Disabled MallocHooks code in Release due to performance concerns. Added enable_malloc_hooks flag to…

runtime/vm/malloc_hooks_test.cc

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 
-#if defined(DART_USE_TCMALLOC) && !defined(PRODUCT)
+#if defined(DART_USE_TCMALLOC) && defined(DEBUG)
 
 #include "platform/assert.h"
 #include "vm/class_finalizer.h"
 #include "vm/globals.h"
 #include "vm/malloc_hooks.h"
 #include "vm/symbols.h"
 #include "vm/unit_test.h"
 
 namespace dart {
 
 static void MallocHookTestBufferInitializer(volatile char* buffer,
                                             uintptr_t size) {
   // Run through the buffer and do something. If we don't do this and the memory
   // in buffer isn't touched, the tcmalloc hooks won't be called.
   for (uintptr_t i = 0; i < size; ++i) {
     buffer[i] = i;
   }
 }
 
 
 UNIT_TEST_CASE(BasicMallocHookTest) {

[rmacnak, 2017/02/17 23:39:22]

If it's available in release mode, it should be tested in release mode too.

bool saved_enable_malloc_hooks = FLAG_enable_malloc_hooks;
FLAG_enable_malloc_hooks = true;
...
FLAG_enable_malloc_hooks = saved_enable_malloc_hooks

[zra, 2017/02/17 23:43:27]

+1

   MallocHooks::InitOnce();
   MallocHooks::ResetStats();
   EXPECT_EQ(0L, MallocHooks::allocation_count());
   EXPECT_EQ(0L, MallocHooks::heap_allocated_memory_in_bytes());
   const intptr_t buffer_size = 10;
   char* buffer = new char[buffer_size];
   MallocHookTestBufferInitializer(buffer, buffer_size);
 
   EXPECT_EQ(1L, MallocHooks::allocation_count());
   EXPECT_EQ(static_cast<intptr_t>(sizeof(char) * buffer_size),
@@ skipping 31 matching lines @@
 
 
   delete[] buffer;
   EXPECT_EQ(0L, MallocHooks::allocation_count());
   EXPECT_EQ(0L, MallocHooks::heap_allocated_memory_in_bytes());
   MallocHooks::TearDown();
 }
 
 };  // namespace dart
 
-#endif  // defined(DART_USE_TCMALLOC) && !defined(PRODUCT)
+#endif  // defined(DART_USE_TCMALLOC) && defined(DEBUG)