Ok this looks like a major fundamental bug in .NET:
Consider the following simple program, which purposely tries to connect to a non-existent database:
class Program
{
static void Main(string[] args)
{
Thread threadOne = new Thread(GetConnectionOne);
Thread threadTwo = new Thread(GetConnectionTwo);
threadOne.Start();
threadTwo.Start();
}
static void GetConnectionOne()
{
try
{
using (SqlConnection conn = new SqlConnection("Data Source=.\\wfea;Initial Catalog=zc;Persist Security Info=True;Trusted_Connection=yes;"))
{
conn.Open();
}
} catch (Exception e)
{
File.AppendAllText("ConnectionOneError.txt", e.Message + "\n" + e.StackTrace + "\n");
}
}
static void GetConnectionTwo()
{
try
{
using (SqlConnection conn = new SqlConnection("Data Source=.\\wfea;Initial Catalog=zc;Persist Security Info=True;Trusted_Connection=yes;"))
{
conn.Open();
}
}
catch (Exception e)
{
File.AppendAllText("ConnectionTwoError.txt", e.Message + "\n" + e.StackTrace + "\n");
}
}
}
Run this program and set breakpoints on the catch blocks. The DBConnection object will attempt to connect for 15 seconds (on both threads), then it will throw an error. Inspect the exception's stack trace, and the stack trace will have TWO call stacks intermingled, as follows:
at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject)
at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)
at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)
at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbCo