Add threaded resolv service.

profiler/src/ResolvService.cpp

@@ -0,0 +1,55 @@
+#ifdef _MSC_VER
+#  include <ws2tcpip.h>
+#else
+#  include <arpa/inet.h>
+#  include <sys/socket.h>
+#  include <netdb.h>
+#endif
+
+#include "ResolvService.hpp"
+
+ResolvService::ResolvService()
+    : m_exit( false )
+    , m_thread( [this] { Worker(); } )
+{
+}
+
+ResolvService::~ResolvService()
+{
+    m_exit.store( true, std::memory_order_relaxed );
+    m_cv.notify_one();
+    m_thread.join();
+}
+
+void ResolvService::Query( uint32_t ip, const std::function<void(std::string&&)>& callback )
+{
+    std::lock_guard<std::mutex> lock( m_lock );
+    m_queue.emplace_back( QueueItem { ip, callback } );
+    m_cv.notify_one();
+}
+
+void ResolvService::Worker()
+{
+    struct sockaddr_in addr = {};
+    addr.sin_family = AF_INET;
+    addr.sin_port = 8086;
+
+    char buf[128];
+
+    for(;;)
+    {
+        std::unique_lock<std::mutex> lock( m_lock );
+        m_cv.wait( lock, [this] { return !m_queue.empty() || m_exit.load( std::memory_order_relaxed ); } );
+        if( m_exit.load( std::memory_order_relaxed ) ) return;
+        auto query = m_queue.back();
+        m_queue.pop_back();
+        lock.unlock();
+
+        addr.sin_addr.s_addr = query.ip;
+        if( getnameinfo( (const struct sockaddr*)&addr, sizeof( sockaddr_in ), buf, 128, nullptr, 0, NI_NOFQDN ) != 0 )
+        {
+            inet_ntop( AF_INET, &query.ip, buf, 17 );
+        }
+        query.callback( buf );
+    }
+}