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.
- Rename BYTESTRING lexem to BYTETEXT, not to collide with 'bytestring' type name
- Add bytestring type with id T_BYTESTRING (0x2c)
- Add from_hex() filter function to create bytestring from hex string
- Add filter test cases for bytestring type
Minor changes by committer.
Hexadecimal bytestring literals have minimal length to not collide
with IP addresses or regular (hexadecimal) number literals.
Allow to use shorter literals with explicit hex: prefix.
For whatever reason, parser allocated a symbol for every parsed keyword
in each scope. That wasted time and memory. The effect is worsened with
recent changes allowing local scopes, so keywords often promote soft
scopes (with no symbols) to real scopes.
Do not allocate a symbol for a keyword. Take care of keywords that could
be promoted to symbols (kw_sym) and do it explicitly.
The symbol table used just symbol name as a key, and used a trick with
active flag to find symbols in active scopes with one hash table lookup.
The disadvantage is that it can degenerate to O(n) for negative queries
in situations where are many symbols with the same name in different
scopes.
Thanks to Yanko Kaneti for the bugreport.
Memory allocation is a fragile part of BIRD and we need checking that
everybody is using the resource pools in an appropriate way. To assure
this, all the resource pools are associated with locking domains and
every resource manipulation is thoroughly checked whether the
appropriate locking domain is locked.
With transitive resource manipulation like resource dumping or mass free
operations, domains are locked and unlocked on the go, thus we require
pool domains to have higher order than their parent to allow for this
transitive operations.
Adding pool locking revealed some cases of insecure memory manipulation
and this commit fixes that as well.
The change 371eb49043 introduced early free
of old_config. Unfortunately, it did not properly check whether it is not
still in use (blocked by obstacle during reconfiguration). Fix that.
It also means that we still could have a short peak when three configs
are in use (when a new reconfig is requeste while the previous one is
still active).
The change 371eb49043 introduced early free
of old_config. Unfortunately, it did not properly check whether it is not
still in use (blocked by obstacle during reconfiguration). Fix that.
It also means that we still could have a short peak when three configs
are in use (when a new reconfig is requeste while the previous one is
still active).
On large configurations, too many threads would spawn with one thread
per loop. Therefore, threads may now run multiple loops at once. The
thread count is configurable and may be changed during run. All threads
are spawned on startup.
This change helps with memory bloating. BIRD filters need large
temporary memory blocks to store their stack and also memory management
keeps its hot page storage per-thread.
Known bugs:
* Thread autobalancing is not yet implemented.
* Low latency loops are executed together with standard loops.
Some of these new BGP role keywords use generic names that collides with
user-defined symbols. Allow them to be redefined. Also remove duplicit
keyword definition for 'prefer'.
BIRD keeps a previous (old) configuration for the purpose of undo. The
existing code frees it after a new configuration is successfully parsed
during reconfiguration. That causes memory usage spikes as there are
temporarily three configurations (old, current, and new). The patch
changes it to free the old one before parsing the new one (as user
already requested a new config). The disadvantage is that undo is
not available after failed reconfiguration.
Define scope for anonymous filters, and also explicitly distinguish block
scopes and function/filter scopes instead of using anonymous / named
distinction.
Anonymous filters forgot to push scope, so variables for them were in
fact defined in the top scope and therefore they shared a frame. This got
broken after rework of variables, which assumed that there is a named
scope for every function/filter.
There were more conflicts that I'd like to see, most notably in route
export. If a bisect identifies this commit with something related, it
may be simply true that this commit introduces that bug. Let's hope it
doesn't happen.
When f_line is done, we have to pop the stack frame. The old code just
removed nominal number of args/vars. Change it to use stored ventry value
modified by number of returned values. This allows to allocate variables
on a stack frame during execution of f_lines instead of just at start.
But we need to know the number of returned values for a f_line. It is 1
for term, 0 for cmd. Store that to f_line during linearization.
When writing flow4 { dst 2001:db8::dead:beef/128; }, BIRD crashed on an
not-well-debuggable segfault as it tried to copy the whole 128-bit
prefix into an IPv4-sized memory.
Use timer (configurable as 'gc period') to schedule routing table
GC/pruning to ensure that prune is done on time but not too often.
Randomize GC timers to avoid concentration of GC events from different
tables in one loop cycle.
Fix a bug that caused minimum inter-GC interval be 5 us instead of 5 s.
Make default 'gc period' adaptive based on number of routing tables,
from 10 s for small setups to 600 s for large ones.
In marge multi-table RS setup, the patch improved time of flushing
a downed peer from 20-30 min to <2 min and removed 40s latencies.
Some tokens are both keywords and symbols. For now, we allow only
specific keywords to be redefined; in future, more of the keywords may
be added to this category.
The redefinable keywords must be specified in any .Y file as follows:
toksym: THE_KEYWORD ;
See proto/bgp/config.Y for an example.
Also dropped a lot of unused terminals.
Changes in internal API:
* Every route attribute must be defined as struct ea_class somewhere.
* Registration of route attributes known at startup must be done by
ea_register_init() from protocol build functions.
* Every attribute has now its symbol registered in a global symbol table
defined as SYM_ATTRIBUTE
* All attribute ID's are dynamically allocated.
* Attribute value custom formatting hook is defined in the ea_class.
* Attribute names are the same for display and filters, always prefixed
by protocol name.
Also added some unit testing code for filters with route attributes.
