以下文字摘自"Windows Internals Fifth Edition "
An object handle is an index into a process-specific handle table, pointed to by the executive
process (EPROCESS) block (described in Chapter 5). The first handle index is 4, the second
8, and so on. A process’s handle table contains pointers to all the objects that the process
has opened a handle to. Handle tables are implemented as a three-level scheme, similar
to the way that the x86 memory management unit implements virtual-to-physical address
152 Windows Internals, Fifth Edition
translation, giving a maximum of more than
16,000,000 handles per process
The test program Testlimit from Sysinternals has an option to open handles to an object
until it cannot open any more handles. You can use this to see how many handles can
be created in a single process on your system. Because handle tables are allocated from
paged pool, you might run out of paged pool before you hit the maximum number of
handles that can be created in a single process. To see how many handles you can create
on your system, follow these steps:
1. Download the Testlimit .zip file from www.microsoft.com/technet/ sysinternals, and
unzip it into a directory.
Run Process Explorer, and then click View and then System Information. Notice
the current and maximum size of paged pool. (To display the maximum pool size
values, Process Explorer must be configured properly to access the symbols for
the kernel image, Ntoskrnl.exe.) Leave this system information display running so
that you can see pool utilization when you run the Testlimit program.
3. Open a command prompt.
4. Run the Testlimit program with the -h switch (do this by typing testlimit –h).
When Testlimit fails to open a new handle, it will display the total number of
handles it was able to create. If the number is less than approximately 16 million,
you are probably running out of paged pool before hitting the theoretical perprocess
handle limit.
5. Close the Command Prompt window; doing this will kill the Testlimit process, thus
closing all the open handles.