Re: [PATCH] Enable index-pack threading in msysgit.

Am 20.03.2014 02:25, schrieb Duy Nguyen:

On Thu, Mar 20, 2014 at 4:35 AM, Stefan Zager [off-list ref] wrote:

quoted

This adds a Windows implementation of pread.  Note that it is NOT
safe to intersperse calls to read() and pread() on a file
descriptor.  According to the ReadFile spec, using the 'overlapped'
argument should not affect the implicit position pointer of the
descriptor.  Experiments have shown that this is, in fact, a lie.

To accomodate that fact, this change also incorporates:

http://article.gmane.org/gmane.comp.version-control.git/196042

... which gives each index-pack thread its own file descriptor.

If the problem is mixing read() and pread() then perhaps it's enough to do

output_fd = dup(output_fd);

Unfortunately not, dup() / DuplicateHandle() just opens another handle to the same file object (i.e. sharing the same file position).