adt - added background object pool test, and fix existing bugs related to the creation of pools with objects that are too small to be used in free lists

lib/include/srsran/adt/pool/background_mem_pool.h

@@ -33,11 +33,7 @@ namespace detail {
  * @tparam BatchSize number of T objects in a batch
  * @tparam ThresholdSize number of T objects below which a new batch needs to be allocated
  */
-template <typename T,
-          size_t BatchSize,
-          size_t ThresholdSize,
-          typename CtorFunc    = default_ctor_operator<T>,
-          typename RecycleFunc = noop_operator>
+template <typename T, size_t BatchSize, size_t ThresholdSize, typename CtorFunc, typename RecycleFunc>
 class base_background_pool
 {
   static_assert(ThresholdSize > 0, "ThresholdSize needs to be positive");
@@ -92,10 +88,8 @@ public:
   void deallocate_node(void* p)
   {
     std::lock_guard<std::mutex> lock(mutex);
-    if (p != nullptr) {
     recycle_func(static_cast<void*>(p));
-      obj_cache.push(static_cast<uint8_t*>(p));
-    }
+    obj_cache.push(static_cast<void*>(p));
   }
 
   void allocate_batch_in_background()
@@ -107,22 +101,22 @@ public:
   }
 
 private:
-  using obj_storage_t = type_storage<T>;
+  using obj_storage_t = type_storage<T, memblock_cache::min_memblock_size()>;
   using batch_obj_t   = std::array<obj_storage_t, BatchSize>;
 
   /// Unprotected allocation of new Batch of Objects
   void allocate_batch_()
   {
-    batch_obj_t* batch = new batch_obj_t();
+    std::unique_ptr<batch_obj_t> batch(new batch_obj_t());
     if (batch == nullptr) {
       srslog::fetch_basic_logger("POOL").warning("Failed to allocate new batch in background thread");
       return;
     }
-    batches.emplace_back(batch);
     for (obj_storage_t& obj_store : *batch) {
-      ctor_func(static_cast<void*>(&obj_store));
-      obj_cache.push(static_cast<void*>(&obj_store));
+      ctor_func(obj_store.addr());
+      obj_cache.push(&obj_store.buffer);
     }
+    batches.emplace_back(std::move(batch));
   }
 
   CtorFunc    ctor_func;
@@ -138,7 +132,7 @@ private:
 
 template <typename T, size_t BatchSize, size_t ThresholdSize>
 using background_mem_pool =
-    detail::base_background_pool<typename std::aligned_storage<sizeof(T), alignof(T)>::type, BatchSize, ThresholdSize>;
+    detail::base_background_pool<T, BatchSize, ThresholdSize, detail::noop_operator, detail::noop_operator>;
 
 template <typename T,
           size_t BatchSize,

lib/include/srsran/adt/pool/mem_pool.h

@@ -58,7 +58,7 @@ public:
   void deallocate_node(void* p)
   {
     if (p != nullptr) {
-      stack.push(static_cast<uint8_t*>(p));
+      stack.push(p);
     }
   }
 
@@ -67,7 +67,7 @@ public:
   {
     static const size_t blocksize = std::max(sizeof(T), memblock_cache::min_memblock_size());
     for (size_t i = 0; i < N; ++i) {
-      stack.push(new uint8_t[blocksize]);
+      stack.push(static_cast<void*>(new uint8_t[blocksize]));
     }
   }
 

lib/include/srsran/adt/pool/memblock_cache.h

@@ -43,6 +43,13 @@ public:
     return *this;
   }
 
+  template <typename T>
+  void push(T* block) noexcept
+  {
+    static_assert(sizeof(T) >= sizeof(node), "Provided memory block is too small");
+    push(static_cast<void*>(block));
+  }
+
   void push(void* block) noexcept
   {
     node* next = ::new (block) node(head);
@@ -57,6 +64,7 @@ public:
     }
     node* last_head = head;
     head            = head->prev;
+    last_head->~node();
     count--;
     return static_cast<void*>(last_head);
   }
@@ -99,7 +107,8 @@ public:
     return *this;
   }
 
-  void push(void* block) noexcept
+  template <typename T>
+  void push(T* block) noexcept
   {
     std::lock_guard<std::mutex> lock(mutex);
     stack.push(block);

lib/test/adt/mem_pool_test.cc

@@ -149,9 +149,11 @@ void test_background_pool()
     srsran::background_obj_pool<C, 16, 4> obj_pool;
 
     srsran::unique_pool_ptr<C> c  = obj_pool.allocate_object();
+    srsran::unique_pool_ptr<C> c2 = obj_pool.allocate_object();
+    srsran::unique_pool_ptr<C> c3 = obj_pool.allocate_object();
     TESTASSERT(C::default_ctor_counter == 16);
   }
-  TESTASSERT(C::dtor_counter == 16);
+  TESTASSERT(C::dtor_counter == 16 and C::dtor_counter == C::default_ctor_counter);
 }
 
 int main(int argc, char** argv)

srsenb/hdr/stack/rrc/rrc_ue.h

@@ -153,7 +153,7 @@ public:
   void  operator delete(void* ptr)noexcept;
   void  operator delete[](void* ptr) = delete;
 
-  using ue_pool_t = srsran::background_obj_pool<ue, 16, 4>;
+  using ue_pool_t = srsran::background_mem_pool<ue, 16, 4>;
   static ue_pool_t* get_ue_pool();
 
 private:

srsenb/src/stack/rrc/rrc_ue.cc

@@ -65,7 +65,7 @@ int rrc::ue::init()
   return SRSRAN_SUCCESS;
 }
 
-srsran::background_obj_pool<rrc::ue, 16, 4>* rrc::ue::get_ue_pool()
+srsran::background_mem_pool<rrc::ue, 16, 4>* rrc::ue::get_ue_pool()
 {
   // Note: batch allocation is going to be explicitly called in enb class construction. The pool object, therefore,
   //       will only be initialized if we instantiate an eNB