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 BT_LIB_LOG_SUPPORTED
  29 # error Please include "lib/logging.h" before including this file.
  30 #endif
  31
  32 #include "lib/assert-pre.h"
  33 #include "common/macros.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 (can be `NULL`) */
  60         struct bt_packet *packet;
  61
  62         /* Owned by this */
  63         struct bt_stream *stream;
  64
  65         struct bt_field *common_context_field;
  66         struct bt_field *specific_context_field;
  67         struct bt_field *payload_field;
  68         bool frozen;
  69 };
  70
  71 BT_HIDDEN
  72 void bt_event_destroy(struct bt_event *event);
  73
  74 BT_HIDDEN
  75 struct bt_event *bt_event_new(struct bt_event_class *event_class);
  76
  77 BT_HIDDEN
  78 void _bt_event_set_is_frozen(const struct bt_event *event, bool is_frozen);
  79
  80 #ifdef BT_DEV_MODE
  81 # define bt_event_set_is_frozen         _bt_event_set_is_frozen
  82 #else
  83 # define bt_event_set_is_frozen(_event, _is_frozen)
  84 #endif
  85
  86 __attribute__((unused))
  87 static inline
  88 void _bt_event_reset_dev_mode(struct bt_event *event)
  89 {
  90         BT_ASSERT(event);
  91
  92         if (event->common_context_field) {
  93                 bt_field_set_is_frozen(
  94                         event->common_context_field, false);
  95                 bt_field_reset(
  96                         event->common_context_field);
  97         }
  98
  99         if (event->specific_context_field) {
 100                 bt_field_set_is_frozen(
 101                         event->specific_context_field, false);
 102                 bt_field_reset(event->specific_context_field);
 103         }
 104
 105         if (event->payload_field) {
 106                 bt_field_set_is_frozen(
 107                         event->payload_field, false);
 108                 bt_field_reset(event->payload_field);
 109         }
 110 }
 111
 112 #ifdef BT_DEV_MODE
 113 # define bt_event_reset_dev_mode        _bt_event_reset_dev_mode
 114 #else
 115 # define bt_event_reset_dev_mode(_x)
 116 #endif
 117
 118 static inline
 119 void bt_event_reset(struct bt_event *event)
 120 {
 121         BT_ASSERT(event);
 122         BT_LIB_LOGD("Resetting event: %!+e", event);
 123         bt_event_set_is_frozen(event, false);
 124         bt_object_put_no_null_check(&event->stream->base);
 125         event->stream = NULL;
 126
 127         if (event->packet) {
 128                 bt_object_put_no_null_check(&event->packet->base);
 129                 event->packet = NULL;
 130         }
 131 }
 132
 133 static inline
 134 void bt_event_recycle(struct bt_event *event)
 135 {
 136         struct bt_event_class *event_class;
 137
 138         BT_ASSERT(event);
 139         BT_LIB_LOGD("Recycling event: %!+e", event);
 140
 141         /*
 142          * Those are the important ordered steps:
 143          *
 144          * 1. Reset the event object (put any permanent reference it
 145          *    has, unfreeze it and its fields in developer mode, etc.),
 146          *    but do NOT put its class's reference. This event class
 147          *    contains the pool to which we're about to recycle this
 148          *    event object, so we must guarantee its existence thanks
 149          *    to this existing reference.
 150          *
 151          * 2. Move the event class reference to our `event_class`
 152          *    variable so that we can set the event's class member
 153          *    to NULL before recycling it. We CANNOT do this after
 154          *    we put the event class reference because this bt_object_put_ref()
 155          *    could destroy the event class, also destroying its
 156          *    event pool, thus also destroying our event object (this
 157          *    would result in an invalid write access).
 158          *
 159          * 3. Recycle the event object.
 160          *
 161          * 4. Put our event class reference.
 162          */
 163         bt_event_reset(event);
 164         event_class = event->class;
 165         BT_ASSERT(event_class);
 166         event->class = NULL;
 167         bt_object_pool_recycle_object(&event_class->event_pool, event);
 168         bt_object_put_no_null_check(&event_class->base);
 169 }
 170
 171 static inline
 172 void bt_event_set_packet(struct bt_event *event, struct bt_packet *packet)
 173 {
 174         BT_ASSERT_PRE_NON_NULL(event, "Event");
 175         BT_ASSERT_PRE_NON_NULL(packet, "Packet");
 176         BT_ASSERT_PRE_EVENT_HOT(event);
 177         BT_ASSERT_PRE(bt_event_class_borrow_stream_class(
 178                 event->class) == packet->stream->class,
 179                 "Packet's stream class and event's stream class differ: "
 180                 "%![event-]+e, %![packet-]+a", event, packet);
 181         BT_ASSERT(event->stream->class->supports_packets);
 182         BT_ASSERT(!event->packet);
 183         event->packet = packet;
 184         bt_object_get_no_null_check_no_parent_check(&event->packet->base);
 185         BT_LIB_LOGD("Set event's packet: %![event-]+e, %![packet-]+a",
 186                 event, packet);
 187 }
 188
 189 static inline
 190 void bt_event_set_stream(struct bt_event *event, struct bt_stream *stream)
 191 {
 192         BT_ASSERT_PRE_NON_NULL(event, "Event");
 193         BT_ASSERT_PRE_NON_NULL(stream, "Stream");
 194         BT_ASSERT_PRE_EVENT_HOT(event);
 195         BT_ASSERT_PRE(bt_event_class_borrow_stream_class(
 196                 event->class) == stream->class,
 197                 "Stream's class and event's stream class differ: "
 198                 "%![event-]+e, %![stream-]+s", event, stream);
 199         BT_ASSERT(!event->stream);
 200         event->stream = stream;
 201         bt_object_get_no_null_check_no_parent_check(&event->stream->base);
 202         BT_LIB_LOGD("Set event's stream: %![event-]+e, %![stream-]+s",
 203                 event, stream);
 204 }
 205
 206 static inline
 207 struct bt_event *bt_event_create(struct bt_event_class *event_class,
 208                 struct bt_packet *packet, struct bt_stream *stream)
 209 {
 210         struct bt_event *event = NULL;
 211
 212         BT_ASSERT(event_class);
 213         BT_ASSERT(stream);
 214         event = bt_object_pool_create_object(&event_class->event_pool);
 215         if (G_UNLIKELY(!event)) {
 216                 BT_LIB_LOGE_APPEND_CAUSE(
 217                         "Cannot allocate one event from event class's event pool: "
 218                         "%![ec-]+E", event_class);
 219                 goto end;
 220         }
 221
 222         if (G_LIKELY(!event->class)) {
 223                 event->class = event_class;
 224                 bt_object_get_no_null_check(&event_class->base);
 225         }
 226
 227         bt_event_set_stream(event, stream);
 228
 229         if (packet) {
 230                 BT_ASSERT(packet);
 231                 bt_event_set_packet(event, packet);
 232         }
 233
 234         goto end;
 235
 236 end:
 237         return event;
 238 }
 239
 240 #endif /* BABELTRACE_TRACE_IR_EVENT_INTERNAL_H */