Disallow passing a SharedArrayBuffer in the transfer list.

include/v8.h

Index: include/v8.h
diff --git a/include/v8.h b/include/v8.h
index 86aa8b7d2d0d3bce9b0163ae0cfd7432776508b1..d699a3c9e00d75990a69e7f6a119f1a3b7f80512 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -1710,6 +1710,19 @@ class V8_EXPORT ValueSerializer {
     virtual Maybe<bool> WriteHostObject(Isolate* isolate, Local<Object> object);
 
     /*
+     * Called when the ValueSerializer is going to serialize a
+     * SharedArrayBuffer object. The embedder must return an ID for the
+     * object, using the same ID if this SharedArrayBuffer has already been
+     * serialized in this buffer. When deserializing, this ID will be passed to
+     * ValueDeserializer::TransferSharedArrayBuffer as |transfer_id|.
+     *
+     * If the object cannot be serialized, an
+     * exception should be thrown and Nothing<uint32_t>() returned.
+     */
+    virtual Maybe<uint32_t> TransferSharedArrayBuffer(Isolate* isolate,

[jbroman, 2016/12/13 20:56:00]

Do we want to use the word "transfer" here, given we're removing it from the
transfer list? (I'm admittedly not up to date on context behind this decision.)

[binji, 2016/12/14 23:58:30]

AIUI, the thought is that transferring is defined by the original value being
detached more than whether the value is serialized or not. Makes some sense I
guess, but it unfortunately complicates the code.

So good point, though I'm not sure what else to call it. Maybe
"ShareSharedArrayBuffer"?

[binji, 2016/12/15 23:24:45]

I went with GetSharedArrayBufferId, I think that's pretty clear.

+                                                      Local<Object> object);

[jbroman, 2016/12/13 20:56:00]

I'd expect the argument to be Local<SharedArrayBuffer> here.

[binji, 2016/12/14 23:58:30]

Done.

+
+    /*
      * Allocates memory for the buffer of at least the size provided. The actual
      * size (which may be greater or equal) is written to |actual_size|. If no
      * buffer has been allocated yet, nullptr will be provided.
@@ -1763,8 +1776,10 @@ class V8_EXPORT ValueSerializer {
   /*
    * Similar to TransferArrayBuffer, but for SharedArrayBuffer.
    */
-  void TransferSharedArrayBuffer(uint32_t transfer_id,
-                                 Local<SharedArrayBuffer> shared_array_buffer);
+  V8_DEPRECATE_SOON("Use Delegate::TransferSharedArrayBuffer",
+                    void TransferSharedArrayBuffer(
+                        uint32_t transfer_id,
+                        Local<SharedArrayBuffer> shared_array_buffer));
 
   /*
    * Write raw data in various common formats to the buffer.