Bug 10465 - Mono crashes when running too many processes
Summary: Mono crashes when running too many processes
Alias: None
Product: Runtime
Classification: Mono
Component: JIT ()
Version: unspecified
Hardware: PC Linux
: --- normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2013-02-20 08:58 UTC by croisharp
Modified: 2014-12-01 04:38 UTC (History)
3 users (show)

Is this bug a regression?: ---
Last known good build:

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Description croisharp 2013-02-20 08:58:26 UTC
I created a test program and it also doesn't work. 
It fails with:

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


CreateProcess: error creating process handle 

and starts only 254 processes on my pc.

Mono JIT compiler version (Debian
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)

I've also big ulimit -u/-v values and this didn't solved the problem.

So this is the test code:

		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");

		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);
			} catch (Exception ex) {
				tw.WriteLine (ex.InnerException+Environment.NewLine+ex.Message + Environment.NewLine + ex.StackTrace, false);
			return null;
Comment 1 Zoltan Varga 2013-02-23 17:35:14 UTC
You can probably work around this problem by calling proc.Close ().
Comment 2 Zoltan Varga 2014-12-01 04:38:28 UTC
This was fixed some time ago.