On Thu, 5 Apr 2007, Jon Steel wrote:

quoted text
> Hi
> 
> Ive found a way to freeze a program when using rThreads and using a
> function pointer back to one of the threads from within a shared
> library. The higher the level of interrupts on the system, the more
> frequently the problem occurs. The problem can be duplicated as follows:
> 
> 1. Create a child rThread
> 2. Pass a function pointer to a shared library
> 3. Get the shared library to call the function pointer
> 
> The program will now lockup, and you must kill -9 it. I originally found
> this in pcap, inside pcap_loop when it tries to call the callback
> function. I have attached a very small project and shared library that
> will reproduce the problem.
> 
> Just run
> 
> ./configure
> ./make
> 
> Then generate a lot of interrupts somehow. I do this by running
> 
> iperf -us   // on the test machine
> iperf -uc xxx.xxx.xxx.xxx -b 500000000 -t 9999 // on some other machine
> 
> Then if you run "./callback 1" and try and kill it with Ctrl-C, it
> should freeze. It may take a few tries though. It usually happens for me
> within 3 or 4 tries if I run iperf really fast. If you run "./callback"
> then it wont lockup. The only difference is that when you pass in the 1,
> it creates the child thread.
> 
> Id like to try this on current but I cant get rThreads compiled for it.
> 
> Does anybody have any insight, or could they test it out on current?

See http://marc.info/?l=openbsd-misc&m=113991745810561&w=2
Behind the scene some works is going on to solve this. 

	-Otto