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 "compat/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_LIB_LOGD("Destroying clock snapshot: %!+k", clock_snapshot);
  43         BT_OBJECT_PUT_REF_AND_RESET(clock_snapshot->clock_class);
  44         g_free(clock_snapshot);
  45 }
  46
  47 BT_HIDDEN
  48 struct bt_clock_snapshot *bt_clock_snapshot_new(
  49                 struct bt_clock_class *clock_class)
  50 {
  51         struct bt_clock_snapshot *ret = NULL;
  52
  53         BT_ASSERT(clock_class);
  54         BT_LIB_LOGD("Creating clock snapshot object: %![cc-]+K=",
  55                 clock_class);
  56         ret = g_new0(struct bt_clock_snapshot, 1);
  57         if (!ret) {
  58                 BT_LOGE_STR("Failed to allocate one clock snapshot.");
  59                 goto end;
  60         }
  61
  62         bt_object_init_unique(&ret->base);
  63         ret->clock_class = clock_class;
  64         bt_object_get_no_null_check(clock_class);
  65         bt_clock_class_freeze(clock_class);
  66         BT_LIB_LOGD("Created clock snapshot object: %!+k", ret);
  67
  68 end:
  69         return ret;
  70 }
  71
  72 BT_HIDDEN
  73 struct bt_clock_snapshot *bt_clock_snapshot_create(
  74                 struct bt_clock_class *clock_class)
  75 {
  76         struct bt_clock_snapshot *clock_snapshot = NULL;
  77
  78         BT_ASSERT(clock_class);
  79         clock_snapshot = bt_object_pool_create_object(&clock_class->cs_pool);
  80         if (!clock_snapshot) {
  81                 BT_LIB_LOGE("Cannot allocate one clock snapshot from clock class's clock snapshot pool: "
  82                         "%![cc-]+K", clock_class);
  83                 goto error;
  84         }
  85
  86         if (G_LIKELY(!clock_snapshot->clock_class)) {
  87                 clock_snapshot->clock_class = clock_class;
  88                 bt_object_get_no_null_check(clock_class);
  89         }
  90
  91         goto end;
  92
  93 error:
  94         if (clock_snapshot) {
  95                 bt_clock_snapshot_recycle(clock_snapshot);
  96                 clock_snapshot = NULL;
  97         }
  98
  99 end:
 100         return clock_snapshot;
 101 }
 102
 103 BT_HIDDEN
 104 void bt_clock_snapshot_recycle(struct bt_clock_snapshot *clock_snapshot)
 105 {
 106         struct bt_clock_class *clock_class;
 107
 108         BT_ASSERT(clock_snapshot);
 109         BT_LIB_LOGD("Recycling clock snapshot: %!+k", clock_snapshot);
 110
 111         /*
 112          * Those are the important ordered steps:
 113          *
 114          * 1. Reset the clock snapshot object, but do NOT put its clock
 115          *    class's reference. This clock class contains the pool to
 116          *    which we're about to recycle this clock snapshot object,
 117          *    so we must guarantee its existence thanks to this existing
 118          *    reference.
 119          *
 120          * 2. Move the clock class reference to our `clock_class`
 121          *    variable so that we can set the clock snapshot's clock
 122          *    class member to NULL before recycling it. We CANNOT do
 123          *    this after we put the clock class reference because this
 124          *    bt_object_put_ref() could destroy the clock class, also
 125          *    destroying its clock snapshot pool, thus also destroying
 126          *    our clock snapshot object (this would result in an invalid
 127          *    write access).
 128          *
 129          * 3. Recycle the clock snapshot object.
 130          *
 131          * 4. Put our clock class reference.
 132          */
 133         bt_clock_snapshot_reset(clock_snapshot);
 134         clock_class = clock_snapshot->clock_class;
 135         BT_ASSERT(clock_class);
 136         clock_snapshot->clock_class = NULL;
 137         bt_object_pool_recycle_object(&clock_class->cs_pool, clock_snapshot);
 138         bt_object_put_ref(clock_class);
 139 }
 140
 141 uint64_t bt_clock_snapshot_get_value(
 142                 const struct bt_clock_snapshot *clock_snapshot)
 143 {
 144         BT_ASSERT_PRE_NON_NULL(clock_snapshot, "Clock snapshot");
 145         BT_ASSERT_PRE(clock_snapshot->is_set,
 146                 "Clock snapshot is not set: %!+k", clock_snapshot);
 147         return clock_snapshot->value_cycles;
 148 }
 149
 150 enum bt_clock_snapshot_get_ns_from_origin_status
 151 bt_clock_snapshot_get_ns_from_origin(
 152                 const struct bt_clock_snapshot *clock_snapshot,
 153                 int64_t *ret_value_ns)
 154 {
 155         int ret = BT_FUNC_STATUS_OK;
 156
 157         BT_ASSERT_PRE_NON_NULL(clock_snapshot, "Clock snapshot");
 158         BT_ASSERT_PRE_NON_NULL(ret_value_ns, "Value (ns) (output)");
 159         BT_ASSERT_PRE(clock_snapshot->is_set,
 160                 "Clock snapshot is not set: %!+k", clock_snapshot);
 161
 162         if (clock_snapshot->ns_from_origin_overflows) {
 163                 BT_LIB_LOGD("Clock snapshot, once converted to nanoseconds from origin, "
 164                         "overflows the signed 64-bit integer range: "
 165                         "%![cs-]+k", clock_snapshot);
 166                 ret = BT_FUNC_STATUS_OVERFLOW;
 167                 goto end;
 168         }
 169
 170         *ret_value_ns = clock_snapshot->ns_from_origin;
 171
 172 end:
 173         return ret;
 174 }
 175
 176 const struct bt_clock_class *bt_clock_snapshot_borrow_clock_class_const(
 177                 const struct bt_clock_snapshot *clock_snapshot)
 178 {
 179         BT_ASSERT_PRE_NON_NULL(clock_snapshot, "Clock snapshot");
 180         return clock_snapshot->clock_class;
 181 }