A tool to synchronize objects:
Objects derived from AISyncClient can signal that they are
'ready' or 'not ready' for up to 32 events (using a bitmask)
at a time. Clients that are created at roughly the same time
as other clients, and which return the same 'key' (a virtual
function returning an AISyncKey object) will be grouped together
and receive events (by means of virtual functions being called)
to notify them of all clients being ready or not for one of the
events (the least significant bit)). The other events can be polled.
This new version does away with all the templates and explicitly
remembers what events each client is ready for instead of just
updating a counter of the number of clients. This was necessary
because a client is removed then the server needs to know if it
was ready or not when it has to be able to update those counters.
This time I chose to just run over all stored clients and AND
and OR the per-client-ready-masks because 1) that information
is available now and 2) the lists will normally contain only
one or two clients, so it's fast enough.
The new version also allows for real key comparison (and derived
keys) instead of just using "hash" value that is compared.
A tool to synchronize objects:
Objects derived from AISyncClient can signal that they are
'ready' or 'not ready' for up to 4 events (using a bitmask)
at a time. Clients that signal to be ready for anything
at roughly the same time as other clients, and which return
the same 'hash' (a virtual function returning a 64bit value)
will be grouped together and receive events (by means of
virtual functions being called) to notify them of all clients
being ready or not for one of the events (syncevent1).
The other three events can be polled.
The memory usage is low (one pointer per client that points
to its AISyncServer object), servers are released to a cache
after about 100 ms (unless there is actual need for synchronization),
so there aren't much of those either.
The CPU usage is extremely low: all events are handled in
parallel in a 32 bit value (6 bits per event to count the
number of registered clients and the number of ready clients
for each event, and the remaining 8 bits to count the
number of reference pointers (which should only be a constant
higher, so that is overkill). To signal to a server that
a client has become ready or not is mostly a function call,
which then takes 1 clock cycle or so before returning.
Registration of a client is slightly more expensive as it
requires a pointer to be added to the end of a std::list.
This tool could easily be used as part of the graphics engine
(not that I intend to do that :p).
