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/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
  38 BT_HIDDEN
  39 void bt_clock_snapshot_destroy(struct bt_clock_snapshot *clock_snapshot)
  40 {
  41         BT_LIB_LOGD("Destroying clock snapshot: %!+k", clock_snapshot);
  42         BT_OBJECT_PUT_REF_AND_RESET(clock_snapshot->clock_class);
  43         g_free(clock_snapshot);
  44 }
  45
  46 BT_HIDDEN
  47 struct bt_clock_snapshot *bt_clock_snapshot_new(
  48                 struct bt_clock_class *clock_class)
  49 {
  50         struct bt_clock_snapshot *ret = NULL;
  51
  52         BT_ASSERT(clock_class);
  53         BT_LIB_LOGD("Creating clock snapshot object: %![cc-]+K=",
  54                 clock_class);
  55         ret = g_new0(struct bt_clock_snapshot, 1);
  56         if (!ret) {
  57                 BT_LOGE_STR("Failed to allocate one clock snapshot.");
  58                 goto end;
  59         }
  60
  61         bt_object_init_unique(&ret->base);
  62         ret->clock_class = clock_class;
  63         bt_object_get_no_null_check(clock_class);
  64         bt_clock_class_freeze(clock_class);
  65         BT_LIB_LOGD("Created clock snapshot object: %!+k", ret);
  66
  67 end:
  68         return ret;
  69 }
  70
  71 BT_HIDDEN
  72 struct bt_clock_snapshot *bt_clock_snapshot_create(
  73                 struct bt_clock_class *clock_class)
  74 {
  75         struct bt_clock_snapshot *clock_snapshot = NULL;
  76
  77         BT_ASSERT(clock_class);
  78         clock_snapshot = bt_object_pool_create_object(&clock_class->cs_pool);
  79         if (!clock_snapshot) {
  80                 BT_LIB_LOGE("Cannot allocate one clock snapshot from clock class's clock snapshot pool: "
  81                         "%![cc-]+K", clock_class);
  82                 goto error;
  83         }
  84
  85         if (G_LIKELY(!clock_snapshot->clock_class)) {
  86                 clock_snapshot->clock_class = clock_class;
  87                 bt_object_get_no_null_check(clock_class);
  88         }
  89
  90         goto end;
  91
  92 error:
  93         if (clock_snapshot) {
  94                 bt_clock_snapshot_recycle(clock_snapshot);
  95                 clock_snapshot = NULL;
  96         }
  97
  98 end:
  99         return clock_snapshot;
 100 }
 101
 102 BT_HIDDEN
 103 void bt_clock_snapshot_recycle(struct bt_clock_snapshot *clock_snapshot)
 104 {
 105         struct bt_clock_class *clock_class;
 106
 107         BT_ASSERT(clock_snapshot);
 108         BT_LIB_LOGD("Recycling clock snapshot: %!+k", clock_snapshot);
 109
 110         /*
 111          * Those are the important ordered steps:
 112          *
 113          * 1. Reset the clock snapshot object, but do NOT put its clock
 114          *    class's reference. This clock class contains the pool to
 115          *    which we're about to recycle this clock snapshot object,
 116          *    so we must guarantee its existence thanks to this existing
 117          *    reference.
 118          *
 119          * 2. Move the clock class reference to our `clock_class`
 120          *    variable so that we can set the clock snapshot's clock
 121          *    class member to NULL before recycling it. We CANNOT do
 122          *    this after we put the clock class reference because this
 123          *    bt_object_put_ref() could destroy the clock class, also
 124          *    destroying its clock snapshot pool, thus also destroying
 125          *    our clock snapshot object (this would result in an invalid
 126          *    write access).
 127          *
 128          * 3. Recycle the clock snapshot object.
 129          *
 130          * 4. Put our clock class reference.
 131          */
 132         bt_clock_snapshot_reset(clock_snapshot);
 133         clock_class = clock_snapshot->clock_class;
 134         BT_ASSERT(clock_class);
 135         clock_snapshot->clock_class = NULL;
 136         bt_object_pool_recycle_object(&clock_class->cs_pool, clock_snapshot);
 137         bt_object_put_ref(clock_class);
 138 }
 139
 140 uint64_t bt_clock_snapshot_get_value(
 141                 const struct bt_clock_snapshot *clock_snapshot)
 142 {
 143         BT_ASSERT_PRE_NON_NULL(clock_snapshot, "Clock snapshot");
 144         BT_ASSERT_PRE(clock_snapshot->is_set,
 145                 "Clock snapshot is not set: %!+k", clock_snapshot);
 146         return clock_snapshot->value_cycles;
 147 }
 148
 149 enum bt_clock_snapshot_status bt_clock_snapshot_get_ns_from_origin(
 150                 const struct bt_clock_snapshot *clock_snapshot,
 151                 int64_t *ret_value_ns)
 152 {
 153         int ret = BT_CLOCK_SNAPSHOT_STATUS_OK;
 154
 155         BT_ASSERT_PRE_NON_NULL(clock_snapshot, "Clock snapshot");
 156         BT_ASSERT_PRE_NON_NULL(ret_value_ns, "Value (ns) (output)");
 157         BT_ASSERT_PRE(clock_snapshot->is_set,
 158                 "Clock snapshot is not set: %!+k", clock_snapshot);
 159
 160         if (clock_snapshot->ns_from_origin_overflows) {
 161                 BT_LIB_LOGD("Clock snapshot, once converted to nanoseconds from origin, "
 162                         "overflows the signed 64-bit integer range: "
 163                         "%![cs-]+k", clock_snapshot);
 164                 ret = BT_CLOCK_SNAPSHOT_STATUS_OVERFLOW;
 165                 goto end;
 166         }
 167
 168         *ret_value_ns = clock_snapshot->ns_from_origin;
 169
 170 end:
 171         return ret;
 172 }
 173
 174 const struct bt_clock_class *bt_clock_snapshot_borrow_clock_class_const(
 175                 const struct bt_clock_snapshot *clock_snapshot)
 176 {
 177         BT_ASSERT_PRE_NON_NULL(clock_snapshot, "Clock snapshot");
 178         return clock_snapshot->clock_class;
 179 }