fix tear-down of worker

lib/src/common/thread_pool.cc

@@ -19,9 +19,10 @@
  *
  */
 
+#include "srslte/common/thread_pool.h"
 #include <assert.h>
+#include <chrono>
 #include <stdio.h>
-#include "srslte/common/thread_pool.h"
 
 #define DEBUG 0
 #define debug_thread(fmt, ...) do { if(DEBUG) printf(fmt, __VA_ARGS__); } while(0)
@@ -311,7 +312,6 @@ void task_thread_pool::stop()
 {
   std::unique_lock<std::mutex> lock(queue_mutex);
   running             = false;
-  do {
   nof_workers_running = 0;
   // next worker that is still running
   for (worker_t& w : workers) {
@@ -323,9 +323,10 @@ void task_thread_pool::stop()
     lock.unlock();
     cv_empty.notify_all();
     lock.lock();
+    while (nof_workers_running > 0) {
       cv_exit.wait(lock);
     }
-  } while (nof_workers_running > 0);
+  }
 }
 
 void task_thread_pool::push_task(const task_t& task)