[lttng-dev] [PATCH lttng-tools 1/4] Rename consumer threads and spawn them in daemon
Mathieu Desnoyers
mathieu.desnoyers at efficios.com
Sat Oct 13 11:41:13 EDT 2012
* David Goulet (dgoulet at efficios.com) wrote:
> The metadata thread is now created in the lttng-consumerd daemon so all
> thread could be controlled inside the daemon.
>
> This is the first step of a consumer thread refactoring which aims at
> moving data and metadata stream operations inside a dedicated thread so
> the session daemon thread does not block and is more efficient at adding
> streams.
>
> The most important concept is that a stream file descriptor MUST be
> opened as quickly as we can than passed to the right thread (for UST
than -> then
> since they are already opened by the session daemon for the kernel).
>
> Signed-off-by: David Goulet <dgoulet at efficios.com>
> ---
> src/bin/lttng-consumerd/lttng-consumerd.c | 18 ++++++++++-----
> src/common/consumer.c | 34 +++++++++--------------------
> src/common/consumer.h | 5 +++--
> 3 files changed, 26 insertions(+), 31 deletions(-)
>
> diff --git a/src/bin/lttng-consumerd/lttng-consumerd.c b/src/bin/lttng-consumerd/lttng-consumerd.c
> index 5952334..946fb02 100644
> --- a/src/bin/lttng-consumerd/lttng-consumerd.c
> +++ b/src/bin/lttng-consumerd/lttng-consumerd.c
> @@ -356,23 +356,31 @@ int main(int argc, char **argv)
> }
> lttng_consumer_set_error_sock(ctx, ret);
>
> - /* Create the thread to manage the receive of fd */
> - ret = pthread_create(&threads[0], NULL, lttng_consumer_thread_receive_fds,
> + /* Create thread to manage the polling/writing of trace metadata */
> + ret = pthread_create(&threads[0], NULL, consumer_thread_metadata_poll,
> + (void *) ctx);
> + if (ret != 0) {
> + perror("pthread_create");
> + goto error;
> + }
> +
> + /* Create thread to manage the polling/writing of trace data */
> + ret = pthread_create(&threads[1], NULL, consumer_thread_data_poll,
> (void *) ctx);
> if (ret != 0) {
> perror("pthread_create");
> goto error;
> }
>
> - /* Create thread to manage the polling/writing of traces */
> - ret = pthread_create(&threads[1], NULL, lttng_consumer_thread_poll_fds,
> + /* Create the thread to manage the receive of fd */
> + ret = pthread_create(&threads[2], NULL, consumer_thread_sessiond_poll,
> (void *) ctx);
> if (ret != 0) {
> perror("pthread_create");
> goto error;
> }
>
> - for (i = 0; i < 2; i++) {
> + for (i = 0; i < 3; i++) {
> ret = pthread_join(threads[i], &status);
> if (ret != 0) {
> perror("pthread_join");
> diff --git a/src/common/consumer.c b/src/common/consumer.c
> index 242b05b..055de1b 100644
> --- a/src/common/consumer.c
> +++ b/src/common/consumer.c
> @@ -1131,6 +1131,8 @@ void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx)
> PERROR("close");
> }
> utils_close_pipe(ctx->consumer_splice_metadata_pipe);
> + /* This should trigger the metadata thread to exit */
> + close(ctx->consumer_metadata_pipe[1]);
this is adding a close, but did not remove any other remove that might
previously be in place elsewhere.
moreover, the close() return value is not tested.
>
> unlink(ctx->consumer_command_sock_path);
> free(ctx);
> @@ -1756,7 +1758,7 @@ error:
> * Thread polls on metadata file descriptor and write them on disk or on the
> * network.
> */
> -void *lttng_consumer_thread_poll_metadata(void *data)
> +void *consumer_thread_metadata_poll(void *data)
> {
> int ret, i, pollfd;
> uint32_t revents, nb_fd;
> @@ -1939,7 +1941,7 @@ end:
> * This thread polls the fds in the set to consume the data and write
> * it to tracefile if necessary.
> */
> -void *lttng_consumer_thread_poll_fds(void *data)
> +void *consumer_thread_data_poll(void *data)
> {
> int num_rdy, num_hup, high_prio, ret, i;
> struct pollfd *pollfd = NULL;
> @@ -1949,19 +1951,9 @@ void *lttng_consumer_thread_poll_fds(void *data)
> int nb_fd = 0;
> struct lttng_consumer_local_data *ctx = data;
> ssize_t len;
> - pthread_t metadata_thread;
> - void *status;
>
> rcu_register_thread();
>
> - /* Start metadata polling thread */
> - ret = pthread_create(&metadata_thread, NULL,
> - lttng_consumer_thread_poll_metadata, (void *) ctx);
> - if (ret < 0) {
> - PERROR("pthread_create metadata thread");
> - goto end;
> - }
> -
> local_stream = zmalloc(sizeof(struct lttng_consumer_stream));
>
> while (1) {
> @@ -2145,19 +2137,13 @@ end:
>
> /*
> * Close the write side of the pipe so epoll_wait() in
> - * lttng_consumer_thread_poll_metadata can catch it. The thread is
> - * monitoring the read side of the pipe. If we close them both, epoll_wait
> - * strangely does not return and could create a endless wait period if the
> - * pipe is the only tracked fd in the poll set. The thread will take care
> - * of closing the read side.
> + * consumer_thread_metadata_poll can catch it. The thread is monitoring the
> + * read side of the pipe. If we close them both, epoll_wait strangely does
> + * not return and could create a endless wait period if the pipe is the
> + * only tracked fd in the poll set. The thread will take care of closing
> + * the read side.
> */
> close(ctx->consumer_metadata_pipe[1]);
this is the second close on the same FD I'm talking about.
thanks,
Mathieu
> - if (ret) {
> - ret = pthread_join(metadata_thread, &status);
> - if (ret < 0) {
> - PERROR("pthread_join metadata thread");
> - }
> - }
>
> rcu_unregister_thread();
> return NULL;
> @@ -2167,7 +2153,7 @@ end:
> * This thread listens on the consumerd socket and receives the file
> * descriptors from the session daemon.
> */
> -void *lttng_consumer_thread_receive_fds(void *data)
> +void *consumer_thread_sessiond_poll(void *data)
> {
> int sock, client_socket, ret;
> /*
> diff --git a/src/common/consumer.h b/src/common/consumer.h
> index d0cd8fd..4b225e4 100644
> --- a/src/common/consumer.h
> +++ b/src/common/consumer.h
> @@ -385,8 +385,9 @@ extern int lttng_consumer_get_produced_snapshot(
> struct lttng_consumer_local_data *ctx,
> struct lttng_consumer_stream *stream,
> unsigned long *pos);
> -extern void *lttng_consumer_thread_poll_fds(void *data);
> -extern void *lttng_consumer_thread_receive_fds(void *data);
> +extern void *consumer_thread_metadata_poll(void *data);
> +extern void *consumer_thread_data_poll(void *data);
> +extern void *consumer_thread_sessiond_poll(void *data);
> extern int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
> int sock, struct pollfd *consumer_sockpoll);
>
> --
> 1.7.10.4
>
>
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> lttng-dev at lists.lttng.org
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--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
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