threadpool: lock mutex in create

In some contrived case, it might theoretically be the case that
destroy is called from another thread, which would modify the
threads array from two threads.

Coverity 208372

1 files changed, 1 insertions, 0 deletions

diff --git a/src/common/threadpool.cpp b/src/common/threadpool.cpp
index 18204eeee..753bf238c 100644
--- a/src/common/threadpool.cpp
+++ b/src/common/threadpool.cpp
@@ -71,6 +71,7 @@ void threadpool::recycle() {
 }
 
 void threadpool::create(unsigned int max_threads) {
+  const boost::unique_lock<boost::mutex> lock(mutex);
   boost::thread::attributes attrs;
   attrs.set_stack_size(THREAD_STACK_SIZE);
   max = max_threads ? max_threads : tools::get_max_concurrency();