lib: rewrite zlog lock-free & TLS-buffered

This is a full rewrite of the "back end" logging code.  It now uses a
lock-free list to iterate over logging targets, and the targets
themselves are as lock-free as possible.  (syslog() may have a hidden
internal mutex in the C library;  the file/fd targets use a single
write() call which should ensure atomicity kernel-side.)

Note that some functionality is lost in this patch:
- Solaris printstack() backtraces are ditched (unlikely to come back)
- the `log-filter` machinery is gone (re-added in followup commit)
- `terminal monitor` is temporarily stubbed out.  The old code had a
  race condition with VTYs going away.  It'll likely come back rewritten
  and with vtysh support.
- The `zebra_ext_log` hook is gone.  Instead, it's now much easier to
  add a "proper" logging target.

v2: TLS buffer to get some actual performance

Signed-off-by: David Lamparter <equinox@diac24.net>

1 files changed, 1 insertions, 5 deletions

diff --git a/tests/lib/test_segv.c b/tests/lib/test_segv.c
index 43ca0837d5..8133637adc 100644
--- a/tests/lib/test_segv.c
+++ b/tests/lib/test_segv.c
@@ -73,11 +73,7 @@ int main(void)
 	master = thread_master_create(NULL);
 	signal_init(master, array_size(sigs), sigs);
 
-	openzlog("testsegv", "NONE", 0, LOG_CONS | LOG_NDELAY | LOG_PID,
-		 LOG_DAEMON);
-	zlog_set_level(ZLOG_DEST_SYSLOG, ZLOG_DISABLED);
-	zlog_set_level(ZLOG_DEST_STDOUT, LOG_DEBUG);
-	zlog_set_level(ZLOG_DEST_MONITOR, ZLOG_DISABLED);
+	zlog_aux_init("NONE: ", LOG_DEBUG);
 
 	thread_execute(master, threadfunc, 0, 0);