locking

Using the synchronized keyword method, using the javap command to view the bytecode, it is found that monitor is used, and if it is possible to call the monitor when the synchronized is implemented, is that my understanding, right? Please correct it if you do not. What is the relationship between them? What is the relationship between the lock and the monitor? From the official documentation of Locks and Synchronization ( https://docs.oracle.com/javase/tutorial/essential/concurrency/locksync.html ): Synchronization is built around an internal entity known as the intrinsic lock or monitor lock

I've got some multi threaded code I'd like to increase the performace of a bit, so I'm wondering if I can get rid of a lock. I've got a field member: private IList<ServerStatus> status; It's updated in a thread like so: status = GetUpdatedStatus(); And it's used in another thread like this: var currentStatus = status; So the question is, can the above yield any problems without locks around the two assignment statements ? I guess the only scenario I can see is currentStatus being null, but then again I'd expect an assignment to be somewhat thread-safe (either it has changed the reference or

I was reading about threading and about locking. It is common practise that you can't (well should not) lock a value type. So the question is, what is the recommended way of locking a value type? I know there's a few ways to go about doing one thing but I haven't seen an example. Although there was a good thread on MSDN forums but I can't seem to find that now. Thanks Use another object for the lock. int valueType; object valueTypeLock = new object(); void Foo() { lock (valueTypeLock) { valueType = 0; } } Kent Boogaart Your question is worded in such a way that it suggests to me that you don't

Update: It is acceptable if this method is not thread safe, but I'm interested in learning how I would make it thread safe. Also, I do not want to lock on a single object for all values of key if I can avoid it. Original Question: Suppose I want to write a higher order function that takes a key and a function, and checks if an object has been cached with the given key. If is has, the cached value is returned. Otherwise, the given function is run and the result is cached and returned. Here's a simplified version of my code: public static T CheckCache<T>(string key, Func<T> fn, DateTime expires)

Dupe: return statement in a lock procedure: inside or outside The title is a little misleading. I know that you can do it, but I'm wondering about the performance implications. consider these two blocks of code. (no error handling) This block has the return outside of the lock public DownloadFile Dequeue() { DownloadFile toReturn = null; lock (QueueModifierLockObject) { toReturn = queue[0]; queue.RemoveAt(0); } return toReturn; } This block has the return statement within the lock public DownloadFile Dequeue() { lock (QueueModifierLockObject) { DownloadFile toReturn = queue[0]; queue.RemoveAt

What is the best way to find the SQL locks along wih the user associated with that lock in SQL Server 2008? Remus Rusanu select * from sys.dm_tran_locks will list all current locks, granted or pending, along with the requesting session id. select * from sys.dm_exec_sessions will list all current sessions, including the client host and login name. But going this way is very seldom what you want. For a more digestible form, use the Activity Monitor and watch the blocking as reported there. Carlos Run this against the master db: SELECT spid,blocked,program_name,loginame,hostname,lastwaittype,*

I haven't had any issues using the same lock for multiple methods so far, but I'm wondering if the following code might actually have issues (performance?) that I'm not aware of: private static readonly object lockObj = new object(); public int GetValue1(int index) { lock(lockObj) { // Collection 1 read and/or write } } public int GetValue2(int index) { lock(lockObj) { // Collection 2 read and/or write } } public int GetValue3(int index) { lock(lockObj) { // Collection 3 read and/or write } } The 3 methods and the collections are not related in anyway. In addition, will it be a problem if this