thread pool: handle exceptions starting threads

src/thread_pool.cpp

@@ -65,6 +65,7 @@ ThreadPool::run(std::function<void()>&& cb)
 
     // launch new thread if necessary
     if (not readyThreads_ && threads_.size() < maxThreads_) {
+        try {
             threads_.emplace_back(std::make_unique<std::thread>([this]() {
                 while (true) {
                     std::function<void()> task;
@@ -92,6 +93,11 @@ ThreadPool::run(std::function<void()>&& cb)
                     }
                 }
             }));
+        } catch(const std::exception& e) {
+            std::cerr << "Exception starting thread: " << e.what() << std::endl;
+            if (threads_.empty())
+                throw;
+        }
     }
 
     // push task to queue