From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtpng3.m.smailru.net (smtpng3.m.smailru.net [94.100.177.149]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id 030ED46971A for ; Tue, 3 Dec 2019 19:33:21 +0300 (MSK) From: Leonid Vasiliev Date: Tue, 3 Dec 2019 19:33:19 +0300 Message-Id: <73ebdf94c8f03fca216de9141c6541870b1ed938.1575390549.git.lvasiliev@tarantool.org> Subject: [Tarantool-patches] [PATCH] Add a cancellation guard to cpipe flush callback List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: alexander.turenko@tarantool.org Cc: tarantool-patches@dev.tarantool.org https://github.com/tarantool/tarantool/issues/4127 https://github.com/tarantool/tarantool/tree/lvasiliev/gh-4127-WAL-thread-stucks We need to set a thread cancellation guard, because another thread may cancel the current thread (write() is a cancellation point in ev_async_send) and the activation of the ev_async watcher through ev_async_send will fail. --- src/lib/core/cbus.c | 13 +++++++++++++ src/tt_pthread.h | 5 +++++ 2 files changed, 18 insertions(+) diff --git a/src/lib/core/cbus.c b/src/lib/core/cbus.c index b3b1280e7..7e9ef91e3 100644 --- a/src/lib/core/cbus.c +++ b/src/lib/core/cbus.c @@ -284,6 +284,17 @@ cpipe_flush_cb(ev_loop *loop, struct ev_async *watcher, int events) /* Trigger task processing when the queue becomes non-empty. */ bool output_was_empty; + /* + * We need to set a thread cancellation guard, because + * another thread may cancel the current thread + * (write() is a cancellation point in ev_async_send) + * and the activation of the ev_async watcher + * through ev_async_send will fail. + */ + + int old_cancel_state; + tt_pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &old_cancel_state); + tt_pthread_mutex_lock(&endpoint->mutex); output_was_empty = stailq_empty(&endpoint->output); /** Flush input */ @@ -297,6 +308,8 @@ cpipe_flush_cb(ev_loop *loop, struct ev_async *watcher, int events) ev_async_send(endpoint->consumer, &endpoint->async); } + + tt_pthread_setcancelstate(old_cancel_state, NULL); } void diff --git a/src/tt_pthread.h b/src/tt_pthread.h index 40b43b112..6bb19eb23 100644 --- a/src/tt_pthread.h +++ b/src/tt_pthread.h @@ -300,6 +300,11 @@ #define tt_pthread_getspecific(key) pthread_getspecific(key) +#define tt_pthread_setcancelstate(state, oldstate) \ +({ int e__ = pthread_setcancelstate(state, oldstate);\ + tt_pthread_error(e__); \ +}) + /** Set the current thread's name */ static inline void -- 2.17.1