1. 关于heap类型
From http://msdn.microsoft.com/en-us/library/wc28wkas%28v=vs.80%29.aspx
有如下几种heap block： _NORMAL_BLOCK, _CLIENT_BLOCK, _FREE_BLOCK,
关于不同heap block区别 http://msdn.microsoft.com/en-us/library/htdyz80k%28v=vs.80%29.aspx
A normal block is ordinary memory allocated by your program. A client block is a special type of memory block used by MFC programs for objects that require a destructor. The MFC new operation creates either a normal block or a client block, as appropriate for the object being created. A CRT block is a block of memory allocated by the CRT library for its own use. The CRT library handles the deallocation for these blocks, so it is unlikely you will see these in the memory leak report unless something is seriously wrong (for example, the CRT library is corrupted). A free block is a block of memory that has been released. An ignore block is a block that you have specifically marked so it doesn't appear in the memory leak report.