On Thu, Dec 05, 2013 at 02:54:41PM +0100, Michal Privoznik wrote: > In 78839da I am trying to join the worker threads. However, I can't > sipmly reuse pool->nWorkers (same applies for pool->nPrioWorkers), > because of the following flow that is currently implemented: > > 1) the main thread executing virThreadPoolFree sets pool->quit = true, > wakes up all the workers and wait on pool->quit_cond. > > 2) A worker is woken up and see quit request. It immediately jumps of > the while() loop and decrements pool->nWorkers (or pool->nPrioWorkers in > case of priority worker). The last thread signalizes pool->quit_cond. > > 3) Main thread is woken up, with both pool->nWorkers and > pool->nPrioWorkers being zero. > > So there's a need to copy the original value of worker thread counts > into local variables. However, these need to set *after* the check for > pool being NULL (dereferencing a NULL is no no). And for safety they can > be set right after the pool is locked. > > Reported-by: John Ferlan <jferlan@xxxxxxxxxx> > Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx> > --- > src/util/virthreadpool.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/src/util/virthreadpool.c b/src/util/virthreadpool.c > index 99f36ec..aa442d1 100644 > --- a/src/util/virthreadpool.c > +++ b/src/util/virthreadpool.c > @@ -242,13 +242,15 @@ void virThreadPoolFree(virThreadPoolPtr pool) > virThreadPoolJobPtr job; > bool priority = false; > size_t i; > - size_t nWorkers = pool->nWorkers; > - size_t nPrioWorkers = pool->nPrioWorkers; > + size_t nWorkers; > + size_t nPrioWorkers; > > if (!pool) > return; > > virMutexLock(&pool->mutex); > + nWorkers = pool->nWorkers; > + nPrioWorkers = pool->nPrioWorkers; > pool->quit = true; > if (pool->nWorkers > 0) > virCondBroadcast(&pool->cond); ACK Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list