如果我调用GlobalLock()而不调用GlobalUnlock()会发生什么?

问题描述

在Win32中，为了将数据粘贴到剪贴板中，我必须调用GlobalAlloc()，然后调用 GlobalLock() 获取指针，然后复制数据，然后调用GlobalUnlock()和SetClipboardData().

In Win32 in order to paste data into the clipboard I have to call GlobalAlloc(), then GlobalLock() to obtain a pointer, then copy data, then call GlobalUnlock() and SetClipboardData().

如果代码是C ++，则在调用GlobalLock()和GlobalUnlock()之间可能会引发异常，并且如果我不注意，则不会调用GlobalUnlock().

If the code is in C++ an exception might be thrown between calls to GlobalLock() and GlobalUnlock() and if I don't take care of this GlobalUnlock() will not be called.

这是一个问题吗?如果我拨打GlobalLock()并出于任何原因跳过配对GlobalUnlock()通话，究竟会发生什么?

It this a problem? What exactly happens if I call GlobalLock() and for whatever reason skip a pairing GlobalUnlock() call?

推荐答案

问题不仅与是否呼叫GlobalUnlock()有关.您必须调用GlobalUnlock()和GlobalFree().必须同时调用这两个函数才能释放您分配的内存:

The Question is not only about if or if not you call GlobalUnlock(). You must call GlobalUnlock() and GlobalFree(). Both must be called in order to release the memory you allocated:

HGLOBAL hdl = NULL;
void *ptr = NULL

  try {
    hdl = GlobalAlloc();
    ptr = GlobalLock(hdl);

    // etc...
    GlobalUnlock(hdl);
    ptr = NULL;
    SetClipboardData(..., hdl );
  }
  catch (...) {
    if(ptr)
        GlobalUnlock(hdl);
    if(hdl)
        GlobalFree(hdl);
    throw;
  }

泄漏将在整个应用程序范围内发生.当您退出Windows应用程序时，所有分配的私有内存都会自动释放

The leak would be application wide. When you exit a windows application, all allocated private memory is released automatically

这篇关于如果我调用GlobalLock()而不调用GlobalUnlock()会发生什么?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！