WIP SharedArrayBuffer implementation

src/d8.cc

Index: src/d8.cc
diff --git a/src/d8.cc b/src/d8.cc
index cf448172f7a9f8afd500a240abbe0d9312647034..9f14109091aeb9c1310a06624093877adbdf6f88 100644
--- a/src/d8.cc
+++ b/src/d8.cc
@@ -1593,6 +1593,18 @@ class ShellArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
 };
 
 
+class ShellSharedArrayBufferAllocator
+    : public v8::SharedArrayBuffer::Allocator {
+ public:
+  virtual void* Allocate(size_t length) {
+    void* data = AllocateUninitialized(length);
+    return data == NULL ? data : memset(data, 0, length);
+  }
+  virtual void* AllocateUninitialized(size_t length) { return malloc(length); }
+  virtual void Free(void* data, size_t) { free(data); }
+};
+
+
 class MockArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
  public:
   void* Allocate(size_t) override { return malloc(1); }
@@ -1601,6 +1613,14 @@ class MockArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
 };
 
 
+class MockSharedArrayBufferAllocator : public v8::SharedArrayBuffer::Allocator {
+ public:
+  void* Allocate(size_t) override { return malloc(1); }
+  void* AllocateUninitialized(size_t length) override { return malloc(1); }
+  void Free(void* p, size_t) override { free(p); }
+};
+
+
 int Shell::Main(int argc, char* argv[]) {
 #if (defined(_WIN32) || defined(_WIN64))
   UINT new_flags =
@@ -1631,10 +1651,14 @@ int Shell::Main(int argc, char* argv[]) {
   SetFlagsFromString("--redirect-code-traces-to=code.asm");
   ShellArrayBufferAllocator array_buffer_allocator;
   MockArrayBufferAllocator mock_arraybuffer_allocator;
+  ShellSharedArrayBufferAllocator shared_array_buffer_allocator;
+  MockSharedArrayBufferAllocator mock_shared_arraybuffer_allocator;
   if (options.mock_arraybuffer_allocator) {
     v8::V8::SetArrayBufferAllocator(&mock_arraybuffer_allocator);
+    v8::V8::SetSharedArrayBufferAllocator(&mock_shared_arraybuffer_allocator);
   } else {
     v8::V8::SetArrayBufferAllocator(&array_buffer_allocator);
+    v8::V8::SetSharedArrayBufferAllocator(&shared_array_buffer_allocator);
   }
   int result = 0;
   Isolate::CreateParams create_params;