Use std::atomic instead of ATOMIC_READ/WRITE_8 macroses

Author: malkia

api/include/opentelemetry/common/macros.h

@@ -337,31 +337,6 @@ point.
 
 #endif
 
-//
-// Atomic wrappers based on compiler intrinsics for memory read/write.
-// The tailing number is read/write length in bits.
-//
-// N.B. Compiler intrinsic is used because the usage of C++ standard library is restricted in the
-// OpenTelemetry C++ API.
-//
-#if defined(__GNUC__)
-
-#  define OPENTELEMETRY_ATOMIC_READ_8(ptr) __atomic_load_n(ptr, __ATOMIC_SEQ_CST)
-#  define OPENTELEMETRY_ATOMIC_WRITE_8(ptr, value) __atomic_store_n(ptr, value, __ATOMIC_SEQ_CST)
-
-#elif defined(_MSC_VER)
-
-#  include <intrin.h>
-
-#  define OPENTELEMETRY_ATOMIC_READ_8(ptr) \
-    static_cast<uint8_t>(_InterlockedCompareExchange8(reinterpret_cast<char *>(ptr), 0, 0))
-#  define OPENTELEMETRY_ATOMIC_WRITE_8(ptr, value) \
-    _InterlockedExchange8(reinterpret_cast<char *>(ptr), static_cast<char>(value))
-
-#else
-#  error port atomics read/write for the current platform
-#endif
-
 /* clang-format on */
 //
 // The if/elif order matters here. If both OPENTELEMETRY_BUILD_IMPORT_DLL and

api/include/opentelemetry/logs/logger.h

@@ -3,6 +3,8 @@
 
 #pragma once
 
+#include <atomic>
+
 #include "opentelemetry/version.h"
 #include "opentelemetry/logs/logger_type_traits.h"
 #include "opentelemetry/logs/severity.h"
@@ -286,7 +288,7 @@ class Logger
 
   inline bool Enabled(Severity severity) const noexcept
   {
-    return static_cast<uint8_t>(severity) >= OPENTELEMETRY_ATOMIC_READ_8(&minimum_severity_);
+    return static_cast<uint8_t>(severity) >= minimum_severity_;
   }
 
   /**
@@ -473,7 +475,7 @@ class Logger
 
   void SetMinimumSeverity(uint8_t severity_or_max) noexcept
   {
-    OPENTELEMETRY_ATOMIC_WRITE_8(&minimum_severity_, severity_or_max);
+    minimum_severity_ = severity_or_max;
   }
 
 private:
@@ -486,7 +488,7 @@ class Logger
   // read/write should be handled. And std::atomic can not be used here because it is not ABI
   // compatible for OpenTelemetry C++ API.
   //
-  mutable uint8_t minimum_severity_{kMaxSeverity};
+  mutable std::atomic<uint8_t> minimum_severity_{kMaxSeverity};
 };
 }  // namespace logs
 OPENTELEMETRY_END_NAMESPACE

api/include/opentelemetry/trace/tracer.h

@@ -4,6 +4,7 @@
 #pragma once
 
 #include <chrono>
+#include <atomic>
 
 #include "opentelemetry/version.h"
 #include "opentelemetry/context/context.h"
@@ -172,7 +173,7 @@ class Tracer
    *
    * @since ABI_VERSION 2
    */
-  bool Enabled() const noexcept { return OPENTELEMETRY_ATOMIC_READ_8(&this->enabled_) != 0; }
+  bool Enabled() const noexcept { return enabled_ != 0; }
 #endif
 
 #if OPENTELEMETRY_ABI_VERSION_NO == 1
@@ -227,17 +228,15 @@ class Tracer
    */
   void UpdateEnabled(const bool enabled) noexcept
   {
-    OPENTELEMETRY_ATOMIC_WRITE_8(&this->enabled_, enabled);
+    enabled_ = enabled;
   }
 #endif
 
 private:
 #if OPENTELEMETRY_ABI_VERSION_NO >= 2
   // Variable to support implementation of Enabled method introduced in ABI V2.
   // Mutable allows enabled_ to be used as 'bool *' (instead of 'const bool *'), with the
-  // OPENTELEMETRY_ATOMIC_READ_8 macro's internal casts when used from a const function.
-  // std::atomic can not be used here because it is not ABI compatible for OpenTelemetry C++ API.
-  mutable bool enabled_ = true;
+  mutable std::atomic<bool> enabled_ = true;
 #endif
 };
 }  // namespace trace