X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fsession.hpp;h=48f3532f182728fc1b7db8ef2cd23a91a9e613eb;hb=cd9adb8b829564212158943a0d279bb35322ab30;hp=0fad8132cc9661b6af65bd4bf4b3562ff5090fc7;hpb=c08136a3fab16fd3f620c8bcd93f25ea68382d00;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/session.hpp b/src/bin/lttng-sessiond/session.hpp
index 0fad8132c..48f3532f1 100644
--- a/src/bin/lttng-sessiond/session.hpp
+++ b/src/bin/lttng-sessiond/session.hpp
@@ -14,6 +14,8 @@
 
 #include <common/hashtable/hashtable.hpp>
 #include <common/dynamic-array.hpp>
+#include <common/make-unique-wrapper.hpp>
+#include <common/pthread-lock.hpp>
 #include <lttng/rotation.h>
 #include <lttng/location.h>
 #include <lttng/lttng-error.h>
@@ -22,12 +24,20 @@
 #include "trace-kernel.hpp"
 #include "consumer.hpp"
 
+#define ASSERT_SESSION_LIST_LOCKED() LTTNG_ASSERT(session_trylock_list())
+
 struct ltt_ust_session;
 
-typedef void (*ltt_session_destroy_notifier)(const struct ltt_session *session,
-		void *user_data);
-typedef void (*ltt_session_clear_notifier)(const struct ltt_session *session,
-		void *user_data);
+using ltt_session_destroy_notifier = void (*)(const struct ltt_session *, void *);
+using ltt_session_clear_notifier = void (*)(const struct ltt_session *, void *);
+
+namespace lttng {
+namespace sessiond {
+namespace details {
+void locked_session_release(ltt_session *session);
+} /* namespace details */
+} /* namespace sessiond */
+} /* namespace lttng */
 
 /*
  * Tracing session list
@@ -65,6 +75,12 @@ struct ltt_session_list {
  * session for both LTTng and UST.
  */
 struct ltt_session {
+	using id_t = uint64_t;
+	using locked_ptr = std::unique_ptr<ltt_session,
+			lttng::details::create_unique_class<ltt_session,
+					lttng::sessiond::details::locked_session_release>::deleter>;
+	using sptr = std::shared_ptr<ltt_session>;
+
 	char name[NAME_MAX];
 	bool has_auto_generated_name;
 	bool name_contains_creation_time;
@@ -82,7 +98,8 @@ struct ltt_session {
 	 */
 	pthread_mutex_t lock;
 	struct cds_list_head list;
-	uint64_t id;		/* session unique identifier */
+	/* session unique identifier */
+	id_t id;
 	/* Indicates if the session has been added to the session list and ht.*/
 	bool published;
 	/* Indicates if a destroy command has been applied to this session. */
@@ -212,9 +229,9 @@ void session_unlock(struct ltt_session *session);
  * In other words, it prevents tracer configurations from changing while they
  * are being transmitted to the various applications.
  */
-void session_lock_list(void);
-int session_trylock_list(void);
-void session_unlock_list(void);
+void session_lock_list();
+int session_trylock_list();
+void session_unlock_list();
 
 void session_destroy(struct ltt_session *session);
 int session_add_destroy_notifier(struct ltt_session *session,
@@ -238,10 +255,10 @@ struct lttng_trace_archive_location *session_get_trace_archive_location(
 		const struct ltt_session *session);
 
 struct ltt_session *session_find_by_name(const char *name);
-struct ltt_session *session_find_by_id(uint64_t id);
+struct ltt_session *session_find_by_id(ltt_session::id_t id);
 
-struct ltt_session_list *session_get_list(void);
-void session_list_wait_empty(void);
+struct ltt_session_list *session_get_list();
+void session_list_wait_empty();
 
 bool session_access_ok(struct ltt_session *session, uid_t uid);
 
@@ -292,4 +309,26 @@ bool session_output_supports_trace_chunks(const struct ltt_session *session);
  */
 bool sample_session_id_by_name(const char *name, uint64_t *id);
 
+namespace lttng {
+namespace sessiond {
+
+/*
+ * Session list lock must be acquired by the caller.
+ * The caller must not keep the ownership of the returned locked session
+ * for longer than strictly necessary. If your intention is to acquire
+ * a reference to an ltt_session, see `find_session_by_id()`.
+ */
+ltt_session::locked_ptr find_locked_session_by_id(ltt_session::id_t id);
+
+/*
+ * Session list lock must be acquired by the caller.
+ * The caller must not keep the ownership of the returned locked session
+ * for longer than strictly necessary. If your intention is to acquire
+ * a reference to an ltt_session, see `find_session_by_id()`.
+ */
+ltt_session::sptr find_session_by_id(ltt_session::id_t id);
+
+} /* namespace sessiond */
+} /* namespace lttng */
+
 #endif /* _LTT_SESSION_H */