windows 如果我调用 GlobalLock()，然后调用 GlobalUnlock() 失败，会发生什么？
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What happens if I call GlobalLock(), then fail to call GlobalUnlock()?
提问by sharptooth
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().
在 Win32 中，为了将数据粘贴到剪贴板中，我必须调用GlobalAlloc()，然后GlobalLock()获取指针，然后复制数据，然后调用GlobalUnlock()和SetClipboardData()。
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.
如果代码是在 C++ 中，则可能会在对GlobalLock()和 的调用之间引发异常GlobalUnlock()，如果我不注意这GlobalUnlock()将不会被调用。
It this a problem? What exactly happens if I call GlobalLock()and for whatever reason skip a pairing GlobalUnlock()call?
这是一个问题吗？如果我打电话GlobalLock()并出于任何原因跳过配对GlobalUnlock()电话，究竟会发生什么？
回答by Michael Burr
More than you ever wanted to know (really) about GlobalLock(), courtesy of Raymond Chen:
比你想知道的更多（真的）GlobalLock()，由 Raymond Chen 提供：
- What was the difference between LocalAlloc and GlobalAlloc?
- A history of GlobalLock, part 1: The early years
- A history of GlobalLock, part 2: Selectors
- A history of GlobalLock, part 3: Transitioning to Win32
- A history of GlobalLock, part 4: A peek at the implementation
- LocalAlloc 和 GlobalAlloc 之间有什么区别？
- GlobalLock 的历史，第 1 部分：早年
- GlobalLock 的历史，第 2 部分：选择器
- GlobalLock 的历史，第 3 部分：过渡到 Win32
- GlobalLock 的历史，第 4 部分：实现一瞥
I'm marking this community wiki because I actually don't know if these articles answer your question. But they're probably worth wading through, at least for a skim.
我标记这个社区维基是因为我实际上不知道这些文章是否回答了您的问题。但它们可能值得一试，至少可以略读一下。
But one way to handle your problem of dealing with the GlobalUnlock() in the face of exceptions is to use an RAII class to manage the GlobalLock()/GlobalUnlock()calls.
但是，在遇到异常时处理 GlobalUnlock() 问题的一种方法是使用 RAII 类来管理GlobalLock()/GlobalUnlock()调用。
回答by RED SOFT ADAIR
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:
问题不仅仅是关于你是否打电话GlobalUnlock()。您必须调用GlobalUnlock()和GlobalFree()。两者都必须被调用才能释放你分配的内存：
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;
}
The leak would be application wide. When you exit a windows application, all allocated private memory is released automatically
泄漏将应用广泛。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
