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Re: USB Overlapped IO general question

Yes, you can do several reads. The completion routines will be called in the order that they complete (which is the order that they were requested).

This is the best way to utilize all the bandwidth available on the USB bus.

David Ferguson
USB Software Team
Apple Computer

At 1:24 PM -0500 12/21/05, Ron Duritsch wrote: 
We have written code for PCI and firewire that will issue several data read
requests at a time, not waiting to get a reply from the first read before we
request the second read. There are several reasons for this, some having to
do with how the camera itself operates it's FIFO.

So my questions is, is this achievable with user space USB 2.0 code on OS X?
I've seen some sample code that does an asynchronous read, then in it's
callback routine issues the next read. But can I issue several reads before
I receive the callback from the first read?

Ron Duritsch
Diagnostic Instruments, Inc.

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