From 2a16a986ce5f1bdb7e96abfe14fcb9f34c9364b6 Mon Sep 17 00:00:00 2001 From: David Herrmann Date: Wed, 27 Nov 2013 10:36:35 +0100 Subject: [PATCH] event: allow EPOLLET as event flag EPOLLET enables edge-triggered mode (see epoll(7) for more). For most use-cases, level-triggered is just fine, but for master-TTYs we need edge-triggered to catch EPOLLHUP. master-TTYs signal EPOLLHUP if no client is connected, but a client may connect some time later (same happens during vhangup(2)). However, epoll doesn't allow masking EPOLLHUP so it's signaled constantly. To avoid this, edge-triggered mode is needed. --- src/libsystemd-bus/sd-event.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/libsystemd-bus/sd-event.c b/src/libsystemd-bus/sd-event.c index 6a6581bec..b5ddf71eb 100644 --- a/src/libsystemd-bus/sd-event.c +++ b/src/libsystemd-bus/sd-event.c @@ -584,7 +584,7 @@ _public_ int sd_event_add_io( assert_return(e, -EINVAL); assert_return(fd >= 0, -EINVAL); - assert_return(!(events & ~(EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLPRI|EPOLLERR|EPOLLHUP)), -EINVAL); + assert_return(!(events & ~(EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLPRI|EPOLLERR|EPOLLHUP|EPOLLET)), -EINVAL); assert_return(callback, -EINVAL); assert_return(ret, -EINVAL); assert_return(e->state != SD_EVENT_FINISHED, -ESTALE); @@ -1022,7 +1022,7 @@ _public_ int sd_event_source_set_io_events(sd_event_source *s, uint32_t events) assert_return(s, -EINVAL); assert_return(s->type == SOURCE_IO, -EDOM); - assert_return(!(events & ~(EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLPRI|EPOLLERR|EPOLLHUP)), -EINVAL); + assert_return(!(events & ~(EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLPRI|EPOLLERR|EPOLLHUP|EPOLLET)), -EINVAL); assert_return(s->event->state != SD_EVENT_FINISHED, -ESTALE); assert_return(!event_pid_changed(s->event), -ECHILD); -- 2.30.2