Fix: compat poll: add missing empty revents checks

[lttng-tools.git] / src / common / consumer.c

diff --git a/src/common/consumer.c b/src/common/consumer.c
index cba4a605a4f8d119d4f324427fe81761b605c240..72c5f3426f0cc4cbfce38d951eff38b0ee188418 100644 (file)
--- a/src/common/consumer.c
+++ b/src/common/consumer.c
@@ -1302,12 +1302,6 @@ struct lttng_consumer_local_data *lttng_consumer_create(
                goto error_quit_pipe;
        }
 
-       ret = pipe(ctx->consumer_thread_pipe);
-       if (ret < 0) {
-               PERROR("Error creating thread pipe");
-               goto error_thread_pipe;
-       }
-
        ret = pipe(ctx->consumer_channel_pipe);
        if (ret < 0) {
                PERROR("Error creating channel pipe");
@@ -1319,20 +1313,11 @@ struct lttng_consumer_local_data *lttng_consumer_create(
                goto error_metadata_pipe;
        }
 
-       ret = utils_create_pipe(ctx->consumer_splice_metadata_pipe);
-       if (ret < 0) {
-               goto error_splice_pipe;
-       }
-
        return ctx;
 
-error_splice_pipe:
-       lttng_pipe_destroy(ctx->consumer_metadata_pipe);
 error_metadata_pipe:
        utils_close_pipe(ctx->consumer_channel_pipe);
 error_channel_pipe:
-       utils_close_pipe(ctx->consumer_thread_pipe);
-error_thread_pipe:
        utils_close_pipe(ctx->consumer_should_quit);
 error_quit_pipe:
        lttng_pipe_destroy(ctx->consumer_wakeup_pipe);
@@ -1404,6 +1389,10 @@ void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx)
 
        DBG("Consumer destroying it. Closing everything.");
 
+       if (!ctx) {
+               return;
+       }
+
        destroy_data_stream_ht(data_ht);
        destroy_metadata_stream_ht(metadata_ht);
 
@@ -1415,13 +1404,11 @@ void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx)
        if (ret) {
                PERROR("close");
        }
-       utils_close_pipe(ctx->consumer_thread_pipe);
        utils_close_pipe(ctx->consumer_channel_pipe);
        lttng_pipe_destroy(ctx->consumer_data_pipe);
        lttng_pipe_destroy(ctx->consumer_metadata_pipe);
        lttng_pipe_destroy(ctx->consumer_wakeup_pipe);
        utils_close_pipe(ctx->consumer_should_quit);
-       utils_close_pipe(ctx->consumer_splice_metadata_pipe);
 
        unlink(ctx->consumer_command_sock_path);
        free(ctx);
@@ -1714,17 +1701,7 @@ ssize_t lttng_consumer_on_read_subbuffer_splice(
                        goto end;
                }
        }
-
-       /*
-        * Choose right pipe for splice. Metadata and trace data are handled by
-        * different threads hence the use of two pipes in order not to race or
-        * corrupt the written data.
-        */
-       if (stream->metadata_flag) {
-               splice_pipe = ctx->consumer_splice_metadata_pipe;
-       } else {
-               splice_pipe = ctx->consumer_thread_pipe;
-       }
+       splice_pipe = stream->splice_pipe;
 
        /* Write metadata stream id before payload */
        if (relayd) {
@@ -1830,7 +1807,8 @@ ssize_t lttng_consumer_on_read_subbuffer_splice(
                /* Splice data out */
                ret_splice = splice(splice_pipe[0], NULL, outfd, NULL,
                                ret_splice, SPLICE_F_MOVE | SPLICE_F_MORE);
-               DBG("Consumer splice pipe to file, ret %zd", ret_splice);
+               DBG("Consumer splice pipe to file (out_fd: %d), ret %zd",
+                               outfd, ret_splice);
                if (ret_splice < 0) {
                        ret = errno;
                        written = -ret;
@@ -2233,6 +2211,11 @@ restart:
                        revents = LTTNG_POLL_GETEV(&events, i);
                        pollfd = LTTNG_POLL_GETFD(&events, i);
 
+                       if (!revents) {
+                               /* No activity for this FD (poll implementation). */
+                               continue;
+                       }
+
                        if (pollfd == lttng_pipe_get_readfd(ctx->consumer_metadata_pipe)) {
                                if (revents & (LPOLLERR | LPOLLHUP )) {
                                        DBG("Metadata thread pipe hung up");
@@ -2803,10 +2786,11 @@ restart:
                        revents = LTTNG_POLL_GETEV(&events, i);
                        pollfd = LTTNG_POLL_GETFD(&events, i);
 
-                       /* Just don't waste time if no returned events for the fd */
                        if (!revents) {
+                               /* No activity for this FD (poll implementation). */
                                continue;
                        }
+
                        if (pollfd == ctx->consumer_channel_pipe[0]) {
                                if (revents & (LPOLLERR | LPOLLHUP)) {
                                        DBG("Channel thread pipe hung up");
@@ -3569,15 +3553,6 @@ int consumer_data_pending(uint64_t id)
                 */
                ret = cds_lfht_is_node_deleted(&stream->node.node);
                if (!ret) {
-                       /*
-                        * An empty output file is not valid. We need at least one packet
-                        * generated per stream, even if it contains no event, so it
-                        * contains at least one packet header.
-                        */
-                       if (stream->output_written == 0) {
-                               pthread_mutex_unlock(&stream->lock);
-                               goto data_pending;
-                       }
                        /* Check the stream if there is data in the buffers. */
                        ret = data_pending(stream);
                        if (ret == 1) {