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 1333263f186e4c2b221fa68d7b73399d1c3be139..0035aae82d51e1afaa538fddfeb6e7463bfa53db 100644 (file)
--- a/src/common/consumer.c
+++ b/src/common/consumer.c
@@ -1430,7 +1430,7 @@ static int write_relayd_metadata_id(int fd,
        ret = lttng_write(fd, (void *) &hdr, sizeof(hdr));
        if (ret < sizeof(hdr)) {
                /*
-                * This error means that the fd's end is closed so ignore the perror
+                * This error means that the fd's end is closed so ignore the PERROR
                 * not to clubber the error output since this can happen in a normal
                 * code path.
                 */
@@ -2212,6 +2212,11 @@ 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");
@@ -2782,10 +2787,11 @@ 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");
@@ -3548,15 +3554,6 @@ 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) {