Re: GNAT/Ada95 Streams Performance Issue

[Larry Hazel <lhhazel@otelco.net>]

Robert Dewar wrote:
> Larry Hazel <lhhazel@otelco.net> wrote in message news:<3D585F63.6010205@otelco.net>...
> 
> 
>>Somewhere around 1990, I wrote a simple file copy program 
>>using Sequential_IO on 
>>files of bytes.
> 
> 
> Note that there is no portable way of doing this in either
> Ada 83 or Ada 95. In practice, instantiating SIO for type
> Character would probably work.
> 
> 
>>This was using the Verdix Ada 83 compiler on a Sun.  I 
>>did this as a test  because C people kept telling me how 
>>slow Ada was.  I wanted to see for myself. 
>>It was consistently faster than the unix cp command.
> 
> 
> Hard to believe, and if true, simply a comment on a truly
> appalling implementation of cp.
> 
> 
>>I suspect there was a 
>>lot of buffering going on behind the scenes.
> 
> 
> That's not enough to account for this surprising result!

Robert,
After reading your reply and trying to remember what I did, I think the byte SIO 
  program was the first attempt and not very fast.  I vaguely remember doing 
something with direct io and large arrays of bytes for the program that was 
faster than cp.
Larry