[MLton-user] strange runtime error with mlton + cygwin

[Matthew Fluet]

On Tue, 6 May 2008, Sami Evangelista wrote:
> i have some problems running a program compiled with mlton.
> this one (sometimes) crash outputting the following error:
>
> CreateFile failed with error 80

It seems that that error message arises from the portion of the runtime 
that attempts to page the heap to disk in order to allocate a larger heap. 
(<src>/runtime/platform/windows.c in the MLton sources.)

Looking at microsoft docs, it seems that error 80 is 'the file exists', 
which shouldn't happen, as a unique temporary file name is generated.

Running your program with '@MLton use-mmap --' will instruct the runtime 
to use Cygwin's emulation of mmap, rather than directly using Win32 memory 
management functions.  Sometimes that behaves better; in particular, may 
succeed in allocating larger heaps without paging the current heap.

There are list readers with more experience with the Cygwin port, and 
perhaps they can offer other insight.