Before kore needed to be built with NOTLS=1 to be able to do non TLS
connections. This has been like this for years.
It is time to allow non TLS listeners without having to rebuild Kore.
This commit changes your configuration format and will break existing
applications their config.
Configurations now get listener {} contexts:
listen default {
bind 127.0.0.1 8888
}
The above will create a listener on 127.0.0.1, port 8888 that will serve
TLS (still the default).
If you want to turn off TLS on that listener, specify "tls no" in that
context.
Domains now need to be attached to a listener:
Eg:
domain * {
attach default
}
For the Python API this kills kore.bind(), and kore.bind_unix(). They are
replaced with:
kore.listen("name", ip=None, port=None, path=None, tls=True).
Now anyone can schedule events and get a callback to work as long
as the user data structure that is added for the event begins
with a kore_event data structure.
All event state is now kept in that kore_event structure and renamed
CONN_[READ|WRITE]_POSSIBLE to KORE_EVENT_[READ|WRITE].
The HTTP layer used to make a copy of each incoming header and its
value for a request. Stop doing that and make HTTP headers zero-copy
all across the board.
This change comes with some api function changes, notably the
http_request_header() function which now takes a const char ** rather
than a char ** out pointer.
This commit also constifies several members of http_request, beware.
Additional rework how the worker processes deal with the accept lock.
Before:
if a worker held the accept lock and it accepted a new connection
it would release the lock for others and back off for 500ms before
attempting to grab the lock again.
This approach worked but under high load this starts becoming obvious.
Now:
- workers not holding the accept lock and not having any connections
will wait less long before returning from kore_platform_event_wait().
- workers not holding the accept lock will no longer blindly wait
an arbitrary amount in kore_platform_event_wait() but will look
at how long until the next lock grab is and base their timeout
on that.
- if a worker its next_lock timeout is up and failed to grab the
lock it will try again in half the time again.
- the worker process holding the lock will when releasing the lock
double check if it still has space for newer connections, if it does
it will keep the lock until it is full. This prevents the lock from
bouncing between several non busy worker processes all the time.
Additional fixes:
- Reduce the number of times we check the timeout list, only do it twice
per second rather then every event tick.
- Fix solo worker count for TLS (we actually hold two processes, not one).
- Make sure we don't accidentally miscalculate the idle time causing new
connections under heavy load to instantly drop.
- Swap from gettimeofday() to clock_gettime() now that MacOS caught up.
This basically turns off the HTTP layer for Kore. It does not
compile in anything for HTTP.
This allows Kore to be used as a network application platform as well.
Added an example for this called nohttp.
Other changes that sneaked in while hacking on this:
* Use calloc(), kill pendantic malloc option.
* Killed off SPDY/3.1 support completely, will be superseded by http2
Note that comes with massive changes to a lot of the core API
functions provided by Kore, these might break your application.
Before Kore would spawn a task thread per task started
if none were available. This was an obvious bad idiom
but never really hit me hard until now.
Kore will now only spawn as many task threads as configured
by "task_threads" and queue up any newly started tasks ontop
of already running threads if the limit was hit.
Do not blindly close the sockets created by socketpair() when
finishing up or destroying a task.
Under heavy load this could turn into a race condition where
the task thread closes its endpoint when at the same time
a new task is registered and socketpair() returns the recently
closed socket back to a new task.
When the task that finished then gets destroyed it closes
the endpoint registered to a new task instead causing Kore
to fatal() out when attempting to read from said socket.
* Always start listening on the task its socket endpoint when
called kore_task_run() instead of at kore_task_bind_request().
* Disable read events on the task its socket endpoint when
kore_task_handle() is called for a finished task. Stops us
from entering a busy loop until kore_task_destroy() is called.
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.
Synchronize access to state/result properly so one
can access these from inside the task as well.
Introduce KORE_TASK_STATE_ABORT which will be set
when a task needs to be abort. You can use this
to create tasks that run in a loop until aborted.
Joris Vink