On Thursday 19 May 2005 11:57, Alex LIU wrote: > On May 18, 2005 9:31 PM, Jeff wrote: > >> But P and Q are different threads and they will be scheduled > >> differently,right?
> > No, they're two different ways of looking at the same thread. They're > > scheduled somewhat differently, but that's just reflecting the two ways > > of > looking at it. If it's runnable on the host, it's runnable inside UML, but > not the other way around. > Then how does the UML thread interact with its corresponding host thread in > TT mode? Also use the switch_pipe? > >> And in the function outer_tramp, the thread A see the thread B was > >> stopped with a SIGSTOP signal. Why? Since the thread B is blocked by > >> the signal SIGUSR1... > > The handler calls suspend_new_thread, which stops itself. > Exactly! I'm wrong... > Then I have another question: > In UML function new_thread_handler, the current sigcontext is defined as > following: > UPT_SC(¤t->thread.regs.regs) = (void *) (&sig + 1); > Why? What does "&sig + 1" mean? I think that's because sig is on the stack, and &sig + 1 points to the datas saved by the kernel when entering the signal handler, i.e. the registers of the caller, saved to be restored on return. -- Paolo Giarrusso, aka Blaisorblade Skype user "PaoloGiarrusso" Linux registered user n. 292729 http://www.user-mode-linux.org/~blaisorblade ------------------------------------------------------- This SF.Net email is sponsored by Oracle Space Sweepstakes Want to be the first software developer in space? Enter now for the Oracle Space Sweepstakes! http://ads.osdn.com/?ad_id=7412&alloc_id=16344&op=click _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel
