Synchronous calls to the same mainloop

[Havoc Pennington]

Havoc Pennington wrote:
> 
> This has a couple of problems; one is that the connection may not be to 
> a bus, so no unique name. Two is that it dispatches while blocking, 
> which the current API guarantees will not happen.
> 
> The answer right now is that to do what you want you must use a 
> nonblocking API or you must use threads.
> 
> A larger answer might be one of the "call stack ID" kind of ideas, but 
> nobody has really tried to figure out in detail how that would work, 
> what API and protocol changes would be involved, etc.

I guess this is a little misleading answer; as Thiago says we did have a 
thread where we decided there were some real disadvantages to the "call 
stack ID" thing in theory (it could not solve all the cases, so really 
just made deadlock bugs more heisenbug-like instead of fixing them).

If we were going to reconsider this it would probably be important to 
dig that thread out of the archives and review some of the thinking.

Anyway, figuring out the API and protocol isn't quite enough, the 
higher-level discussion of whether it's a good idea in the first place 
would also need revisiting.

Havoc