Bug 1692 - Changing process priority sometimes fails with "Process not found"
Summary: Changing process priority sometimes fails with "Process not found"
Alias: None
Product: Runtime
Classification: Mono
Component: JIT ()
Version: unspecified
Hardware: PC Linux
: --- normal
Target Milestone: ---
Assignee: Bugzilla
Depends on:
Reported: 2011-10-26 08:08 UTC by Kari Takanen
Modified: 2011-11-04 13:33 UTC (History)
2 users (show)

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

test.cs (902 bytes, text/x-csharp)
2011-10-26 08:08 UTC, Kari Takanen

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Description Kari Takanen 2011-10-26 08:08:32 UTC
Created attachment 769 [details]

Doing "oProc.PriorityClass = System.Diagnostics.ProcessPriorityClass.Idle;" sometimes fails and sometimes works. A simple test program, which executes the "df" command multiple times, is attached.

Usually the command gets executed once and the program dies with

Unhandled Exception: System.ComponentModel.Win32Exception: Process not found
  at System.Diagnostics.Process.set_PriorityClass (ProcessPriorityClass value) [0x00000] in <filename unknown>:0
  at (wrapper remoting-invoke-with-check) System.Diagnostics.Process:set_PriorityClass (System.Diagnostics.ProcessPriorityClass)
  at Example.Test.Main (System.String[] args) [0x00000] in <filename unknown>:0

But sometimes it runs through the whole loop without errors.

Tested on Linux using Mono JIT compiler version 2.11 (master/91eb198 Tue Oct 25 10:16:19 EEST 2011).
Comment 1 Zoltan Varga 2011-11-04 13:33:30 UTC
This is not a bug, MS.NET also throws an exception if the process has already exited:

System.InvalidOperationException: Cannot process request because the process (3380) has exited.
   at System.Diagnostics.Process.GetProcessHandle(Int32 access, Boolean throwIfExited)
   at System.Diagnostics.Process.set_PriorityClass(ProcessPriorityClass value)
   at Example.Test.Main(String[] args)

Fixed mono to throw the same exception.