Fri, 14 Feb 2003 20:45:13 GMT
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> (message from Laurent
Pautet on Fri, 14 Feb 2003 10:13:03 +0100)
On 13/02, james hopper wrote:
| Both os x and linux. what i was doing was passing real time radar
| images from our sim code on the server to the display app on another
| computer. the difference was quite dramatic. i could get 60 hz with
| AdaSockets, but only about 10hz with gnat sockets. i was in a bit of
| a rush and never really went into what was causing the difference.
I compared transferring 1024 bytes in a round-trip using UDP over a
quiet 100BT switched LAN between two PowerPC cards running VxWorks.
The stack was out of the box, no tuning.
GNAT (3.15a1) Sockets: 1050 us
C: 1008 us
Not surprising really, no buffering in this case and the GNAT code is
a pretty thin skin over the OS.
What was fun was working out why the C compiler wouldn't accept the
asm() statement to read the timebase register; I didn't spot the -ansi
in the Tornado command line that means you have to say
__asm__(). Foo. Much less grief with GNAT.