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

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright 2017-2018 Philippe Proulx <pproulx@efficios.com>
   5  */
   6
   7 #define BT_LOG_TAG "LIB/CLOCK-SNAPSHOT"
   8 #include "lib/logging.h"
   9
  10 #include "lib/assert-pre.h"
  11 #include "common/uuid.h"
  12 #include "clock-class.h"
  13 #include "clock-snapshot.h"
  14 #include <babeltrace2/trace-ir/clock-snapshot.h>
  15 #include "compat/compiler.h"
  16 #include <babeltrace2/types.h>
  17 #include "compat/string.h"
  18 #include <inttypes.h>
  19 #include "lib/object.h"
  20 #include "common/assert.h"
  21 #include "lib/func-status.h"
  22
  23 BT_HIDDEN
  24 void bt_clock_snapshot_destroy(struct bt_clock_snapshot *clock_snapshot)
  25 {
  26         BT_ASSERT(clock_snapshot);
  27         BT_LIB_LOGD("Destroying clock snapshot: %!+k", clock_snapshot);
  28         BT_OBJECT_PUT_REF_AND_RESET(clock_snapshot->clock_class);
  29         g_free(clock_snapshot);
  30 }
  31
  32 BT_HIDDEN
  33 struct bt_clock_snapshot *bt_clock_snapshot_new(
  34                 struct bt_clock_class *clock_class)
  35 {
  36         struct bt_clock_snapshot *ret = NULL;
  37
  38         BT_ASSERT(clock_class);
  39         BT_LIB_LOGD("Creating clock snapshot object: %![cc-]+K=",
  40                 clock_class);
  41         ret = g_new0(struct bt_clock_snapshot, 1);
  42         if (!ret) {
  43                 BT_LIB_LOGE_APPEND_CAUSE(
  44                         "Failed to allocate one clock snapshot.");
  45                 goto end;
  46         }
  47
  48         bt_object_init_unique(&ret->base);
  49         ret->clock_class = clock_class;
  50         bt_object_get_ref_no_null_check(clock_class);
  51         bt_clock_class_freeze(clock_class);
  52         BT_LIB_LOGD("Created clock snapshot object: %!+k", ret);
  53
  54 end:
  55         return ret;
  56 }
  57
  58 BT_HIDDEN
  59 struct bt_clock_snapshot *bt_clock_snapshot_create(
  60                 struct bt_clock_class *clock_class)
  61 {
  62         struct bt_clock_snapshot *clock_snapshot = NULL;
  63
  64         BT_ASSERT_DBG(clock_class);
  65         clock_snapshot = bt_object_pool_create_object(&clock_class->cs_pool);
  66         if (!clock_snapshot) {
  67                 BT_LIB_LOGE_APPEND_CAUSE(
  68                         "Cannot allocate one clock snapshot from clock class's clock snapshot pool: "
  69                         "%![cc-]+K", clock_class);
  70                 goto end;
  71         }
  72
  73         if (G_LIKELY(!clock_snapshot->clock_class)) {
  74                 clock_snapshot->clock_class = clock_class;
  75                 bt_object_get_ref_no_null_check(clock_class);
  76         }
  77
  78 end:
  79         return clock_snapshot;
  80 }
  81
  82 BT_HIDDEN
  83 void bt_clock_snapshot_recycle(struct bt_clock_snapshot *clock_snapshot)
  84 {
  85         struct bt_clock_class *clock_class;
  86
  87         BT_ASSERT_DBG(clock_snapshot);
  88         BT_LIB_LOGD("Recycling clock snapshot: %!+k", clock_snapshot);
  89
  90         /*
  91          * Those are the important ordered steps:
  92          *
  93          * 1. Reset the clock snapshot object, but do NOT put its clock
  94          *    class's reference. This clock class contains the pool to
  95          *    which we're about to recycle this clock snapshot object,
  96          *    so we must guarantee its existence thanks to this existing
  97          *    reference.
  98          *
  99          * 2. Move the clock class reference to our `clock_class`
 100          *    variable so that we can set the clock snapshot's clock
 101          *    class member to NULL before recycling it. We CANNOT do
 102          *    this after we put the clock class reference because this
 103          *    bt_object_put_ref() could destroy the clock class, also
 104          *    destroying its clock snapshot pool, thus also destroying
 105          *    our clock snapshot object (this would result in an invalid
 106          *    write access).
 107          *
 108          * 3. Recycle the clock snapshot object.
 109          *
 110          * 4. Put our clock class reference.
 111          */
 112         bt_clock_snapshot_reset(clock_snapshot);
 113         clock_class = clock_snapshot->clock_class;
 114         BT_ASSERT_DBG(clock_class);
 115         clock_snapshot->clock_class = NULL;
 116         bt_object_pool_recycle_object(&clock_class->cs_pool, clock_snapshot);
 117         bt_object_put_ref(clock_class);
 118 }
 119
 120 uint64_t bt_clock_snapshot_get_value(
 121                 const struct bt_clock_snapshot *clock_snapshot)
 122 {
 123         BT_ASSERT_PRE_DEV_NON_NULL(clock_snapshot, "Clock snapshot");
 124         BT_ASSERT_PRE_DEV(clock_snapshot->is_set,
 125                 "Clock snapshot is not set: %!+k", clock_snapshot);
 126         return clock_snapshot->value_cycles;
 127 }
 128
 129 enum bt_clock_snapshot_get_ns_from_origin_status
 130 bt_clock_snapshot_get_ns_from_origin(
 131                 const struct bt_clock_snapshot *clock_snapshot,
 132                 int64_t *ret_value_ns)
 133 {
 134         int ret = BT_FUNC_STATUS_OK;
 135
 136         BT_ASSERT_PRE_DEV_NO_ERROR();
 137         BT_ASSERT_PRE_DEV_NON_NULL(clock_snapshot, "Clock snapshot");
 138         BT_ASSERT_PRE_DEV_NON_NULL(ret_value_ns, "Value (ns) (output)");
 139         BT_ASSERT_PRE_DEV(clock_snapshot->is_set,
 140                 "Clock snapshot is not set: %!+k", clock_snapshot);
 141
 142         if (clock_snapshot->ns_from_origin_overflows) {
 143                 BT_LIB_LOGE_APPEND_CAUSE(
 144                         "Clock snapshot, once converted to nanoseconds from origin, "
 145                         "overflows the signed 64-bit integer range: "
 146                         "%![cs-]+k", clock_snapshot);
 147                 ret = BT_FUNC_STATUS_OVERFLOW_ERROR;
 148                 goto end;
 149         }
 150
 151         *ret_value_ns = clock_snapshot->ns_from_origin;
 152
 153 end:
 154         return ret;
 155 }
 156
 157 const struct bt_clock_class *bt_clock_snapshot_borrow_clock_class_const(
 158                 const struct bt_clock_snapshot *clock_snapshot)
 159 {
 160         BT_ASSERT_PRE_DEV_NON_NULL(clock_snapshot, "Clock snapshot");
 161         return clock_snapshot->clock_class;
 162 }