include/lttng/handle.h

   1 /*
   2  * Copyright (C) 2014 - David Goulet <dgoulet@efficios.com>
   3  *
   4  * This library is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License, version 2.1 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This library is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this library; if not, write to the Free Software Foundation,
  15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18 #ifndef LTTNG_HANDLE_H
  19 #define LTTNG_HANDLE_H
  20
  21 #include <lttng/domain.h>
  22
  23 #ifdef __cplusplus
  24 extern "C" {
  25 #endif
  26
  27 /*
  28  * Handle used as a context for commands.
  29  *
  30  * The structures should be initialized to zero before use.
  31  */
  32 #define LTTNG_HANDLE_PADDING1              16
  33 struct lttng_handle {
  34         char session_name[LTTNG_NAME_MAX];
  35         struct lttng_domain domain;
  36
  37         char padding[LTTNG_HANDLE_PADDING1];
  38 };
  39
  40 /*
  41  * Create an handle used as a context for every request made to the library.
  42  *
  43  * This handle contains the session name and domain on which the command will
  44  * be executed. A domain is basically a tracer like the kernel or user space.
  45  *
  46  * A NULL domain indicates that the handle is not bound to a specific domain.
  47  * This is mostly used for actions that apply on a session and not on a domain
  48  * (e.g lttng_set_consumer_url).
  49  *
  50  * Return a newly allocated handle that should be freed using
  51  * lttng_destroy_handle. On error, NULL is returned.
  52  */
  53 extern struct lttng_handle *lttng_create_handle(const char *session_name,
  54                 struct lttng_domain *domain);
  55
  56 /*
  57  * Destroy an handle that has been previously created with lttng_create_handle.
  58  *
  59  * It free the given pointer making it unusable.
  60  */
  61 extern void lttng_destroy_handle(struct lttng_handle *handle);
  62
  63
  64 #ifdef __cplusplus
  65 }
  66 #endif
  67
  68 #endif /* LTTNG_HANDLE_H */