如何避免C#多進程中的僵尸進程

在C#中，避免產生僵尸進程（Zombie Process）的方法主要包括以下幾點：

1. 使用Process類的Exited事件來監控子進程的退出。當子進程退出時，可以在事件處理函數中調用WaitForExit()方法確保子進程被正確清理。

var process = new Process();
process.StartInfo.FileName = "your_executable";
process.EnableRaisingEvents = true;
process.Exited += (sender, args) =>
{
    process.WaitForExit();
    Console.WriteLine("子進程已退出");
};
process.Start();

2. 在父進程中調用WaitForExit()方法等待子進程退出。這樣可以確保子進程在父進程中被正確清理。

var process = new Process();
process.StartInfo.FileName = "your_executable";
process.Start();
process.WaitForExit();

3. 如果你需要在父進程中同時運行多個子進程，可以考慮使用Task或Parallel類庫來并行執行子進程。這樣可以更好地管理子進程的生命周期。

var tasks = new List<Task>();
foreach (var executable in executables)
{
    tasks.Add(Task.Run(() =>
    {
        var process = new Process();
        process.StartInfo.FileName = executable;
        process.Start();
        process.WaitForExit();
    }));
}
Task.WaitAll(tasks.ToArray());

4. 如果你需要在子進程中創建新的進程，可以考慮使用JobObject來管理子進程。JobObject可以確保所有子進程都被正確清理，避免僵尸進程的產生。

using Microsoft.Win32.SafeHandles;
using System.Runtime.InteropServices;

[DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
static extern IntPtr CreateJobObject(IntPtr lpJobAttributes, string lpName);

[DllImport("kernel32.dll")]
static extern bool SetInformationJobObject(IntPtr hJob, JobObjectInfoType infoType, IntPtr lpJobObjectInfo, uint cbJobObjectInfoLength);

[DllImport("kernel32.dll", SetLastError = true)]
static extern bool AssignProcessToJobObject(IntPtr job, IntPtr process);

public enum JobObjectInfoType
{
    AssociateCompletionPortInformation = 7,
    BasicLimitInformation = 2,
    BasicUIRestrictions = 4,
    EndOfJobTimeInformation = 6,
    ExtendedLimitInformation = 9,
    SecurityLimitInformation = 5,
    GroupInformation = 11
}

[StructLayout(LayoutKind.Sequential)]
struct JOBOBJECT_EXTENDED_LIMIT_INFORMATION
{
    public JOBOBJECT_BASIC_LIMIT_INFORMATION BasicLimitInformation;
    public IO_COUNTERS IoInfo;
    public UIntPtr ProcessMemoryLimit;
    public UIntPtr JobMemoryLimit;
    public UIntPtr PeakProcessMemoryUsed;
    public UIntPtr PeakJobMemoryUsed;
}

[StructLayout(LayoutKind.Sequential)]
struct JOBOBJECT_BASIC_LIMIT_INFORMATION
{
    public long PerProcessUserTimeLimit;
    public long PerJobUserTimeLimit;
    public uint LimitFlags;
    public UIntPtr MinimumWorkingSetSize;
    public UIntPtr MaximumWorkingSetSize;
    public uint ActiveProcessLimit;
    public UIntPtr Affinity;
    public uint PriorityClass;
    public uint SchedulingClass;
}

[StructLayout(LayoutKind.Sequential)]
struct IO_COUNTERS
{
    public ulong ReadOperationCount;
    public ulong WriteOperationCount;
    public ulong OtherOperationCount;
    public ulong ReadTransferCount;
    public ulong WriteTransferCount;
    public ulong OtherTransferCount;
}

public static void CreateJobObjectForProcess(Process process)
{
    var job = CreateJobObject(IntPtr.Zero, null);
    var extendedInfo = new JOBOBJECT_EXTENDED_LIMIT_INFORMATION
    {
        BasicLimitInformation = new JOBOBJECT_BASIC_LIMIT_INFORMATION
        {
            LimitFlags = 0x2000 // JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE
        }
    };

    int length = Marshal.SizeOf(typeof(JOBOBJECT_EXTENDED_LIMIT_INFORMATION));
    IntPtr extendedInfoPtr = Marshal.AllocHGlobal(length);
    Marshal.StructureToPtr(extendedInfo, extendedInfoPtr, false);

    if (!SetInformationJobObject(job, JobObjectInfoType.ExtendedLimitInformation, extendedInfoPtr, (uint)length))
    {
        throw new Exception("Could not set information job object.");
    }

    if (!AssignProcessToJobObject(job, process.Handle))
    {
        throw new Exception("Could not assign process to job object.");
    }
}

通過以上方法，你可以在C#中有效地避免產生僵尸進程。