Fix: kernel consumer: signal metadata ready condition variable

[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 ecacadfd5bae7dc2b423bdae3b5023cb835d797b..46a9f52c0ac2406787f2743213da3380b2a503d4 100644 (file)
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -41,7 +41,7 @@
 
 #include "kernel-consumer.h"
 
-extern struct lttng_consumer_global_data consumer_data;
+extern struct lttng_consumer_global_data the_consumer_data;
 extern int consumer_poll_timeout;
 
 /*
@@ -494,7 +494,7 @@ int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
        case LTTNG_CONSUMER_ADD_CHANNEL:
        {
                struct lttng_consumer_channel *new_channel;
-               int ret_send_status, ret_add_channel;
+               int ret_send_status, ret_add_channel = 0;
                const uint64_t chunk_id = msg.u.channel.chunk_id.value;
 
                health_code_update();
@@ -1699,8 +1699,23 @@ 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
@@ -1733,6 +1748,8 @@ 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) {