Move pending futures count's ownership to Command.

This is to make the count global across batches created from
the same Command.

src/backends/redis/batch.cpp

@@ -113,24 +113,24 @@ namespace redis {
 	} //unnamed namespace
 
 	struct Batch::LocalData {
-		LocalData ( void ) :
+		explicit LocalData ( std::atomic_size_t& parPendingFutures ) :
 			free_cmd_slot(),
 			futures_mutex(),
-			pending_futures(0)
+			pending_futures(parPendingFutures)
 		{
 		}
 
 		std::condition_variable free_cmd_slot;
 		std::mutex futures_mutex;
-		std::atomic_size_t pending_futures;
+		std::atomic_size_t& pending_futures;
 	};
 
 	Batch::Batch (Batch&&) = default;
 
-	Batch::Batch (AsyncConnection* parConn) :
+	Batch::Batch (AsyncConnection* parConn, std::atomic_size_t& parPendingFutures) :
 		m_futures(),
 		m_replies(),
-		m_local_data(new LocalData),
+		m_local_data(new LocalData(parPendingFutures)),
 		m_async_conn(parConn)
 	{
 		assert(m_async_conn);

src/backends/redis/batch.hpp

@@ -54,7 +54,7 @@ namespace redis {
 	private:
 		struct LocalData;
 
-		explicit Batch ( AsyncConnection* parConn );
+		explicit Batch ( AsyncConnection* parConn, std::atomic<std::size_t>& parPendingFutures );
 		void run_pvt ( int parArgc, const char** parArgv, std::size_t* parLengths );
 
 		std::vector<std::future<Reply>> m_futures;

src/backends/redis/command.cpp

@@ -23,6 +23,7 @@
 #include <cassert>
 #include <algorithm>
 #include <stdexcept>
+#include <atomic>
 
 //See docs directory for info about hiredis/libev with multithreading
 
@@ -33,12 +34,14 @@ namespace redis {
 	struct Command::LocalData {
 		explicit LocalData (Command* parCommand, std::string&& parAddress, uint16_t parPort) :
 			async_connection(std::move(parAddress), parPort),
-			lua_scripts(parCommand)
+			lua_scripts(parCommand),
+			pending_futures(0)
 		{
 		}
 
 		AsyncConnection async_connection;
 		ScriptManager lua_scripts;
+		std::atomic_size_t pending_futures;
 	};
 
 	Command::Command (std::string&& parAddress, uint16_t parPort) :
@@ -79,7 +82,7 @@ namespace redis {
 
 	Batch Command::make_batch() {
 		assert(is_connected());
-		return Batch(&m_local_data->async_connection);
+		return Batch(&m_local_data->async_connection, m_local_data->pending_futures);
 	}
 
 	Script Command::make_script (const std::string &parScript) {