Fix: bump minimal urcu dependency to 0.11

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

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index eeec3a65e7d877291a82ba9d63bf2fb6dc8f30a3..245f4ee46ee552eb60c75b7ca17156ed7ebd8d71 100644 (file)
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -403,16 +403,12 @@ static int lttng_kconsumer_snapshot_metadata(
 
                ret_read = lttng_consumer_read_subbuffer(metadata_stream, ctx, true);
                if (ret_read < 0) {
-                       if (ret_read != -EAGAIN) {
-                               ERR("Kernel snapshot reading metadata subbuffer (ret: %zd)",
-                                               ret_read);
-                               ret = ret_read;
-                               goto error_snapshot;
-                       }
-                       /* ret_read is negative at this point so we will exit the loop. */
-                       continue;
+                       ERR("Kernel snapshot reading metadata subbuffer (ret: %zd)",
+                                       ret_read);
+                       ret = ret_read;
+                       goto error_snapshot;
                }
-       } while (ret_read >= 0);
+       } while (ret_read > 0);
 
        if (use_relayd) {
                close_relayd_stream(metadata_stream);
@@ -1311,6 +1307,24 @@ error_rotate_channel:
                                msg.u.trace_chunk_exists.chunk_id);
                goto end_msg_sessiond;
        }
+       case LTTNG_CONSUMER_OPEN_CHANNEL_PACKETS:
+       {
+               const uint64_t key = msg.u.open_channel_packets.key;
+               struct lttng_consumer_channel *channel =
+                               consumer_find_channel(key);
+
+               if (channel) {
+                       pthread_mutex_lock(&channel->lock);
+                       ret_code = lttng_consumer_open_channel_packets(channel);
+                       pthread_mutex_unlock(&channel->lock);
+               } else {
+                       WARN("Channel %" PRIu64 " not found", key);
+                       ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
+               }
+
+               health_code_update();
+               goto end_msg_sessiond;
+       }
        default:
                goto end_nosignal;
        }
@@ -1513,6 +1527,17 @@ int get_subbuffer_common(struct lttng_consumer_stream *stream,
 
        ret = kernctl_get_next_subbuf(stream->wait_fd);
        if (ret) {
+               /*
+                * The caller only expects -ENODATA when there is no data to
+                * read, but the kernel tracer returns -EAGAIN when there is
+                * currently no data for a non-finalized stream, and -ENODATA
+                * when there is no data for a finalized stream. Those can be
+                * combined into a -ENODATA return value.
+                */
+               if (ret == -EAGAIN) {
+                       ret = -ENODATA;
+               }
+
                goto end;
        }
 
@@ -1594,6 +1619,16 @@ int get_next_subbuffer_metadata_check(struct lttng_consumer_stream *stream,
                        subbuffer->info.metadata.padded_subbuf_size,
                        coherent ? "true" : "false");
 end:
+       /*
+        * The caller only expects -ENODATA when there is no data to read, but
+        * the kernel tracer returns -EAGAIN when there is currently no data
+        * for a non-finalized stream, and -ENODATA when there is no data for a
+        * finalized stream. Those can be combined into a -ENODATA return value.
+        */
+       if (ret == -EAGAIN) {
+               ret = -ENODATA;
+       }
+
        return ret;
 }
 
@@ -1618,8 +1653,23 @@ int put_next_subbuffer(struct lttng_consumer_stream *stream,
 static
 bool is_get_next_check_metadata_available(int tracer_fd)
 {
-       return kernctl_get_next_subbuf_metadata_check(tracer_fd, NULL) !=
-                       -ENOTTY;
+       const int ret = kernctl_get_next_subbuf_metadata_check(tracer_fd, NULL);
+       const bool available = ret != -ENOTTY;
+
+       if (ret == 0) {
+               /* get succeeded, make sure to put the subbuffer. */
+               kernctl_put_subbuf(tracer_fd);
+       }
+
+       return available;
+}
+
+static
+int signal_metadata(struct lttng_consumer_stream *stream,
+               struct lttng_consumer_local_data *ctx)
+{
+       ASSERT_LOCKED(stream->metadata_rdv_lock);
+       return pthread_cond_broadcast(&stream->metadata_rdv) ? -errno : 0;
 }
 
 static
@@ -1652,6 +1702,8 @@ int lttng_kconsumer_set_stream_ops(
                        metadata_bucket_destroy(stream->metadata_bucket);
                        stream->metadata_bucket = NULL;
                }
+
+               stream->read_subbuffer_ops.on_sleep = signal_metadata;
        }
 
        if (!stream->read_subbuffer_ops.get_next_subbuffer) {