USB bulk read & pthreads

[Jay Cornwall]

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Hi

I've been trying (unsuccessfully) to make the thread-based pppoa3 program 
(from http://speedtouch.sf.net/) able to work correctly under FreeBSD. Near 
identical code works fine under Linux, but the threading doesn't work at all 
in FreeBSD.

The problem seems to be a result of reading from a USB endpoint file 
descriptor, which invokes tsleep() within the kernel 
(/sys/dev/usb/usbdi_util.c:432) while it waits for data to read. This has the 
effect of blocking the whole process, rather than just the thread which 
called the read.

I'm sure there are good reasons for implementing it in this way, but I'd be 
interested to hear what they are, and if any alternative approaches had 
been/are being considered.

Forgive my lack of knowledge with the FreeBSD kernel, I've only been using it 
for a couple of weeks. :(

Cheers,
Jay

- -- 
http://www.evilrealms.net/ - Systems Administrator & Developer
http://www.ic.ac.uk/ - Imperial College, 2nd year CS student
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