Thread Local Storage
All threads of a process share its virtual address space. The local variables of a function are unique to each thread that runs the function. However, the static and global variables are shared by all threads in the process. With thread local storage (TLS), you can provide unique data for each thread that the process can access using a global index. One thread allocates the index, which can be used by the other threads to retrieve the unique data associated with the index.
The constant TLS_MINIMUM_AVAILABLE defines the minimum number of TLS indexes available in each process. This minimum is guaranteed to be at least 64 for all systems. The limits are as follows:
System Limit
Windows Server 2003, Windows XP, and Windows 2000 1088 indexes per process
Windows Me/98 80 indexes per process
Windows NT and Windows 95 64 indexes per process
但是，注意看第2句，好像又是nt系列特有的？
6.7. The .tls Section
The .tls section provides direct PE/COFF support for static Thread Local Storage (TLS). TLS is a special storage class supported by Windows NT, in which a data object is not an automatic (stack) variable, yet it is local to each individual thread that runs the code. Thus, each thread can maintain a different value for a variable declared using TLS.
good!
