Moved flush call to logger::_log_msg() function.

include/spdlog/details/line_logger_impl.h

@@ -46,11 +46,6 @@ inline spdlog::details::line_logger::~line_logger()
 #endif
         _callback_logger->_log_msg(_log_msg);
     }
-
-    if (_log_msg.level >= _callback_logger->_flush_level)
-    {
-        _callback_logger->flush();
-    }
 }
 
 //

include/spdlog/details/logger_impl.h

@@ -290,6 +290,10 @@ inline void spdlog::logger::_log_msg(details::log_msg& msg)
     _formatter->format(msg);
     for (auto &sink : _sinks)
         sink->log(msg);
+
+    const auto flush_level = _flush_level.load(std::memory_order_relaxed);
+    if (msg.level >= flush_level)
+        flush();
 }
 
 inline void spdlog::logger::_set_pattern(const std::string& pattern)