You’re probably looking forwith (updlock, holdlock). This will make a select grab an exclusive lock, which is required for updates, instead of a shared lock. The holdlock hint tells SQL Server to keep the lock until the transaction ends. FROM TABLE_ITEM with (updlock, holdlock)
The technique you describe isn’t just common: it’s the one technique that has been proven to work all the time. There are a few other rules you should follow when coding threaded code in C++, though, among which the most important may be: don’t hold a lock when calling a virtual function: even if at … Read more
Files accessed through a share will be locked by the system process (PID 4). Try opening compmgmt.msc -> System Tools -> Shared Folders -> Open Files to see if the locked file is listed there See also the sysinternals forum for a way to replicate this. Not all applications lock files when they are opened, … Read more
I like to beat dead horses! 🙂 The “lightest” way to increment the count from multiple threads is: Interlocked.Increment(ref count); But as others have pointed out: if you’re doing it inside Parallel.ForEach then you’re probably doing something wrong. I’m suspecting that for some reason you’re using ForEach but you need an index to the item … Read more
In order to call wait() on an object, you have to hold the synchronized lock on that object (though the lock is actually released while the thread is waiting): synchronized (serverAddr) { serverAddr.wait(); } I have to admit that why you’re wanting to do this baffles me in this case…
You want the OMP_SET_LOCK/OMP_UNSET_LOCK functions: https://hpc.llnl.gov/tuts/openMP/#OMP_SET_LOCK Basically: omp_lock_t writelock; omp_init_lock(&writelock); #pragma omp parallel for for ( i = 0; i < x; i++ ) { // some stuff omp_set_lock(&writelock); // one thread at a time stuff omp_unset_lock(&writelock); // some stuff } omp_destroy_lock(&writelock); Most locking routines such as pthreads semaphores and sysv semaphores work on that … Read more
Should work in Windows: File file = new File(“file.txt”); boolean fileIsNotLocked = file.renameTo(file);