From f0409c6d05dc3747bf629596d9fe21c60a0a8f1f Mon Sep 17 00:00:00 2001
From: greg7mdp <greg7mdp@gmail.com>
Date: Sun, 11 Sep 2022 12:16:35 -0400
Subject: [PATCH] Fix access of protected member, and add test for templated
 swap()

---
 parallel_hashmap/phmap.h                   |  9 +++++++--
 tests/flat_hash_map_test.cc                | 10 ++++++++++
 tests/parallel_flat_hash_map_mutex_test.cc |  2 ++
 tests/parallel_hash_map_test.cc            | 18 ++++++++++++++++++
 4 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/parallel_hashmap/phmap.h b/parallel_hashmap/phmap.h
index cf6789e..48173fe 100644
--- a/parallel_hashmap/phmap.h
+++ b/parallel_hashmap/phmap.h
@@ -3372,6 +3372,11 @@ public:
         fCallback(set);
     }
 
+    // unsafe, for internal use only
+    Inner& get_inner(size_t idx) {
+        return  sets_[idx];
+    }
+
     // Extension API: support for heterogeneous keys.
     //
     //   std::unordered_set<std::string> s;
@@ -3485,8 +3490,8 @@ public:
         for (size_t i=0; i<num_tables; ++i)
         {
             typename Lockable::UniqueLock l(sets_[i]);
-            typename Lockable2::UniqueLock l2(that.sets_[i]);
-            swap(sets_[i].set_, that.sets_[i].set_);
+            typename Lockable2::UniqueLock l2(that.get_inner(i));
+            swap(sets_[i].set_, that.get_inner(i).set_);
         }
     }
 
diff --git a/tests/flat_hash_map_test.cc b/tests/flat_hash_map_test.cc
index d6d50d2..f64bbdd 100644
--- a/tests/flat_hash_map_test.cc
+++ b/tests/flat_hash_map_test.cc
@@ -22,6 +22,10 @@
     #define THIS_EXTRA_TPL_PARAMS 
 #endif
 
+#ifndef THIS_EXTRA_TPL_PARAMS_NULLMUTEX
+    #define THIS_EXTRA_TPL_PARAMS_NULLMUTEX 
+#endif
+
 #include "parallel_hashmap/phmap.h"
 
 #if defined(PHMAP_HAVE_STD_ANY)
@@ -62,6 +66,12 @@ template <class K, class V, class H = phmap::priv::hash_default_hash<K>,
           class Alloc =  phmap::priv::Allocator<
               phmap::priv::Pair<const K, V>>>
 using ThisMap = THIS_HASH_MAP<K, V, H, Eq, Alloc THIS_EXTRA_TPL_PARAMS>;
+    
+template <class K, class V, class H = phmap::priv::hash_default_hash<K>,
+          class Eq = phmap::priv::hash_default_eq<K>,
+          class Alloc =  phmap::priv::Allocator<
+              phmap::priv::Pair<const K, V>>>
+using ThisMap_NullMutex = THIS_HASH_MAP<K, V, H, Eq, Alloc THIS_EXTRA_TPL_PARAMS_NULLMUTEX>;
 
 static_assert(!std::is_standard_layout<NonStandardLayout>(), "");
 
diff --git a/tests/parallel_flat_hash_map_mutex_test.cc b/tests/parallel_flat_hash_map_mutex_test.cc
index 73dbf7b..e88e7da 100644
--- a/tests/parallel_flat_hash_map_mutex_test.cc
+++ b/tests/parallel_flat_hash_map_mutex_test.cc
@@ -9,4 +9,6 @@
     #define THIS_EXTRA_TPL_PARAMS , 4, boost::upgrade_mutex
 #endif
 
+#define THIS_EXTRA_TPL_PARAMS_NULLMUTEX , 4, phmap::NullMutex
+
 #include "parallel_hash_map_test.cc"
diff --git a/tests/parallel_hash_map_test.cc b/tests/parallel_hash_map_test.cc
index 4812e06..0188691 100644
--- a/tests/parallel_hash_map_test.cc
+++ b/tests/parallel_hash_map_test.cc
@@ -9,6 +9,24 @@ namespace phmap {
 namespace priv {
 namespace {
 
+TEST(THIS_TEST_NAME, Swap) {
+    using Map = ThisMap<int, int>;
+    using MapB = ThisMap_NullMutex<int, int>;
+    
+    Map t;
+    EXPECT_TRUE(t.find(0) == t.end());
+    auto res = t.emplace(0, 1);
+    EXPECT_TRUE(res.second);
+    EXPECT_EQ(1, t.size());
+    MapB u;
+    t.swap(u);
+    EXPECT_EQ(0, t.size());
+    EXPECT_EQ(1, u.size());
+    EXPECT_TRUE(t.find(0) == t.end());
+    EXPECT_TRUE(u[0] == 1);
+}
+
+
 TEST(THIS_TEST_NAME, IfContains) {
     // ----------------
     // test if_contains