From a1de8fcc86468f9ae88786634face3e327e2f3b3 Mon Sep 17 00:00:00 2001 From: Yannick Lamarre Date: Thu, 25 Apr 2019 18:23:30 -0400 Subject: [PATCH] Adapt poll layer behaviour to match the epoll layer MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Signed-off-by: Yannick Lamarre Signed-off-by: Jérémie Galarneau --- src/common/compat/compat-poll.c | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-) diff --git a/src/common/compat/compat-poll.c b/src/common/compat/compat-poll.c index b45b39dc6..2318920ae 100644 --- a/src/common/compat/compat-poll.c +++ b/src/common/compat/compat-poll.c @@ -1,5 +1,6 @@ /* * Copyright (C) 2011 - David Goulet + * Copyright (C) 2019 - Yannick Lamarre * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License, version 2 only, @@ -204,10 +205,10 @@ int compat_poll_mod(struct lttng_poll_event *events, int fd, uint32_t req_events) { int i; - bool fd_found = false; struct compat_poll_event_array *current; - if (events == NULL || events->current.events == NULL || fd < 0) { + if (events == NULL || events->current.nb_fd == 0 || + events->current.events == NULL || fd < 0) { ERR("Bad compat poll mod arguments"); goto error; } @@ -216,16 +217,16 @@ int compat_poll_mod(struct lttng_poll_event *events, int fd, for (i = 0; i < current->nb_fd; i++) { if (current->events[i].fd == fd) { - fd_found = true; current->events[i].events = req_events; events->need_update = 1; break; } } - if (!fd_found) { - goto error; - } + /* + * The epoll flavor doesn't flag modifying a non-included FD as an + * error. + */ return 0; @@ -238,11 +239,12 @@ error: */ int compat_poll_del(struct lttng_poll_event *events, int fd) { - int new_size, i, count = 0, ret; + int i, count = 0, ret; + uint32_t new_size; struct compat_poll_event_array *current; - if (events == NULL || events->current.events == NULL || fd < 0) { - ERR("Wrong arguments for poll del"); + if (events == NULL || events->current.nb_fd == 0 || + events->current.events == NULL || fd < 0) { goto error; } @@ -257,13 +259,20 @@ int compat_poll_del(struct lttng_poll_event *events, int fd) count++; } } + + /* The fd was not in our set, return no error as with epoll. */ + if (current->nb_fd == count) { + goto end; + } + /* No fd duplicate should be ever added into array. */ assert(current->nb_fd - 1 == count); current->nb_fd = count; /* Resize array if needed. */ new_size = 1U << utils_get_count_order_u32(current->nb_fd); - if (new_size != current->alloc_size && new_size >= current->init_size) { + if (new_size != current->alloc_size && new_size >= current->init_size + && current->nb_fd != 0) { ret = resize_poll_event(current, new_size); if (ret < 0) { goto error; @@ -272,6 +281,7 @@ int compat_poll_del(struct lttng_poll_event *events, int fd) events->need_update = 1; +end: return 0; error: -- 2.34.1