of course - SRW lock allow shared access only if no waiters ( request to exclusive access) on lock. so even if lock in shared mode, new shared request can bloc

of course - SRW lock allow shared access only if no waiters ( request to exclusive access) on lock. so even if lock in shared mode, new shared request can block, if was waiter(exclusive) already. in case OP no exactly this, but anyway - i be say that shared access is only hint to system, that it can optimize access - and allow multiple shared threads inside lock. but this was not always