Fix/improve 'must free heap allocations' code (#9209)

Summary:
Added missing include, and cleaned up to make same mistake less
likely in future (minimize conditional compilation)

Fixes https://github.com/facebook/rocksdb/issues/9183

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9209

Test Plan: added to existing test

Reviewed By: mrambacher

Differential Revision: D32631390

Pulled By: pdillinger

fbshipit-source-id: 63a0501855cf5fac9e22ca1e5c4f53725dbf3f93

cache/cache_test.cc

@@ -609,6 +609,9 @@ TEST_P(CacheTest, SetCapacity) {
   for (size_t i = 5; i < 10; i++) {
     cache->Release(handles[i]);
   }
+
+  // Make sure this doesn't crash or upset ASAN/valgrind
+  cache->DisownData();
 }
 
 TEST_P(LRUCacheTest, SetStrictCapacityLimit) {

cache/clock_cache.cc

@@ -33,11 +33,11 @@ std::shared_ptr<Cache> NewClockCache(
 #ifndef ROCKSDB_USE_RTTI
 #define TBB_USE_EXCEPTIONS 0
 #endif
-#include "tbb/concurrent_hash_map.h"
-
 #include "cache/sharded_cache.h"
+#include "port/lang.h"
 #include "port/malloc.h"
 #include "port/port.h"
+#include "tbb/concurrent_hash_map.h"
 #include "util/autovector.h"
 #include "util/mutexlock.h"
 
@@ -809,9 +809,10 @@ class ClockCache final : public ShardedCache {
   }
 
   void DisownData() override {
-#ifndef MUST_FREE_HEAP_ALLOCATIONS
+    // Leak data only if that won't generate an ASAN/valgrind warning
-    shards_ = nullptr;
+    if (!kMustFreeHeapAllocations) {
-#endif
+      shards_ = nullptr;
+    }
   }
 
   void WaitAll(std::vector<Handle*>& /*handles*/) override {}

cache/lru_cache.cc

@@ -15,6 +15,7 @@
 
 #include "monitoring/perf_context_imp.h"
 #include "monitoring/statistics.h"
+#include "port/lang.h"
 #include "util/mutexlock.h"
 
 namespace ROCKSDB_NAMESPACE {
@@ -704,11 +705,11 @@ uint32_t LRUCache::GetHash(Handle* handle) const {
 }
 
 void LRUCache::DisownData() {
-// Do not drop data if compile with ASAN to suppress leak warning.
+  // Leak data only if that won't generate an ASAN/valgrind warning
-#ifndef MUST_FREE_HEAP_ALLOCATIONS
+  if (!kMustFreeHeapAllocations) {
-  shards_ = nullptr;
+    shards_ = nullptr;
-  num_shards_ = 0;
+    num_shards_ = 0;
-#endif
+  }
 }
 
 size_t LRUCache::TEST_GetLRUSize() {

port/lang.h

@@ -42,8 +42,10 @@
 //   STATIC_AVOID_DESTRUCTION(Foo, foo)(arg1, arg2);
 #ifdef MUST_FREE_HEAP_ALLOCATIONS
 #define STATIC_AVOID_DESTRUCTION(Type, name) static Type name
+constexpr bool kMustFreeHeapAllocations = true;
 #else
 #define STATIC_AVOID_DESTRUCTION(Type, name) static Type& name = *new Type
+constexpr bool kMustFreeHeapAllocations = false;
 #endif
 
 // TSAN (Thread sanitizer)