Let's say I have a Counter model that saves a value that needs to be increased with every call to increaseValue(). How can I safely do this?

// This function needs to be safe from being executed concurrently

function increaseValue()

{

   $c = Counter::first();

   $c->value = $c->value + 1;

   $c->save();

}

Let's say two users simultaneously request a page that increase this counter (The infamous visitor counter). How can I prevent that user 1 reads the current count (say 300) and adds 1 to it, while user 2 simultaneously does the same?

Last updated 8 years ago

I missed the part of the documentation about pessimistic locking. So one can lock the table using lockForUpdate() like in:

Db::table('users')->where('votes', '>', 100)->lockForUpdate()->get();