[Performance counter] Gen 0 heap size [Description] 
Displays the maximum bytes that can be allocated in generation 0; it does not indicate the current number of bytes allocated in generation 0. A generation 0 garbage collection occurs when the allocations since the last collection exceed this size. The generation 0 size is tuned by the garbage collector and can change during the execution of the application. At the end of a generation 0 collection the size of the generation 0 heap is 0 bytes. This counter displays the size, in bytes, of allocations that invokes the next generation 0 garbage collection. This counter is updated at the end of a garbage collection, not at each allocation.