Make NoReloadScope thread safe

runtime/vm/atomic.h

 // Copyright (c) 2013, 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.
 
 #ifndef VM_ATOMIC_H_
 #define VM_ATOMIC_H_
 
 #include "platform/globals.h"
 
 #include "vm/allocation.h"
@@ skipping 16 matching lines @@
   // that are accessed by generated code.
   static void IncrementBy(intptr_t* p, intptr_t value);
   static void IncrementInt64By(int64_t* p, int64_t value);
 
   // Atomically fetch the value at p and decrement the value at p.
   // Returns the original value at p.
   //
   // NOTE: Not to be used for any atomic operations involving memory locations
   // that are accessed by generated code.
   static uintptr_t FetchAndDecrement(uintptr_t* p);
+  static intptr_t FetchAndDecrement(intptr_t* p);

[Florian Schneider, 2016/09/16 16:22:41]

Not needed? If we need both variants, I'd make this a template function (see
LoadRelaxed)

[Cutch, 2016/09/16 16:45:30]

Oops. I meant to delete this.

 
   // Atomically decrement the value at p by 'value'.
   //
   // NOTE: Not to be used for any atomic operations involving memory locations
   // that are accessed by generated code.
   static void DecrementBy(intptr_t* p, intptr_t value);
 
   // Atomically compare *ptr to old_value, and if equal, store new_value.
   // Returns the original value at ptr.
   //
@@ skipping 31 matching lines @@
 #include "vm/atomic_linux.h"
 #elif defined(TARGET_OS_MACOS)
 #include "vm/atomic_macos.h"
 #elif defined(TARGET_OS_WINDOWS)
 #include "vm/atomic_win.h"
 #else
 #error Unknown target os.
 #endif
 
 #endif  // VM_ATOMIC_H_