TestPoolItem ctor 1, dtor 0, count 1
Thread main: items in use: 1
TestPoolItem ctor 2, dtor 0, count 2
Thread extra: items in use: 1
TestPoolItem ctor 3, dtor 0, count 3
Thread main: items in use: 2
TestPoolItem ctor 4, dtor 0, count 4
Thread extra: items in use: 2
TestPoolItem ctor 4, dtor 0, count 4
Thread main: items in use: 1
TestPoolItem ctor 4, dtor 0, count 4
Thread extra: items in use: 1
TestPoolItem ctor 4, dtor 0, count 4
Thread main: items in use: 2
TestPoolItem ctor 4, dtor 0, count 4
Thread extra: items in use: 2
TestPoolItem ctor 5, dtor 0, count 5
Thread main: items in use: 3
TestPoolItem ctor 6, dtor 0, count 6
Thread extra: items in use: 3
TestPoolItem ctor 7, dtor 0, count 7
Thread main: items in use: 4
TestPoolItem ctor 8, dtor 0, count 8
Thread extra: items in use: 4
TestPoolItem ctor 8, dtor 0, count 8
Thread main: items in use: 3
TestPoolItem ctor 8, dtor 0, count 8
Thread extra: items in use: 3
TestPoolItem ctor 8, dtor 1, count 7
Thread main: items in use: 2
TestPoolItem ctor 8, dtor 2, count 6
Thread extra: items in use: 2
TestPoolItem ctor 8, dtor 3, count 5
Thread main: items in use: 1
TestPoolItem ctor 8, dtor 4, count 4
Thread extra: items in use: 1
TestPoolItem ctor 8, dtor 5, count 3
Thread main: items in use: 0
TestPoolItem ctor 8, dtor 6, count 2
Thread extra: items in use: 0
Thread main is DONE.
main: Joining extra
Thread extra is DONE.
main: joined extra
