Optimize Stream close flag

It is more efficient to use atomic bool instead of
an ordinary boolean with mutex [0]

[0] https://stackoverflow.com/questions/15056237/which-is-more-efficient-basic-mutex-lock-or-atomic-integer

include/ert/http2comm/Stream.hpp

@@ -40,6 +40,7 @@ SOFTWARE.
 #pragma once
 
 #include <mutex>
+#include <atomic>
 #include <sstream>
 #include <memory>
 #include <chrono>
@@ -80,7 +81,7 @@ class Stream : public std::enable_shared_from_this<Stream>
     const nghttp2::asio_http2::server::response& res_;
     std::shared_ptr<std::stringstream> request_;
     Http2Server *server_;
-    bool closed_;
+    std::shared_ptr<std::atomic_bool> closed_;
     std::chrono::microseconds reception_us_{}; // timestamp in microsecods
 
     // Completes the nghttp2 transaction (res.end())
@@ -96,8 +97,9 @@ class Stream : public std::enable_shared_from_this<Stream>
            Http2Server *server) : req_(req),
         res_(res),
         request_(request),
-        server_(server),
-        closed_(false) {}
+        server_(server) {
+        closed_ = std::make_shared<std::atomic_bool> (false);
+    }
     Stream(const Stream&) = delete;
     ~Stream() = default;
     Stream& operator=(const Stream&) = delete;

src/Stream.cpp

@@ -181,7 +181,7 @@ void Stream::commit(unsigned int statusCode,
         self->res_.io_service().post([self, statusCode, headers, responseBody]()
         {
             std::lock_guard<std::mutex> lg(self->mutex_);
-            if (self->closed_)
+            if (self->closed_->load())
             {
                 return;
             }
@@ -197,8 +197,7 @@ void Stream::commit(unsigned int statusCode,
 
 void Stream::close()
 {
-    std::lock_guard<std::mutex> guard(mutex_);
-    closed_ = true;
+    closed_->store(true);
 }
 
 }