src/lib/trace-ir/clock-snapshot.c

   1 /*
   2  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to deal
   6  * in the Software without restriction, including without limitation the rights
   7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  * copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  20  * SOFTWARE.
  21  */
  22
  23 #define BT_LOG_TAG "LIB/CLOCK-SNAPSHOT"
  24 #include "lib/logging.h"
  25
  26 #include "lib/assert-pre.h"
  27 #include "common/uuid.h"
  28 #include "clock-class.h"
  29 #include "clock-snapshot.h"
  30 #include <babeltrace2/trace-ir/clock-snapshot-const.h>
  31 #include "compat/compiler.h"
  32 #include <babeltrace2/types.h>
  33 #include "compat/string.h"
  34 #include <inttypes.h>
  35 #include "lib/object.h"
  36 #include "common/assert.h"
  37 #include "lib/func-status.h"
  38
  39 BT_HIDDEN
  40 void bt_clock_snapshot_destroy(struct bt_clock_snapshot *clock_snapshot)
  41 {
  42         BT_ASSERT(clock_snapshot);
  43         BT_LIB_LOGD("Destroying clock snapshot: %!+k", clock_snapshot);
  44         BT_OBJECT_PUT_REF_AND_RESET(clock_snapshot->clock_class);
  45         g_free(clock_snapshot);
  46 }
  47
  48 BT_HIDDEN
  49 struct bt_clock_snapshot *bt_clock_snapshot_new(
  50                 struct bt_clock_class *clock_class)
  51 {
  52         struct bt_clock_snapshot *ret = NULL;
  53
  54         BT_ASSERT(clock_class);
  55         BT_LIB_LOGD("Creating clock snapshot object: %![cc-]+K=",
  56                 clock_class);
  57         ret = g_new0(struct bt_clock_snapshot, 1);
  58         if (!ret) {
  59                 BT_LIB_LOGE_APPEND_CAUSE(
  60                         "Failed to allocate one clock snapshot.");
  61                 goto end;
  62         }
  63
  64         bt_object_init_unique(&ret->base);
  65         ret->clock_class = clock_class;
  66         bt_object_get_ref_no_null_check(clock_class);
  67         bt_clock_class_freeze(clock_class);
  68         BT_LIB_LOGD("Created clock snapshot object: %!+k", ret);
  69
  70 end:
  71         return ret;
  72 }
  73
  74 BT_HIDDEN
  75 struct bt_clock_snapshot *bt_clock_snapshot_create(
  76                 struct bt_clock_class *clock_class)
  77 {
  78         struct bt_clock_snapshot *clock_snapshot = NULL;
  79
  80         BT_ASSERT_DBG(clock_class);
  81         clock_snapshot = bt_object_pool_create_object(&clock_class->cs_pool);
  82         if (!clock_snapshot) {
  83                 BT_LIB_LOGE_APPEND_CAUSE(
  84                         "Cannot allocate one clock snapshot from clock class's clock snapshot pool: "
  85                         "%![cc-]+K", clock_class);
  86                 goto end;
  87         }
  88
  89         if (G_LIKELY(!clock_snapshot->clock_class)) {
  90                 clock_snapshot->clock_class = clock_class;
  91                 bt_object_get_ref_no_null_check(clock_class);
  92         }
  93
  94 end:
  95         return clock_snapshot;
  96 }
  97
  98 BT_HIDDEN
  99 void bt_clock_snapshot_recycle(struct bt_clock_snapshot *clock_snapshot)
 100 {
 101         struct bt_clock_class *clock_class;
 102
 103         BT_ASSERT_DBG(clock_snapshot);
 104         BT_LIB_LOGD("Recycling clock snapshot: %!+k", clock_snapshot);
 105
 106         /*
 107          * Those are the important ordered steps:
 108          *
 109          * 1. Reset the clock snapshot object, but do NOT put its clock
 110          *    class's reference. This clock class contains the pool to
 111          *    which we're about to recycle this clock snapshot object,
 112          *    so we must guarantee its existence thanks to this existing
 113          *    reference.
 114          *
 115          * 2. Move the clock class reference to our `clock_class`
 116          *    variable so that we can set the clock snapshot's clock
 117          *    class member to NULL before recycling it. We CANNOT do
 118          *    this after we put the clock class reference because this
 119          *    bt_object_put_ref() could destroy the clock class, also
 120          *    destroying its clock snapshot pool, thus also destroying
 121          *    our clock snapshot object (this would result in an invalid
 122          *    write access).
 123          *
 124          * 3. Recycle the clock snapshot object.
 125          *
 126          * 4. Put our clock class reference.
 127          */
 128         bt_clock_snapshot_reset(clock_snapshot);
 129         clock_class = clock_snapshot->clock_class;
 130         BT_ASSERT_DBG(clock_class);
 131         clock_snapshot->clock_class = NULL;
 132         bt_object_pool_recycle_object(&clock_class->cs_pool, clock_snapshot);
 133         bt_object_put_ref(clock_class);
 134 }
 135
 136 uint64_t bt_clock_snapshot_get_value(
 137                 const struct bt_clock_snapshot *clock_snapshot)
 138 {
 139         BT_ASSERT_PRE_DEV_NON_NULL(clock_snapshot, "Clock snapshot");
 140         BT_ASSERT_PRE_DEV(clock_snapshot->is_set,
 141                 "Clock snapshot is not set: %!+k", clock_snapshot);
 142         return clock_snapshot->value_cycles;
 143 }
 144
 145 enum bt_clock_snapshot_get_ns_from_origin_status
 146 bt_clock_snapshot_get_ns_from_origin(
 147                 const struct bt_clock_snapshot *clock_snapshot,
 148                 int64_t *ret_value_ns)
 149 {
 150         int ret = BT_FUNC_STATUS_OK;
 151
 152         BT_ASSERT_PRE_DEV_NO_ERROR();
 153         BT_ASSERT_PRE_DEV_NON_NULL(clock_snapshot, "Clock snapshot");
 154         BT_ASSERT_PRE_DEV_NON_NULL(ret_value_ns, "Value (ns) (output)");
 155         BT_ASSERT_PRE_DEV(clock_snapshot->is_set,
 156                 "Clock snapshot is not set: %!+k", clock_snapshot);
 157
 158         if (clock_snapshot->ns_from_origin_overflows) {
 159                 BT_LIB_LOGE_APPEND_CAUSE(
 160                         "Clock snapshot, once converted to nanoseconds from origin, "
 161                         "overflows the signed 64-bit integer range: "
 162                         "%![cs-]+k", clock_snapshot);
 163                 ret = BT_FUNC_STATUS_OVERFLOW_ERROR;
 164                 goto end;
 165         }
 166
 167         *ret_value_ns = clock_snapshot->ns_from_origin;
 168
 169 end:
 170         return ret;
 171 }
 172
 173 const struct bt_clock_class *bt_clock_snapshot_borrow_clock_class_const(
 174                 const struct bt_clock_snapshot *clock_snapshot)
 175 {
 176         BT_ASSERT_PRE_DEV_NON_NULL(clock_snapshot, "Clock snapshot");
 177         return clock_snapshot->clock_class;
 178 }