Instead of having individual memory contexts scattered across different
files and called different names, add a single memory context called
isc_g_mctx that replaces named_g_mctx and various other global memory
contexts in various utilities and tests.
There is only a single network manager running on top of the loop
manager (except for tests). Refactor the network manager to be a
singleton (a single instance) and change the unit tests, so that the
shorter read timeouts apply only to a specific handle, not the whole
extra 'connect_nm' network manager instance.
All the applications built on top of the loop manager were required to
create just a single instance of the loop manager. Refactor the loop
manager to not expose this instance to the callers and keep the loop
manager object internal to the isc_loop compilation unit.
This significantly simplifies a number of data structures and calls to
the isc_loop API.
previously, dns_name_fromtext() took both a target name and an
optional target buffer parameter, which could override the name's
dedicated buffer. this interface is unnecessarily complex.
we now have two functions, dns_name_fromtext() to convert text
into a dns_name that has a dedicated buffer, and dns_name_wirefromtext()
to convert text into uncompressed DNS wire format and append it to a
target buffer.
in cases where it really is necessary to have both, we can use
dns_name_fromtext() to load the dns_name, then dns_name_towire()
to append the wire format to the target buffer.
the isc_mem allocation functions can no longer fail; as a result,
ISC_R_NOMEMORY is now rarely used: only when an external library
such as libjson-c or libfstrm could return NULL. (even in
these cases, arguably we should assert rather than returning
ISC_R_NOMEMORY.)
code and comments that mentioned ISC_R_NOMEMORY have been
cleaned up, and the following functions have been changed to
type void, since (in most cases) the only value they could
return was ISC_R_SUCCESS:
- dns_dns64_create()
- dns_dyndb_create()
- dns_ipkeylist_resize()
- dns_kasp_create()
- dns_kasp_key_create()
- dns_keystore_create()
- dns_order_create()
- dns_order_add()
- dns_peerlist_new()
- dns_tkeyctx_create()
- dns_view_create()
- dns_zone_setorigin()
- dns_zone_setfile()
- dns_zone_setstream()
- dns_zone_getdbtype()
- dns_zone_setjournal()
- dns_zone_setkeydirectory()
- isc_lex_openstream()
- isc_portset_create()
- isc_symtab_create()
(the exception is dns_view_create(), which could have returned
other error codes in the event of a crypto library failure when
calling isc_file_sanitize(), but that should be a RUNTIME_CHECK
anyway.)
Instead of cleaning the dns_badcache opportunistically, add per-loop
LRU, so each thread-loop can clean the expired entries. This also
allows removal of the atomic operations as the badcache entries are now
immutable, instead of updating the badcache entry in place, the old
entry is now deleted from the hashtable and the LRU list, and the new
entry is inserted in the LRU.
Remove the complicated mechanism that could be (in theory) used by
external libraries to register new categories and modules with
statically defined lists in <isc/log.h>. This is similar to what we
have done for <isc/result.h> result codes. All the libraries are now
internal to BIND 9, so we don't need to provide a mechanism to register
extra categories and modules.
New version of clang (19) has introduced a stricter checks when mixing
integer (and float types) with enums. In this case, we used enum {}
as C17 doesn't have constexpr yet. Change the time conversion constants
to be static const unsigned int instead of enum values.
dns_difftuple_create() could only return success, so change
its type to void and clean up all the calls to it.
other functions that only returned a result value because of it
have been cleaned up in the same way.
if we had a method to get the running loop, similar to how
isc_tid() gets the current thread ID, we can simplify loop
and loopmgr initialization.
remove most uses of isc_loop_current() in favor of isc_loop().
in some places where that was the only reason to pass loopmgr,
remove loopmgr from the function parameters.
by default, QPDB is the database used by named and all tools and
unit tests. the old default of RBTDB can now be restored by using
"configure --with-zonedb=rbt --with-cachedb=rbt".
some tests have been fixed so they will work correctly with either
database.
CHANGES and release notes have been updated to reflect this change.
replace the string "rbt" throughout BIND with "qp" so that
qpdb databases will be used by default instead of rbtdb.
rbtdb databases can still be used by specifying "database rbt;"
in a zone statement.
Because we don't use jemalloc functions directly, but only via the
libisc library, the dynamic linker might pull the jemalloc library
too late when memory has been already allocated via standard libc
allocator.
Add a workaround round isc_mem_create() that makes the dynamic linker
to pull jemalloc earlier than libc.
Reusing TCP connections with dns_dispatch_gettcp() used linear linked
list to lookup existing outgoing TCP connections that could be reused.
Replace the linked list with per-loop cds_lfht hashtable to speedup the
lookups. We use cds_lfht because it allows non-unique node insertion
that we need to check for dispatches in different connection states.
The dns_dispatchmgr object was only set in the dns_view object making it
prone to use-after-free in the dns_xfrin unit when shutting down named.
Remove dns_view_setdispatchmgr() and optionally pass the dispatchmgr
directly to dns_view_create() when it is attached and not just assigned,
so the dns_dispatchmgr doesn't cease to exist too early.
The dns_view_getdnsdispatchmgr() is now protected by the RCU lock, the
dispatchmgr reference is incremented, so the caller needs to detach from
it, and the function can return NULL in case the dns_view has been
already shut down.
This change makes the zone table lock-free for reads. Previously, the
zone table used a red-black tree, which is not thread safe, so the hot
read path acquired both the per-view mutex and the per-zonetable
rwlock. (The double locking was to fix to cleanup races on shutdown.)
One visible difference is that zones are not necessarily shut down
promptly: it depends on when the qp-trie garbage collector cleans up
the zone table. The `catz` system test checks several times that zones
have been deleted; the test now checks for zones to be removed from
the server configuration, instead of being fully shut down. The catz
test does not churn through enough zones to trigger a gc, so the zones
are not fully detached until the server exits.
After this change, it is still possible to improve the way we handle
changes to the zone table, for instance, batching changes, or better
compaction heuristics.
as there is no further use of isc_task in BIND, this commit removes
it, along with isc_taskmgr, isc_event, and all other related types.
functions that accepted taskmgr as a parameter have been cleaned up.
as a result of this change, some functions can no longer fail, so
they've been changed to type void, and their callers have been
updated accordingly.
the tasks table has been removed from the statistics channel and
the stats version has been updated. dns_dyndbctx has been changed
to reference the loopmgr instead of taskmgr, and DNS_DYNDB_VERSION
has been udpated as well.
The mechanism for associating a worker task to a database now
uses loops rather than tasks.
For this reason, the parameters to dns_cache_create() have been
updated to take a loop manager rather than a task manager.
The dns_cache API contained a cache cleaning mechanism that would be
disabled for 'rbt' based cache. As named doesn't have any other cache
implementations, remove the cache cleaning mechanism from dns_cache API.
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.
Move the libtest code into a 'libtest' subdirectory and make it
one of the SUBDIRS in the tests Makefile. having it at the top level
required having "." as one of the subdirs, and that caused the
unit tests to be executed twice.
