From b1c2370dde9ade180c638e5d9a4797f085322b5b Mon Sep 17 00:00:00 2001 From: "Wladimir J. van der Laan" Date: Tue, 6 Feb 2018 19:27:13 +0100 Subject: [PATCH] http: Join worker threads before deleting work queue This prevents a potential race condition if control flow ends up in `ShutdownHTTPServer` before the thread gets to `queue->Run()`, deleting the work queue while workers are still going to use it. Meant to fix #12362. Signed-off-by: Wladimir J. van der Laan --- src/httpserver.cpp | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/src/httpserver.cpp b/src/httpserver.cpp index a022d220e00..a554dcb0971 100644 --- a/src/httpserver.cpp +++ b/src/httpserver.cpp @@ -449,6 +449,7 @@ bool UpdateHTTPServerLogging(bool enable) { std::thread threadHTTP; std::future threadResult; +static std::vector g_thread_http_workers; bool StartHTTPServer() { @@ -460,8 +461,7 @@ bool StartHTTPServer() threadHTTP = std::thread(std::move(task), eventBase, eventHTTP); for (int i = 0; i < rpcThreads; i++) { - std::thread rpc_worker(HTTPWorkQueueRun, workQueue); - rpc_worker.detach(); + g_thread_http_workers.emplace_back(HTTPWorkQueueRun, workQueue); } return true; } @@ -487,6 +487,10 @@ void StopHTTPServer() if (workQueue) { LogPrint(BCLog::HTTP, "Waiting for HTTP worker threads to exit\n"); workQueue->WaitExit(); + for (auto& thread: g_thread_http_workers) { + thread.join(); + } + g_thread_http_workers.clear(); delete workQueue; workQueue = nullptr; }