X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fcommon%2Fkernel-consumer%2Fkernel-consumer.c;h=40d0f71960fb6204019b508bd0ca1caffb4f838c;hb=f50f23d9f80ed9fae7fe5c49aee65e813e0031c8;hp=13cbe2149de6852ed08e6532f6025ff3e382a103;hpb=e316aad5fbbe3782872083cb68dfdd58bccea811;p=lttng-tools.git diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c index 13cbe2149..40d0f7196 100644 --- a/src/common/kernel-consumer/kernel-consumer.c +++ b/src/common/kernel-consumer/kernel-consumer.c @@ -88,6 +88,7 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, int sock, struct pollfd *consumer_sockpoll) { ssize_t ret; + enum lttng_error_code ret_code = LTTNG_OK; struct lttcomm_consumer_msg msg; ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); @@ -96,6 +97,14 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, return ret; } if (msg.cmd_type == LTTNG_CONSUMER_STOP) { + /* + * Notify the session daemon that the command is completed. + * + * On transport layer error, the function call will print an error + * message so handling the returned code is a bit useless since we + * return an error code anyway. + */ + (void) consumer_send_status_msg(sock, ret_code); return -ENOENT; } @@ -105,6 +114,7 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, switch (msg.cmd_type) { case LTTNG_CONSUMER_ADD_RELAYD_SOCKET: { + /* Session daemon status message are handled in the following call. */ ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index, msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll, &msg.u.relayd_sock.sock); @@ -114,6 +124,13 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, { struct lttng_consumer_channel *new_channel; + /* First send a status message before receiving the fds. */ + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_nosignal; + } + DBG("consumer_add_channel %d", msg.u.channel.channel_key); new_channel = consumer_allocate_channel(msg.u.channel.channel_key, -1, -1, @@ -138,11 +155,18 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, } case LTTNG_CONSUMER_ADD_STREAM: { - int fd; + int fd, stream_pipe; struct consumer_relayd_sock_pair *relayd = NULL; struct lttng_consumer_stream *new_stream; int alloc_ret = 0; + /* First send a status message before receiving the fds. */ + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_nosignal; + } + /* block */ if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { rcu_read_unlock(); @@ -157,6 +181,17 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, return ret; } + /* + * Send status code to session daemon only if the recv works. If the + * above recv() failed, the session daemon is notified through the + * error socket and the teardown is eventually done. + */ + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_nosignal; + } + new_stream = consumer_allocate_stream(msg.u.stream.channel_key, msg.u.stream.stream_key, fd, fd, @@ -168,6 +203,7 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, msg.u.stream.gid, msg.u.stream.net_index, msg.u.stream.metadata_flag, + msg.u.stream.session_id, &alloc_ret); if (new_stream == NULL) { switch (alloc_ret) { @@ -224,27 +260,26 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, } } - /* Send stream to the metadata thread */ + /* Get the right pipe where the stream will be sent. */ if (new_stream->metadata_flag) { - do { - ret = write(ctx->consumer_metadata_pipe[1], &new_stream, - sizeof(new_stream)); - } while (ret < 0 && errno == EINTR); - if (ret < 0) { - PERROR("write metadata pipe"); - consumer_del_stream(new_stream, NULL); - } + stream_pipe = ctx->consumer_metadata_pipe[1]; } else { - ret = consumer_add_stream(new_stream); - if (ret) { - ERR("Consumer add stream %d failed. Continuing", - new_stream->key); - consumer_del_stream(new_stream, NULL); - goto end_nosignal; - } + stream_pipe = ctx->consumer_data_pipe[1]; } - DBG("Kernel consumer_add_stream (%d)", fd); + do { + ret = write(stream_pipe, &new_stream, sizeof(new_stream)); + } while (ret < 0 && errno == EINTR); + if (ret < 0) { + PERROR("Consumer write %s stream to pipe %d", + new_stream->metadata_flag ? "metadata" : "data", + stream_pipe); + consumer_del_stream(new_stream, NULL); + goto end_nosignal; + } + + DBG("Kernel consumer ADD_STREAM %s (fd: %d) with relayd id %" PRIu64, + msg.u.stream.path_name, fd, new_stream->relayd_stream_id); break; } case LTTNG_CONSUMER_UPDATE_STREAM: @@ -263,7 +298,7 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, relayd = consumer_find_relayd(index); if (relayd == NULL) { ERR("Unable to find relayd %" PRIu64, index); - goto end_nosignal; + ret_code = LTTNG_ERR_NO_CONSUMER; } /* @@ -276,28 +311,43 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, * * The destroy can happen either here or when a stream fd hangs up. */ - consumer_flag_relayd_for_destroy(relayd); + if (relayd) { + consumer_flag_relayd_for_destroy(relayd); + } + + ret = consumer_send_status_msg(sock, ret_code); + if (ret < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_nosignal; + } goto end_nosignal; } + case LTTNG_CONSUMER_DATA_PENDING: + { + int32_t ret; + uint64_t id = msg.u.data_pending.session_id; + + DBG("Kernel consumer data pending command for id %" PRIu64, id); + + ret = consumer_data_pending(id); + + /* Send back returned value to session daemon */ + ret = lttcomm_send_unix_sock(sock, &ret, sizeof(ret)); + if (ret < 0) { + PERROR("send data pending ret code"); + } + + /* + * No need to send back a status message since the data pending + * returned value is the response. + */ + break; + } default: goto end_nosignal; } - /* - * Wake-up the other end by writing a null byte in the pipe (non-blocking). - * Important note: Because writing into the pipe is non-blocking (and - * therefore we allow dropping wakeup data, as long as there is wakeup data - * present in the pipe buffer to wake up the other end), the other end - * should perform the following sequence for waiting: - * - * 1) empty the pipe (reads). - * 2) perform update operation. - * 3) wait on the pipe (poll). - */ - do { - ret = write(ctx->consumer_poll_pipe[1], "", 1); - } while (ret < 0 && errno == EINTR); end_nosignal: rcu_read_unlock(); @@ -481,3 +531,32 @@ error: return ret; } +/* + * Check if data is still being extracted from the buffers for a specific + * stream. Consumer data lock MUST be acquired before calling this function + * and the stream lock. + * + * Return 1 if the traced data are still getting read else 0 meaning that the + * data is available for trace viewer reading. + */ +int lttng_kconsumer_data_pending(struct lttng_consumer_stream *stream) +{ + int ret; + + assert(stream); + + ret = kernctl_get_next_subbuf(stream->wait_fd); + if (ret == 0) { + /* There is still data so let's put back this subbuffer. */ + ret = kernctl_put_subbuf(stream->wait_fd); + assert(ret == 0); + ret = 1; /* Data is pending */ + goto end; + } + + /* Data is NOT pending and ready to be read. */ + ret = 0; + +end: + return ret; +}