>> both mmcache and apc does not have "crash recover" > > The concept of a crash recover is somewhat flawed in my opinion. The only > way to really do this is to catch SIGSEGV, SIGBUS and other such fatal > signals and twiddle a knob somewhere in shared memory that tells other > processes to flush the cache. The problem with doing this is that once > you get a SEGV, it really isn't safe to do anything like that. You run a > very serious risk of ending up in an infinite crash loop where you catch
> the crash, try to set the crash-recover flag, crash trying to do that, > catch the crash, etc. > > -Rasmus > without crash recover, corrupted share mem will trigger the crash too in another process. sorry for my low experience on C and sharemem but IMHO, it not that hard it easy to make a reset_flag at top or bottom of sharemem flag is just an int, not pointer it won't crash unless the sharemem is unavailable, or the pointer to the share mem is corrupted, maybe possible? after all we can reset the signalhandler when we're going to operate on the flag remember to log something when share mem is going to reset(no matter can or cannot obtain write lock to reset)
