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-pre.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 <inttypes.h>
  18 #include <stdbool.h>
  19
  20 #include "field.h"
  21 #include "field-wrapper.h"
  22 #include "packet.h"
  23 #include "stream-class.h"
  24 #include "stream.h"
  25 #include "trace.h"
  26 #include "lib/func-status.h"
  27
  28 struct bt_stream *bt_packet_borrow_stream(struct bt_packet *packet)
  29 {
  30         BT_ASSERT_PRE_DEV_NON_NULL(packet, "Packet");
  31         return packet->stream;
  32 }
  33
  34 const struct bt_stream *bt_packet_borrow_stream_const(
  35                 const struct bt_packet *packet)
  36 {
  37         return bt_packet_borrow_stream((void *) packet);
  38 }
  39
  40 struct bt_field *bt_packet_borrow_context_field(struct bt_packet *packet)
  41 {
  42         BT_ASSERT_PRE_DEV_NON_NULL(packet, "Packet");
  43         return packet->context_field ? packet->context_field->field : NULL;
  44 }
  45
  46 const struct bt_field *bt_packet_borrow_context_field_const(
  47                 const struct bt_packet *packet)
  48 {
  49         return bt_packet_borrow_context_field((void *) packet);
  50 }
  51
  52 BT_HIDDEN
  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 BT_HIDDEN
  97 void bt_packet_recycle(struct bt_packet *packet)
  98 {
  99         struct bt_stream *stream;
 100
 101         BT_ASSERT(packet);
 102         BT_LIB_LOGD("Recycling packet: %!+a", packet);
 103
 104         /*
 105          * Those are the important ordered steps:
 106          *
 107          * 1. Reset the packet object (put any permanent reference it
 108          *    has, unfreeze it and its fields in developer mode, etc.),
 109          *    but do NOT put its stream's reference. This stream
 110          *    contains the pool to which we're about to recycle this
 111          *    packet object, so we must guarantee its existence thanks
 112          *    to this existing reference.
 113          *
 114          * 2. Move the stream reference to our `stream`
 115          *    variable so that we can set the packet's stream member
 116          *    to NULL before recycling it. We CANNOT do this after
 117          *    we put the stream reference because this bt_object_put_ref()
 118          *    could destroy the stream, also destroying its
 119          *    packet pool, thus also destroying our packet object (this
 120          *    would result in an invalid write access).
 121          *
 122          * 3. Recycle the packet object.
 123          *
 124          * 4. Put our stream reference.
 125          */
 126         reset_packet(packet);
 127         stream = packet->stream;
 128         BT_ASSERT(stream);
 129         packet->stream = NULL;
 130         bt_object_pool_recycle_object(&stream->packet_pool, packet);
 131         bt_object_put_ref_no_null_check(&stream->base);
 132 }
 133
 134 BT_HIDDEN
 135 void bt_packet_destroy(struct bt_packet *packet)
 136 {
 137         BT_LIB_LOGD("Destroying packet: %!+a", packet);
 138
 139         if (packet->context_field) {
 140                 if (packet->stream) {
 141                         BT_LOGD_STR("Recycling packet's context field.");
 142                         recycle_context_field(packet->context_field,
 143                                 packet->stream->class);
 144                 } else {
 145                         bt_field_wrapper_destroy(packet->context_field);
 146                 }
 147
 148                 packet->context_field = NULL;
 149         }
 150
 151         BT_LOGD_STR("Putting packet's stream.");
 152         BT_OBJECT_PUT_REF_AND_RESET(packet->stream);
 153         g_free(packet);
 154 }
 155
 156 BT_HIDDEN
 157 struct bt_packet *bt_packet_new(struct bt_stream *stream)
 158 {
 159         struct bt_packet *packet = NULL;
 160         struct bt_trace_class *trace_class = NULL;
 161
 162         BT_ASSERT(stream);
 163         BT_LIB_LOGD("Creating packet object: %![stream-]+s", stream);
 164         packet = g_new0(struct bt_packet, 1);
 165         if (!packet) {
 166                 BT_LIB_LOGE_APPEND_CAUSE(
 167                         "Failed to allocate one packet object.");
 168                 goto error;
 169         }
 170
 171         bt_object_init_shared(&packet->base,
 172                 (bt_object_release_func) bt_packet_recycle);
 173         packet->stream = stream;
 174         bt_object_get_ref_no_null_check(stream);
 175         trace_class = bt_stream_class_borrow_trace_class_inline(stream->class);
 176         BT_ASSERT(trace_class);
 177
 178         if (stream->class->packet_context_fc) {
 179                 BT_LOGD_STR("Creating initial packet context field.");
 180                 packet->context_field = bt_field_wrapper_create(
 181                         &stream->class->packet_context_field_pool,
 182                         stream->class->packet_context_fc);
 183                 if (!packet->context_field) {
 184                         BT_LIB_LOGE_APPEND_CAUSE(
 185                                 "Cannot create packet context field wrapper.");
 186                         goto error;
 187                 }
 188         }
 189
 190         BT_LIB_LOGD("Created packet object: %!+a", packet);
 191         goto end;
 192
 193 error:
 194         BT_OBJECT_PUT_REF_AND_RESET(packet);
 195
 196 end:
 197         return packet;
 198 }
 199
 200 struct bt_packet *bt_packet_create(const struct bt_stream *c_stream)
 201 {
 202         struct bt_packet *packet = NULL;
 203         struct bt_stream *stream = (void *) c_stream;
 204
 205         BT_ASSERT_PRE_NO_ERROR();
 206         BT_ASSERT_PRE_NON_NULL(stream, "Stream");
 207         BT_ASSERT_PRE(stream->class->supports_packets,
 208                 "Stream class does not support packets: %![sc-]+S",
 209                 stream->class);
 210         packet = bt_object_pool_create_object(&stream->packet_pool);
 211         if (G_UNLIKELY(!packet)) {
 212                 BT_LIB_LOGE_APPEND_CAUSE(
 213                         "Cannot allocate one packet from stream's packet pool: "
 214                         "%![stream-]+s", stream);
 215                 goto end;
 216         }
 217
 218         if (G_LIKELY(!packet->stream)) {
 219                 packet->stream = stream;
 220                 bt_object_get_ref_no_null_check_no_parent_check(
 221                         &packet->stream->base);
 222         }
 223
 224 end:
 225         return (void *) packet;
 226 }
 227
 228 void bt_packet_get_ref(const struct bt_packet *packet)
 229 {
 230         bt_object_get_ref(packet);
 231 }
 232
 233 void bt_packet_put_ref(const struct bt_packet *packet)
 234 {
 235         bt_object_put_ref(packet);
 236 }