I know that it is not a big problem for most users, but allowing a very
large number of notifications while using linear search is a bit dumb.
I can fix this with a very small modification to
struct Notification:
{char *channel ;char *payload ;uint32 hash ;struct Notification *left ;struct Notification *right ;
}
AsyncExistsPendingNotify does an iterative binary tree search.
The tree is insert-only, there is no need for rebalancing, and the code
is quite simple.
Any comments?