locking

I am developing an application that needs to display a passcode screen whenever a user leaves the app and comes back (be it through a screen lock, or going back to the home screen through the back or home button). I had it working using the following: The starting activity would call for the passcode check on startup, and each activity added the following functionality to their onPause method: @Override public void onPause() { super.onPause(); if (!isFinishing()) { new PasscodeCheckTask(this.getApplicationContext(),this).execute(); } } The PassocdeCheckTask looks like the following. It checks

I have an ASP.NET site with a fairly slow search function, and I want to improve performance by adding the results to the cache for one hour using the query as the cache-key: using System; using System.Web; using System.Web.Caching; public class Search { private static object _cacheLock = new object(); public static string DoSearch(string query) { string results = ""; if (HttpContext.Current.Cache[query] == null) { lock (_cacheLock) { if (HttpContext.Current.Cache[query] == null) { results = GetResultsFromSlowDb(query); HttpContext.Current.Cache.Add(query, results, null, DateTime.Now.AddHours

I have a large table that get populated from a view. This is done because the view takes a long time to run and it is easier to have the data readily available in a table. A procedure is run every so often that updates the table. TRUNCATE TABLE LargeTable INSERT INTO LargeTable SELECT * FROM viewLargeView WITH (HOLDLOCK) I would like to lock this table when inserting so if someone tries to select a record they will not receive none after the truncate. The lock I am using seems to lock the view and not the table. Is there a better way to approach this problem? Darren BEGIN TRY BEGIN TRANSACTION

I was wondering if anyone had a relatively simple solution for us. We created an app to be used by our clients on android devices that we give them. We would like the client to only be able to use our app and have limited access to everything else (i.e. settings, email etc.) What is the best way to achieve this without using 3rd party apps. Thank you in advance! This may not help but the L preview has a task locking feature included that may be of some insight, I'm not aware of how it functions as yet Task locking The L Developer Preview introduces a new task locking API that lets you

When a process in the kernel space is holding a spin_lock , the process cannot be preempted due to any of the following conditions : When the time-slice of the process gets exhausted When a high priority process becomes runnable When an interrupt occurs However the process can yield the processor if it blocks, sleeps, or explicitly call schedule() . Is my understanding correct? When a process in the kernel space is holding a mutex_lock , can the process be preempted due to the above conditions listed as 1, 2 and 3. Current implementations of spin locks use two entirely separate mechanisms to

Is there a way to ensure that blocked threads get woken up in the same order as they got blocked? I read somewhere that this would be called a "strong lock" but I found no resources on that. On Mac OS X one can design a FIFO queue that stores all the thread ids of the blocked threads and then use the nifty function pthread_cond_signal_thread_np() to wake up one specific thread - which is obviously non-standard and non-portable. One way I can think of is to use a similar queue and at the unlock() point send a broadcast() to all threads and have them check which one is the next in line. But this