Previously:
* applications were using isc_app as the base unit for running the
application and signal handling.
* networking was handled in the netmgr layer, which would start a
number of threads, each with a uv_loop event loop.
* task/event handling was done in the isc_task unit, which used
netmgr event loops to run the isc_event calls.
In this refactoring:
* the network manager now uses isc_loop instead of maintaining its
own worker threads and event loops.
* the taskmgr that manages isc_task instances now also uses isc_loopmgr,
and every isc_task runs on a specific isc_loop bound to the specific
thread.
* applications have been updated as necessary to use the new API.
* new ISC_LOOP_TEST macros have been added to enable unit tests to
run isc_loop event loops. unit tests have been updated to use this
where needed.
This commit introduces new APIs for applications and signal handling,
intended to replace isc_app for applications built on top of libisc.
* isc_app will be replaced with isc_loopmgr, which handles the
starting and stopping of applications. In isc_loopmgr, the main
thread is not blocked, but is part of the working thread set.
The loop manager will start a number of threads, each with a
uv_loop event loop running. Setup and teardown functions can be
assigned which will run when the loop starts and stops, and
jobs can be scheduled to run in the meantime. When
isc_loopmgr_shutdown() is run from any the loops, all loops
will shut down and the application can terminate.
* signal handling will now be handled with a separate isc_signal unit.
isc_loopmgr only handles SIGTERM and SIGINT for application
termination, but the application may install additional signal
handlers, such as SIGHUP as a signal to reload configuration.
* new job running primitives, isc_job and isc_async, have been added.
Both units schedule callbacks (specifying a callback function and
argument) on an event loop. The difference is that isc_job unit is
unlocked and not thread-safe, so it can be used to efficiently
run jobs in the same thread, while isc_async is thread-safe and
uses locking, so it can be used to pass jobs from one thread to
another.
* isc_tid will be used to track the thread ID in isc_loop worker
threads.
* unit tests have been added for the new APIs.
Luckily we don't rely on SphinxDirective functionality which does not
exist in 1.6.7. Replace it with docutils Directive.
transform_content() callback was added only in Sphinx 3.0.0.
Detect if it was not called and call it manually.
The transform_content() function requires access to inner "contentnode"
which is created inside run(). This workaround relies on the order of
node as it was in the pre-3.0.0 versions, but it should not matter as
new versions will not trigger the workaround.
Since !6413 we discourage opt-out, so we should not be advertising it in
the examples. Even worse, it was just thrown into the command line
without even mentioning its meaning in the surrounding text.
Related: !6413
The "max-zone-ttl" option should now be configured as part of
"dnssec-policy". The option with the same name in "zone" and
"options" is hereby flagged as deprecated, and its functionality
will be removed in a future release.
Remove "external" from the list of legal values for the -M command-line
option as it has not been allowed since the internal memory allocator
was removed by commit 55ace5d3aa.
Make the style of the relevant paragraph more in line with the next one
and split its contents up into an unordered list of options for improved
readability.
Ondřej Surý
Matthijs Mekking
Michal Nowak
Michał Kępień
Aram Sargsyan
Petr Špaček
Suzanne GoldlustandPetr Špaček
Mark Andrews
Evan Hunt
Greg ChoulesandPetr Špaček