Mirror/zeek
1
0
Fork 0
mirror of https://github.com/zeek/zeek.git synced 2025-10-01 22:28:20 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Supervisor: Make last_signal atomic to squelch data race

Browse source 
When the stem process terminates and SIGCHLD is sent to the supervisor,
the signal might be handled by the main thread or any other threads that
aren't blocking SIGCHLD explicitly. Convert last_signal to a std::atomic<int>
such that non-main threads can safely set last_signal without triggering
data race as reported by TSAN. This doesn't make it less racy to work
last_signal, but it appears we only use it for debug printing anyhow and
another option might have been to just remove last_signal altogether.

Follow-up for #4849
This commit is contained in:
Arne Welzel 2025-09-29 14:41:11 +02:00
parent 3abc1116a1
commit 31d7df915e
2 changed files with 3 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

2
src/supervisor/Supervisor.cc
View file

@ -415,7 +415,7 @@ static ForkResult fork_with_stdio_redirect(const char* where) {
void Supervisor::HandleChildSignal() {
if ( last_signal >= 0 ) {
DBG_LOG(DBG_SUPERVISOR, "Supervisor received signal %d", last_signal);
DBG_LOG(DBG_SUPERVISOR, "Supervisor received signal %d", last_signal.load());
last_signal = -1;
}

3
src/supervisor/Supervisor.h
View file

@ -3,6 +3,7 @@
#pragma once
#include <sys/types.h>
#include <atomic>
#include <chrono>
#include <map>
#include <memory>
@ -323,7 +324,7 @@ private:
Config config;
pid_t stem_pid;
int last_signal = -1;
std::atomic<int> last_signal = -1;
std::unique_ptr<detail::PipePair> stem_pipe;
detail::LineBufferedPipe stem_stdout;
detail::LineBufferedPipe stem_stderr;