c# - 运行太多进程时 Mono 崩溃

Question

我想建立一个视频转换队列，所以服务器运行一个单声道程序，从队列中提取一个视频并运行 ffmpeg 来转换它。当运行许多 ffmpeg 进程时，单声道给我错误。

所以我用 ping 创建了一个测试用例，因为它是一个像 ffmpeg 一样长时间运行的测试用例。

    static TextWriter tw = new StreamWriter("error.txt");
    private static int _started;
    public static void Main (string[] args)
    {

        for (int i=0; i<1000; i++) {
            Start ("ping", "localhost");

        }
        Console.WriteLine("Memory: " + (GC.GetTotalMemory(true) / 1024) + "KB");
        Console.WriteLine(_started);
        tw.Flush();
        Console.ReadLine();
    }

    public static Process Start (string name, string args)
    {
        try {
            var proc = new ProcessStartInfo {
                    FileName = name,
                    Arguments = args,
                    RedirectStandardOutput = true,
                    CreateNoWindow = false,
                    RedirectStandardError = false,
                    UseShellExecute = false,
                    RedirectStandardInput = false,
            };
            Process.Start (proc);
            _started++;
        } catch (Exception ex) {
            tw.WriteLine (ex.InnerException+Environment.NewLine+ex.Message + Environment.NewLine + ex.StackTrace, false);
            tw.Flush();
        }
        return null;
    }

运行时，会抛出与 ffmpeg 相同的错误

ApplicationName='ping', CommandLine='localhost', CurrentDirectory=''
  at System.Diagnostics.Process.Start_noshell
(System.Diagnostics.ProcessStartInfo startInfo, System.Diagnostics.Process
process) [0x00000] in <filename unknown>:0 
  at System.Diagnostics.Process.Start_common
(System.Diagnostics.ProcessStartInfo startInfo, System.Diagnostics.Process
process) [0x00000] in <filename unknown>:0 
  at System.Diagnostics.Process.Start (System.Diagnostics.ProcessStartInfo
startInfo) [0x00000] in <filename unknown>:0 
  at test1.MainClass.Start (System.String name, System.String args) [0x00000]
in <filename unknown>:0

和

CreateProcess: error creating process handle

这就是我的环境:

Mono JIT compiler version 2.10.8.1 (Debian 2.10.8.1-5ubuntu1)
Copyright (C) 2002-2011 Novell, Inc, Xamarin, Inc and Contributors. www.mono-project.com
    TLS:           __thread
    SIGSEGV:       altstack
    Notifications: epoll
    Architecture:  amd64
    Disabled:      none
    Misc:          softdebug 
    LLVM:          supported, not enabled.
    GC:            Included Boehm (with typed GC and Parallel Mark)

和极限值

core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 31439
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 31439
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

我想继续我的项目，但因为这个异常我不能，在使用 mono 工作 1 年后我真的很喜欢它，并且因为这个麻烦不想学习其他语言。

我希望我的代码有问题，而不是单声道运行时。

所以我的临时解决方案:

    public static void Start (string cmd, int time)
    {
        new Thread (p =>
        {
            try {
                Mono.Unix.Native.Syscall.system (String.Format("timeout {0} {1}", time, cmd));
            } catch (Exception ex) {
                //log it
            }
        }
        ).Start ();
    }

Answer 1

您必须在 Process 实例上调用 WaitForExit 和 Dispose。

所以您的 Start 方法看起来像这样:

public static void Start (string name, string args)
{
    new Thread (() =>
    {
        try {
            var proc = new ProcessStartInfo {
                    FileName = name,
                    Arguments = args,
                    RedirectStandardOutput = true,
                    CreateNoWindow = false,
                    RedirectStandardError = false,
                    UseShellExecute = false,
                    RedirectStandardInput = false,
            };
            using (var p = new Process ()) {
                p.StartInfo = proc;
                p.Start ();
                p.WaitForExit ();
            }
            _started++;
        } catch (Exception ex) {
            tw.WriteLine (ex.InnerException+Environment.NewLine+ex.Message + Environment.NewLine + ex.StackTrace, false);
            tw.Flush();
        }
    }).Start ();
}