Added a method to the server object that lets a user set the graceful close

timeout time to something other than the default of 500ms.

dlib/server/server_kernel.cpp

@@ -21,7 +21,8 @@ namespace dlib
         thread_count(0),
         thread_count_signaler(thread_count_mutex),
         max_connections(1000),
-        thread_count_zero(thread_count_mutex)
+        thread_count_zero(thread_count_mutex),
+        graceful_close_timeout(500)
     {
     }
 
@@ -36,6 +37,28 @@ namespace dlib
 
 // ----------------------------------------------------------------------------------------
 
+    unsigned long server::
+    get_graceful_close_timeout (
+    ) const
+    {
+        auto_mutex lock(max_connections_mutex);
+        return graceful_close_timeout;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+    void server::
+    set_graceful_close_timeout (
+        unsigned long timeout
+    ) 
+    {
+        auto_mutex lock(max_connections_mutex);
+        graceful_close_timeout = timeout;
+    }
+
+// ----------------------------------------------------------------------------------------
+
+
     int server::
     get_max_connections (
     ) const
@@ -85,6 +108,7 @@ namespace dlib
         listening_ip = "";        
         listening_port = 0;
         max_connections = 1000;
+        graceful_close_timeout = 500;
         listening_port_mutex.unlock();
         listening_ip_mutex.unlock();
         max_connections_mutex.unlock();
@@ -185,6 +209,7 @@ namespace dlib
                 listening_ip = "";        
                 listening_port = 0;
                 max_connections = 1000;
+                graceful_close_timeout = 500;
                 listening_port_mutex.unlock();
                 listening_ip_mutex.unlock();
                 max_connections_mutex.unlock();
@@ -304,7 +329,7 @@ namespace dlib
             try{cons.add(client_temp);}
             catch(...)
             { 
-                sock.reset();;
+                sock.reset();
                 delete client;
                 cons_mutex.unlock();
 
@@ -326,7 +351,8 @@ namespace dlib
             try{
             temp = new param (
                             *this,
-                            *client
+                            *client,
+                            get_graceful_close_timeout() 
                             );
             } catch (...) 
             {
@@ -545,10 +571,11 @@ namespace dlib
         connection* temp;
         if (p.the_server.cons.is_member(&p.new_connection))
             p.the_server.cons.remove(&p.new_connection,temp);
-        try{ close_gracefully(&p.new_connection); } 
-        catch (...) { sdlog << LERROR << "close_gracefully() threw"; } 
         p.the_server.cons_mutex.unlock();
 
+        try{ close_gracefully(&p.new_connection, p.graceful_close_timeout); } 
+        catch (...) { sdlog << LERROR << "close_gracefully() threw"; } 
+
         // decrement the thread count and signal if it is now zero
         p.the_server.thread_count_mutex.lock();
         --p.the_server.thread_count;

dlib/server/server_kernel.h

@@ -45,7 +45,8 @@ namespace dlib
                 thread_count_signaler   == a signaler associated with thread_count_mutex
                 thread_count_zero       == a signaler associated with thread_count_mutex
                 max_connections         == 1000 
-                max_connections_mutex   == a mutex for max_connections
+                max_connections_mutex   == a mutex for max_connections and graceful_close_timeout
+                graceful_close_timeout  == 500 
              
             CONVENTION
                 listening_port          == get_listening_port()
@@ -85,14 +86,17 @@ namespace dlib
         {
             param (
                 server& server_,
-                connection& new_connection_
+                connection& new_connection_,
+                unsigned long graceful_close_timeout_
             ) :
                 the_server(server_),
-                new_connection(new_connection_)
+                new_connection(new_connection_),
+                graceful_close_timeout(graceful_close_timeout_)
             {}
 
             server& the_server;
             connection& new_connection;
+            unsigned long graceful_close_timeout; 
         };
         
 
@@ -146,6 +150,13 @@ namespace dlib
             void start_async (
             );
 
+            void set_graceful_close_timeout (
+                unsigned long timeout
+            );
+
+            unsigned long get_graceful_close_timeout (
+            ) const;
+
         private:
 
             void start_async_helper (
@@ -200,6 +211,7 @@ namespace dlib
             signaler thread_count_zero;
             scoped_ptr<thread_function> async_start_thread;
             scoped_ptr<listener> sock;
+            unsigned long graceful_close_timeout;
 
 
             // restricted functions

dlib/server/server_kernel_abstract.h

@@ -15,10 +15,11 @@ namespace dlib
 
         /*!
             INITIAL VALUE
-                get_listening_ip()      == ""
-                get_listening_port()    == 0
-                is_running()            == false
-                get_max_connections()   == 1000
+                get_listening_ip()           == ""
+                get_listening_port()         == 0
+                is_running()                 == false
+                get_max_connections()        == 1000
+                get_graceful_close_timeout() == 500 
 
 
             CALLBACK FUNCTIONS
@@ -242,6 +243,28 @@ namespace dlib
                     - std::bad_alloc
             !*/
     
+            void set_graceful_close_timeout (
+                unsigned long timeout
+            );
+            /*!
+                ensures
+                    - #get_graceful_close_timeout() == timeout
+            !*/
+
+            unsigned long get_graceful_close_timeout (
+            ) const;
+            /*!
+                ensures
+                    - When on_connect() terminates, it will close the connection using
+                      close_gracefully().  This is done so that any data still in the
+                      operating system's output buffers gets a chance to be properly
+                      transmitted to the remote host.  Part of this involves waiting for
+                      the remote host to close their end of the connection.  Therefore,
+                      get_graceful_close_timeout() returns the timeout, in milliseconds,
+                      that we wait for the remote host to close their end of the
+                      connection.  This is the timeout value given to close_gracefully().
+            !*/
+
         private:
 
             virtual void on_connect (