MySQL Bugs: #36688: SemaphoreFullException when closing application

Bug #36688	SemaphoreFullException when closing application
Submitted:	13 May 2008 15:24	Modified:	22 Jul 2008 18:04
Reporter:	Paul Bowden
Status:	Closed
Category:	Connector/Net	Severity:	S2 (Serious)
Version:	5.1.6	OS:	Microsoft Windows (XP SP2 & Vista)
Assigned to:		Target Version:
Tags:	exception, Semaphore

Description:
I have just upgraded from 5.1.2 -> 5.1.6, and now when I close my application I receive a
SemaphoreFullException.

System.Threading.SemaphoreFullException was unhandled
  Message="Adding the given count to the semaphore would cause it to exceed its maximum
count."
  Source="System"
  StackTrace:
       at System.Threading.Semaphore.Release(Int32 releaseCount)
       at System.Threading.Semaphore.Release()
       at MySql.Data.MySqlClient.MySqlPool.RemoveConnection(Driver driver)
       at MySql.Data.MySqlClient.MySqlPoolManager.RemoveConnection(Driver driver)
       at MySql.Data.MySqlClient.Driver.Dispose(Boolean disposing)
       at MySql.Data.MySqlClient.NativeDriver.Dispose(Boolean disposing)
       at MySql.Data.MySqlClient.Driver.Close()
       at MySql.Data.MySqlClient.NativeDriver.Finalize()

I can see others complaining about this issue in bugs #30642 and #30816

How to repeat:
Uninstall previous connector, install 5.1.6. We then recompile our application and the
problem will happen after shutdown (main has returned).

I'm receiving the same exception after installing 5.1.6 this morning 14/5/2008

Hi Paul and thanks for your report. The only relevant change I can find is:
- Fixed problem with connections staying open after being used with SqlDataSource.
   The problem was that we were not returning an enumerator for our reader with the
closeReader option set to true when we were supposed to.(Bug #34460)

As there is no test case attached I will use my own from Bug#30642.

I have just the same problem.
I'm using MySQL connector 5.1.6, Windows XP Portuguese.
MySQL server 5.0.45 running on Linux.

The problem happens whenever you create two connections.

Sample code:

using System;
using System.Windows.Forms;
using MySql.Data.MySqlClient;

namespace MySQLbug
{
   /// <summary>
   /// Description of MainForm.
   /// </summary>
   public partial class MainForm : Form {
      public MainForm() {
         InitializeComponent();
         DoSomething();
         DoSomething();     //again, or something else that opens a connection
      }

      private void DoSomething() {
         MySqlConnection con = null;
         MySqlCommand com = null;

         try {
            con = new MySqlConnection("Database=db; Data Source=server; User Id=uid;
Password=pass");
            com = new MySqlCommand();
            com.Connection = con;
            com.Connection.Open();
         } catch (MySqlException) {
         } finally {
            if (com != null) {
               com.Dispose();
               com = null;
            }
            if (con != null) {
               try {
                  con.Close();
               } catch (MySqlException) {}
               con.Dispose();
               con = null;
            }
         }
      }
   }
}

End of sample code.

Whenever you close the form the System.Threading.SemaphoreFullException is thrown. And
from my point of view both connections were properly closed.

If you just comment one of calls the exception won't be thrown.

Just downloaded .Net connector 5.2.2 and the poblem is gone :)

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/46888

Fixed in 5.1.7.  Not a bug in 5.2+

when The v5.1.7 to release ?

Might be still a little bit.  So far I only have two changes for 5.1.7 and I need to get
5.2.3 and 5.3 beta out first.

Is it possible to give a rough timescale for the 5.1.7 release, i.e. this month, next
month etc?

This will allow me to determine whether to patch 5.1.6 manually, or wait for the release.

Regards,

Paul

Paul

It will likely drop the first part of next month since I won't get to it this week and I'm
on vacation next week.  I would like to squeeze a few more fixes into it before it drops
too.  I'm working on getting the snapshot system back up and functional which should start
producing 5.1, 5.2, and 5.3 snapshots of the trees.

Any update on this? Also the snapshots don't appear to be up to date yet. Also checked out
5.1.6 but it has files missing...

An entry has been added to the 5.1.7 Changelog:

SemaphoreFullException is generated when application is closed.

[16 May 12:26] Bernardo Marques  

is right, thanks for you help!

Any idea on when version 5.1.7 will be released, or when the snapshots will be back up?

I have the same problem. 
When is 5.1.7 coming out?

Please can you tell us when 5.1.7 will be released with this bug fixed. It is causing me
serious problems

Guys, sorry, I am not ignoring you but I just don't know... There is a whole rigorous
process running in background before connector is released. Maybe Reggie knows more.

Guys

I hear you that you are waiting for 5.1.7.  I've been very busy with several other
projects but also getting as many bug fixes as I can into 5.1.7 for the release.  I am
hoping to do a formal release this week.

I don't want to seem insensitive but we are an open source shop and the full sources for
5.1.7 are available to you today.  Just go to http://svn.mysql.com and go into the area
for Connector/net and you'll see how to hook up your SVN client to our public repo.  I
know it's not a replacement for an official binary but if someone *has* to have it today
then just grab the source and build.  It should build with VS 2005 and 2008 with no
problem.

Hi Reggie,

I have downloaded the 5.1 branch, installed the Vistual Studio 2005 SDK, modified
MySql.VisualStudio.csproj to set the path for Microsoft.VsSDK.targets, however when I try
to build the solution I get some errors (see below). Do I need to install anything else?

Error	1	Cryptographic failure while signing assembly
'C:\MySQL\5.1\Driver\obj\Debug\MySql.Data.dll' -- 'The key container name 'ConnectorNet'
does not exist'	MySql.Data

Error	4	The name 'TryGetValue' does not exist in the current
context	C:\MySQL\5.1\Driver\Source\MySqlConnectionStringBuilder.cs	1182	13	MySql.Data.CF

Error	5	The best overloaded method match for
'System.Text.StringBuilder.AppendFormat(System.IFormatProvider, string, params object[])'
has some invalid
arguments	C:\MySQL\5.1\Driver\Source\MySqlConnectionStringBuilder.cs	1191	17	MySql.Data.CF

Error	6	Argument '1': cannot convert from 'string' to
'System.IFormatProvider'	C:\MySQL\5.1\Driver\Source\MySqlConnectionStringBuilder.cs	1191	4
8	MySql.Data.CF

Error	7	Argument '3': cannot convert from 'object' to
'object[]'	C:\MySQL\5.1\Driver\Source\MySqlConnectionStringBuilder.cs	1191	69	MySql.Data.C
F

Paul

Just disable the mysql.data.cf project as that is for the compact framework (I'm working
on that fix).  Also, you can either create a new signing key or just comment out that line
from the assemblyinfo.cs file.

//[16 May 12:26] Bernardo Marques
//Just downloaded .Net connector 5.2.2 and the poblem is gone :)

wow, thanks.. it's working now

I have 5.2.2 and this is still a problem for me.

"   at System.Threading.Semaphore.Release(Int32 releaseCount)\r\n   at
System.Threading.Semaphore.Release()\r\n   at
MySql.Data.MySqlClient.MySqlPool.RemoveConnection(Driver driver)\r\n   at
MySql.Data.MySqlClient.MySqlPoolManager.RemoveConnection(Driver driver)\r\n   at
MySql.Data.MySqlClient.Driver.Dispose(Boolean disposing)\r\n   at
MySql.Data.MySqlClient.NativeDriver.Dispose(Boolean disposing)\r\n   at
MySql.Data.MySqlClient.Driver.Close()\r\n   at
MySql.Data.MySqlClient.NativeDriver.Finalize()"

...

Any updates on when 5.1.7 is being released?

Please download connector 5.1.7 to solve this problem.