deadlock

I have the following code: Note: I simplified the code as much as possible for readability. If I forgot any critical pieces let me know. public class User(){ private Relations relations; public User(){ relations = new Relations(this); } public getRelations(){ return relations; } } public class Relations(){ private User user; public Relations(User user){ this.user = user; } public synchronized void setRelation(User user2){ Relations relations2 = user2.getRelations(); synchronized(relations2){ storeRelation(user2); if(!relations2.hasRelation(user)) relations2.setRelation(user); } } public

Ive got a thread that does some work in the background and passes updates to the Form using the Invoke, BeginInvoke methods. The thread is created after the form is displayed so no issue there. The issue is how to correctly shutdown. My worker thread has the ability to be asked to exit, and will exit some time soon after that (miliseconds). However if the form has closed first the Invoke stuff breaks. I tried adding a Thread.Join to the forms closing event, but of course this causes a deadlock, even for BeginInvoke since somhow a Thread.Join blocks a BeginInvoke on that thread... What is the

I think this is going to be one of those simple-when-you-see-it problems, but it has got me baffled. [ STOP PRESS: I was right. Solution was found. See the answers. ] I am using Python's unittest framework to test a multi-threaded app. Nice and straight forward - I have 5 or so worker threads monitoring a common queue, and a single producer thread making work-items for them. The producer thread is being triggered by a test-case. In this test, only one task is being put on the queue. The processing it does is in the test is just a stub for the real processing, so the worker thread does a 5

I've programmed in a number of languages, but I am not aware of deadlocks in my code. I took this to mean it doesn't happen. Does this happen frequently (in programming, not in the databases) enough that I should be concerned about it? Deadlocks could arise if two conditions are true: you have mutilple theads, and they contend for more than one resource. Do you write multi-threaded code? You might do this explicitly by starting your own threads, or you might work in a framework where the threads are created out of your sight, and so you're running in more than one thread without you seeing

I have a code in C# for windows service which is mainly responsible to update records in a table in my database, but I get always a lot of errors in my log, all errors are about deadlock of resource, This is the error: System.Data.SqlClient.SqlException (0x80131904): Transaction (Process ID 57) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction. at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action 1 wrapCloseInAction) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning

I have an issue with a deadlock in SQL Server that I haven't been able to resolve. Basically I have a large number of concurrent connections (from many machines) that are executing transactions where they first delete a range of entries and then re-insert entries within the same range with a bulk insert. Essentially, the transaction looks like this BEGIN TRANSACTION T1 DELETE FROM [TableName] WITH( XLOCK HOLDLOCK ) WHERE [Id]=@Id AND [SubId]=@SubId INSERT BULK [TableName] ( [Id] Int , [SubId] Int , [Text] VarChar(max) COLLATE SQL_Latin1_General_CP1_CI_AS ) WITH(CHECK_CONSTRAINTS, FIRE_TRIGGERS