description: #⁠ Avoid deadlocks by connection reusage:
#⁠* Assume that you have both an IDbSet<T1> and IDbSet<T2>
#⁠* Use a TransactionScope()
#⁠* Create the DbContext
#⁠* Create an instance of T1 where you initialize a property T1.X with an instance of T2 queried from the IDbSet<T2>
#⁠* Add the instance of T1 to the IDbSet<T1>
#⁠* Call SaveChanges()
#⁠* Results in a no wait lock because:
#⁠** Adding the instance of T1 partially loads the IDbSet<T1> and therefore creates a lock on the table
#⁠** SaveChanges() reopens the existing connection which produces a new FbConnectionInternal which tries to write something to a locked table
#⁠* Solution: Reuse the internal connection when the FbConnection gets reopened
#⁠ Allow usage of CreateDatabaseIfNotExists DB initializer
#⁠* There's a call to context.Database.Exists() while a new TransactionScope(TransactionScopeOption.Suppress) is active
#⁠* Solution: Allow Enlist without an active transaction

=>

1. Avoid deadlocks by connection reusage:
- Assume that you have both an IDbSet<T1> and IDbSet<T2>
- Use a TransactionScope()
- Create the DbContext
- Create an instance of T1 where you initialize a property T1.X with an instance of T2 queried from the IDbSet<T2>
- Add the instance of T1 to the IDbSet<T1>
- Call SaveChanges()
- Results in a no wait lock because:
- Adding the instance of T1 partially loads the IDbSet<T1> and therefore creates a lock on the table
- SaveChanges() reopens the existing connection which produces a new FbConnectionInternal which tries to write something to a locked table
- Solution: Reuse the internal connection when the FbConnection gets reopened
2. Allow usage of CreateDatabaseIfNotExists DB initializer
- There's a call to context.Database.Exists() while a new TransactionScope(TransactionScopeOption.Suppress) is active
- Solution: Allow Enlist without an active transaction

Attachment: DNET524-0001.patch [ 12380 ]

Attachment: UnitTests.patch [ 12381 ]

status: Open [ 1 ] => Closed [ 6 ]

resolution: Incomplete [ 4 ]