The problem happened like this:
1. Single route for the given net in table
2. A feed is started
3. The route is deleted (from another thread)
4. The feed finds an empty net, exports nothing, ignores journal (here is bug)
5. The route is added
6. The export transitions from FEEDING to READY
7. While processing the journal, the route deletion and addition combines into noop.
This way routes mysteriously disappeared in specific cases of link instability.
Problem fixed by explicitly marking the empty-net journal entries as processed in step 4.
This variant of logging avoids calling write() for every log line,
allowing for waitless logging. This makes heavy logging less heavy
and more useful for race condition debugging.
The original logging routines were locking a common mutex. This led to
massive underperformance and unwanted serialization when heavily logging
due to lock contention. Now the logging is lockless, though still
serializing on write() syscalls to the same filedescriptor.
This change also brings in a persistent logging channel structures and
thus avoids writing into active configuration data structures during
regular run.
Undefined paths and clists should use typed f_val with empty adata
instead of just void f_val. Use common initializer to handle both
variables and eattrs.
List of arguments for function calls is constructed in reverse and then
reverted. This was done in function_call grammar rule. Do the reverse
directly in var_list grammar rule. This fixes reverse order of arguments
in method calls.
- Extend method descriptors with type signature
- Daisy chain method descriptors for the same symbol
- Dispatch methods for same symbol based on type signature
- Split add/delete/filter operations to multiple methods
- Replace ad-hoc dispatch of old-style syntax with scope-based dispatch
- Also change method->arg_num to count initial arg
It still needs some improvements, like better handling of untyped
expressions and better error reporting when no dispatch can be done.
The multiple dispatch could also be extended to dispatch regular
function-like expressions in a uniform way.
Methods can now be called as x.m(y), as long as x can have its type
inferred in config time. If used as a command, it modifies the object,
if used as a value, it keeps the original object intact.
Also functions add(x,y), delete(x,y), filter(x,y) and prepend(x,y) now
spit a warning and are considered deprecated.
It's also possible to call a method on a constant, see filter/test.conf
for examples like bgp_path = +empty+.prepend(1).
Inside instruction definitions (filter/f-inst.c), a METHOD_CONSTRUCTOR()
call is added, which registers the instruction as a method for the type
of its first argument. Each type has its own method symbol table and
filter parser switches between them based on the inferred type of the
object calling the method.
Also FI_CLIST_(ADD|DELETE|FILTER) instructions have been split to allow
for this method dispatch. With type inference, it's now possible.
This is a backport cherry-pick of commits
165156beebcce974e8ea
from the v3.0 branch as we need symbol hashes directly inside their
scopes for more general usage than before.
