ConcurrentHashMap Deletion Test

Summary: Add hazptr_cleanup to ConcurrentHashMap destructor & add a test to ensure deletion is working.

Reviewed By: djwatson

Differential Revision: D6951359

fbshipit-source-id: 277c304a0e5073605010b14764d05a27e6e10b2d

folly/concurrency/ConcurrentHashMap.h

@@ -158,6 +158,7 @@ class ConcurrentHashMap {
         Allocator().deallocate((uint8_t*)seg, sizeof(SegmentT));
       }
     }
+    folly::hazptr::hazptr_cleanup(folly::hazptr::default_hazptr_domain());
   }
 
   bool empty() const noexcept {

folly/concurrency/test/ConcurrentHashMapTest.cpp

@@ -569,3 +569,27 @@ TEST(ConcurrentHashMap, RefcountTest) {
     foomap.insert_or_assign(1, i);
   }
 }
+
+struct Wrapper {
+  Wrapper() = default;
+  ~Wrapper() {
+    del = true;
+  }
+
+  static bool del;
+};
+
+bool Wrapper::del = false;
+
+TEST(ConcurrentHashMap, Deletion) {
+  EXPECT_FALSE(Wrapper::del);
+
+  {
+    ConcurrentHashMap<int, std::shared_ptr<Wrapper>> map;
+
+    map.insert(0, std::make_shared<Wrapper>());
+    map.erase(0);
+  }
+
+  EXPECT_TRUE(Wrapper::del);
+}