Fix: rename close_stream and use it in delete session

[lttng-tools.git] / src / bin / lttng-relayd / main.c

diff --git a/src/bin/lttng-relayd/main.c b/src/bin/lttng-relayd/main.c
index ba97ab3d78a05bd2cec21c564b8ce4ca6bf35262..f12b1a335b6bd0eaf99a49bfa3bc234149fc833d 100644 (file)
--- a/src/bin/lttng-relayd/main.c
+++ b/src/bin/lttng-relayd/main.c
@@ -111,6 +111,9 @@ static gid_t relayd_gid;
 /* Global relay stream hash table. */
 struct lttng_ht *relay_streams_ht;
 
+/* Global relay viewer stream hash table. */
+struct lttng_ht *viewer_streams_ht;
+
 /*
  * usage function on stderr
  */
@@ -761,15 +764,20 @@ void deferred_free_session(struct rcu_head *head)
        free(session);
 }
 
-static void close_stream(struct relay_stream *stream,
-               struct lttng_ht *viewer_streams_ht, struct lttng_ht *ctf_traces_ht)
+/*
+ * Close a given stream. The stream is freed using a call RCU.
+ *
+ * RCU read side lock MUST be acquired. If NO close_stream_check() was called
+ * BEFORE the stream lock MUST be acquired.
+ */
+static void destroy_stream(struct relay_stream *stream,
+               struct lttng_ht *ctf_traces_ht)
 {
        int delret;
        struct relay_viewer_stream *vstream;
        struct lttng_ht_iter iter;
 
        assert(stream);
-       assert(viewer_streams_ht);
 
        delret = close(stream->fd);
        if (delret < 0) {
@@ -783,8 +791,7 @@ static void close_stream(struct relay_stream *stream,
                }
        }
 
-       vstream = live_find_viewer_stream_by_id(stream->stream_handle,
-                       viewer_streams_ht);
+       vstream = live_find_viewer_stream_by_id(stream->stream_handle);
        if (vstream) {
                /*
                 * Set the last good value into the viewer stream. This is done
@@ -827,29 +834,22 @@ void relay_delete_session(struct relay_command *cmd,
        rcu_read_lock();
        cds_lfht_for_each_entry(relay_streams_ht->ht, &iter.iter, node, node) {
                node = lttng_ht_iter_get_node_ulong(&iter);
-               if (node) {
-                       stream = caa_container_of(node,
-                                       struct relay_stream, stream_n);
-                       if (stream->session == cmd->session) {
-                               ret = close(stream->fd);
-                               if (ret < 0) {
-                                       PERROR("close stream fd on delete session");
-                               }
-                               ret = lttng_ht_del(relay_streams_ht, &iter);
-                               assert(!ret);
-                               call_rcu(&stream->rcu_node,
-                                       deferred_free_stream);
-                       }
-                       /* Cleanup index of that stream. */
-                       relay_index_destroy_by_stream_id(stream->stream_handle,
-                                       indexes_ht);
+               if (!node) {
+                       continue;
                }
+               stream = caa_container_of(node, struct relay_stream, stream_n);
+               if (stream->session == cmd->session) {
+                       destroy_stream(stream, cmd->ctf_traces_ht);
+               }
+               /* Cleanup index of that stream. */
+               relay_index_destroy_by_stream_id(stream->stream_handle, indexes_ht);
        }
+
+       /* Make this session not visible anymore. */
        iter.iter.node = &cmd->session->session_n.node;
        ret = lttng_ht_del(sessions_ht, &iter);
        assert(!ret);
-       call_rcu(&cmd->session->rcu_node,
-                       deferred_free_session);
+       call_rcu(&cmd->session->rcu_node, deferred_free_session);
        rcu_read_unlock();
 }
 
@@ -1073,7 +1073,7 @@ err_free_stream:
  */
 static
 int relay_close_stream(struct lttcomm_relayd_hdr *recv_hdr,
-               struct relay_command *cmd, struct lttng_ht *viewer_streams_ht)
+               struct relay_command *cmd)
 {
        int ret, send_ret;
        struct relay_session *session = cmd->session;
@@ -1113,7 +1113,7 @@ int relay_close_stream(struct lttcomm_relayd_hdr *recv_hdr,
        stream->close_flag = 1;
 
        if (close_stream_check(stream)) {
-               close_stream(stream, viewer_streams_ht, cmd->ctf_traces_ht);
+               destroy_stream(stream, cmd->ctf_traces_ht);
        }
 
 end_unlock:
@@ -1803,7 +1803,7 @@ int relay_process_control(struct lttcomm_relayd_hdr *recv_hdr,
                ret = relay_send_version(recv_hdr, cmd, ctx->sessions_ht);
                break;
        case RELAYD_CLOSE_STREAM:
-               ret = relay_close_stream(recv_hdr, cmd, ctx->viewer_streams_ht);
+               ret = relay_close_stream(recv_hdr, cmd);
                break;
        case RELAYD_DATA_PENDING:
                ret = relay_data_pending(recv_hdr, cmd);
@@ -1837,7 +1837,7 @@ end:
  */
 static
 int relay_process_data(struct relay_command *cmd,
-               struct lttng_ht *indexes_ht, struct lttng_ht *viewer_streams_ht)
+               struct lttng_ht *indexes_ht)
 {
        int ret = 0, rotate_index = 0, index_created = 0;
        struct relay_stream *stream;
@@ -2009,7 +2009,7 @@ int relay_process_data(struct relay_command *cmd,
 
        /* Check if we need to close the FD */
        if (close_stream_check(stream)) {
-               close_stream(stream, viewer_streams_ht, cmd->ctf_traces_ht);
+               destroy_stream(stream, cmd->ctf_traces_ht);
        }
 
 end_rcu_unlock:
@@ -2311,8 +2311,7 @@ restart:
                                                continue;
                                        }
 
-                                       ret = relay_process_data(relay_connection, indexes_ht,
-                                                       relay_ctx->viewer_streams_ht);
+                                       ret = relay_process_data(relay_connection, indexes_ht);
                                        /* connection closed */
                                        if (ret < 0) {
                                                relay_cleanup_poll_connection(&events, pollfd);
@@ -2482,8 +2481,8 @@ int main(int argc, char **argv)
        }
 
        /* tables of streams indexed by stream ID */
-       relay_ctx->viewer_streams_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
-       if (!relay_ctx->viewer_streams_ht) {
+       viewer_streams_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
+       if (!viewer_streams_ht) {
                goto exit_relay_ctx_viewer_streams;
        }
 
@@ -2536,7 +2535,7 @@ exit_dispatcher:
                PERROR("pthread_join");
                goto error;     /* join error, exit without cleanup */
        }
-       lttng_ht_destroy(relay_ctx->viewer_streams_ht);
+       lttng_ht_destroy(viewer_streams_ht);
 
 exit_relay_ctx_viewer_streams:
        lttng_ht_destroy(relay_streams_ht);