From 349c043de57b03355aae399afa36c90acd89f1ab Mon Sep 17 00:00:00 2001
From: Oblivion <ehsan.sadroid@gmail.com>
Date: Fri, 21 Oct 2022 22:08:29 +0000
Subject: [PATCH 1/4]  return nostd::unique_ptr for Sync Instruments

---
 api/include/opentelemetry/metrics/meter.h     | 19 +++++++------
 api/include/opentelemetry/metrics/noop.h      | 24 ++++++++--------
 .../sdk/metrics/async_instruments.h           |  3 +-
 sdk/include/opentelemetry/sdk/metrics/meter.h | 12 ++++----
 .../sdk/metrics/state/observable_registry.h   |  7 +++--
 sdk/src/metrics/async_instruments.cc          |  4 +--
 sdk/src/metrics/meter.cc                      | 24 ++++++++--------
 sdk/src/metrics/state/observable_registry.cc  | 28 ++++++++++---------
 8 files changed, 63 insertions(+), 58 deletions(-)

diff --git a/api/include/opentelemetry/metrics/meter.h b/api/include/opentelemetry/metrics/meter.h
index 0bc9b7116c..8b078f42fa 100644
--- a/api/include/opentelemetry/metrics/meter.h
+++ b/api/include/opentelemetry/metrics/meter.h
@@ -9,6 +9,7 @@
 #  include "opentelemetry/nostd/shared_ptr.h"
 #  include "opentelemetry/nostd/span.h"
 #  include "opentelemetry/nostd/string_view.h"
+#  include "opentelemetry/nostd/unique_ptr.h"
 #  include "opentelemetry/version.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
@@ -28,7 +29,7 @@ class Meter
   virtual ~Meter() = default;
 
   /**
-   * Creates a Counter with the passed characteristics and returns a shared_ptr to that Counter.
+   * Creates a Counter with the passed characteristics and returns a unique_ptr to that Counter.
    *
    * @param name the name of the new Counter.
    * @param description a brief description of what the Counter is used for.
@@ -36,12 +37,12 @@ class Meter
    * @return a shared pointer to the created Counter.
    */
 
-  virtual nostd::shared_ptr<Counter<long>> CreateLongCounter(
+  virtual nostd::unique_ptr<Counter<long>> CreateLongCounter(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept = 0;
 
-  virtual nostd::shared_ptr<Counter<double>> CreateDoubleCounter(
+  virtual nostd::unique_ptr<Counter<double>> CreateDoubleCounter(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept = 0;
@@ -65,19 +66,19 @@ class Meter
       nostd::string_view unit        = "") noexcept = 0;
 
   /**
-   * Creates a Histogram with the passed characteristics and returns a shared_ptr to that Histogram.
+   * Creates a Histogram with the passed characteristics and returns a unique_ptr to that Histogram.
    *
    * @param name the name of the new Histogram.
    * @param description a brief description of what the Histogram is used for.
    * @param unit the unit of metric values following https://unitsofmeasure.org/ucum.html.
    * @return a shared pointer to the created Histogram.
    */
-  virtual nostd::shared_ptr<Histogram<long>> CreateLongHistogram(
+  virtual nostd::unique_ptr<Histogram<long>> CreateLongHistogram(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept = 0;
 
-  virtual nostd::shared_ptr<Histogram<double>> CreateDoubleHistogram(
+  virtual nostd::unique_ptr<Histogram<double>> CreateDoubleHistogram(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept = 0;
@@ -101,7 +102,7 @@ class Meter
       nostd::string_view unit        = "") noexcept = 0;
 
   /**
-   * Creates an UpDownCounter with the passed characteristics and returns a shared_ptr to that
+   * Creates an UpDownCounter with the passed characteristics and returns a unique_ptr to that
    * UpDownCounter.
    *
    * @param name the name of the new UpDownCounter.
@@ -109,12 +110,12 @@ class Meter
    * @param unit the unit of metric values following https://unitsofmeasure.org/ucum.html.
    * @return a shared pointer to the created UpDownCounter.
    */
-  virtual nostd::shared_ptr<UpDownCounter<long>> CreateLongUpDownCounter(
+  virtual nostd::unique_ptr<UpDownCounter<long>> CreateLongUpDownCounter(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept = 0;
 
-  virtual nostd::shared_ptr<UpDownCounter<double>> CreateDoubleUpDownCounter(
+  virtual nostd::unique_ptr<UpDownCounter<double>> CreateDoubleUpDownCounter(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept = 0;
diff --git a/api/include/opentelemetry/metrics/noop.h b/api/include/opentelemetry/metrics/noop.h
index ce2d8e0cfd..bd444cf85a 100644
--- a/api/include/opentelemetry/metrics/noop.h
+++ b/api/include/opentelemetry/metrics/noop.h
@@ -87,19 +87,19 @@ class NoopObservableInstrument : public ObservableInstrument
 class NoopMeter final : public Meter
 {
 public:
-  nostd::shared_ptr<Counter<long>> CreateLongCounter(nostd::string_view name,
+  nostd::unique_ptr<Counter<long>> CreateLongCounter(nostd::string_view name,
                                                      nostd::string_view description = "",
                                                      nostd::string_view unit = "") noexcept override
   {
-    return nostd::shared_ptr<Counter<long>>{new NoopCounter<long>(name, description, unit)};
+    return nostd::unique_ptr<Counter<long>>{new NoopCounter<long>(name, description, unit)};
   }
 
-  nostd::shared_ptr<Counter<double>> CreateDoubleCounter(
+  nostd::unique_ptr<Counter<double>> CreateDoubleCounter(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override
   {
-    return nostd::shared_ptr<Counter<double>>{new NoopCounter<double>(name, description, unit)};
+    return nostd::unique_ptr<Counter<double>>{new NoopCounter<double>(name, description, unit)};
   }
 
   nostd::shared_ptr<ObservableInstrument> CreateLongObservableCounter(
@@ -120,20 +120,20 @@ class NoopMeter final : public Meter
         new NoopObservableInstrument(name, description, unit));
   }
 
-  nostd::shared_ptr<Histogram<long>> CreateLongHistogram(
+  nostd::unique_ptr<Histogram<long>> CreateLongHistogram(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override
   {
-    return nostd::shared_ptr<Histogram<long>>{new NoopHistogram<long>(name, description, unit)};
+    return nostd::unique_ptr<Histogram<long>>{new NoopHistogram<long>(name, description, unit)};
   }
 
-  nostd::shared_ptr<Histogram<double>> CreateDoubleHistogram(
+  nostd::unique_ptr<Histogram<double>> CreateDoubleHistogram(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override
   {
-    return nostd::shared_ptr<Histogram<double>>{new NoopHistogram<double>(name, description, unit)};
+    return nostd::unique_ptr<Histogram<double>>{new NoopHistogram<double>(name, description, unit)};
   }
 
   nostd::shared_ptr<ObservableInstrument> CreateLongObservableGauge(
@@ -154,21 +154,21 @@ class NoopMeter final : public Meter
         new NoopObservableInstrument(name, description, unit));
   }
 
-  nostd::shared_ptr<UpDownCounter<long>> CreateLongUpDownCounter(
+  nostd::unique_ptr<UpDownCounter<long>> CreateLongUpDownCounter(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override
   {
-    return nostd::shared_ptr<UpDownCounter<long>>{
+    return nostd::unique_ptr<UpDownCounter<long>>{
         new NoopUpDownCounter<long>(name, description, unit)};
   }
 
-  nostd::shared_ptr<UpDownCounter<double>> CreateDoubleUpDownCounter(
+  nostd::unique_ptr<UpDownCounter<double>> CreateDoubleUpDownCounter(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override
   {
-    return nostd::shared_ptr<UpDownCounter<double>>{
+    return nostd::unique_ptr<UpDownCounter<double>>{
         new NoopUpDownCounter<double>(name, description, unit)};
   }
 
diff --git a/sdk/include/opentelemetry/sdk/metrics/async_instruments.h b/sdk/include/opentelemetry/sdk/metrics/async_instruments.h
index 13a059962c..5c192be73c 100644
--- a/sdk/include/opentelemetry/sdk/metrics/async_instruments.h
+++ b/sdk/include/opentelemetry/sdk/metrics/async_instruments.h
@@ -17,7 +17,8 @@ namespace metrics
 
 class AsyncWritableMetricStorage;
 
-class ObservableInstrument : public opentelemetry::metrics::ObservableInstrument
+class ObservableInstrument : public opentelemetry::metrics::ObservableInstrument,
+                             public std::enable_shared_from_this<ObservableInstrument>
 {
 public:
   ObservableInstrument(InstrumentDescriptor instrument_descriptor,
diff --git a/sdk/include/opentelemetry/sdk/metrics/meter.h b/sdk/include/opentelemetry/sdk/metrics/meter.h
index b2c86a7e49..183eba3675 100644
--- a/sdk/include/opentelemetry/sdk/metrics/meter.h
+++ b/sdk/include/opentelemetry/sdk/metrics/meter.h
@@ -35,12 +35,12 @@ class Meter final : public opentelemetry::metrics::Meter
       std::unique_ptr<opentelemetry::sdk::instrumentationscope::InstrumentationScope> scope =
           opentelemetry::sdk::instrumentationscope::InstrumentationScope::Create("")) noexcept;
 
-  nostd::shared_ptr<opentelemetry::metrics::Counter<long>> CreateLongCounter(
+  nostd::unique_ptr<opentelemetry::metrics::Counter<long>> CreateLongCounter(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override;
 
-  nostd::shared_ptr<opentelemetry::metrics::Counter<double>> CreateDoubleCounter(
+  nostd::unique_ptr<opentelemetry::metrics::Counter<double>> CreateDoubleCounter(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override;
@@ -55,12 +55,12 @@ class Meter final : public opentelemetry::metrics::Meter
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override;
 
-  nostd::shared_ptr<opentelemetry::metrics::Histogram<long>> CreateLongHistogram(
+  nostd::unique_ptr<opentelemetry::metrics::Histogram<long>> CreateLongHistogram(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override;
 
-  nostd::shared_ptr<opentelemetry::metrics::Histogram<double>> CreateDoubleHistogram(
+  nostd::unique_ptr<opentelemetry::metrics::Histogram<double>> CreateDoubleHistogram(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override;
@@ -75,12 +75,12 @@ class Meter final : public opentelemetry::metrics::Meter
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override;
 
-  nostd::shared_ptr<opentelemetry::metrics::UpDownCounter<long>> CreateLongUpDownCounter(
+  nostd::unique_ptr<opentelemetry::metrics::UpDownCounter<long>> CreateLongUpDownCounter(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override;
 
-  nostd::shared_ptr<opentelemetry::metrics::UpDownCounter<double>> CreateDoubleUpDownCounter(
+  nostd::unique_ptr<opentelemetry::metrics::UpDownCounter<double>> CreateDoubleUpDownCounter(
       nostd::string_view name,
       nostd::string_view description = "",
       nostd::string_view unit        = "") noexcept override;
diff --git a/sdk/include/opentelemetry/sdk/metrics/state/observable_registry.h b/sdk/include/opentelemetry/sdk/metrics/state/observable_registry.h
index bf76145f03..9e54f611bd 100644
--- a/sdk/include/opentelemetry/sdk/metrics/state/observable_registry.h
+++ b/sdk/include/opentelemetry/sdk/metrics/state/observable_registry.h
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #pragma once
+#include <future>
 #ifndef ENABLE_METRICS_PREVIEW
 
 #  include "opentelemetry/common/timestamp.h"
@@ -21,7 +22,7 @@ struct ObservableCallbackRecord
 {
   opentelemetry::metrics::ObservableCallbackPtr callback;
   void *state;
-  opentelemetry::metrics::ObservableInstrument *instrument;
+  std::shared_ptr<opentelemetry::metrics::ObservableInstrument> instrument;
 };
 
 class ObservableRegistry
@@ -29,11 +30,11 @@ class ObservableRegistry
 public:
   void AddCallback(opentelemetry::metrics::ObservableCallbackPtr callback,
                    void *state,
-                   opentelemetry::metrics::ObservableInstrument *instrument);
+                   std::shared_ptr<opentelemetry::metrics::ObservableInstrument> instrument);
 
   void RemoveCallback(opentelemetry::metrics::ObservableCallbackPtr callback,
                       void *state,
-                      opentelemetry::metrics::ObservableInstrument *instrument);
+                      std::shared_ptr<opentelemetry::metrics::ObservableInstrument> instrument);
 
   void Observe(opentelemetry::common::SystemTimestamp collection_ts);
 
diff --git a/sdk/src/metrics/async_instruments.cc b/sdk/src/metrics/async_instruments.cc
index 916ca765af..0a4f1b4081 100644
--- a/sdk/src/metrics/async_instruments.cc
+++ b/sdk/src/metrics/async_instruments.cc
@@ -26,13 +26,13 @@ ObservableInstrument::ObservableInstrument(InstrumentDescriptor instrument_descr
 void ObservableInstrument::AddCallback(opentelemetry::metrics::ObservableCallbackPtr callback,
                                        void *state) noexcept
 {
-  observable_registry_->AddCallback(callback, state, this);
+  observable_registry_->AddCallback(callback, state, shared_from_this());
 }
 
 void ObservableInstrument::RemoveCallback(opentelemetry::metrics::ObservableCallbackPtr callback,
                                           void *state) noexcept
 {
-  observable_registry_->RemoveCallback(callback, state, this);
+  observable_registry_->RemoveCallback(callback, state, shared_from_this());
 }
 
 const InstrumentDescriptor &ObservableInstrument::GetInstrumentDescriptor()
diff --git a/sdk/src/metrics/meter.cc b/sdk/src/metrics/meter.cc
index 8d36509c34..38bfe968e9 100644
--- a/sdk/src/metrics/meter.cc
+++ b/sdk/src/metrics/meter.cc
@@ -33,7 +33,7 @@ Meter::Meter(
       observable_registry_(new ObservableRegistry())
 {}
 
-nostd::shared_ptr<metrics::Counter<long>> Meter::CreateLongCounter(nostd::string_view name,
+nostd::unique_ptr<metrics::Counter<long>> Meter::CreateLongCounter(nostd::string_view name,
                                                                    nostd::string_view description,
                                                                    nostd::string_view unit) noexcept
 {
@@ -41,11 +41,11 @@ nostd::shared_ptr<metrics::Counter<long>> Meter::CreateLongCounter(nostd::string
       std::string{name.data(), name.size()}, std::string{description.data(), description.size()},
       std::string{unit.data(), unit.size()}, InstrumentType::kCounter, InstrumentValueType::kLong};
   auto storage = RegisterSyncMetricStorage(instrument_descriptor);
-  return nostd::shared_ptr<metrics::Counter<long>>(
+  return nostd::unique_ptr<metrics::Counter<long>>(
       new LongCounter(instrument_descriptor, std::move(storage)));
 }
 
-nostd::shared_ptr<metrics::Counter<double>> Meter::CreateDoubleCounter(
+nostd::unique_ptr<metrics::Counter<double>> Meter::CreateDoubleCounter(
     nostd::string_view name,
     nostd::string_view description,
     nostd::string_view unit) noexcept
@@ -55,7 +55,7 @@ nostd::shared_ptr<metrics::Counter<double>> Meter::CreateDoubleCounter(
       std::string{unit.data(), unit.size()}, InstrumentType::kCounter,
       InstrumentValueType::kDouble};
   auto storage = RegisterSyncMetricStorage(instrument_descriptor);
-  return nostd::shared_ptr<metrics::Counter<double>>{
+  return nostd::unique_ptr<metrics::Counter<double>>{
       new DoubleCounter(instrument_descriptor, std::move(storage))};
 }
 
@@ -87,7 +87,7 @@ Meter::CreateDoubleObservableCounter(nostd::string_view name,
       new ObservableInstrument(instrument_descriptor, std::move(storage), observable_registry_)};
 }
 
-nostd::shared_ptr<metrics::Histogram<long>> Meter::CreateLongHistogram(
+nostd::unique_ptr<metrics::Histogram<long>> Meter::CreateLongHistogram(
     nostd::string_view name,
     nostd::string_view description,
     nostd::string_view unit) noexcept
@@ -97,11 +97,11 @@ nostd::shared_ptr<metrics::Histogram<long>> Meter::CreateLongHistogram(
       std::string{unit.data(), unit.size()}, InstrumentType::kHistogram,
       InstrumentValueType::kLong};
   auto storage = RegisterSyncMetricStorage(instrument_descriptor);
-  return nostd::shared_ptr<metrics::Histogram<long>>{
+  return nostd::unique_ptr<metrics::Histogram<long>>{
       new LongHistogram(instrument_descriptor, std::move(storage))};
 }
 
-nostd::shared_ptr<metrics::Histogram<double>> Meter::CreateDoubleHistogram(
+nostd::unique_ptr<metrics::Histogram<double>> Meter::CreateDoubleHistogram(
     nostd::string_view name,
     nostd::string_view description,
     nostd::string_view unit) noexcept
@@ -111,7 +111,7 @@ nostd::shared_ptr<metrics::Histogram<double>> Meter::CreateDoubleHistogram(
       std::string{unit.data(), unit.size()}, InstrumentType::kHistogram,
       InstrumentValueType::kDouble};
   auto storage = RegisterSyncMetricStorage(instrument_descriptor);
-  return nostd::shared_ptr<metrics::Histogram<double>>{
+  return nostd::unique_ptr<metrics::Histogram<double>>{
       new DoubleHistogram(instrument_descriptor, std::move(storage))};
 }
 
@@ -143,7 +143,7 @@ nostd::shared_ptr<opentelemetry::metrics::ObservableInstrument> Meter::CreateDou
       new ObservableInstrument(instrument_descriptor, std::move(storage), observable_registry_)};
 }
 
-nostd::shared_ptr<metrics::UpDownCounter<long>> Meter::CreateLongUpDownCounter(
+nostd::unique_ptr<metrics::UpDownCounter<long>> Meter::CreateLongUpDownCounter(
     nostd::string_view name,
     nostd::string_view description,
     nostd::string_view unit) noexcept
@@ -153,11 +153,11 @@ nostd::shared_ptr<metrics::UpDownCounter<long>> Meter::CreateLongUpDownCounter(
       std::string{unit.data(), unit.size()}, InstrumentType::kUpDownCounter,
       InstrumentValueType::kLong};
   auto storage = RegisterSyncMetricStorage(instrument_descriptor);
-  return nostd::shared_ptr<metrics::UpDownCounter<long>>{
+  return nostd::unique_ptr<metrics::UpDownCounter<long>>{
       new LongUpDownCounter(instrument_descriptor, std::move(storage))};
 }
 
-nostd::shared_ptr<metrics::UpDownCounter<double>> Meter::CreateDoubleUpDownCounter(
+nostd::unique_ptr<metrics::UpDownCounter<double>> Meter::CreateDoubleUpDownCounter(
     nostd::string_view name,
     nostd::string_view description,
     nostd::string_view unit) noexcept
@@ -167,7 +167,7 @@ nostd::shared_ptr<metrics::UpDownCounter<double>> Meter::CreateDoubleUpDownCount
       std::string{unit.data(), unit.size()}, InstrumentType::kUpDownCounter,
       InstrumentValueType::kDouble};
   auto storage = RegisterSyncMetricStorage(instrument_descriptor);
-  return nostd::shared_ptr<metrics::UpDownCounter<double>>{
+  return nostd::unique_ptr<metrics::UpDownCounter<double>>{
       new DoubleUpDownCounter(instrument_descriptor, std::move(storage))};
 }
 
diff --git a/sdk/src/metrics/state/observable_registry.cc b/sdk/src/metrics/state/observable_registry.cc
index 0d6d770f87..3f2f579449 100644
--- a/sdk/src/metrics/state/observable_registry.cc
+++ b/sdk/src/metrics/state/observable_registry.cc
@@ -15,9 +15,10 @@ namespace sdk
 namespace metrics
 {
 
-void ObservableRegistry::AddCallback(opentelemetry::metrics::ObservableCallbackPtr callback,
-                                     void *state,
-                                     opentelemetry::metrics::ObservableInstrument *instrument)
+void ObservableRegistry::AddCallback(
+    opentelemetry::metrics::ObservableCallbackPtr callback,
+    void *state,
+    std::shared_ptr<opentelemetry::metrics::ObservableInstrument> instrument)
 {
   // TBD - Check if existing
   std::unique_ptr<ObservableCallbackRecord> record(
@@ -26,9 +27,10 @@ void ObservableRegistry::AddCallback(opentelemetry::metrics::ObservableCallbackP
   callbacks_.push_back(std::move(record));
 }
 
-void ObservableRegistry::RemoveCallback(opentelemetry::metrics::ObservableCallbackPtr callback,
-                                        void *state,
-                                        opentelemetry::metrics::ObservableInstrument *instrument)
+void ObservableRegistry::RemoveCallback(
+    opentelemetry::metrics::ObservableCallbackPtr callback,
+    void *state,
+    std::shared_ptr<opentelemetry::metrics::ObservableInstrument> instrument)
 {
   std::lock_guard<std::mutex> lock_guard{callbacks_m_};
   auto new_end = std::remove_if(
@@ -45,13 +47,13 @@ void ObservableRegistry::Observe(opentelemetry::common::SystemTimestamp collecti
   std::lock_guard<std::mutex> lock_guard{callbacks_m_};
   for (auto &callback_wrap : callbacks_)
   {
-    auto value_type =
-        static_cast<opentelemetry::sdk::metrics::ObservableInstrument *>(callback_wrap->instrument)
-            ->GetInstrumentDescriptor()
-            .value_type_;
-    auto storage =
-        static_cast<opentelemetry::sdk::metrics::ObservableInstrument *>(callback_wrap->instrument)
-            ->GetMetricStorage();
+    auto value_type = std::static_pointer_cast<opentelemetry::sdk::metrics::ObservableInstrument>(
+                          callback_wrap->instrument)
+                          ->GetInstrumentDescriptor()
+                          .value_type_;
+    auto storage = std::static_pointer_cast<opentelemetry::sdk::metrics::ObservableInstrument>(
+                       callback_wrap->instrument)
+                       ->GetMetricStorage();
     if (!storage)
     {
       OTEL_INTERNAL_LOG_ERROR("[ObservableRegistry::Observe] - Error during observe."

From b65512e478b74b16ec96c270c2ec4bfe3866bc55 Mon Sep 17 00:00:00 2001
From: Oblivion <ehsan.sadroid@gmail.com>
Date: Sat, 22 Oct 2022 07:10:55 +0000
Subject: [PATCH 2/4] fix

---
 .../sdk/metrics/async_instruments.h           |  3 +-
 .../sdk/metrics/state/observable_registry.h   |  6 ++--
 sdk/src/metrics/async_instruments.cc          |  4 +--
 sdk/src/metrics/state/observable_registry.cc  | 28 ++++++++---------
 sdk/test/metrics/BUILD                        | 30 +++++++++++++++++++
 5 files changed, 49 insertions(+), 22 deletions(-)

diff --git a/sdk/include/opentelemetry/sdk/metrics/async_instruments.h b/sdk/include/opentelemetry/sdk/metrics/async_instruments.h
index 5c192be73c..13a059962c 100644
--- a/sdk/include/opentelemetry/sdk/metrics/async_instruments.h
+++ b/sdk/include/opentelemetry/sdk/metrics/async_instruments.h
@@ -17,8 +17,7 @@ namespace metrics
 
 class AsyncWritableMetricStorage;
 
-class ObservableInstrument : public opentelemetry::metrics::ObservableInstrument,
-                             public std::enable_shared_from_this<ObservableInstrument>
+class ObservableInstrument : public opentelemetry::metrics::ObservableInstrument
 {
 public:
   ObservableInstrument(InstrumentDescriptor instrument_descriptor,
diff --git a/sdk/include/opentelemetry/sdk/metrics/state/observable_registry.h b/sdk/include/opentelemetry/sdk/metrics/state/observable_registry.h
index 9e54f611bd..156d6d87cc 100644
--- a/sdk/include/opentelemetry/sdk/metrics/state/observable_registry.h
+++ b/sdk/include/opentelemetry/sdk/metrics/state/observable_registry.h
@@ -22,7 +22,7 @@ struct ObservableCallbackRecord
 {
   opentelemetry::metrics::ObservableCallbackPtr callback;
   void *state;
-  std::shared_ptr<opentelemetry::metrics::ObservableInstrument> instrument;
+  opentelemetry::metrics::ObservableInstrument *instrument;
 };
 
 class ObservableRegistry
@@ -30,11 +30,11 @@ class ObservableRegistry
 public:
   void AddCallback(opentelemetry::metrics::ObservableCallbackPtr callback,
                    void *state,
-                   std::shared_ptr<opentelemetry::metrics::ObservableInstrument> instrument);
+                   opentelemetry::metrics::ObservableInstrument *instrument);
 
   void RemoveCallback(opentelemetry::metrics::ObservableCallbackPtr callback,
                       void *state,
-                      std::shared_ptr<opentelemetry::metrics::ObservableInstrument> instrument);
+                      opentelemetry::metrics::ObservableInstrument *instrument);
 
   void Observe(opentelemetry::common::SystemTimestamp collection_ts);
 
diff --git a/sdk/src/metrics/async_instruments.cc b/sdk/src/metrics/async_instruments.cc
index 0a4f1b4081..916ca765af 100644
--- a/sdk/src/metrics/async_instruments.cc
+++ b/sdk/src/metrics/async_instruments.cc
@@ -26,13 +26,13 @@ ObservableInstrument::ObservableInstrument(InstrumentDescriptor instrument_descr
 void ObservableInstrument::AddCallback(opentelemetry::metrics::ObservableCallbackPtr callback,
                                        void *state) noexcept
 {
-  observable_registry_->AddCallback(callback, state, shared_from_this());
+  observable_registry_->AddCallback(callback, state, this);
 }
 
 void ObservableInstrument::RemoveCallback(opentelemetry::metrics::ObservableCallbackPtr callback,
                                           void *state) noexcept
 {
-  observable_registry_->RemoveCallback(callback, state, shared_from_this());
+  observable_registry_->RemoveCallback(callback, state, this);
 }
 
 const InstrumentDescriptor &ObservableInstrument::GetInstrumentDescriptor()
diff --git a/sdk/src/metrics/state/observable_registry.cc b/sdk/src/metrics/state/observable_registry.cc
index 3f2f579449..0d6d770f87 100644
--- a/sdk/src/metrics/state/observable_registry.cc
+++ b/sdk/src/metrics/state/observable_registry.cc
@@ -15,10 +15,9 @@ namespace sdk
 namespace metrics
 {
 
-void ObservableRegistry::AddCallback(
-    opentelemetry::metrics::ObservableCallbackPtr callback,
-    void *state,
-    std::shared_ptr<opentelemetry::metrics::ObservableInstrument> instrument)
+void ObservableRegistry::AddCallback(opentelemetry::metrics::ObservableCallbackPtr callback,
+                                     void *state,
+                                     opentelemetry::metrics::ObservableInstrument *instrument)
 {
   // TBD - Check if existing
   std::unique_ptr<ObservableCallbackRecord> record(
@@ -27,10 +26,9 @@ void ObservableRegistry::AddCallback(
   callbacks_.push_back(std::move(record));
 }
 
-void ObservableRegistry::RemoveCallback(
-    opentelemetry::metrics::ObservableCallbackPtr callback,
-    void *state,
-    std::shared_ptr<opentelemetry::metrics::ObservableInstrument> instrument)
+void ObservableRegistry::RemoveCallback(opentelemetry::metrics::ObservableCallbackPtr callback,
+                                        void *state,
+                                        opentelemetry::metrics::ObservableInstrument *instrument)
 {
   std::lock_guard<std::mutex> lock_guard{callbacks_m_};
   auto new_end = std::remove_if(
@@ -47,13 +45,13 @@ void ObservableRegistry::Observe(opentelemetry::common::SystemTimestamp collecti
   std::lock_guard<std::mutex> lock_guard{callbacks_m_};
   for (auto &callback_wrap : callbacks_)
   {
-    auto value_type = std::static_pointer_cast<opentelemetry::sdk::metrics::ObservableInstrument>(
-                          callback_wrap->instrument)
-                          ->GetInstrumentDescriptor()
-                          .value_type_;
-    auto storage = std::static_pointer_cast<opentelemetry::sdk::metrics::ObservableInstrument>(
-                       callback_wrap->instrument)
-                       ->GetMetricStorage();
+    auto value_type =
+        static_cast<opentelemetry::sdk::metrics::ObservableInstrument *>(callback_wrap->instrument)
+            ->GetInstrumentDescriptor()
+            .value_type_;
+    auto storage =
+        static_cast<opentelemetry::sdk::metrics::ObservableInstrument *>(callback_wrap->instrument)
+            ->GetMetricStorage();
     if (!storage)
     {
       OTEL_INTERNAL_LOG_ERROR("[ObservableRegistry::Observe] - Error during observe."
diff --git a/sdk/test/metrics/BUILD b/sdk/test/metrics/BUILD
index 336fbc8b03..5d3076b8be 100644
--- a/sdk/test/metrics/BUILD
+++ b/sdk/test/metrics/BUILD
@@ -1,5 +1,20 @@
 load("//bazel:otel_cc_benchmark.bzl", "otel_cc_benchmark")
 
+cc_test(
+    name = "meter_test",
+    srcs = [
+        "meter_test.cc",
+    ],
+    tags = [
+        "metrics",
+        "test",
+    ],
+    deps = [
+        "//sdk/src/metrics",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
 cc_test(
     name = "meter_provider_sdk_test",
     srcs = [
@@ -112,6 +127,21 @@ cc_test(
     ],
 )
 
+cc_test(
+    name = "async_instruments_test",
+    srcs = [
+        "async_instruments_test.cc",
+    ],
+    tags = [
+        "metrics",
+        "test",
+    ],
+    deps = [
+        "//sdk/src/metrics",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
+
 cc_test(
     name = "async_metric_storage_test",
     srcs = [

From bbaaba190d9559e89d32b456e0b8e04eab03a7ed Mon Sep 17 00:00:00 2001
From: Ehsan Saei <71217171+esigo@users.noreply.github.com>
Date: Sat, 22 Oct 2022 13:13:25 +0200
Subject: [PATCH 3/4] fix test race

---
 sdk/test/metrics/meter_test.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sdk/test/metrics/meter_test.cc b/sdk/test/metrics/meter_test.cc
index b4cd12416c..4f412740db 100644
--- a/sdk/test/metrics/meter_test.cc
+++ b/sdk/test/metrics/meter_test.cc
@@ -82,12 +82,12 @@ TEST(MeterTest, StressMultiThread)
   MetricReader *metric_reader_ptr = nullptr;
   auto meter                      = InitMeter(&metric_reader_ptr, "stress_test_meter");
   std::atomic<unsigned> threadCount(0);
-  size_t numIterations = MAX_ITERATIONS_MT;
+  std::atomic<size_t> numIterations(MAX_ITERATIONS_MT);
   std::atomic<bool> do_collect{false}, do_sync_create{true}, do_async_create{false};
   std::vector<nostd::shared_ptr<opentelemetry::metrics::ObservableInstrument>>
       observable_instruments;
   std::vector<std::thread> meter_operation_threads;
-  size_t instrument_id = 0;
+  std::atomic<size_t> instrument_id(0);
   while (numIterations--)
   {
     for (size_t i = 0; i < MAX_THREADS; i++)

From 10ecb1a7aa37a8dec2bba41fdeba6243b4404541 Mon Sep 17 00:00:00 2001
From: Oblivion <ehsan.sadroid@gmail.com>
Date: Mon, 24 Oct 2022 17:23:12 +0000
Subject: [PATCH 4/4] comment

---
 .../opentelemetry/sdk/metrics/state/observable_registry.h        | 1 -
 1 file changed, 1 deletion(-)

diff --git a/sdk/include/opentelemetry/sdk/metrics/state/observable_registry.h b/sdk/include/opentelemetry/sdk/metrics/state/observable_registry.h
index 156d6d87cc..bf76145f03 100644
--- a/sdk/include/opentelemetry/sdk/metrics/state/observable_registry.h
+++ b/sdk/include/opentelemetry/sdk/metrics/state/observable_registry.h
@@ -2,7 +2,6 @@
 // SPDX-License-Identifier: Apache-2.0
 
 #pragma once
-#include <future>
 #ifndef ENABLE_METRICS_PREVIEW
 
 #  include "opentelemetry/common/timestamp.h"