Instead of letting http_requests spin, if we cannot allocate
a connection for the request we will queue them up put them to sleep.
When a connection becomes available, we'll wake up a request that
was waiting for a connection and let it continue.
This completely avoids consuming massive amounts of cpu time
when dealing with thousands of requests waiting for a pgsql
worker to become ready.
Gone is the ugly KORE_PGSQL macro that hid an overly complex
state machine for the pgsql api.
Gone is the pgsql array that was attached to http_requests.
Gone are the callback hacks inside the pgsql api.
Instead, I strongly encourage people to use the new state machine
api Kore offers to properly deal with asynchronous queries.
The pgsql example in examples/pgsql has been updated to reflect
these changes.
These 2 functions can be used to move an HTTP request
from/to the active http_requests list. Effectively
putting them to "sleep" or "waking them up".
Sprinkle this through the pgsql and task code.
If used correctly greatly reduces overhead for
managing sleeping tasks.
Joris Vink