add LeakDetector feature to luajit::Context, luajit::Thread, and nf7::Lambda

core/luajit/context.cc

@@ -1,6 +1,7 @@
 // No copyright
 #include "core/luajit/context.hh"
 
+#include "iface/common/leak_detector.hh"
 #include "iface/subsys/concurrency.hh"
 #include "iface/subsys/parallelism.hh"
 
@@ -50,8 +51,11 @@ void TaskContext::Push(const nf7::Value& v) noexcept {
 }
 
 
+namespace {
 template <typename T>
-class ContextImpl final : public Context {
+class ContextImpl final :
+    public Context,
+    private LeakDetector<ContextImpl<T>> {
  public:
   ContextImpl(const char* name, Kind kind, Env& env)
       : Context(name, kind), tasq_(env.Get<T>()) {
@@ -93,6 +97,7 @@ class ContextImpl final : public Context {
  private:
   std::shared_ptr<T> tasq_;
 };
+}  // namespace
 
 std::shared_ptr<Context> Context::Create(Env& env, Kind kind) {
   switch (kind) {

core/luajit/lambda_test.cc

@@ -13,6 +13,7 @@
 #include "core/luajit/context_test.hh"
 
 
+namespace {
 class LuaJIT_Lambda : public nf7::core::luajit::test::ContextFixture {
  public:
   using ContextFixture::ContextFixture;
@@ -55,6 +56,7 @@ class LuaJIT_Lambda : public nf7::core::luajit::test::ContextFixture {
     EXPECT_EQ(sut->abortCount(), expectAbort);
   }
 };
+}  // namespace
 
 
 TEST_P(LuaJIT_Lambda, Run) {

core/luajit/thread.hh

@@ -8,11 +8,15 @@
 
 #include <lua.hpp>
 
+#include "iface/common/leak_detector.hh"
+
 #include "core/luajit/context.hh"
 
 namespace nf7::core::luajit {
 
-class Thread : public std::enable_shared_from_this<Thread> {
+class Thread :
+    public std::enable_shared_from_this<Thread>,
+    private LeakDetector<Thread> {
  public:
   struct DoNotCallConstructorDirectly { };
 

core/luajit/thread_test.cc

@@ -8,6 +8,7 @@
 #include "core/luajit/context_test.hh"
 
 
+namespace {
 class LuaJIT_Thread : public nf7::core::luajit::test::ContextFixture {
  public:
   using ContextFixture::ContextFixture;
@@ -32,6 +33,7 @@ class LuaJIT_Thread : public nf7::core::luajit::test::ContextFixture {
     EXPECT_EQ(called, 1);
   }
 };
+}  // namespace
 
 
 TEST_P(LuaJIT_Thread, ResumeWithSingleReturn) {

iface/CMakeLists.txt

@@ -13,6 +13,7 @@ target_sources(nf7_iface
     common/container.hh
     common/exception.hh
     common/future.hh
+    common/leak_detector.hh
     common/observer.hh
     common/task.hh
     common/task_context.hh
@@ -33,6 +34,7 @@ target_sources(nf7_iface_test
     common/dealer_test.cc
     common/container_test.cc
     common/future_test.cc
+    common/leak_detector_test.cc
     common/observer_test.cc
     common/observer_test.hh
     common/task_test.cc

iface/common/container_test.cc

@@ -5,6 +5,7 @@
 
 #include <string>
 
+namespace {
 class Object {
  public:
   virtual ~Object() = default;
@@ -30,6 +31,7 @@ class BRecursive : public IB {
  private:
   std::shared_ptr<IB> b_;
 };
+}  // namespace
 
 TEST(SimpleContainer, FetchIsolated) {
   SUT sut {{

iface/common/leak_detector.hh

@@ -0,0 +1,45 @@
+// No copyright
+#pragma once
+
+#include <atomic>
+#include <cassert>
+#include <cstdint>
+#include <cstdlib>
+#include <iostream>
+
+namespace nf7 {
+#if !defined(NDEBUG)
+
+  template <typename T>
+  class LeakDetector {
+   public:
+    LeakDetector() { (void) checker_; ++count_; }
+    virtual ~LeakDetector() noexcept { --count_; }
+
+   private:
+    struct Checker {
+      ~Checker() {
+        if (count_ > 0) {
+          std::cerr << "LEAK DETECTED: " << typeid(T).name() << std::endl;
+        }
+      }
+    };
+
+   public:
+    static uint64_t count() noexcept { return count_; }
+
+   private:
+    static inline Checker               checker_;
+    static inline std::atomic<uint64_t> count_ = 0;
+  };
+
+#else
+
+  template <typename T>
+  class LeakDetector {
+   public:
+    static uint64_t count() noexcept { return 0; }
+  };
+
+#endif
+}  // namespace nf7

iface/common/leak_detector_test.cc

@@ -0,0 +1,21 @@
+// No copyright
+#include "iface/common/leak_detector.hh"
+
+#include <gtest/gtest.h>
+
+#include <memory>
+
+
+namespace {
+class A : private nf7::LeakDetector<A> { };
+}  // namespace
+
+#if !defined(NDEBUG)
+TEST(LeakDetector, Counter) {
+  {
+    A a;
+    EXPECT_EQ(nf7::LeakDetector<A>::count(), 1);
+  }
+  EXPECT_EQ(nf7::LeakDetector<A>::count(), 0);
+}
+#endif

iface/lambda.hh

@@ -6,13 +6,14 @@
 #include <vector>
 
 #include "iface/common/dealer.hh"
+#include "iface/common/leak_detector.hh"
 #include "iface/common/exception.hh"
 #include "iface/common/observer.hh"
 #include "iface/common/value.hh"
 
 namespace nf7 {
 
-class Lambda {
+class Lambda : private LeakDetector<Lambda> {
  public:
   Lambda() = delete;
   Lambda(const std::shared_ptr<Taker<Value>>& taker,