Util.Run() cannot run consecutive scripts with identical data connection

nescafe

I have created a few daily jobs as separate .linq files which I call from a main .linq script which iterates all "Daily - *.linq" files in the same directory, runs them and e-mails me the result:

(this is a small part with the relevant faulting line)

  foreach (var file in Directory.EnumerateFiles(path, "Daily - *.linq"))
  {
    sb.AppendFormat("<h2>{0}</h2>", Path.GetFileNameWithoutExtension(file));
    sb.Append(Util.Run(file, QueryResultFormat.HtmlFragment).AsString());
  }

I noticed strange behavior in some LINQ files which I could not explain. The error message I get is:

Daily - [Script name]

System.Exception: error CS0006: Metadata file 'C:\Users\Administrator\AppData\Local\Temp\LINQPad\_hgtdtpol\TypedDataContext_tukxem.dll' could not be found

   at LINQPad.TaskExtensions.GetResult[T](Task`1 t)
   at LINQPad.ChildAppHost.GetResult()
   at LINQPad.ObjectModel.QueryExecuter.AsString()
   at UserQuery.Main() in d:\LINQPad\RunDaily.linq:line 24

Today I found out this is not specific to Task Scheduler, user account or lprun.exe as it seems reproducible in LINQPad itself, so I'll post it here.

Steps to reproduce the problem:
1. Create a LINQPad file with a data connection (e.g. LINQ-to-SQL), the command or expression is not relevant to the problem.

MyScript.linq:

<Query Kind="Expression">
  <Connection>
    <ID>60154894-9165-4f77-b527-0bc717db8966</ID>
    <Persist>true</Persist>
    <Server>(local)</Server>
    <NoPluralization>true</NoPluralization>
    <NoCapitalization>true</NoCapitalization>
    <Database>master</Database>
    <ShowServer>true</ShowServer>
  </Connection>
</Query>

"Test"

2. Create another LINQPad script which calls this script. In production, I'm calling different scripts with the same connection. To reproduce the problem, multiple runs to the same script is enought to reproduce the problem.

var path = Path.GetDirectoryName(Util.CurrentQueryPath);
var script = Path.Combine(path, "MyScript.linq");
for (var i = 0; i < 10; i++)
{
  Util.Run(script, QueryResultFormat.HtmlFragment).AsString().Dump();
}

3. Run the main script, this is the result:

<div>Test<br /></div>
<div>Test<br /></div>
<div>Test<br /></div>

6FileNotFoundException4
Could not load file or assembly file:///C:\Users\Administrator\AppData\Local\Temp\LINQPad5\_rcvluirq\TypedDataContext_kqzkmz.dll or one of its dependencies. 

I have found a workaround for this issue:
- Change the connection ID in the scripts that share the same connection.

Version(s) affected:
- v4.57.02
- v5.02.05

nescafe

Joe, as you're currently zooming in on the Util.Run() functionality, this problem still occurs in latest beta (v5.20.02).



Work-around is to add a wait of at least 100 milliseconds between each run.

for (var i = 0; i < 10; i++)
{
  Util.Run(script, QueryResultFormat.HtmlFragment).AsString().Dump();
  Thread.Sleep(100);
}

nescafe

I think this can be solved by including the main process ID in the dll name (hash) generation

JoeAlbahari

Thanks for the repro - the problem is caused by LINQPad prematurely cleaning up a cached data context assembly. This will be fixed for the next build.

JoeAlbahari

This is now fixed in the 5.21 beta:
http://www.linqpad.net/download.aspx#beta

nescafe

Tested - works correctly.