Make TLV Logging cache threadsafe #16299
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
sjanusz-r7
force-pushed
the
make-tlv-logging-cache-threadsafe
branch
from
69746cf
to
b7006a4
Compare
| @@ -108,25 +109,31 @@ def self.get_commands(*extensions) | |||
| # @param Integer value The value of the TLV type to retrieve the TLV type names for. | |||
| # @return [Array<Symbol>] An array of symbols of all TLV types that are defined with the value. Can be empty. | |||
| def self.get_tlv_names(value) | |||
| return @@cached_tlv_types[value] unless @@cached_tlv_types[value].nil? || @@cached_tlv_types[value].empty? | |||
| @@tlv_cache_mutex.synchronize_read do | |||
There was a problem hiding this comment.
What impacts could this have on throughput?
There was a problem hiding this comment.
Performance shouldn't be an issue here, as exclusive write access will only be needed once to hydrate the cache at the start, from that point onwards it's purely reader access - which is the optimised codepath
That aside; I've created a separate issue to fix the thread safety issue in the reader/writer lock itself: rapid7/rex-core#27
sjanusz-r7
force-pushed
the
make-tlv-logging-cache-threadsafe
branch
from
b7006a4
to
a092c45
Compare
sjanusz-r7
force-pushed
the
make-tlv-logging-cache-threadsafe
branch
from
a092c45
to
558d8bb
Compare
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR fixes a potential issue of the same TLV types being defined multiple times when multiple threads want to get a list of TLV types.
Example:
Verification
msfconsoleuse payload/python/meterpreter_reverse_tcpset lhost ...generate -f raw -o shell.pyseq 5; do python3 shell.py; done"oneOf(COMMAND_ID,COMMAND_ID)is not present.