Previously, netmgr, taskmgr, timermgr and socketmgr all had their own
isc_<*>mgr_create() and isc_<*>mgr_destroy() functions. The new
isc_managers_create() and isc_managers_destroy() fold all four into a
single function and makes sure the objects are created and destroy in
correct order.
Especially now, when taskmgr runs on top of netmgr, the correct order is
important and when the code was duplicated at many places it's easy to
make mistake.
The former isc_<*>mgr_create() and isc_<*>mgr_destroy() functions were
made private and a single call to isc_managers_create() and
isc_managers_destroy() is required at the program startup / shutdown.
This commit changes the taskmgr to run the individual tasks on the
netmgr internal workers. While an effort has been put into keeping the
taskmgr interface intact, couple of changes have been made:
* The taskmgr has no concept of universal privileged mode - rather the
tasks are either privileged or unprivileged (normal). The privileged
tasks are run as a first thing when the netmgr is unpaused. There
are now four different queues in in the netmgr:
1. priority queue - netievent on the priority queue are run even when
the taskmgr enter exclusive mode and netmgr is paused. This is
needed to properly start listening on the interfaces, free
resources and resume.
2. privileged task queue - only privileged tasks are queued here and
this is the first queue that gets processed when network manager
is unpaused using isc_nm_resume(). All netmgr workers need to
clean the privileged task queue before they all proceed normal
operation. Both task queues are processed when the workers are
finished.
3. task queue - only (traditional) task are scheduled here and this
queue along with privileged task queues are process when the
netmgr workers are finishing. This is needed to process the task
shutdown events.
4. normal queue - this is the queue with netmgr events, e.g. reading,
sending, callbacks and pretty much everything is processed here.
* The isc_taskmgr_create() now requires initialized netmgr (isc_nm_t)
object.
* The isc_nm_destroy() function now waits for indefinite time, but it
will print out the active objects when in tracing mode
(-DNETMGR_TRACE=1 and -DNETMGR_TRACE_VERBOSE=1), the netmgr has been
made a little bit more asynchronous and it might take longer time to
shutdown all the active networking connections.
* Previously, the isc_nm_stoplistening() was a synchronous operation.
This has been changed and the isc_nm_stoplistening() just schedules
the child sockets to stop listening and exits. This was needed to
prevent a deadlock as the the (traditional) tasks are now executed on
the netmgr threads.
* The socket selection logic in isc__nm_udp_send() was flawed, but
fortunatelly, it was broken, so we never hit the problem where we
created uvreq_t on a socket from nmhandle_t, but then a different
socket could be picked up and then we were trying to run the send
callback on a socket that had different threadid than currently
running.
Since all the libraries are internal now, just cleanup the ISCAPI remnants
in isc_socket, isc_task and isc_timer APIs. This means, there's one less
layer as following changes have been done:
* struct isc_socket and struct isc_socketmgr have been removed
* struct isc__socket and struct isc__socketmgr have been renamed
to struct isc_socket and struct isc_socketmgr
* struct isc_task and struct isc_taskmgr have been removed
* struct isc__task and struct isc__taskmgr have been renamed
to struct isc_task and struct isc_taskmgr
* struct isc_timer and struct isc_timermgr have been removed
* struct isc__timer and struct isc__timermgr have been renamed
to struct isc_timer and struct isc_timermgr
* All the associated code that dealt with typing isc_<foo>
to isc__<foo> and back has been removed.
Previously, the taskmgr, timermgr and socketmgr had a constructor
variant, that would create the mgr on top of existing appctx. This was
no longer true and isc_<*>mgr was just calling isc_<*>mgr_create()
directly without any extra code.
This commit just cleans up the extra function.
Previously isc_thread_join() would return ISC_R_UNEXPECTED on a failure to
create new thread. All such occurences were caught and wrapped into assert
function at higher level. The function was simplified to assert directly in the
isc_thread_join() function and all caller level assertions were removed.
Previously isc_thread_create() would return ISC_R_UNEXPECTED on a failure to
create new thread. All such occurences were caught and wrapped into assert
function at higher level. The function was simplified to assert directly in the
isc_thread_create() function and all caller level assertions were removed.
Using isc_mem_put(mctx, ...) + isc_mem_detach(mctx) required juggling with the
local variables when mctx was part of the freed object. The isc_mem_putanddetach
function can handle this case internally, but it wasn't used everywhere. This
commit apply the semantic patching plus bit of manual work to replace all such
occurrences with proper usage of isc_mem_putanddetach().
This work cleans up the API which includes couple of things:
1. Make the isc_appctx_t type fully opaque
2. Protect all access to the isc_app_t members via stdatomics
3. sigwait() is part of POSIX.1, remove dead non-sigwait code
4. Remove unused code: isc_appctx_set{taskmgr,sockmgr,timermgr}
The race condition is the timer elapses before isc__timer_create()
returns the pointer to the caller. Assigning the return pointer before
enabling the timer will fix it.
3818. [bug] Stop lying to the optimizer that 'void *arg' is a
constant in isc_event_allocate.
(cherry picked from commit 39b52695771532e3df0c83a9b6683f899afa403a)
to 10. Allow setting this in named.conf using the new
'resolver-query-timeout' option, which specifies a max
time in seconds. 0 means 'default' and anything longer
than 30 will be silently set to 30. [RT #22852]
