fix memory pool test - placed the pool state into a shared_ptr so that the callbacks still have a valid handle when the pool is destroyed

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

@@ -38,13 +38,17 @@ class base_background_pool
 {
   static_assert(ThresholdSize > 0, "ThresholdSize needs to be positive");
   static_assert(BatchSize > 1, "BatchSize needs to be higher than 1");
+  using pool_type = base_background_pool<T, BatchSize, ThresholdSize, CtorFunc, RecycleFunc>;
 
 public:
-  explicit base_background_pool(bool lazy_start = false, CtorFunc ctor_func_ = {}, RecycleFunc recycle_func_ = {}) :
-    ctor_func(ctor_func_), recycle_func(recycle_func_)
+  explicit base_background_pool(size_t      initial_size  = BatchSize,
+                                CtorFunc    ctor_func_    = {},
+                                RecycleFunc recycle_func_ = {}) :
+    ctor_func(ctor_func_), recycle_func(recycle_func_), state(std::make_shared<detached_pool_state>(this))
   {
-    if (not lazy_start) {
-      allocate_batch_in_background();
+    int nof_batches = ceilf(initial_size / (float)BatchSize);
+    while (nof_batches-- > 0) {
+      allocate_batch_();
     }
   }
   base_background_pool(base_background_pool&&)      = delete;
@@ -53,7 +57,8 @@ public:
   base_background_pool& operator=(const base_background_pool&) = delete;
   ~base_background_pool()
   {
-    std::lock_guard<std::mutex> lock(mutex);
+    std::lock_guard<std::mutex> lock(state->mutex);
+    state->pool = nullptr;
     for (std::unique_ptr<batch_obj_t>& batch : batches) {
       for (obj_storage_t& obj_store : *batch) {
         obj_store.destroy();
@@ -66,16 +71,13 @@ public:
   void* allocate_node(size_t sz)
   {
     srsran_assert(sz == sizeof(T), "Mismatch of allocated node size=%zd and object size=%zd", sz, sizeof(T));
-    std::lock_guard<std::mutex> lock(mutex);
+    std::lock_guard<std::mutex> lock(state->mutex);
     void*                       block = obj_cache.try_pop();
 
     if (block != nullptr) {
       // allocation successful
       if (obj_cache.size() < ThresholdSize) {
-        get_background_workers().push_task([this]() {
-          std::lock_guard<std::mutex> lock(mutex);
-          allocate_batch_();
-        });
+        allocate_batch_in_background();
       }
       return block;
     }
@@ -87,21 +89,24 @@ public:
 
   void deallocate_node(void* p)
   {
-    std::lock_guard<std::mutex> lock(mutex);
+    std::lock_guard<std::mutex> lock(state->mutex);
     recycle_func(static_cast<void*>(p));
     obj_cache.push(static_cast<void*>(p));
   }
 
   void allocate_batch_in_background()
   {
-    get_background_workers().push_task([this]() {
-      std::lock_guard<std::mutex> lock(mutex);
-      allocate_batch_();
+    std::shared_ptr<detached_pool_state> state_copy = state;
+    get_background_workers().push_task([state_copy]() {
+      std::lock_guard<std::mutex> lock(state_copy->mutex);
+      if (state_copy->pool != nullptr) {
+        state_copy->pool->allocate_batch_();
+      }
     });
   }
 
 private:
-  using obj_storage_t = type_storage<T, memblock_cache::min_memblock_size()>;
+  using obj_storage_t = type_storage<T, memblock_cache::min_memblock_size(), memblock_cache::min_memblock_align()>;
   using batch_obj_t   = std::array<obj_storage_t, BatchSize>;
 
   /// Unprotected allocation of new Batch of Objects
@@ -122,8 +127,14 @@ private:
   CtorFunc    ctor_func;
   RecycleFunc recycle_func;
 
+  struct detached_pool_state {
+    std::mutex mutex;
+    pool_type* pool;
+    explicit detached_pool_state(pool_type* pool_) : pool(pool_) {}
+  };
+  std::shared_ptr<detached_pool_state> state;
+
   // memory stack to cache allocate memory chunks
-  std::mutex                                 mutex;
   memblock_cache                             obj_cache;
   std::vector<std::unique_ptr<batch_obj_t> > batches;
 };
@@ -147,12 +158,17 @@ class background_obj_pool
   struct pool_deleter {
     mem_pool_type* pool;
     explicit pool_deleter(mem_pool_type* pool_) : pool(pool_) {}
-    void operator()(void* ptr) { pool->deallocate_node(ptr); }
+    void operator()(void* ptr)
+    {
+      if (ptr != nullptr) {
+        pool->deallocate_node(ptr);
+      }
+    }
   };
 
 public:
-  background_obj_pool(CtorFunc&& ctor_func = {}, RecycleFunc&& recycle_func = {}) :
-    pool(false, std::forward<CtorFunc>(ctor_func), std::forward<RecycleFunc>(recycle_func))
+  explicit background_obj_pool(size_t initial_size, CtorFunc&& ctor_func = {}, RecycleFunc&& recycle_func = {}) :
+    pool(initial_size, std::forward<CtorFunc>(ctor_func), std::forward<RecycleFunc>(recycle_func))
   {}
 
   unique_pool_ptr<T> allocate_object()

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

@@ -27,6 +27,7 @@ class memblock_cache
 
 public:
   constexpr static size_t min_memblock_size() { return sizeof(node); }
+  constexpr static size_t min_memblock_align() { return alignof(node); }
 
   memblock_cache() = default;
 
@@ -46,7 +47,7 @@ public:
   template <typename T>
   void push(T* block) noexcept
   {
-    static_assert(sizeof(T) >= sizeof(node), "Provided memory block is too small");
+    static_assert(sizeof(T) >= sizeof(node) and alignof(T) >= alignof(node), "Provided memory block is too small");
     push(static_cast<void*>(block));
   }
 

lib/test/adt/mem_pool_test.cc

@@ -147,14 +147,18 @@ void test_background_pool()
   C::default_ctor_counter = 0;
   C::dtor_counter         = 0;
   {
-    srsran::background_obj_pool<C, 16, 4> obj_pool;
+    srsran::background_obj_pool<C, 16, 4>    obj_pool(16);
+    std::vector<srsran::unique_pool_ptr<C> > objs;
 
-    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();
+    for (size_t i = 0; i < 16 - 4; ++i) {
+      objs.push_back(obj_pool.allocate_object());
+    }
     TESTASSERT(C::default_ctor_counter == 16);
+
+    // This will trigger a new batch allocation in the background
+    objs.push_back(obj_pool.allocate_object());
   }
-  TESTASSERT(C::dtor_counter == 16 and C::dtor_counter == C::default_ctor_counter);
+  TESTASSERT(C::dtor_counter == C::default_ctor_counter);
 }
 
 int main(int argc, char** argv)

srsenb/src/stack/rrc/rrc_ue.cc

@@ -65,11 +65,11 @@ int rrc::ue::init()
   return SRSRAN_SUCCESS;
 }
 
-srsran::background_mem_pool<rrc::ue, 16, 4>* rrc::ue::get_ue_pool()
+rrc::ue::ue_pool_t* 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
-  static rrc::ue::ue_pool_t ue_pool(true);
+  static rrc::ue::ue_pool_t ue_pool;
   return &ue_pool;
 }