/*
* 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,
extern "C" {
#endif
+struct lttng_session_descriptor;
+struct lttng_destruction_handle;
+
/*
* Basic session information.
*
*
* The structures should be initialized to zero before use.
*/
-#define LTTNG_SESSION_PADDING1 12
+#define LTTNG_SESSION_PADDING1 8
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];
+ /*
+ * End of public attributes.
+ * The remaining fields are used to deal with ABI management concerns.
+ */
+
+ /*
+ * 32-bit architectures are already naturally aligned on 4 bytes after
+ * 'live_timer_interval'. However, the offset does not result in a
+ * natural alignment on 64-bit architectures. Adding 4 bytes of
+ * padding here results in an aligned offset after 'alignement_padding'
+ * for both bitnesses.
+ *
+ * This was added since not all compilers appear to align unions in the
+ * same way. Some (e.g. MSVC) do not seem to impose an alignement
+ * constraint while others (e.g. gcc, clang, icc) seem to align it to
+ * ensure 'ptr' is naturally aligned.
+ */
+ char alignment_padding[4];
+ union {
+ /*
+ * Ensure the 'extended' union has the same size for both
+ * 32-bit and 64-bit builds.
+ */
+ 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.
*
* 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.
*/
*/
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.
/*
* 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.
*
extern int lttng_list_tracker_pids(struct lttng_handle *handle,
int *enabled, int32_t **pids, size_t *nr_pids);
-/*
- * Ask the session daemon where the data for this session is currently being
- * written to. If rotations occured during a session, this call is useful to
- * know the location of the last chunk.
- *
- * Return 0 and allocate chunk_path if rotations occured for this session, the
- * caller needs to free chunk_path.
- * Return 1 if no rotation occured during the session, chunk_path is left
- * unallocated.
- *
- * Return a negative LTTng error code on error (readable with lttng_strerror).
- *
- * FIXME: Return an lttng_location object rather than a path.
- */
-extern int lttng_session_get_current_archive_location(const char *session_name,
- char **chunk_path);
-
#ifdef __cplusplus
}
#endif
projects / lttng-tools.git / blobdiff