Signed-off-by: David Goulet <[email protected]>
---
src/common/consumer.c | 66 +++++++++++++++++++++++---
src/common/kernel-consumer/kernel-consumer.c | 19 ++------
src/common/ust-consumer/ust-consumer.c | 19 ++------
3 files changed, 66 insertions(+), 38 deletions(-)
diff --git a/src/common/consumer.c b/src/common/consumer.c
index e61a227..cf0e715 100644
--- a/src/common/consumer.c
+++ b/src/common/consumer.c
@@ -2657,6 +2657,33 @@ error:
}
/*
+ * Try to lock the stream mutex.
+ *
+ * On success, 1 is returned else 0 indicating that the mutex is NOT lock.
+ */
+static int stream_try_lock(struct lttng_consumer_stream *stream)
+{
+ int ret;
+
+ assert(stream);
+
+ /*
+ * Try to lock the stream mutex. On failure, we know that the stream is
+ * being used else where hence there is data still being extracted.
+ */
+ ret = pthread_mutex_trylock(&stream->lock);
+ if (ret == EBUSY) {
+ ret = 0;
+ goto end;
+ }
+
+ ret = 1;
+
+end:
+ return ret;
+}
+
+/*
* Check if for a given session id there is still data needed to be extract
* from the buffers.
*
@@ -2696,17 +2723,43 @@ int consumer_data_available(uint64_t id)
ht->hash_fct((void *)((unsigned long) id), 0x42UL),
ht->match_fct, (void *)((unsigned long) id),
&iter.iter, stream, node_session_id.node) {
- /* Check the stream for data. */
- ret = data_available(stream);
- if (ret == 0) {
+ /* If this call fails, the stream is being used hence data
pending. */
+ ret = stream_try_lock(stream);
+ if (!ret) {
goto data_not_available;
}
+ /*
+ * A removed node from the hash table indicates that the stream
has
+ * been deleted thus having a guarantee that the buffers are
closed
+ * on the consumer side. However, data can still be transmitted
+ * over the network so don't skip the relayd check.
+ */
+ ret = cds_lfht_is_node_deleted(&stream->node.node);
+ if (!ret) {
+ /* Check the stream if there is data in the buffers. */
+ ret = data_available(stream);
+ if (ret == 0) {
+ pthread_mutex_unlock(&stream->lock);
+ goto data_not_available;
+ }
+ }
+
+ /* Relayd check */
if (stream->net_seq_idx != -1) {
relayd = consumer_find_relayd(stream->net_seq_idx);
- assert(relayd);
+ if (!relayd) {
+ /*
+ * At this point, if the relayd object is not
available for the
+ * given stream, it is because the relayd is
being cleanup so
+ * every stream associated with it (for a
session id value) are
+ * or wil be marked for deletion hence not
having data pending
+ * anymore.
+ */
+ pthread_mutex_unlock(&stream->lock);
+ goto data_not_available;
+ }
- pthread_mutex_lock(&stream->lock);
pthread_mutex_lock(&relayd->ctrl_sock_mutex);
if (stream->metadata_flag) {
ret =
relayd_quiescent_control(&relayd->control_sock);
@@ -2715,11 +2768,12 @@ int consumer_data_available(uint64_t id)
stream->relayd_stream_id,
stream->next_net_seq_num);
}
pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
- pthread_mutex_unlock(&stream->lock);
if (ret == 0) {
+ pthread_mutex_unlock(&stream->lock);
goto data_not_available;
}
}
+ pthread_mutex_unlock(&stream->lock);
}
/*
diff --git a/src/common/kernel-consumer/kernel-consumer.c
b/src/common/kernel-consumer/kernel-consumer.c
index 249df8a..196deee 100644
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -485,7 +485,8 @@ error:
/*
* Check if data is still being extracted from the buffers for a specific
- * stream. Consumer data lock MUST be acquired before calling this function.
+ * stream. Consumer data lock MUST be acquired before calling this function
+ * and the stream lock.
*
* Return 0 if the traced data are still getting read else 1 meaning that the
* data is available for trace viewer reading.
@@ -496,31 +497,17 @@ int lttng_kconsumer_data_available(struct
lttng_consumer_stream *stream)
assert(stream);
- /*
- * Try to lock the stream mutex. On failure, we know that the stream is
- * being used else where hence there is data still being extracted.
- */
- ret = pthread_mutex_trylock(&stream->lock);
- if (ret == EBUSY) {
- /* Data not available */
- ret = 0;
- goto end;
- }
- /* The stream is now locked so we can do our ustctl calls */
-
ret = kernctl_get_next_subbuf(stream->wait_fd);
if (ret == 0) {
/* There is still data so let's put back this subbuffer. */
ret = kernctl_put_subbuf(stream->wait_fd);
assert(ret == 0);
- goto end_unlock;
+ goto end;
}
/* Data is available to be read for this stream. */
ret = 1;
-end_unlock:
- pthread_mutex_unlock(&stream->lock);
end:
return ret;
}
diff --git a/src/common/ust-consumer/ust-consumer.c
b/src/common/ust-consumer/ust-consumer.c
index e8e3f93..4d3671a 100644
--- a/src/common/ust-consumer/ust-consumer.c
+++ b/src/common/ust-consumer/ust-consumer.c
@@ -526,7 +526,8 @@ error:
/*
* Check if data is still being extracted from the buffers for a specific
- * stream. Consumer data lock MUST be acquired before calling this function.
+ * stream. Consumer data lock MUST be acquired before calling this function
+ * and the stream lock.
*
* Return 0 if the traced data are still getting read else 1 meaning that the
* data is available for trace viewer reading.
@@ -539,31 +540,17 @@ int lttng_ustconsumer_data_available(struct
lttng_consumer_stream *stream)
DBG("UST consumer checking data availability");
- /*
- * Try to lock the stream mutex. On failure, we know that the stream is
- * being used else where hence there is data still being extracted.
- */
- ret = pthread_mutex_trylock(&stream->lock);
- if (ret == EBUSY) {
- /* Data not available */
- ret = 0;
- goto end;
- }
- /* The stream is now locked so we can do our ustctl calls */
-
ret = ustctl_get_next_subbuf(stream->chan->handle, stream->buf);
if (ret == 0) {
/* There is still data so let's put back this subbuffer. */
ret = ustctl_put_subbuf(stream->chan->handle, stream->buf);
assert(ret == 0);
- goto end_unlock;
+ goto end;
}
/* Data is available to be read for this stream. */
ret = 1;
-end_unlock:
- pthread_mutex_unlock(&stream->lock);
end:
return ret;
}
--
1.7.10.4
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