src/lib/trace-ir/event.h

   1 #ifndef BABELTRACE_TRACE_IR_EVENT_INTERNAL_H
   2 #define BABELTRACE_TRACE_IR_EVENT_INTERNAL_H
   3
   4 /*
   5  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   6  * Copyright 2013, 2014 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a copy
   9  * of this software and associated documentation files (the "Software"), to deal
  10  * in the Software without restriction, including without limitation the rights
  11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12  * copies of the Software, and to permit persons to whom the Software is
  13  * furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  24  * SOFTWARE.
  25  */
  26
  27 /* Protection: this file uses BT_LIB_LOG*() macros directly */
  28 #ifndef BABELTRACE_LIB_LOGGING_INTERNAL_H
  29 # error Please include <lib/lib-logging.h> before including this file.
  30 #endif
  31
  32 #include "lib/assert-pre.h"
  33 #include "common/babeltrace.h"
  34 #include <babeltrace2/value.h>
  35 #include <babeltrace2/trace-ir/stream-class.h>
  36 #include <babeltrace2/trace-ir/stream.h>
  37 #include <babeltrace2/trace-ir/packet.h>
  38 #include <babeltrace2/trace-ir/field.h>
  39 #include "lib/object.h"
  40 #include "common/assert.h"
  41 #include <glib.h>
  42
  43 #include "event-class.h"
  44 #include "field.h"
  45 #include "field-wrapper.h"
  46 #include "packet.h"
  47 #include "stream.h"
  48
  49 #define BT_ASSERT_PRE_EVENT_HOT(_event) \
  50         BT_ASSERT_PRE_HOT(((const struct bt_event *) (_event)),         \
  51                 "Event", ": %!+e", (_event))
  52
  53 struct bt_event {
  54         struct bt_object base;
  55
  56         /* Owned by this */
  57         struct bt_event_class *class;
  58
  59         /* Owned by this */
  60         struct bt_packet *packet;
  61
  62         struct bt_field *common_context_field;
  63         struct bt_field *specific_context_field;
  64         struct bt_field *payload_field;
  65         bool frozen;
  66 };
  67
  68 BT_HIDDEN
  69 void bt_event_destroy(struct bt_event *event);
  70
  71 BT_HIDDEN
  72 struct bt_event *bt_event_new(struct bt_event_class *event_class);
  73
  74 BT_HIDDEN
  75 void _bt_event_set_is_frozen(const struct bt_event *event, bool is_frozen);
  76
  77 #ifdef BT_DEV_MODE
  78 # define bt_event_set_is_frozen         _bt_event_set_is_frozen
  79 #else
  80 # define bt_event_set_is_frozen(_event, _is_frozen)
  81 #endif
  82
  83 BT_UNUSED
  84 static inline
  85 void _bt_event_reset_dev_mode(struct bt_event *event)
  86 {
  87         BT_ASSERT(event);
  88
  89         if (event->common_context_field) {
  90                 bt_field_set_is_frozen(
  91                         event->common_context_field, false);
  92                 bt_field_reset(
  93                         event->common_context_field);
  94         }
  95
  96         if (event->specific_context_field) {
  97                 bt_field_set_is_frozen(
  98                         event->specific_context_field, false);
  99                 bt_field_reset(event->specific_context_field);
 100         }
 101
 102         if (event->payload_field) {
 103                 bt_field_set_is_frozen(
 104                         event->payload_field, false);
 105                 bt_field_reset(event->payload_field);
 106         }
 107 }
 108
 109 #ifdef BT_DEV_MODE
 110 # define bt_event_reset_dev_mode        _bt_event_reset_dev_mode
 111 #else
 112 # define bt_event_reset_dev_mode(_x)
 113 #endif
 114
 115 static inline
 116 void bt_event_reset(struct bt_event *event)
 117 {
 118         BT_ASSERT(event);
 119         BT_LIB_LOGD("Resetting event: %!+e", event);
 120         bt_event_set_is_frozen(event, false);
 121         bt_object_put_no_null_check(&event->packet->base);
 122         event->packet = NULL;
 123 }
 124
 125 static inline
 126 void bt_event_recycle(struct bt_event *event)
 127 {
 128         struct bt_event_class *event_class;
 129
 130         BT_ASSERT(event);
 131         BT_LIB_LOGD("Recycling event: %!+e", event);
 132
 133         /*
 134          * Those are the important ordered steps:
 135          *
 136          * 1. Reset the event object (put any permanent reference it
 137          *    has, unfreeze it and its fields in developer mode, etc.),
 138          *    but do NOT put its class's reference. This event class
 139          *    contains the pool to which we're about to recycle this
 140          *    event object, so we must guarantee its existence thanks
 141          *    to this existing reference.
 142          *
 143          * 2. Move the event class reference to our `event_class`
 144          *    variable so that we can set the event's class member
 145          *    to NULL before recycling it. We CANNOT do this after
 146          *    we put the event class reference because this bt_object_put_ref()
 147          *    could destroy the event class, also destroying its
 148          *    event pool, thus also destroying our event object (this
 149          *    would result in an invalid write access).
 150          *
 151          * 3. Recycle the event object.
 152          *
 153          * 4. Put our event class reference.
 154          */
 155         bt_event_reset(event);
 156         event_class = event->class;
 157         BT_ASSERT(event_class);
 158         event->class = NULL;
 159         bt_object_pool_recycle_object(&event_class->event_pool, event);
 160         bt_object_put_no_null_check(&event_class->base);
 161 }
 162
 163 static inline
 164 void bt_event_set_packet(struct bt_event *event, struct bt_packet *packet)
 165 {
 166         BT_ASSERT_PRE_NON_NULL(event, "Event");
 167         BT_ASSERT_PRE_NON_NULL(packet, "Packet");
 168         BT_ASSERT_PRE_EVENT_HOT(event);
 169         BT_ASSERT_PRE(bt_event_class_borrow_stream_class(
 170                 event->class) == packet->stream->class,
 171                 "Packet's stream class and event's stream class differ: "
 172                 "%![event-]+e, %![packet-]+a", event, packet);
 173
 174         BT_ASSERT(!event->packet);
 175         event->packet = packet;
 176         bt_object_get_no_null_check_no_parent_check(&event->packet->base);
 177         BT_LIB_LOGV("Set event's packet: %![event-]+e, %![packet-]+a",
 178                 event, packet);
 179 }
 180
 181 static inline
 182 struct bt_event *bt_event_create(struct bt_event_class *event_class,
 183                 struct bt_packet *packet)
 184 {
 185         struct bt_event *event = NULL;
 186
 187         BT_ASSERT(event_class);
 188         event = bt_object_pool_create_object(&event_class->event_pool);
 189         if (unlikely(!event)) {
 190                 BT_LIB_LOGE("Cannot allocate one event from event class's event pool: "
 191                         "%![ec-]+E", event_class);
 192                 goto end;
 193         }
 194
 195         if (likely(!event->class)) {
 196                 event->class = event_class;
 197                 bt_object_get_no_null_check(&event_class->base);
 198         }
 199
 200         BT_ASSERT(packet);
 201         bt_event_set_packet(event, packet);
 202         goto end;
 203
 204 end:
 205         return event;
 206 }
 207
 208 #endif /* BABELTRACE_TRACE_IR_EVENT_INTERNAL_H */