include/lttng/handle.h

   1 /*
   2  * Copyright (C) 2014 David Goulet <dgoulet@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #ifndef LTTNG_HANDLE_H
   9 #define LTTNG_HANDLE_H
  10
  11 #include <lttng/domain.h>
  12
  13 #ifdef __cplusplus
  14 extern "C" {
  15 #endif
  16
  17 /*
  18  * Handle used as a context for commands.
  19  *
  20  * The structures should be initialized to zero before use.
  21  */
  22 #define LTTNG_HANDLE_PADDING1              16
  23 struct lttng_handle {
  24         char session_name[LTTNG_NAME_MAX];
  25         struct lttng_domain domain;
  26
  27         char padding[LTTNG_HANDLE_PADDING1];
  28 };
  29
  30 /*
  31  * Create an handle used as a context for every request made to the library.
  32  *
  33  * This handle contains the session name and domain on which the command will
  34  * be executed. A domain is basically a tracer like the kernel or user space.
  35  *
  36  * A NULL domain indicates that the handle is not bound to a specific domain.
  37  * This is mostly used for actions that apply on a session and not on a domain
  38  * (e.g lttng_set_consumer_url).
  39  *
  40  * Return a newly allocated handle that should be freed using
  41  * lttng_destroy_handle. On error, NULL is returned.
  42  */
  43 extern struct lttng_handle *lttng_create_handle(const char *session_name,
  44                 struct lttng_domain *domain);
  45
  46 /*
  47  * Destroy an handle that has been previously created with lttng_create_handle.
  48  *
  49  * It free the given pointer making it unusable.
  50  */
  51 extern void lttng_destroy_handle(struct lttng_handle *handle);
  52
  53
  54 #ifdef __cplusplus
  55 }
  56 #endif
  57
  58 #endif /* LTTNG_HANDLE_H */