Linux Firefox ESR 17.0.9 appers to spin-wait rather than block-wait on SOCKS
Per the summary, Linux Firefox 17.0.9 as include in TBB x86_64 2.3.25-13 appears to poll-wait rather than block-wait on SOCKS requests. Observed this when attempting to access an unresponsive site, in this case core.onion.
The spin caused the VM to largely lock-up, badly enough that the kernel reported 120 second non-responsive "hung-tasks" on several threads including 'tor'. However this particular aspect may be largely a result of running in a single VCPU KVM instance.
See Firefox using all CPU in 'top' when this happens. Behaves a little better when 'renice -n10' is used to lower FF's priority.
Seems to me the behavior should be to block-wait and that other Firefox windows should remain responsive while one window is blocked waiting for a reply that will never arrive.
Have set 'tor' threads to run realtime priority, RR class at -27 per 'top', which might affect the behavior here, though it really shouldn't matter.