Clean-up: ust-consumer: fix -Wshadow issues in lttng_ustconsumer_recv_cmd

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

diff --git a/include/lttng/session.h b/include/lttng/session.h
index 6c54d7e4f5e55fc5fe4dde03ff8a4812e5411a97..f13f83916a0c45f38a1d515a6100dd92046a1256 100644 (file)
--- a/include/lttng/session.h
+++ b/include/lttng/session.h
@@ -1,18 +1,9 @@
 /*
- * Copyright (C) 2014 - David Goulet <dgoulet@efficios.com>
+ * 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,
- * as published by the Free Software Foundation.
+ * SPDX-License-Identifier: LGPL-2.1-only
  *
- * This library is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
- * for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this library; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #ifndef LTTNG_SESSION_H
@@ -22,7 +13,11 @@
 extern "C" {
 #endif
 
+#include <lttng/constant.h>
+
+struct lttng_handle;
 struct lttng_session_descriptor;
+struct lttng_destruction_handle;
 
 /*
  * Basic session information.
@@ -32,7 +27,7 @@ struct lttng_session_descriptor;
  *
  * 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];
        /*
@@ -49,7 +44,29 @@ struct lttng_session {
        uint32_t snapshot_mode;
        unsigned int live_timer_interval;       /* usec */
 
+       /*
+        * 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;
@@ -132,6 +149,21 @@ 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 occurred 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.
@@ -175,39 +207,6 @@ extern enum lttng_error_code lttng_session_get_creation_time(
 extern int lttng_set_session_shm_path(const char *session_name,
                const char *shm_path);
 
-/*
- * Add PID to session tracker.
- *
- * A pid argument >= 0 adds the PID to the session tracker.
- * A pid argument of -1 means "track all PIDs".
- *
- * Return 0 on success else a negative LTTng error code.
- */
-extern int lttng_track_pid(struct lttng_handle *handle, int pid);
-
-/*
- * Remove PID from session tracker.
- *
- * A pid argument >= 0 removes the PID from the session tracker.
- * A pid argument of -1 means "untrack all PIDs".
- *
- * Return 0 on success else a negative LTTng error code.
- */
-extern int lttng_untrack_pid(struct lttng_handle *handle, int pid);
-
-/*
- * List PIDs in the tracker.
- *
- * enabled is set to whether the PID tracker is enabled.
- * pids is set to an allocated array of PIDs currently tracked. On
- * success, pids must be freed by the caller.
- * nr_pids is set to the number of entries contained by the pids array.
- *
- * Returns 0 on success, else a negative LTTng error code.
- */
-extern int lttng_list_tracker_pids(struct lttng_handle *handle,
-               int *enabled, int32_t **pids, size_t *nr_pids);
-
 #ifdef __cplusplus
 }
 #endif