Bug #114390 Calling ef6 sync method with high concurrency would be deadlocking
Submitted: 18 Mar 2024 13:16 Modified: 25 Mar 2024 12:32
Reporter: Michael Scofield Scofield Email Updates:
Status: Verified Impact on me:
None 
Category:Connector / NET Severity:S1 (Critical)
Version:8.3.0 OS:Windows (windows 11)
Assigned to: CPU Architecture:Any

[18 Mar 2024 13:16] Michael Scofield Scofield 
Description:
asp.net webapp with ef6 and mysql.data.entityframework sync method like IQueryable.Count, IQueryable.ToList, in high concurrency the connection has on ressponse. 
eg:
        public int GetCount()
        {
            var count = SampleDbContext
                .Projects
                .AsQueryable()
                .Count();

            return count;
        }

How to repeat:
In asp.net mvc or webapi controller call this method        
        public ActionResult Index()
        {
            var count = SampleDbContext
                .Projects
                .AsQueryable()
                .Count();

            return View();
        }

Suggested fix:
In MySql.Data and MySql.Data.EnetityFramework
change the sync method likes
    public override bool Read() => ReadAsync(false, CancellationToken.None).GetAwaiter().GetResult();
to 
    public override bool Read() => ReadAsync(false, CancellationToken.None).ConfigureAwait(false).GetAwaiter().GetResult();

or

use Fody.ConfigureAwait easily.
[19 Mar 2024 13:03] MySQL Verification Team 
Hello Michael,

Thank you for the bug report.
Could you please provide complete repeatable test case to reproduce this issue at our end?

Regards,
Ashwini Patil
[25 Mar 2024 12:32] MySQL Verification Team 
Hello Michael,

Thank you for the test code.
Verified as described.

Regards,
Ashwini Patil