Fix: lttng-ctl: public session.h control API: restore 0 success return value

[lttng-tools.git] / include / lttng / session.h

diff --git a/include/lttng/session.h b/include/lttng/session.h
index 599892d13508d7470f829f6c89da84b18aea6b9c..395df32450889d806aa0efd805a7a2cd67f4c219 100644 (file)
--- a/include/lttng/session.h
+++ b/include/lttng/session.h
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2014 - David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2019 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
  *
  * This library is free software; you can redistribute it and/or modify it
  * under the terms of the GNU Lesser General Public License, version 2.1 only,
@@ -22,6 +23,9 @@
 extern "C" {
 #endif
 
+struct lttng_session_descriptor;
+struct lttng_destruction_handle;
+
 /*
  * Basic session information.
  *
@@ -33,15 +37,43 @@ extern "C" {
 #define LTTNG_SESSION_PADDING1             12
 struct lttng_session {
        char name[LTTNG_NAME_MAX];
-       /* The path where traces are written */
+       /*
+        * Human-readable representation of the trace's destination.
+        * In the case of a local tracing session, a path is provided:
+        *     /path/to/the/output
+        *
+        * In the case of a remote (network) tracing session, the string has
+        * the following format:
+        *     net://hostname/path:ctrl_port [data: data_port]
+        */
        char path[PATH_MAX];
        uint32_t enabled;       /* enabled/started: 1, disabled/stopped: 0 */
        uint32_t snapshot_mode;
        unsigned int live_timer_interval;       /* usec */
 
-       char padding[LTTNG_SESSION_PADDING1];
+       union {
+               char padding[LTTNG_SESSION_PADDING1];
+               void *ptr;
+       } extended;
 };
 
+/*
+ * Create a session on the session daemon from a session descriptor.
+ *
+ * See the session descriptor API description in session-descriptor.h
+ *
+ * Note that unspecified session descriptor parameters, such as a session's
+ * name, are updated in the session descriptor if the creation of the session
+ * succeeds. This allows users to query the session's auto-generated name
+ * after its creation. Note that other attributes can be queried using the
+ * session listing API.
+ *
+ * Returns LTTNG_OK on success. See lttng-error.h for the meaning of the other
+ * return codes.
+ */
+extern enum lttng_error_code lttng_create_session_ext(
+               struct lttng_session_descriptor *session_descriptor);
+
 /*
  * Create a tracing session using a name and an optional URL.
  *
@@ -76,8 +108,7 @@ extern int lttng_create_session_snapshot(const char *name,
  * indexes are sent and metadata is checked for each packet.
  *
  * Name can't be NULL. If no URL is given, the default is to send the data to
- * net://127.0.0.1. The timer_interval is in usec and by default set to 1000000
- * (1 second).
+ * net://127.0.0.1. The timer_interval is in usec.
  *
  * Return 0 on success else a negative LTTng error code.
  */
@@ -103,6 +134,21 @@ extern int lttng_create_session_live(const char *name, const char *url,
  */
 extern int lttng_destroy_session(const char *name);
 
+/*
+ * Destroy a tracing session.
+ *
+ * Performs the same function as lttng_destroy_session(), but provides
+ * an lttng_destruction_handle which can be used to wait for the completion
+ * of the session's destruction. The lttng_destroy_handle can also be used
+ * obtain the status and archive location of any implicit session
+ * rotation that may have occured during the session's destruction.
+ *
+ * Returns LTTNG_OK on success. The returned handle is owned by the caller
+ * and must be free'd using lttng_destruction_handle_destroy().
+ */
+extern enum lttng_error_code lttng_destroy_session_ext(const char *session_name,
+               struct lttng_destruction_handle **handle);
+
 /*
  * Behaves exactly like lttng_destroy_session but does not wait for data
  * availability.
@@ -112,11 +158,28 @@ extern int lttng_destroy_session_no_wait(const char *name);
 /*
  * List all the tracing sessions.
  *
- * Return the size (number of entries) of the "lttng_session" array. Caller
- * must free sessions. On error, a negative LTTng error code is returned.
+ * Return the number of entries of the "lttng_session" array. The caller
+ * must free the returned sessions array directly using free().
+ *
+ * On error, a negative LTTng error code is returned.
  */
 extern int lttng_list_sessions(struct lttng_session **sessions);
 
+/*
+ * Get the creation time of an lttng_session object on the session daemon.
+ *
+ * This function must only be used with lttng_session objects returned
+ * by lttng_list_sessions() or lttng_session_create().
+ *
+ * The creation time returned is a UNIX timestamp; the number of seconds since
+ * Epoch (1970-01-01 00:00:00 +0000 (UTC)).
+ *
+ * Returns LTTNG_OK on success. See lttng-error.h for the meaning of the other
+ * return codes.
+ */
+extern enum lttng_error_code lttng_session_get_creation_time(
+               const struct lttng_session *session, uint64_t *creation_time);
+
 /*
  * Set the shared memory path for a session.
  *