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>
Even though currently we are freeing the pool of worker threads at the
daemon very end, nothing holds us back in joining the worker threads.
Moreover, we avoid leaks like this:
==26697== 1,680 bytes in 5 blocks are possibly lost in loss record 913 of 942
==26697== at 0x4C2BDE4: calloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==26697== by 0x4011131: allocate_dtv (in /lib64/ld-2.16.so)
==26697== by 0x401176D: _dl_allocate_tls (in /lib64/ld-2.16.so)
==26697== by 0x8499602: pthread_create@@GLIBC_2.2.5 (in /lib64/libpthread-2.16.so)
==26697== by 0x52F53E9: virThreadCreate (virthreadpthread.c:188)
==26697== by 0x52F5D4F: virThreadPoolNew (virthreadpool.c:221)
==26697== by 0x53F30DB: virNetServerNew (virnetserver.c:377)
==26697== by 0x11C6ED: main (libvirtd.c:1366)
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
