of the CLR starting up?

尝试在循环中运行测试 50 次并忽略第一个结果.

Try running the test 50 times in a loop and ignoring the first result.

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