Reintroducing MallocHooks changes with fix for hooks being called when in execvpe after a fork whil…

runtime/vm/hash_map_test.cc

Index: runtime/vm/hash_map_test.cc
diff --git a/runtime/vm/hash_map_test.cc b/runtime/vm/hash_map_test.cc
index b3afddedf4942cecffdd117660d7e59a9cd875f6..2f49b362983d7b82dbff7e4b8f43748025a778fc 100644
--- a/runtime/vm/hash_map_test.cc
+++ b/runtime/vm/hash_map_test.cc
@@ -31,6 +31,9 @@ TEST_CASE(DirectChainedHashMap) {
   EXPECT(map.LookupValue(&v1) == &v1);
   EXPECT(map.LookupValue(&v2) == &v2);
   EXPECT(map.LookupValue(&v3) == &v1);
+  EXPECT(map.Remove(&v1));
+  EXPECT(map.Lookup(&v1) == NULL);
+  map.Insert(&v1);
   DirectChainedHashMap<PointerKeyValueTrait<TestValue> > map2(map);
   EXPECT(map2.LookupValue(&v1) == &v1);
   EXPECT(map2.LookupValue(&v2) == &v2);
@@ -38,6 +41,64 @@ TEST_CASE(DirectChainedHashMap) {
 }
 
 
+TEST_CASE(DirectChainedHashMapInsertRemove) {
+  DirectChainedHashMap<PointerKeyValueTrait<TestValue> > map;
+  EXPECT(map.IsEmpty());
+  TestValue v1(1);
+  TestValue v2(3);  // Note: v1, v2, v3 should have the same hash.
+  TestValue v3(5);
+
+  // Start with adding and removing the same element.
+  map.Insert(&v1);
+  EXPECT(map.LookupValue(&v1) == &v1);
+  EXPECT(map.Remove(&v1));
+  EXPECT(map.Lookup(&v1) == NULL);
+
+  // Inserting v2 first should put it at the head of the list.
+  map.Insert(&v2);
+  map.Insert(&v1);
+  EXPECT(map.LookupValue(&v2) == &v2);
+  EXPECT(map.LookupValue(&v1) == &v1);
+
+  // Check to see if removing the head of the list causes issues.
+  EXPECT(map.Remove(&v2));
+  EXPECT(map.Lookup(&v2) == NULL);
+  EXPECT(map.LookupValue(&v1) == &v1);
+
+  // Reinsert v2, which will place it at the back of the hash map list.
+  map.Insert(&v2);
+  EXPECT(map.LookupValue(&v2) == &v2);
+
+  // Remove from the back of the hash map list.
+  EXPECT(map.Remove(&v2));
+  EXPECT(map.Lookup(&v2) == NULL);
+  EXPECT(map.Remove(&v1));
+  EXPECT(map.Lookup(&v1) == NULL);
+
+  // Check to see that removing an invalid element returns false.
+  EXPECT(!map.Remove(&v1));
+
+  // One last case: remove from the middle of a hash map list.
+  map.Insert(&v1);
+  map.Insert(&v2);
+  map.Insert(&v3);
+
+  EXPECT(map.LookupValue(&v1) == &v1);
+  EXPECT(map.LookupValue(&v2) == &v2);
+  EXPECT(map.LookupValue(&v3) == &v3);
+
+  EXPECT(map.Remove(&v2));
+  EXPECT(map.LookupValue(&v1) == &v1);
+  EXPECT(map.Lookup(&v2) == NULL);
+  EXPECT(map.LookupValue(&v3) == &v3);
+
+  EXPECT(map.Remove(&v1));
+  EXPECT(map.Remove(&v3));
+
+  EXPECT(map.IsEmpty());
+}
+
+
 TEST_CASE(MallocDirectChainedHashMap) {
   MallocDirectChainedHashMap<PointerKeyValueTrait<TestValue> > map;
   EXPECT(map.IsEmpty());