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Date: Wed, 12 Mar 2008 07:59:56 -0700
From: Brian Dessent <brian AT dessent DOT net>
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Subject: Re: Bug: C-prog from Win dies in fork; gdb.exe also won't run
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Dave Korn wrote:

>   The native API, to the very best of my knowledge, exports exactly the same
> set of interfaces to every subsystem.  Can you explain exactly what you're
> talking about here?

Microsoft Windows Internals, 4th. Ed (Russinovich & Solomon), p. 60:

> Because POSIX.1 compliance was a mandatory goal for Windows, the 
> operating system was designed to ensure that the required base system 
> support was present to allow for the implementation of a POSIX.1 
> subsystem (such as the fork function, which is implemented in the 
> Windows executive, and the support for hard file links in the Windows 
> file system).

p.394:

> The POSIX subsystem takes advantage of copy-on-write to implement the 
> fork function. Typically, when a UNIX application calls the fork 
> function to create another process, the first thing that the new process 
> does is call the exec function to reinitialize the address space with an 
> executable program. Instead of copying the entire address space on fork, 
> the new process shares the pages in the parent process by marking them 
> copy-on-write.

Brian

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