From: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Date: Fri, 7 Aug 2020 19:39:24 +0000 (-0400)
Subject: condition: introduce reference counting
X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=commitdiff_plain;h=4655b864b310dca6b4346770351a0e6a261ba5a1

condition: introduce reference counting

This will allows easier management of the trigger ownership of its associated
condition and action objects.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I46420b03bd4bf7948bc2d1f44985edfe86c27c61
---

diff --git a/include/lttng/condition/condition-internal.h b/include/lttng/condition/condition-internal.h
index 98a830942..405199b42 100644
--- a/include/lttng/condition/condition-internal.h
+++ b/include/lttng/condition/condition-internal.h
@@ -14,6 +14,7 @@
 #include <common/payload.h>
 #include <stdbool.h>
 #include <urcu/list.h>
+#include <urcu/ref.h>
 #include <stdint.h>
 #include <sys/types.h>
 
@@ -29,6 +30,8 @@ typedef ssize_t (*condition_create_from_payload_cb)(
 		struct lttng_condition **condition);
 
 struct lttng_condition {
+	/* Reference counting is only exposed to internal users. */
+	struct urcu_ref ref;
 	enum lttng_condition_type type;
 	condition_validate_cb validate;
 	condition_serialize_cb serialize;
@@ -42,6 +45,12 @@ struct lttng_condition_comm {
 	char payload[];
 };
 
+LTTNG_HIDDEN
+void lttng_condition_get(struct lttng_condition *condition);
+
+LTTNG_HIDDEN
+void lttng_condition_put(struct lttng_condition *condition);
+
 LTTNG_HIDDEN
 void lttng_condition_init(struct lttng_condition *condition,
 		enum lttng_condition_type type);
diff --git a/src/common/condition.c b/src/common/condition.c
index 367f4a38b..427c49e09 100644
--- a/src/common/condition.c
+++ b/src/common/condition.c
@@ -23,15 +23,36 @@ enum lttng_condition_type lttng_condition_get_type(
 }
 
 void lttng_condition_destroy(struct lttng_condition *condition)
+{
+	lttng_condition_put(condition);
+}
+
+static void condition_destroy_ref(struct urcu_ref *ref)
+{
+	struct lttng_condition *condition =
+		container_of(ref, struct lttng_condition, ref);
+
+	condition->destroy(condition);
+}
+
+LTTNG_HIDDEN
+void lttng_condition_get(struct lttng_condition *condition)
+{
+	urcu_ref_get(&condition->ref);
+}
+
+LTTNG_HIDDEN
+void lttng_condition_put(struct lttng_condition *condition)
 {
 	if (!condition) {
 		return;
 	}
 
 	assert(condition->destroy);
-	condition->destroy(condition);
+	urcu_ref_put(&condition->ref, condition_destroy_ref);
 }
 
+
 LTTNG_HIDDEN
 bool lttng_condition_validate(const struct lttng_condition *condition)
 {
@@ -171,4 +192,5 @@ void lttng_condition_init(struct lttng_condition *condition,
 		enum lttng_condition_type type)
 {
 	condition->type = type;
+	urcu_ref_init(&condition->ref);
 }