Re: STDIN, STDOUT and pipes

On 01/08/2008, at 9:04 AM, Larry Ducie wrote:

IMHO user spaces suck, but may be a good choice for this. But, if I want to store the data in a permanent object I'd put it in a stream file. If I want a buffer I can write to I'd use a pointer. I did some pretty extensive bench tests on user spaces vs pointers approx 3 years ago on three different iSeries configurations and in all cases the pointer was between 10 and 100 times faster. The auto- extend capability of a user space does, however, give it an advantage. But I'd rather code for the allocate/reallocate of a pointer than consider a user space.

There is no real difference between *USRSPC storage and allocated storage (other than the permanence of the *USRSPC).

If you're using the QUSCHGUS and QUSRTVUS APIs then I can believe they'll be slower than direct pointer access to storage however you can get a pointer to the user space and then it's just as fast as your allocated storage method.

If you see significantly slower access times using a pointer to a user space than using a pointer to allocated storage then I'd like to see your test code.

Regards,
Simon Coulter.
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