不會自動釋放的。

需要WSACleanup來對應WSAStartup，請看MSDN中這段說明：

An application must call one WSACleanup call for every successful

WSAStartup call to allow third-party DLLs to make use of a Ws2_32.dll on

behalf of an application. This means, for example, that if an application calls

WSAStartup three times, it must call WSACleanup three times. The

first two calls to WSACleanup do nothing except decrement an internal

counter; the final WSACleanup call for the task does all necessary

resource deallocation for the task.