src/lib/trace-ir/packet.c

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright 2016-2018 Philippe Proulx <pproulx@efficios.com>
   5  */
   6
   7 #define BT_LOG_TAG "LIB/PACKET"
   8 #include "lib/logging.h"
   9
  10 #include "lib/assert-cond.h"
  11 #include <babeltrace2/trace-ir/packet.h>
  12 #include <babeltrace2/trace-ir/trace.h>
  13 #include <babeltrace2/trace-ir/stream-class.h>
  14 #include <babeltrace2/trace-ir/stream.h>
  15 #include "lib/object.h"
  16 #include "common/assert.h"
  17 #include <stdbool.h>
  18
  19 #include "field.h"
  20 #include "field-wrapper.h"
  21 #include "packet.h"
  22 #include "stream-class.h"
  23 #include "stream.h"
  24
  25 BT_EXPORT
  26 struct bt_stream *bt_packet_borrow_stream(struct bt_packet *packet)
  27 {
  28         BT_ASSERT_PRE_DEV_PACKET_NON_NULL(packet);
  29         return packet->stream;
  30 }
  31
  32 BT_EXPORT
  33 const struct bt_stream *bt_packet_borrow_stream_const(
  34                 const struct bt_packet *packet)
  35 {
  36         return bt_packet_borrow_stream((void *) packet);
  37 }
  38
  39 BT_EXPORT
  40 struct bt_field *bt_packet_borrow_context_field(struct bt_packet *packet)
  41 {
  42         BT_ASSERT_PRE_DEV_PACKET_NON_NULL(packet);
  43         return packet->context_field ? packet->context_field->field : NULL;
  44 }
  45
  46 BT_EXPORT
  47 const struct bt_field *bt_packet_borrow_context_field_const(
  48                 const struct bt_packet *packet)
  49 {
  50         return bt_packet_borrow_context_field((void *) packet);
  51 }
  52
  53 void _bt_packet_set_is_frozen(const struct bt_packet *packet, bool is_frozen)
  54 {
  55         if (!packet) {
  56                 return;
  57         }
  58
  59         BT_LIB_LOGD("Setting packet's frozen state: %![packet-]+a, "
  60                 "is-frozen=%d", packet, is_frozen);
  61
  62         if (packet->context_field) {
  63                 BT_LOGD_STR("Setting packet's context field's frozen state.");
  64                 bt_field_set_is_frozen(packet->context_field->field,
  65                         is_frozen);
  66         }
  67
  68         ((struct bt_packet *) packet)->frozen = is_frozen;
  69 }
  70
  71 static inline
  72 void reset_packet(struct bt_packet *packet)
  73 {
  74         BT_ASSERT(packet);
  75         BT_LIB_LOGD("Resetting packet: %!+a", packet);
  76         bt_packet_set_is_frozen(packet, false);
  77
  78         if (packet->context_field) {
  79                 bt_field_set_is_frozen(packet->context_field->field, false);
  80                 bt_field_reset(packet->context_field->field);
  81         }
  82 }
  83
  84 static
  85 void recycle_context_field(struct bt_field_wrapper *context_field,
  86                 struct bt_stream_class *stream_class)
  87 {
  88         BT_ASSERT(context_field);
  89         BT_LIB_LOGD("Recycling packet context field: "
  90                 "addr=%p, %![sc-]+S, %![field-]+f", context_field,
  91                 stream_class, context_field->field);
  92         bt_object_pool_recycle_object(&stream_class->packet_context_field_pool,
  93                 context_field);
  94 }
  95
  96 void bt_packet_recycle(struct bt_packet *packet)
  97 {
  98         struct bt_stream *stream;
  99
 100         BT_ASSERT(packet);
 101         BT_LIB_LOGD("Recycling packet: %!+a", packet);
 102
 103         /*
 104          * Those are the important ordered steps:
 105          *
 106          * 1. Reset the packet object (put any permanent reference it
 107          *    has, unfreeze it and its fields in developer mode, etc.),
 108          *    but do NOT put its stream's reference. This stream
 109          *    contains the pool to which we're about to recycle this
 110          *    packet object, so we must guarantee its existence thanks
 111          *    to this existing reference.
 112          *
 113          * 2. Move the stream reference to our `stream`
 114          *    variable so that we can set the packet's stream member
 115          *    to NULL before recycling it. We CANNOT do this after
 116          *    we put the stream reference because this bt_object_put_ref()
 117          *    could destroy the stream, also destroying its
 118          *    packet pool, thus also destroying our packet object (this
 119          *    would result in an invalid write access).
 120          *
 121          * 3. Recycle the packet object.
 122          *
 123          * 4. Put our stream reference.
 124          */
 125         reset_packet(packet);
 126         stream = packet->stream;
 127         BT_ASSERT(stream);
 128         packet->stream = NULL;
 129         bt_object_pool_recycle_object(&stream->packet_pool, packet);
 130         bt_object_put_ref_no_null_check(&stream->base);
 131 }
 132
 133 void bt_packet_destroy(struct bt_packet *packet)
 134 {
 135         BT_LIB_LOGD("Destroying packet: %!+a", packet);
 136
 137         if (packet->context_field) {
 138                 if (packet->stream) {
 139                         BT_LOGD_STR("Recycling packet's context field.");
 140                         recycle_context_field(packet->context_field,
 141                                 packet->stream->class);
 142                 } else {
 143                         bt_field_wrapper_destroy(packet->context_field);
 144                 }
 145
 146                 packet->context_field = NULL;
 147         }
 148
 149         BT_LOGD_STR("Putting packet's stream.");
 150         BT_OBJECT_PUT_REF_AND_RESET(packet->stream);
 151         g_free(packet);
 152 }
 153
 154 struct bt_packet *bt_packet_new(struct bt_stream *stream)
 155 {
 156         struct bt_packet *packet = NULL;
 157         struct bt_trace_class *trace_class = NULL;
 158
 159         BT_ASSERT(stream);
 160         BT_LIB_LOGD("Creating packet object: %![stream-]+s", stream);
 161         packet = g_new0(struct bt_packet, 1);
 162         if (!packet) {
 163                 BT_LIB_LOGE_APPEND_CAUSE(
 164                         "Failed to allocate one packet object.");
 165                 goto error;
 166         }
 167
 168         bt_object_init_shared(&packet->base,
 169                 (bt_object_release_func) bt_packet_recycle);
 170         packet->stream = stream;
 171         bt_object_get_ref_no_null_check(stream);
 172         trace_class = bt_stream_class_borrow_trace_class_inline(stream->class);
 173         BT_ASSERT(trace_class);
 174
 175         if (stream->class->packet_context_fc) {
 176                 BT_LOGD_STR("Creating initial packet context field.");
 177                 packet->context_field = bt_field_wrapper_create(
 178                         &stream->class->packet_context_field_pool,
 179                         stream->class->packet_context_fc);
 180                 if (!packet->context_field) {
 181                         BT_LIB_LOGE_APPEND_CAUSE(
 182                                 "Cannot create packet context field wrapper.");
 183                         goto error;
 184                 }
 185         }
 186
 187         BT_LIB_LOGD("Created packet object: %!+a", packet);
 188         goto end;
 189
 190 error:
 191         BT_OBJECT_PUT_REF_AND_RESET(packet);
 192
 193 end:
 194         return packet;
 195 }
 196
 197 BT_EXPORT
 198 struct bt_packet *bt_packet_create(const struct bt_stream *c_stream)
 199 {
 200         struct bt_packet *packet = NULL;
 201         struct bt_stream *stream = (void *) c_stream;
 202
 203         BT_ASSERT_PRE_NO_ERROR();
 204         BT_ASSERT_PRE_STREAM_NON_NULL(stream);
 205         BT_ASSERT_PRE("stream-class-supports-packets",
 206                 stream->class->supports_packets,
 207                 "Stream class does not support packets: %![sc-]+S",
 208                 stream->class);
 209         packet = bt_object_pool_create_object(&stream->packet_pool);
 210         if (G_UNLIKELY(!packet)) {
 211                 BT_LIB_LOGE_APPEND_CAUSE(
 212                         "Cannot allocate one packet from stream's packet pool: "
 213                         "%![stream-]+s", stream);
 214                 goto end;
 215         }
 216
 217         if (G_LIKELY(!packet->stream)) {
 218                 packet->stream = stream;
 219                 bt_object_get_ref_no_null_check_no_parent_check(
 220                         &packet->stream->base);
 221         }
 222
 223 end:
 224         return (void *) packet;
 225 }
 226
 227 BT_EXPORT
 228 void bt_packet_get_ref(const struct bt_packet *packet)
 229 {
 230         bt_object_get_ref(packet);
 231 }
 232
 233 BT_EXPORT
 234 void bt_packet_put_ref(const struct bt_packet *packet)
 235 {
 236         bt_object_put_ref(packet);
 237 }