Forum OpenACS Q&A: Re: AOLserver 4.0 Install instructions
If you have time to investigate further, i would suggest to take out the patch and try to reproduce the bug in a clean-house environment. It seems related to threads with a larger footprint (nobody saw it except openacs applications).
The fact that this helped out somehow (in a big way) is important to know.
I also noticed that NsRuAtReadyProcs() is extern, but it is only defined in nsd.h, not include/ns.h. This means, as I just learned, that it can't be in a module, it has to be compiled into libnsd. Btw, the only place I found any *Procs() called was in nsmain.c.
The registered callback is TriggerDriver, and the use of TriggerDriver has changed. The similar SockTrigger used to be conditional during Sock Close, but now TriggerDriver gets called anytime there is mutex unlock on the driver pointer structure (except in ns_driver query, where it is called inside the mutex). Maybe an important one is the fact that TriggerDriver gets called if, from Tcl, you query the driver! So some new Tcl diagnostic code could unstick the driver thread, maybe like a scheduled proc.