From d3814b5400bc383ee8645cd76017e2aa6fea5dfe Mon Sep 17 00:00:00 2001
From: =?utf8?q?J=C3=A9r=C3=A9mie=20Galarneau?=
 <jeremie.galarneau@efficios.com>
Date: Thu, 19 Mar 2015 21:43:00 -0400
Subject: [PATCH] ir: add weak reference to parent trace to bt_ctf_stream_class
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Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
---
 formats/ctf/ir/stream-class.c                 | 22 ++++++++++++++++++
 formats/ctf/ir/trace.c                        | 23 ++++++++++++++++---
 .../babeltrace/ctf-ir/stream-class-internal.h |  7 ++++++
 3 files changed, 49 insertions(+), 3 deletions(-)

diff --git a/formats/ctf/ir/stream-class.c b/formats/ctf/ir/stream-class.c
index 9ef5ca79..22ea8a5d 100644
--- a/formats/ctf/ir/stream-class.c
+++ b/formats/ctf/ir/stream-class.c
@@ -666,6 +666,28 @@ end:
 	return ret;
 }
 
+BT_HIDDEN
+int bt_ctf_stream_class_set_trace(struct bt_ctf_stream_class *stream_class,
+		struct bt_ctf_trace *trace)
+{
+	int ret = 0;
+
+	if (!stream_class) {
+		ret = -1;
+		goto end;
+	}
+
+	if (stream_class->trace && trace) {
+		/* Already attached to a trace */
+		ret = -1;
+		goto end;
+	}
+
+	stream_class->trace = trace;
+end:
+	return ret;
+}
+
 static
 void bt_ctf_stream_class_destroy(struct bt_ctf_ref *ref)
 {
diff --git a/formats/ctf/ir/trace.c b/formats/ctf/ir/trace.c
index e7dcfdae..476d62c3 100644
--- a/formats/ctf/ir/trace.c
+++ b/formats/ctf/ir/trace.c
@@ -62,6 +62,13 @@ const unsigned int field_type_aliases_sizes[] = {
 	[FIELD_TYPE_ALIAS_UINT64_T] = 64,
 };
 
+static
+void put_stream_class(struct bt_ctf_stream_class *stream_class)
+{
+	(void) bt_ctf_stream_class_set_trace(stream_class, NULL);
+	bt_ctf_stream_class_put(stream_class);
+}
+
 struct bt_ctf_trace *bt_ctf_trace_create(void)
 {
 	struct bt_ctf_trace *trace = NULL;
@@ -74,11 +81,11 @@ struct bt_ctf_trace *bt_ctf_trace_create(void)
 	bt_ctf_trace_set_byte_order(trace, BT_CTF_BYTE_ORDER_NATIVE);
 	bt_ctf_ref_init(&trace->ref_count);
 	trace->clocks = g_ptr_array_new_with_free_func(
-		(GDestroyNotify)bt_ctf_clock_put);
+		(GDestroyNotify) bt_ctf_clock_put);
 	trace->streams = g_ptr_array_new_with_free_func(
-		(GDestroyNotify)bt_ctf_stream_put);
+		(GDestroyNotify) bt_ctf_stream_put);
 	trace->stream_classes = g_ptr_array_new_with_free_func(
-		(GDestroyNotify)bt_ctf_stream_class_put);
+		(GDestroyNotify) put_stream_class);
 	if (!trace->clocks || !trace->stream_classes || !trace->streams) {
 		goto error_destroy;
 	}
@@ -403,6 +410,13 @@ int bt_ctf_trace_add_stream_class(struct bt_ctf_trace *trace,
 		}
 	}
 
+	/* Set weak reference to trace in stream class */
+	ret = bt_ctf_stream_class_set_trace(stream_class, trace);
+	if (ret) {
+		/* Stream class already part of another trace */
+		goto end;
+	}
+
 	bt_ctf_stream_class_get(stream_class);
 	g_ptr_array_add(trace->stream_classes, stream_class);
 
@@ -425,6 +439,9 @@ int bt_ctf_trace_add_stream_class(struct bt_ctf_trace *trace,
 	bt_ctf_attributes_freeze(trace->environment);
 
 end:
+	if (ret) {
+		(void) bt_ctf_stream_class_set_trace(stream_class, NULL);
+	}
 	return ret;
 }
 
diff --git a/include/babeltrace/ctf-ir/stream-class-internal.h b/include/babeltrace/ctf-ir/stream-class-internal.h
index 8301fea0..3b368d1d 100644
--- a/include/babeltrace/ctf-ir/stream-class-internal.h
+++ b/include/babeltrace/ctf-ir/stream-class-internal.h
@@ -31,6 +31,7 @@
 #include <babeltrace/ctf-writer/clock.h>
 #include <babeltrace/ctf-writer/event-fields.h>
 #include <babeltrace/ctf-writer/event-types.h>
+#include <babeltrace/ctf-ir/trace.h>
 #include <babeltrace/babeltrace-internal.h>
 #include <babeltrace/ctf/types.h>
 #include <glib.h>
@@ -44,6 +45,8 @@ struct bt_ctf_stream_class {
 	uint32_t id;
 	uint32_t next_event_id;
 	uint32_t next_stream_id;
+	/* Weak reference; a stream class does not have ownership of a trace */
+	struct bt_ctf_trace *trace;
 	struct bt_ctf_field_type *packet_context_type;
 	struct bt_ctf_field_type *event_header_type;
 	struct bt_ctf_field_type *event_context_type;
@@ -67,4 +70,8 @@ BT_HIDDEN
 int _bt_ctf_stream_class_set_id(struct bt_ctf_stream_class *stream_class,
 		uint32_t id);
 
+BT_HIDDEN
+int bt_ctf_stream_class_set_trace(struct bt_ctf_stream_class *stream_class,
+		struct bt_ctf_trace *trace);
+
 #endif /* BABELTRACE_CTF_IR_STREAM_CLASS_INTERNAL_H */
-- 
2.34.1