lib/ctf-ir/clock-value.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 "CLOCK-VALUE"
  24 #include <babeltrace/lib-logging-internal.h>
  25
  26 #include <babeltrace/assert-pre-internal.h>
  27 #include <babeltrace/compat/uuid-internal.h>
  28 #include <babeltrace/ctf-ir/clock-class-internal.h>
  29 #include <babeltrace/ctf-ir/clock-value-internal.h>
  30 #include <babeltrace/ref.h>
  31 #include <babeltrace/compiler-internal.h>
  32 #include <babeltrace/types.h>
  33 #include <babeltrace/compat/string-internal.h>
  34 #include <inttypes.h>
  35 #include <babeltrace/object-internal.h>
  36 #include <babeltrace/assert-internal.h>
  37
  38 BT_HIDDEN
  39 void bt_clock_value_destroy(struct bt_clock_value *clock_value)
  40 {
  41         BT_LIB_LOGD("Destroying clock value: %!+k", clock_value);
  42         bt_put(clock_value->clock_class);
  43         g_free(clock_value);
  44 }
  45
  46 BT_HIDDEN
  47 struct bt_clock_value *bt_clock_value_new(struct bt_clock_class *clock_class)
  48 {
  49         struct bt_clock_value *ret = NULL;
  50
  51         BT_ASSERT(clock_class);
  52         BT_LIB_LOGD("Creating clock value object: %![cc-]+K=",
  53                 clock_class);
  54         ret = g_new0(struct bt_clock_value, 1);
  55         if (!ret) {
  56                 BT_LOGE_STR("Failed to allocate one clock value.");
  57                 goto end;
  58         }
  59
  60         bt_object_init_unique(&ret->base);
  61         ret->clock_class = bt_get(clock_class);
  62         bt_clock_class_freeze(clock_class);
  63         BT_LIB_LOGD("Created clock value object: %!+k", ret);
  64
  65 end:
  66         return ret;
  67 }
  68
  69 BT_HIDDEN
  70 struct bt_clock_value *bt_clock_value_create(struct bt_clock_class *clock_class)
  71 {
  72         struct bt_clock_value *clock_value = NULL;
  73
  74         BT_ASSERT(clock_class);
  75         clock_value = bt_object_pool_create_object(&clock_class->cv_pool);
  76         if (!clock_value) {
  77                 BT_LIB_LOGE("Cannot allocate one clock value from clock class's clock value pool: "
  78                         "%![cc-]+K", clock_class);
  79                 goto error;
  80         }
  81
  82         if (likely(!clock_value->clock_class)) {
  83                 clock_value->clock_class = bt_get(clock_class);
  84         }
  85
  86         goto end;
  87
  88 error:
  89         if (clock_value) {
  90                 bt_clock_value_recycle(clock_value);
  91                 clock_value = NULL;
  92         }
  93
  94 end:
  95         return clock_value;
  96 }
  97
  98 BT_HIDDEN
  99 void bt_clock_value_recycle(struct bt_clock_value *clock_value)
 100 {
 101         struct bt_clock_class *clock_class;
 102
 103         BT_ASSERT(clock_value);
 104         BT_LIB_LOGD("Recycling clock value: %!+k", clock_value);
 105
 106         /*
 107          * Those are the important ordered steps:
 108          *
 109          * 1. Reset the clock value 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 value object, so
 112          *    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 value's clock class
 117          *    member to NULL before recycling it. We CANNOT do this
 118          *    after we put the clock class reference because this
 119          *    bt_put() could destroy the clock class, also destroying
 120          *    its clock value pool, thus also destroying our clock value
 121          *    object (this would result in an invalid write access).
 122          *
 123          * 3. Recycle the clock value object.
 124          *
 125          * 4. Put our clock class reference.
 126          */
 127         bt_clock_value_reset(clock_value);
 128         clock_class = clock_value->clock_class;
 129         BT_ASSERT(clock_class);
 130         clock_value->clock_class = NULL;
 131         bt_object_pool_recycle_object(&clock_class->cv_pool, clock_value);
 132         bt_put(clock_class);
 133 }
 134
 135 uint64_t bt_clock_value_get_value(struct bt_clock_value *clock_value)
 136 {
 137         BT_ASSERT_PRE_NON_NULL(clock_value, "Clock value");
 138         BT_ASSERT_PRE(clock_value->is_set,
 139                 "Clock value is not set: %!+k", clock_value);
 140         return clock_value->value_cycles;
 141 }
 142
 143 int bt_clock_value_get_ns_from_origin(struct bt_clock_value *clock_value,
 144                 int64_t *ret_value_ns)
 145 {
 146         int ret = 0;
 147         BT_ASSERT_PRE_NON_NULL(clock_value, "Clock value");
 148         BT_ASSERT_PRE_NON_NULL(ret_value_ns, "Value (ns) (output)");
 149         BT_ASSERT_PRE(clock_value->is_set,
 150                 "Clock value is not set: %!+k", clock_value);
 151
 152         if (clock_value->ns_from_origin_overflows) {
 153                 BT_LIB_LOGD("Clock value, once converted to nanoseconds from origin, "
 154                         "overflows the signed 64-bit integer range: "
 155                         "%![cv-]+k", clock_value);
 156                 ret = -1;
 157                 goto end;
 158         }
 159
 160         *ret_value_ns = clock_value->ns_from_origin;
 161
 162 end:
 163         return ret;
 164 }
 165
 166 struct bt_clock_class *bt_clock_value_borrow_clock_class(
 167                 struct bt_clock_value *clock_value)
 168 {
 169         BT_ASSERT_PRE_NON_NULL(clock_value, "Clock value");
 170         return clock_value->clock_class;
 171 }