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 <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 BT_EXPORT
  29 struct bt_stream *bt_packet_borrow_stream(struct bt_packet *packet)
  30 {
  31         BT_ASSERT_PRE_DEV_PACKET_NON_NULL(packet);
  32         return packet->stream;
  33 }
  34
  35 BT_EXPORT
  36 const struct bt_stream *bt_packet_borrow_stream_const(
  37                 const struct bt_packet *packet)
  38 {
  39         return bt_packet_borrow_stream((void *) packet);
  40 }
  41
  42 BT_EXPORT
  43 struct bt_field *bt_packet_borrow_context_field(struct bt_packet *packet)
  44 {
  45         BT_ASSERT_PRE_DEV_PACKET_NON_NULL(packet);
  46         return packet->context_field ? packet->context_field->field : NULL;
  47 }
  48
  49 BT_EXPORT
  50 const struct bt_field *bt_packet_borrow_context_field_const(
  51                 const struct bt_packet *packet)
  52 {
  53         return bt_packet_borrow_context_field((void *) packet);
  54 }
  55
  56 void _bt_packet_set_is_frozen(const struct bt_packet *packet, bool is_frozen)
  57 {
  58         if (!packet) {
  59                 return;
  60         }
  61
  62         BT_LIB_LOGD("Setting packet's frozen state: %![packet-]+a, "
  63                 "is-frozen=%d", packet, is_frozen);
  64
  65         if (packet->context_field) {
  66                 BT_LOGD_STR("Setting packet's context field's frozen state.");
  67                 bt_field_set_is_frozen(packet->context_field->field,
  68                         is_frozen);
  69         }
  70
  71         ((struct bt_packet *) packet)->frozen = is_frozen;
  72 }
  73
  74 static inline
  75 void reset_packet(struct bt_packet *packet)
  76 {
  77         BT_ASSERT(packet);
  78         BT_LIB_LOGD("Resetting packet: %!+a", packet);
  79         bt_packet_set_is_frozen(packet, false);
  80
  81         if (packet->context_field) {
  82                 bt_field_set_is_frozen(packet->context_field->field, false);
  83                 bt_field_reset(packet->context_field->field);
  84         }
  85 }
  86
  87 static
  88 void recycle_context_field(struct bt_field_wrapper *context_field,
  89                 struct bt_stream_class *stream_class)
  90 {
  91         BT_ASSERT(context_field);
  92         BT_LIB_LOGD("Recycling packet context field: "
  93                 "addr=%p, %![sc-]+S, %![field-]+f", context_field,
  94                 stream_class, context_field->field);
  95         bt_object_pool_recycle_object(&stream_class->packet_context_field_pool,
  96                 context_field);
  97 }
  98
  99 void bt_packet_recycle(struct bt_packet *packet)
 100 {
 101         struct bt_stream *stream;
 102
 103         BT_ASSERT(packet);
 104         BT_LIB_LOGD("Recycling packet: %!+a", packet);
 105
 106         /*
 107          * Those are the important ordered steps:
 108          *
 109          * 1. Reset the packet object (put any permanent reference it
 110          *    has, unfreeze it and its fields in developer mode, etc.),
 111          *    but do NOT put its stream's reference. This stream
 112          *    contains the pool to which we're about to recycle this
 113          *    packet object, so we must guarantee its existence thanks
 114          *    to this existing reference.
 115          *
 116          * 2. Move the stream reference to our `stream`
 117          *    variable so that we can set the packet's stream member
 118          *    to NULL before recycling it. We CANNOT do this after
 119          *    we put the stream reference because this bt_object_put_ref()
 120          *    could destroy the stream, also destroying its
 121          *    packet pool, thus also destroying our packet object (this
 122          *    would result in an invalid write access).
 123          *
 124          * 3. Recycle the packet object.
 125          *
 126          * 4. Put our stream reference.
 127          */
 128         reset_packet(packet);
 129         stream = packet->stream;
 130         BT_ASSERT(stream);
 131         packet->stream = NULL;
 132         bt_object_pool_recycle_object(&stream->packet_pool, packet);
 133         bt_object_put_ref_no_null_check(&stream->base);
 134 }
 135
 136 void bt_packet_destroy(struct bt_packet *packet)
 137 {
 138         BT_LIB_LOGD("Destroying packet: %!+a", packet);
 139
 140         if (packet->context_field) {
 141                 if (packet->stream) {
 142                         BT_LOGD_STR("Recycling packet's context field.");
 143                         recycle_context_field(packet->context_field,
 144                                 packet->stream->class);
 145                 } else {
 146                         bt_field_wrapper_destroy(packet->context_field);
 147                 }
 148
 149                 packet->context_field = NULL;
 150         }
 151
 152         BT_LOGD_STR("Putting packet's stream.");
 153         BT_OBJECT_PUT_REF_AND_RESET(packet->stream);
 154         g_free(packet);
 155 }
 156
 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 BT_EXPORT
 201 struct bt_packet *bt_packet_create(const struct bt_stream *c_stream)
 202 {
 203         struct bt_packet *packet = NULL;
 204         struct bt_stream *stream = (void *) c_stream;
 205
 206         BT_ASSERT_PRE_NO_ERROR();
 207         BT_ASSERT_PRE_STREAM_NON_NULL(stream);
 208         BT_ASSERT_PRE("stream-class-supports-packets",
 209                 stream->class->supports_packets,
 210                 "Stream class does not support packets: %![sc-]+S",
 211                 stream->class);
 212         packet = bt_object_pool_create_object(&stream->packet_pool);
 213         if (G_UNLIKELY(!packet)) {
 214                 BT_LIB_LOGE_APPEND_CAUSE(
 215                         "Cannot allocate one packet from stream's packet pool: "
 216                         "%![stream-]+s", stream);
 217                 goto end;
 218         }
 219
 220         if (G_LIKELY(!packet->stream)) {
 221                 packet->stream = stream;
 222                 bt_object_get_ref_no_null_check_no_parent_check(
 223                         &packet->stream->base);
 224         }
 225
 226 end:
 227         return (void *) packet;
 228 }
 229
 230 BT_EXPORT
 231 void bt_packet_get_ref(const struct bt_packet *packet)
 232 {
 233         bt_object_get_ref(packet);
 234 }
 235
 236 BT_EXPORT
 237 void bt_packet_put_ref(const struct bt_packet *packet)
 238 {
 239         bt_object_put_ref(packet);
 240 }