X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Flib%2Flttng-ctl%2Fchannel.c;h=16bd298be330e4dfcbc274326c22825669fd5346;hp=49a3684dbb1cbad3c6fb11ae5818238fdf806f0a;hb=c0a66c84b5b2484b75798aec7543b680b4d4ab6c;hpb=3647288fe42b25340f905046f3bd9aef21e12aaa diff --git a/src/lib/lttng-ctl/channel.c b/src/lib/lttng-ctl/channel.c index 49a3684db..16bd298be 100644 --- a/src/lib/lttng-ctl/channel.c +++ b/src/lib/lttng-ctl/channel.c @@ -1,18 +1,8 @@ /* - * Copyright (C) 2017 - Jérémie Galarneau + * Copyright (C) 2017 Jérémie Galarneau * - * This library is free software; you can redistribute it and/or modify it - * under the terms of the GNU Lesser General Public License, version 2.1 only, - * as published by the Free Software Foundation. + * SPDX-License-Identifier: LGPL-2.1-only * - * This library is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License - * for more details. - * - * You should have received a copy of the GNU Lesser General Public License - * along with this library; if not, write to the Free Software Foundation, - * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include @@ -26,8 +16,7 @@ #include #include #include "lttng-ctl-helper.h" -#include -#include +#include static int handshake(struct lttng_notification_channel *channel); @@ -108,17 +97,22 @@ struct lttng_notification *create_notification_from_current_message( { ssize_t ret; struct lttng_notification *notification = NULL; - struct lttng_buffer_view view; if (channel->reception_buffer.size <= sizeof(struct lttng_notification_channel_message)) { goto end; } - view = lttng_buffer_view_from_dynamic_buffer(&channel->reception_buffer, - sizeof(struct lttng_notification_channel_message), -1); + { + struct lttng_payload_view view = lttng_payload_view_from_dynamic_buffer( + &channel->reception_buffer, + sizeof(struct lttng_notification_channel_message), + -1); + + ret = lttng_notification_create_from_payload( + &view, ¬ification); + } - ret = lttng_notification_create_from_buffer(&view, ¬ification); if (ret != channel->reception_buffer.size - sizeof(struct lttng_notification_channel_message)) { lttng_notification_destroy(notification); @@ -211,6 +205,7 @@ lttng_notification_channel_get_next_notification( struct lttng_notification *notification = NULL; enum lttng_notification_channel_status status = LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; + struct lttng_poll_event events; if (!channel || !_notification) { status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; @@ -239,10 +234,40 @@ lttng_notification_channel_get_next_notification( goto end_unlock; } + /* + * Block on interruptible epoll/poll() instead of the message reception + * itself as the recvmsg() wrappers always restart on EINTR. We choose + * to wait using interruptible epoll/poll() in order to: + * 1) Return if a signal occurs, + * 2) Not deal with partially received messages. + * + * The drawback to this approach is that we assume that messages + * are complete/well formed. If a message is shorter than its + * announced length, receive_message() will block on recvmsg() + * and never return (even if a signal is received). + */ + ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); + if (ret < 0) { + status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; + goto end_unlock; + } + ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR); + if (ret < 0) { + status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; + goto end_clean_poll; + } + ret = lttng_poll_wait_interruptible(&events, -1); + if (ret <= 0) { + status = (ret == -1 && errno == EINTR) ? + LTTNG_NOTIFICATION_CHANNEL_STATUS_INTERRUPTED : + LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; + goto end_clean_poll; + } + ret = receive_message(channel); if (ret) { status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; - goto end_unlock; + goto end_clean_poll; } switch (get_current_message_type(channel)) { @@ -251,7 +276,7 @@ lttng_notification_channel_get_next_notification( channel); if (!notification) { status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; - goto end_unlock; + goto end_clean_poll; } break; case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: @@ -261,15 +286,15 @@ lttng_notification_channel_get_next_notification( default: /* Protocol error. */ status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; - goto end_unlock; + goto end_clean_poll; } +end_clean_poll: + lttng_poll_clean(&events); end_unlock: pthread_mutex_unlock(&channel->lock); + *_notification = notification; end: - if (_notification) { - *_notification = notification; - } return status; } @@ -366,11 +391,7 @@ lttng_notification_channel_has_pending_notification( int ret; enum lttng_notification_channel_status status = LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; - fd_set read_fds; - struct timeval timeout; - - FD_ZERO(&read_fds); - memset(&timeout, 0, sizeof(timeout)); + struct lttng_poll_event events; if (!channel || !_notification_pending) { status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; @@ -405,48 +426,57 @@ lttng_notification_channel_has_pending_notification( * message if we see data available on the socket. If the peer does * not respect the protocol, this may block indefinitely. */ - FD_SET(channel->socket, &read_fds); - do { - ret = select(channel->socket + 1, &read_fds, NULL, NULL, &timeout); - } while (ret < 0 && errno == EINTR); - + ret = lttng_poll_create(&events, 1, LTTNG_CLOEXEC); + if (ret < 0) { + status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; + goto end_unlock; + } + ret = lttng_poll_add(&events, channel->socket, LPOLLIN | LPOLLERR); + if (ret < 0) { + status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; + goto end_clean_poll; + } + /* timeout = 0: return immediately. */ + ret = lttng_poll_wait_interruptible(&events, 0); if (ret == 0) { /* No data available. */ *_notification_pending = false; - goto end_unlock; + goto end_clean_poll; } else if (ret < 0) { status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; - goto end_unlock; + goto end_clean_poll; } /* Data available on socket. */ ret = receive_message(channel); if (ret) { status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; - goto end_unlock; + goto end_clean_poll; } switch (get_current_message_type(channel)) { case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION: ret = enqueue_notification_from_current_message(channel); if (ret) { - goto end; + goto end_clean_poll; } *_notification_pending = true; break; case LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_NOTIFICATION_DROPPED: ret = enqueue_dropped_notification(channel); if (ret) { - goto end; + goto end_clean_poll; } *_notification_pending = true; break; default: /* Protocol error. */ status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; - goto end_unlock; + goto end_clean_poll; } +end_clean_poll: + lttng_poll_clean(&events); end_unlock: pthread_mutex_unlock(&channel->lock); end: @@ -578,12 +608,12 @@ enum lttng_notification_channel_status send_condition_command( ssize_t ret; enum lttng_notification_channel_status status = LTTNG_NOTIFICATION_CHANNEL_STATUS_OK; - struct lttng_dynamic_buffer buffer; + struct lttng_payload payload; struct lttng_notification_channel_message cmd_header = { .type = (int8_t) type, }; - lttng_dynamic_buffer_init(&buffer); + lttng_payload_init(&payload); if (!channel) { status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; @@ -600,24 +630,25 @@ enum lttng_notification_channel_status send_condition_command( goto end_unlock; } - ret = lttng_dynamic_buffer_append(&buffer, &cmd_header, + ret = lttng_dynamic_buffer_append(&payload.buffer, &cmd_header, sizeof(cmd_header)); if (ret) { status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; goto end_unlock; } - ret = lttng_condition_serialize(condition, &buffer); + ret = lttng_condition_serialize(condition, &payload); if (ret) { status = LTTNG_NOTIFICATION_CHANNEL_STATUS_INVALID; goto end_unlock; } /* Update payload length. */ - ((struct lttng_notification_channel_message *) buffer.data)->size = - (uint32_t) (buffer.size - sizeof(cmd_header)); + ((struct lttng_notification_channel_message *) payload.buffer.data)->size = + (uint32_t) (payload.buffer.size - sizeof(cmd_header)); - ret = lttcomm_send_unix_sock(socket, buffer.data, buffer.size); + ret = lttcomm_send_unix_sock( + socket, payload.buffer.data, payload.buffer.size); if (ret < 0) { status = LTTNG_NOTIFICATION_CHANNEL_STATUS_ERROR; goto end_unlock; @@ -631,7 +662,7 @@ enum lttng_notification_channel_status send_condition_command( end_unlock: pthread_mutex_unlock(&channel->lock); end: - lttng_dynamic_buffer_reset(&buffer); + lttng_payload_reset(&payload); return status; }