MySQL Bugs: #16844: Objects are not GC-d when using StoredProcedure command type.

Bug #16844	Objects are not GC-d when using StoredProcedure command type.
Submitted:	27 Jan 2006 14:55	Modified:	25 Nov 2006 14:43
Reporter:	Pavel Bulanov	Email Updates:
Status:	No Feedback	Impact on me:	None
Category:	Connector / NET	Severity:	S2 (Serious)
Version:	1.0.7 (connector)	OS:	Windows (Windows XP)
Assigned to:	Assigned Account	CPU Architecture:	Any

Description:
Executing a MySQLCommand of StoredProcedure type results in objects are not garbage collected.

I create a MySQLCommand, assign CommandType.StoredProcedure to CommandType property, set up MySQLConnection add parameters.

Then I ExecuteReader to retrieve results.

Reader is used inside "using" block, as well as command and connection.

But finally I have a lot of auxiliary MySQLCommand objects left - they are not collected.

Connection is definitely closed (checked by looking at MySQL Server connections).
All objects created are explicity disposed (via using, and this works - checked with debugger).

I track the memory with memory profiler and got the following results:
1) all my objects are disposed and got collected
2) Memory is consumed by subsidiary MySQLCommand objects
3) These objects are created in the following methods (explored by Reflector):
private string StoredProcedure.GetParameterList(MySqlCommand procCmd, out string returns, string procType)
Driver.public virtual void Configure(MySqlConnection connection)
Driver.private void LoadCharacterSets()
4) In this methods created commands are not Closed or disposed directly!!

How to repeat:
Run the following code (approximate):

/// <summary>
        /// Creates new stored procedure command.
        /// </summary>
        protected static IDbCommand CreateStoredProcedure(String name)
        {
            IDbCommand result = new MySqlCommand(name);
            result.CommandType = CommandType.StoredProcedure;
            return result;
        }

using (MySQLConnection connection = new MySqlConnection(connectionString))
{
  using(IDbCommand command = CreateStoredProcedure(GetProcedureName()))
{
  command.Connection = connection;
    using (IDataReader reader = command.ExecuteReader())
                {
                    using (FieldReader fieldReader = new FieldReader(reader))
                    {
                        // some code here
                    }
                }
 }
}

Execute this many times - a number of objects never being disposed is a result.

Suggested fix:
Close connections explicit in the above methods.

By the way, MySQL server version is 5.0.15.

Connectior is of version 1.0.7, .NET framework 1.1.

Will it be paid attention to?

Hey! Is anyone here!

Does it not concern anyone?

Pavel

Yes, someone is here and this does concern us. We are looking at this issue.

Pavel

Yes, someone is here and this does concern us. We are looking at this issue.

How it is going?

More than 1 month have passed.

It seems that it's not just this but whenever cmd.ExecuteReader() is called MySqlDataReader is leaving non-disposed objects.

What's the status of this bug?

Pavel

What profiler are you using and can you post the code that shows the problem?

I've executed a stored procedure inside a using block and checked with the ANTS profiler and found no object not collected.  One thing you should be aware of is that the garbage collector in .NET does not run that often.  In my test, I put the code that executed the sproc inside a method and then called that method followed by a call to GC.Collect.  This will force a garbage collection and make sure that any objects that will  eventually be collected are collected immediately.  I then take a snapshot using the profiler and look for any MySQL related objects.

No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".