External/libvirt
1
0
Fork 0
mirror of https://gitlab.com/libvirt/libvirt.git synced 2025-01-11 23:37:42 +00:00
Code Issues Packages Projects Releases Wiki Activity

virThreadPoolFree: Set n(Prio)Workers after the pool is locked

Browse Source 
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@redhat.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This commit is contained in:
Michal Privoznik 2013-12-05 14:39:52 +01:00
parent 90f9ccb4f2
commit e925aad324
1 changed files with 4 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/util/virthreadpool.c
View File

@ -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);