lib/babeltrace/ctf/callbacks.h

   1 #ifndef _BABELTRACE_CTF_CALLBACKS_H
   2 #define _BABELTRACE_CTF_CALLBACKS_H
   3
   4 /*
   5  * BabelTrace
   6  *
   7  * CTF events API
   8  *
   9  * Copyright 2011-2012 EfficiOS Inc. and Linux Foundation
  10  *
  11  * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  12  *         Julien Desfossez <julien.desfossez@efficios.com>
  13  *
  14  * Permission is hereby granted, free of charge, to any person obtaining
  15  * a copy of this software and associated documentation files (the
  16  * "Software"), to deal in the Software without restriction, including
  17  * without limitation the rights to use, copy, modify, merge, publish,
  18  * distribute, sublicense, and/or sell copies of the Software, and to
  19  * permit persons to whom the Software is furnished to do so, subject to
  20  * the following conditions:
  21  *
  22  * The above copyright notice and this permission notice shall be
  23  * included in all copies or substantial portions of the Software.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  26  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  27  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  28  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  29  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  30  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33
  34 #include <babeltrace/format.h>
  35
  36 #ifdef __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 /* Forward declarations */
  41 struct bt_ctf_iter;
  42 struct bt_dependencies;
  43
  44 enum bt_cb_ret {
  45         BT_CB_OK                = 0,
  46         BT_CB_OK_STOP           = 1,
  47         BT_CB_ERROR_STOP        = 2,
  48         BT_CB_ERROR_CONTINUE    = 3,
  49 };
  50
  51 /*
  52  * Receives a variable number of strings as parameter, ended with NULL.
  53  */
  54 struct bt_dependencies *bt_dependencies_create(const char *first, ...);
  55
  56 /*
  57  * struct bt_dependencies must be destroyed explicitly if not passed as
  58  * parameter to a bt_ctf_iter_add_callback().
  59  */
  60 void bt_dependencies_destroy(struct bt_dependencies *dep);
  61
  62 /*
  63  * bt_ctf_iter_add_callback: Add a callback to iterator.
  64  *
  65  * @iter: trace collection iterator (input)
  66  * @event: event to target. 0 for all events.
  67  * @private_data: private data pointer to pass to the callback
  68  * @flags: specific flags controlling the behavior of this callback
  69  *         (or'd).
  70  *
  71  * @callback: function pointer to call
  72  * @depends: struct bt_dependency detailing the required computation results.
  73  *           Ends with 0. NULL is accepted as empty dependency.
  74  * @weak_depends: struct bt_dependency detailing the optional computation
  75  *                results that can be optionally consumed by this
  76  *                callback. NULL is accepted as empty dependency.
  77  * @provides: struct bt_dependency detailing the computation results
  78  *            provided by this callback.
  79  *            Ends with 0. NULL is accepted as empty dependency.
  80  *
  81  * "depends", "weak_depends" and "provides" memory is handled by the
  82  * babeltrace library after this call succeeds or fails. These objects
  83  * can still be used by the caller until the babeltrace iterator is
  84  * destroyed, but they belong to the babeltrace library.
  85  *
  86  * (note to implementor: we need to keep a gptrarray of struct
  87  * bt_dependencies to "garbage collect" in struct bt_ctf_iter, and
  88  * dependencies need to have a refcount to handle the case where they
  89  * would be passed to more than one iterator. Upon iterator detroy, we
  90  * iterate on all the gc ptrarray and decrement the refcounts, freeing
  91  * if we reach 0.)
  92  * (note to implementor: we calculate the dependency graph when
  93  * bt_ctf_iter_read_event() is executed after a
  94  * bt_ctf_iter_add_callback(). Beware that it is valid to create/add
  95  * callbacks/read/add more callbacks/read some more.)
  96  */
  97 int bt_ctf_iter_add_callback(struct bt_ctf_iter *iter,
  98                 bt_intern_str event, void *private_data, int flags,
  99                 enum bt_cb_ret (*callback)(struct bt_ctf_event *ctf_data,
 100                                            void *caller_data),
 101                 struct bt_dependencies *depends,
 102                 struct bt_dependencies *weak_depends,
 103                 struct bt_dependencies *provides);
 104
 105 /*
 106  * For flags parameter above.
 107  */
 108 enum {
 109         BT_FLAGS_FREE_PRIVATE_DATA      = (1 << 0),
 110 };
 111
 112 #ifdef __cplusplus
 113 }
 114 #endif
 115
 116 #endif /*_BABELTRACE_CTF_CALLBACKS_H */