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_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(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 error;
  87         }
  88
  89         if (G_LIKELY(!clock_snapshot->clock_class)) {
  90                 clock_snapshot->clock_class = clock_class;
  91                 bt_object_get_no_null_check(clock_class);
  92         }
  93
  94         goto end;
  95
  96 error:
  97         if (clock_snapshot) {
  98                 bt_clock_snapshot_recycle(clock_snapshot);
  99                 clock_snapshot = NULL;
 100         }
 101
 102 end:
 103         return clock_snapshot;
 104 }
 105
 106 BT_HIDDEN
 107 void bt_clock_snapshot_recycle(struct bt_clock_snapshot *clock_snapshot)
 108 {
 109         struct bt_clock_class *clock_class;
 110
 111         BT_ASSERT(clock_snapshot);
 112         BT_LIB_LOGD("Recycling clock snapshot: %!+k", clock_snapshot);
 113
 114         /*
 115          * Those are the important ordered steps:
 116          *
 117          * 1. Reset the clock snapshot object, but do NOT put its clock
 118          *    class's reference. This clock class contains the pool to
 119          *    which we're about to recycle this clock snapshot object,
 120          *    so we must guarantee its existence thanks to this existing
 121          *    reference.
 122          *
 123          * 2. Move the clock class reference to our `clock_class`
 124          *    variable so that we can set the clock snapshot's clock
 125          *    class member to NULL before recycling it. We CANNOT do
 126          *    this after we put the clock class reference because this
 127          *    bt_object_put_ref() could destroy the clock class, also
 128          *    destroying its clock snapshot pool, thus also destroying
 129          *    our clock snapshot object (this would result in an invalid
 130          *    write access).
 131          *
 132          * 3. Recycle the clock snapshot object.
 133          *
 134          * 4. Put our clock class reference.
 135          */
 136         bt_clock_snapshot_reset(clock_snapshot);
 137         clock_class = clock_snapshot->clock_class;
 138         BT_ASSERT(clock_class);
 139         clock_snapshot->clock_class = NULL;
 140         bt_object_pool_recycle_object(&clock_class->cs_pool, clock_snapshot);
 141         bt_object_put_ref(clock_class);
 142 }
 143
 144 uint64_t bt_clock_snapshot_get_value(
 145                 const struct bt_clock_snapshot *clock_snapshot)
 146 {
 147         BT_ASSERT_PRE_DEV_NON_NULL(clock_snapshot, "Clock snapshot");
 148         BT_ASSERT_PRE_DEV(clock_snapshot->is_set,
 149                 "Clock snapshot is not set: %!+k", clock_snapshot);
 150         return clock_snapshot->value_cycles;
 151 }
 152
 153 enum bt_clock_snapshot_get_ns_from_origin_status
 154 bt_clock_snapshot_get_ns_from_origin(
 155                 const struct bt_clock_snapshot *clock_snapshot,
 156                 int64_t *ret_value_ns)
 157 {
 158         int ret = BT_FUNC_STATUS_OK;
 159
 160         BT_ASSERT_PRE_DEV_NON_NULL(clock_snapshot, "Clock snapshot");
 161         BT_ASSERT_PRE_DEV_NON_NULL(ret_value_ns, "Value (ns) (output)");
 162         BT_ASSERT_PRE_DEV(clock_snapshot->is_set,
 163                 "Clock snapshot is not set: %!+k", clock_snapshot);
 164
 165         if (clock_snapshot->ns_from_origin_overflows) {
 166                 BT_LIB_LOGE_APPEND_CAUSE(
 167                         "Clock snapshot, once converted to nanoseconds from origin, "
 168                         "overflows the signed 64-bit integer range: "
 169                         "%![cs-]+k", clock_snapshot);
 170                 ret = BT_FUNC_STATUS_OVERFLOW_ERROR;
 171                 goto end;
 172         }
 173
 174         *ret_value_ns = clock_snapshot->ns_from_origin;
 175
 176 end:
 177         return ret;
 178 }
 179
 180 const struct bt_clock_class *bt_clock_snapshot_borrow_clock_class_const(
 181                 const struct bt_clock_snapshot *clock_snapshot)
 182 {
 183         BT_ASSERT_PRE_DEV_NON_NULL(clock_snapshot, "Clock snapshot");
 184         return clock_snapshot->clock_class;
 185 }