Re: [libvirt] [PATCH 01/11] Introduce qemuDomainObjExitMonitorAlive

On Wed, Dec 17, 2014 at 01:18:41PM +0100, Michal Privoznik wrote: > On 16.12.2014 17:41, Ján Tomko wrote: >> The domain might disappear during the time in monitor when >> the virDomainObjPtr is unlocked, so the caller needs to check >> if it's still alive. >> >> Introduce a helper function for the callers that want to report >> an error in this case. >> --- >> src/qemu/qemu_domain.c | 17 +++++++++++++++++ >> src/qemu/qemu_domain.h | 3 +++ >> 2 files changed, 20 insertions(+) >> >> diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c >> index 8dd427a..d074429 100644 >> --- a/src/qemu/qemu_domain.c >> +++ b/src/qemu/qemu_domain.c >> @@ -1606,6 +1606,23 @@ void qemuDomainObjExitMonitor(virQEMUDriverPtr driver, >> qemuDomainObjExitMonitorInternal(driver, obj); >> } >> >> +/* obj must NOT be locked before calling >> + * >> + * Same as qemuDomainObjExitMonitor, but reports an error and >> + * returns -1 if the domain is no longer alive after exiting the monitor > > Can you state explicitly that this function needs to be called whenever the > domain object or vm->def, or privdata (any runtime info held within vm in > general) is used after ExitMonitor()?

Are there any cases where that is not true ? eg could we just avoid introducing this new function, by making the existing funtion check liveliness every time. That would avoid the class of bugs you outline above entirely.