The code synchronizes on a boxed primitive constant, such as an Integer.

private static Integer count = 0;
...
  synchronized(count) { 
     count++;
     }
...

Since Integer objects can be cached and shared, this code could be synchronizing on the same object as other, unrelated code, leading to unresponsiveness and possible deadlock

This rule is deprecated, use {rule:squid:S1860} instead.