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