src/lib/trace-ir/event.h

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   5  * Copyright 2013, 2014 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   6  */
   7
   8 #ifndef BABELTRACE_TRACE_IR_EVENT_INTERNAL_H
   9 #define BABELTRACE_TRACE_IR_EVENT_INTERNAL_H
  10
  11 /* Protection: this file uses BT_LIB_LOG*() macros directly */
  12 #ifndef BT_LIB_LOG_SUPPORTED
  13 # error Please include "lib/logging.h" before including this file.
  14 #endif
  15
  16 #include "lib/assert-cond.h"
  17 #include "common/macros.h"
  18 #include <babeltrace2/value.h>
  19 #include <babeltrace2/trace-ir/stream-class.h>
  20 #include <babeltrace2/trace-ir/stream.h>
  21 #include <babeltrace2/trace-ir/packet.h>
  22 #include <babeltrace2/trace-ir/field.h>
  23 #include "lib/object.h"
  24 #include "common/assert.h"
  25 #include <glib.h>
  26 #include <stdbool.h>
  27
  28 #include "event-class.h"
  29 #include "field.h"
  30 #include "field-wrapper.h"
  31 #include "packet.h"
  32 #include "stream.h"
  33
  34 #define BT_ASSERT_PRE_DEV_EVENT_HOT(_event)                             \
  35         BT_ASSERT_PRE_DEV_HOT(((const struct bt_event *) (_event)),     \
  36                 "Event", ": %!+e", (_event))
  37
  38 struct bt_event {
  39         struct bt_object base;
  40
  41         /* Owned by this */
  42         struct bt_event_class *class;
  43
  44         /* Owned by this (can be `NULL`) */
  45         struct bt_packet *packet;
  46
  47         /* Owned by this */
  48         struct bt_stream *stream;
  49
  50         struct bt_field *common_context_field;
  51         struct bt_field *specific_context_field;
  52         struct bt_field *payload_field;
  53         bool frozen;
  54 };
  55
  56 BT_HIDDEN
  57 void bt_event_destroy(struct bt_event *event);
  58
  59 BT_HIDDEN
  60 struct bt_event *bt_event_new(struct bt_event_class *event_class);
  61
  62 BT_HIDDEN
  63 void _bt_event_set_is_frozen(const struct bt_event *event, bool is_frozen);
  64
  65 #ifdef BT_DEV_MODE
  66 # define bt_event_set_is_frozen         _bt_event_set_is_frozen
  67 #else
  68 # define bt_event_set_is_frozen(_event, _is_frozen)
  69 #endif
  70
  71 __attribute__((unused))
  72 static inline
  73 void _bt_event_reset_dev_mode(struct bt_event *event)
  74 {
  75         BT_ASSERT_DBG(event);
  76
  77         if (event->common_context_field) {
  78                 bt_field_set_is_frozen(
  79                         event->common_context_field, false);
  80                 bt_field_reset(
  81                         event->common_context_field);
  82         }
  83
  84         if (event->specific_context_field) {
  85                 bt_field_set_is_frozen(
  86                         event->specific_context_field, false);
  87                 bt_field_reset(event->specific_context_field);
  88         }
  89
  90         if (event->payload_field) {
  91                 bt_field_set_is_frozen(
  92                         event->payload_field, false);
  93                 bt_field_reset(event->payload_field);
  94         }
  95 }
  96
  97 #ifdef BT_DEV_MODE
  98 # define bt_event_reset_dev_mode        _bt_event_reset_dev_mode
  99 #else
 100 # define bt_event_reset_dev_mode(_x)
 101 #endif
 102
 103 static inline
 104 void bt_event_reset(struct bt_event *event)
 105 {
 106         BT_ASSERT_DBG(event);
 107         BT_LIB_LOGD("Resetting event: %!+e", event);
 108         bt_event_set_is_frozen(event, false);
 109         bt_object_put_ref_no_null_check(&event->stream->base);
 110         event->stream = NULL;
 111
 112         if (event->packet) {
 113                 bt_object_put_ref_no_null_check(&event->packet->base);
 114                 event->packet = NULL;
 115         }
 116 }
 117
 118 static inline
 119 void bt_event_recycle(struct bt_event *event)
 120 {
 121         struct bt_event_class *event_class;
 122
 123         BT_ASSERT_DBG(event);
 124         BT_LIB_LOGD("Recycling event: %!+e", event);
 125
 126         /*
 127          * Those are the important ordered steps:
 128          *
 129          * 1. Reset the event object (put any permanent reference it
 130          *    has, unfreeze it and its fields in developer mode, etc.),
 131          *    but do NOT put its class's reference. This event class
 132          *    contains the pool to which we're about to recycle this
 133          *    event object, so we must guarantee its existence thanks
 134          *    to this existing reference.
 135          *
 136          * 2. Move the event class reference to our `event_class`
 137          *    variable so that we can set the event's class member
 138          *    to NULL before recycling it. We CANNOT do this after
 139          *    we put the event class reference because this bt_object_put_ref()
 140          *    could destroy the event class, also destroying its
 141          *    event pool, thus also destroying our event object (this
 142          *    would result in an invalid write access).
 143          *
 144          * 3. Recycle the event object.
 145          *
 146          * 4. Put our event class reference.
 147          */
 148         bt_event_reset(event);
 149         event_class = event->class;
 150         BT_ASSERT_DBG(event_class);
 151         event->class = NULL;
 152         bt_object_pool_recycle_object(&event_class->event_pool, event);
 153         bt_object_put_ref_no_null_check(&event_class->base);
 154 }
 155
 156 static inline
 157 void bt_event_set_packet(struct bt_event *event, struct bt_packet *packet)
 158 {
 159         BT_ASSERT_PRE_DEV_NON_NULL(event, "Event");
 160         BT_ASSERT_PRE_DEV_NON_NULL(packet, "Packet");
 161         BT_ASSERT_PRE_DEV_EVENT_HOT(event);
 162         BT_ASSERT_PRE_DEV(bt_event_class_borrow_stream_class(
 163                 event->class) == packet->stream->class,
 164                 "Packet's stream class and event's stream class differ: "
 165                 "%![event-]+e, %![packet-]+a", event, packet);
 166         BT_ASSERT_DBG(event->stream->class->supports_packets);
 167         BT_ASSERT_DBG(!event->packet);
 168         event->packet = packet;
 169         bt_object_get_ref_no_null_check_no_parent_check(&event->packet->base);
 170         BT_LIB_LOGD("Set event's packet: %![event-]+e, %![packet-]+a",
 171                 event, packet);
 172 }
 173
 174 static inline
 175 void bt_event_set_stream(struct bt_event *event, struct bt_stream *stream)
 176 {
 177         BT_ASSERT_PRE_DEV_NON_NULL(event, "Event");
 178         BT_ASSERT_PRE_DEV_NON_NULL(stream, "Stream");
 179         BT_ASSERT_PRE_DEV_EVENT_HOT(event);
 180         BT_ASSERT_PRE_DEV(bt_event_class_borrow_stream_class(
 181                 event->class) == stream->class,
 182                 "Stream's class and event's stream class differ: "
 183                 "%![event-]+e, %![stream-]+s", event, stream);
 184         BT_ASSERT_DBG(!event->stream);
 185         event->stream = stream;
 186         bt_object_get_ref_no_null_check_no_parent_check(&event->stream->base);
 187         BT_LIB_LOGD("Set event's stream: %![event-]+e, %![stream-]+s",
 188                 event, stream);
 189 }
 190
 191 static inline
 192 struct bt_event *bt_event_create(struct bt_event_class *event_class,
 193                 struct bt_packet *packet, struct bt_stream *stream)
 194 {
 195         struct bt_event *event = NULL;
 196
 197         BT_ASSERT_DBG(event_class);
 198         BT_ASSERT_DBG(stream);
 199         event = bt_object_pool_create_object(&event_class->event_pool);
 200         if (G_UNLIKELY(!event)) {
 201                 BT_LIB_LOGE_APPEND_CAUSE(
 202                         "Cannot allocate one event from event class's event pool: "
 203                         "%![ec-]+E", event_class);
 204                 goto end;
 205         }
 206
 207         if (G_LIKELY(!event->class)) {
 208                 event->class = event_class;
 209                 bt_object_get_ref_no_null_check(&event_class->base);
 210         }
 211
 212         bt_event_set_stream(event, stream);
 213
 214         if (packet) {
 215                 BT_ASSERT_DBG(packet);
 216                 bt_event_set_packet(event, packet);
 217         }
 218
 219         goto end;
 220
 221 end:
 222         return event;
 223 }
 224
 225 #endif /* BABELTRACE_TRACE_IR_EVENT_INTERNAL_H */