--- /dev/null
+/*
+ * Copyright (C) 2013 Julien Desfossez <jdesfossez@efficios.com>
+ * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#define _LGPL_SOURCE
+#include <common/common.h>
+#include <urcu/rculist.h>
+
+#include "lttng-relayd.h"
+#include "ctf-trace.h"
+#include "session.h"
+#include "viewer-session.h"
+#include "viewer-stream.h"
+#include "stream.h"
+
+struct relay_viewer_session *viewer_session_create(void)
+{
+ struct relay_viewer_session *vsession;
+
+ vsession = (relay_viewer_session *) zmalloc(sizeof(*vsession));
+ if (!vsession) {
+ goto end;
+ }
+ CDS_INIT_LIST_HEAD(&vsession->session_list);
+end:
+ return vsession;
+}
+
+int viewer_session_set_trace_chunk_copy(struct relay_viewer_session *vsession,
+ struct lttng_trace_chunk *relay_session_trace_chunk)
+{
+ int ret = 0;
+ struct lttng_trace_chunk *viewer_chunk;
+
+ lttng_trace_chunk_put(vsession->current_trace_chunk);
+ vsession->current_trace_chunk = NULL;
+
+ DBG("Copying relay session's current trace chunk to the viewer session");
+ if (!relay_session_trace_chunk) {
+ goto end;
+ }
+
+ viewer_chunk = lttng_trace_chunk_copy(relay_session_trace_chunk);
+ if (!viewer_chunk) {
+ ERR("Failed to create a viewer trace chunk from the relay session's current chunk");
+ ret = -1;
+ goto end;
+ }
+
+ vsession->current_trace_chunk = viewer_chunk;
+end:
+ return ret;
+}
+
+/* The existence of session must be guaranteed by the caller. */
+enum lttng_viewer_attach_return_code viewer_session_attach(
+ struct relay_viewer_session *vsession,
+ struct relay_session *session)
+{
+ enum lttng_viewer_attach_return_code viewer_attach_status =
+ LTTNG_VIEWER_ATTACH_OK;
+
+ ASSERT_LOCKED(session->lock);
+
+ /* Will not fail, as per the ownership guarantee. */
+ if (!session_get(session)) {
+ viewer_attach_status = LTTNG_VIEWER_ATTACH_UNK;
+ goto end;
+ }
+ if (session->viewer_attached) {
+ viewer_attach_status = LTTNG_VIEWER_ATTACH_ALREADY;
+ } else {
+ int ret;
+
+ LTTNG_ASSERT(!vsession->current_trace_chunk);
+ session->viewer_attached = true;
+
+ ret = viewer_session_set_trace_chunk_copy(vsession,
+ session->current_trace_chunk);
+ if (ret) {
+ /*
+ * The live protocol does not define a generic error
+ * value for the "attach" command. The "unknown"
+ * status is used so that the viewer may handle this
+ * failure as if the session didn't exist anymore.
+ */
+ DBG("Failed to create a viewer trace chunk from the current trace chunk of session \"%s\", returning LTTNG_VIEWER_ATTACH_UNK",
+ session->session_name);
+ viewer_attach_status = LTTNG_VIEWER_ATTACH_UNK;
+ }
+ }
+
+ if (viewer_attach_status == LTTNG_VIEWER_ATTACH_OK) {
+ pthread_mutex_lock(&vsession->session_list_lock);
+ /* Ownership is transfered to the list. */
+ cds_list_add_rcu(&session->viewer_session_node,
+ &vsession->session_list);
+ pthread_mutex_unlock(&vsession->session_list_lock);
+ } else {
+ /* Put our local ref. */
+ session_put(session);
+ }
+end:
+ return viewer_attach_status;
+}
+
+/* The existence of session must be guaranteed by the caller. */
+static int viewer_session_detach(struct relay_viewer_session *vsession,
+ struct relay_session *session)
+{
+ int ret = 0;
+
+ pthread_mutex_lock(&session->lock);
+ if (!session->viewer_attached) {
+ ret = -1;
+ } else {
+ session->viewer_attached = false;
+ }
+
+ if (!ret) {
+ pthread_mutex_lock(&vsession->session_list_lock);
+ cds_list_del_rcu(&session->viewer_session_node);
+ pthread_mutex_unlock(&vsession->session_list_lock);
+ /* Release reference held by the list. */
+ session_put(session);
+ }
+ /* Safe since we know the session exists. */
+ pthread_mutex_unlock(&session->lock);
+ return ret;
+}
+
+void viewer_session_destroy(struct relay_viewer_session *vsession)
+{
+ lttng_trace_chunk_put(vsession->current_trace_chunk);
+ free(vsession);
+}
+
+/*
+ * Release ownership of all the streams of one session and detach the viewer.
+ */
+void viewer_session_close_one_session(struct relay_viewer_session *vsession,
+ struct relay_session *session)
+{
+ struct lttng_ht_iter iter;
+ struct relay_viewer_stream *vstream;
+
+ /*
+ * TODO: improvement: create more efficient list of
+ * vstream per session.
+ */
+ cds_lfht_for_each_entry(viewer_streams_ht->ht, &iter.iter,
+ vstream, stream_n.node) {
+ if (!viewer_stream_get(vstream)) {
+ continue;
+ }
+ if (vstream->stream->trace->session != session) {
+ viewer_stream_put(vstream);
+ continue;
+ }
+ /* Put local reference. */
+ viewer_stream_put(vstream);
+ /*
+ * We have reached one of the viewer stream's lifetime
+ * end condition. This "put" will cause the proper
+ * teardown of the viewer stream.
+ */
+ viewer_stream_put(vstream);
+ }
+ lttng_trace_chunk_put(vsession->current_trace_chunk);
+ vsession->current_trace_chunk = NULL;
+ viewer_session_detach(vsession, session);
+}
+
+void viewer_session_close(struct relay_viewer_session *vsession)
+{
+ struct relay_session *session;
+
+ rcu_read_lock();
+ cds_list_for_each_entry_rcu(session,
+ &vsession->session_list, viewer_session_node) {
+ viewer_session_close_one_session(vsession, session);
+ }
+ rcu_read_unlock();
+}
+
+/*
+ * Check if a connection is attached to a session.
+ * Return 1 if attached, 0 if not attached, a negative value on error.
+ */
+int viewer_session_is_attached(struct relay_viewer_session *vsession,
+ struct relay_session *session)
+{
+ struct relay_session *iter;
+ int found = 0;
+
+ pthread_mutex_lock(&session->lock);
+ if (!vsession) {
+ goto end;
+ }
+ if (!session->viewer_attached) {
+ goto end;
+ }
+ rcu_read_lock();
+ cds_list_for_each_entry_rcu(iter,
+ &vsession->session_list,
+ viewer_session_node) {
+ if (session == iter) {
+ found = 1;
+ goto end_rcu_unlock;
+ }
+ }
+end_rcu_unlock:
+ rcu_read_unlock();
+end:
+ pthread_mutex_unlock(&session->lock);
+ return found;
+}
projects / lttng-tools.git / blobdiff