[Libdlo] Synchronous vs. asynchronous USB

[Steve (Endurance)]

On 26 May, Phil Endecott <spam_from_libdlo at chezphil.org> wrote:
> Steve (Endurance) wrote:
> > It was also specified to be single threaded.
>
> That's important.  Can you explain some more?  I would hope that, for 
> example, a program could talk to two devices using two threads, one per 
> device, if it wanted to.  Adding some notes about thread-safety to the 
> documentation would be a really good idea...

The main point here is that no effort is made by libdlo to deal with any of
the dlo_ API calls being reentered by a thread whilst some other thread is
already in there doing something. So any list structures, buffers, calls
into other libraries (libusb) and so on have no semaphores or other
protection from getting all messed up. This isn't an oversight; it was a
design decision to keep it simple for a single threaded application to drive.

Making libdlo support multithreading isn't too hard a task, it's just
something that hasn't been done.

Steve

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