From 48ce9170b057ddd2165b0239a92aede15849f7a3 Mon Sep 17 00:00:00 2001 From: Egor Tensin Date: Mon, 12 Jun 2023 01:42:08 +0200 Subject: use signalfd to stop on SIGTERM Is this an overkill? I don't know. The thing is, correctly intercepting SIGTERM (also SIGINT, etc.) is incredibly tricky. For example, before this commit, my I/O loops in server.c and worker.c were inherently racy. This was immediately obvious if you tried to run the tests. The tests (especially the Valgrind flavour) would run a worker, wait until it prints a "Waiting for a new command" line, and try to kill it using SIGTERM. The problem is, the global_stop_flag check could have already been executed by the worker, and it would hang forever in recv(). The solution seems to be to use signalfd and select()/poll(). I've never used either before, but it seems to work well enough - at least the very same tests pass and don't hang now. --- src/CMakeLists.txt | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'src/CMakeLists.txt') diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt index af6e9fb..fb94b3a 100644 --- a/src/CMakeLists.txt +++ b/src/CMakeLists.txt @@ -39,6 +39,7 @@ generate_sql_header(sqlite) add_my_executable(server server_main.c server.c cmd_line.c command.c + event_loop.c file.c msg.c net.c @@ -48,6 +49,7 @@ add_my_executable(server server_main.c server.c sqlite.c storage.c storage_sqlite.c + string.c tcp_server.c worker_queue.c) target_link_libraries(server PRIVATE pthread sqlite3) @@ -63,11 +65,13 @@ add_my_executable(worker worker_main.c worker.c ci.c cmd_line.c command.c + event_loop.c file.c git.c msg.c net.c process.c run_queue.c - signal.c) + signal.c + string.c) target_link_libraries(worker PRIVATE git2 pthread) -- cgit v1.2.3