adt lib additions - add the ability to perform timedwait for popping from a blocking queue

lib/include/srslte/adt/circular_buffer.h

@@ -189,7 +189,6 @@ public:
   base_blocking_queue(PushingFunc push_func_, PoppingFunc pop_func_, Args&&... args) :
     circ_buffer(std::forward<Args>(args)...), push_func(push_func_), pop_func(pop_func_)
   {}
-  ~base_blocking_queue() { stop(); }
 
   void stop()
   {
@@ -220,6 +219,7 @@ public:
     pop_(obj, true);
     return obj;
   }
+  bool pop_wait_for(T& obj, const std::chrono::microseconds& duration) { return pop_(obj, true, &duration); }
   void clear()
   {
     std::lock_guard<std::mutex> lock(mutex);
@@ -273,6 +273,8 @@ protected:
   PoppingFunc             pop_func;
   CircBuffer              circ_buffer;
 
+  ~base_blocking_queue() { stop(); }
+
   bool push_(const T& t, bool block_mode)
   {
     std::unique_lock<std::mutex> lock(mutex);
@@ -324,7 +326,7 @@ protected:
     return {};
   }
 
-  bool pop_(T& obj, bool block)
+  bool pop_(T& obj, bool block, const std::chrono::microseconds* duration = nullptr)
   {
     std::unique_lock<std::mutex> lock(mutex);
     if (not active) {
@@ -335,11 +337,14 @@ protected:
         return false;
       }
       nof_waiting++;
-      while (circ_buffer.empty() and active) {
-        cvar_empty.wait(lock);
+      if (duration == nullptr) {
+        cvar_empty.wait(lock, [this]() { return not circ_buffer.empty() or not active; });
+      } else {
+        cvar_empty.wait_for(lock, *duration, [this]() { return not circ_buffer.empty() or not active; });
       }
       nof_waiting--;
-      if (not active) {
+      if (circ_buffer.empty()) {
+        // either queue got deactivated or there was a timeout
         return false;
       }
     }