race-condition

I am fresh to jQuery's implementation of it's AJAX methods. I have a simple setup that accesses two different pages, one which takes 10 seconds to complete (I have a timer set on it) and one which checks on the status of the first page. The two functions are progressCheck() which requests its page every second with the latest status and beginLogin() which takes 10 seconds to load. I set a value in the user object on the server that both pages access through symfony 1.4. The issue is that the progressCheck() works correctly until I click beginLogin() , then no changes are made until beginLogin(

I would like to apply a reduce on this piece of my kernel code (1 dimensional data): __local float sum = 0; int i; for(i = 0; i < length; i++) sum += //some operation depending on i here; Instead of having just 1 thread that performs this operation, I would like to have n threads (with n = length) and at the end having 1 thread to make the total sum. In pseudo code, I would like to able to write something like this: int i = get_global_id(0); __local float sum = 0; sum += //some operation depending on i here; barrier(CLK_LOCAL_MEM_FENCE); if(i == 0) res = sum; Is there a way? I have a race

I was wondering whether it's easy to make a race condition using MRI ruby(2.0.0) and some global variables, but as it turns out it's not that easy. It looks like it should fail at some point, but it doesn't and I've been running it for 10 minutes. This is the code I've been trying to achieve it: def inc(*) a = $x a += 1 a *= 3000 a /= 3000 $x = a end THREADS = 10 COUNT = 5000 loop do $x = 1 THREADS.times.map do Thread.new { COUNT.times(&method(:inc)) } end.each(&:join) break puts "woo hoo!" if $x != THREADS * COUNT + 1 end puts $x Why am I not able to generate (or detect) the expected race

I have a class in which I am populating a map liveSocketsByDatacenter from a single background thread every 30 seconds inside updateLiveSockets() method and then I have a method getNextSocket() which will be called by multiple reader threads to get a live socket available which uses the same map to get this information. public class SocketManager { private static final Random random = new Random(); private final ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor(); private final AtomicReference<Map<Datacenters, List<SocketHolder>>> liveSocketsByDatacenter = new

I know this has been asked before, but I'm still confused and would like to avoid any problems before I go into programming if possible. I plan on having an internal website with at least 100 users active at any given time. Users would post an item (inserted into db with a 0 as its value) and that item would be shown via a php site (db query). Users then get the option to press a button and lock that item as theirs (assign the value of that item as their id) How do I ensure that 2 or more users don't retrieve the same item at the same time. I know in programming like c++ I would just use plain

in my server/server.js Meteor.methods({ saveOnServer: function() { var totalCount = Collections.find({ "some": "condition" }).count(); if (totalCount) { var customerId = Collections.update('someId', { "$addToSet": { objects: object } }, function(err) { if (err) { throw err; } else { return true; } }); } else {} } }); I'm afraid that when saveOnServer() is called by 2 clients at the same time, it will return the same totalCount for each client and basically end up inserting same integer number into object id. The end goal is to insert row on the server side with an atomic operation that only

When using shared memory, each process may mmap the shared region into a different area of its respective address space. This means that when storing pointers within the shared region, you need to store them as offsets of the start of the shared region. Unfortunately, this complicates use of atomic instructions (e.g. if you're trying to write a lock free algorithm ). For example, say you have a bunch of reference counted nodes in shared memory, created by a single writer. The writer periodically atomically updates a pointer 'p' to point to a valid node with positive reference count. Readers

I just wonder whether a race condition occurs in the code below: int readingFiles; async Task<string> ReadFile (string file) { ++readingFiles; var text = await Stream.ReadFileAsync(file); --readingFiles; return text; } If ReadFile method is executed by a thread pool thread, readingFiles will be accessed by two different threads and the readingFiles variable is not protected by any synchronization idioms. It means that the first update to readingFiles should not be visible to the other thread executing "--readingFiles". However, I've NEVER seen that readingFiles equals -1 after "--readingFiles"