- The
grow(|delta|) method, when invoked, performs the following steps:
+
+ To grow the memory buffer associated with a [=memory address=] |memaddr| by |delta|, perform the following steps:
+
1. Let |store| be the [=surrounding agent=]'s [=associated store=].
- 1. Let |memaddr| be **this**.\[[Memory]].
1. Let |ret| be the [=mem_size=](|store|, |memaddr|).
1. Let |store| be [=mem_grow=](|store|, |memaddr|, |delta|).
1. If |store| is [=error=], throw a {{RangeError}} exception.
1. Set the [=surrounding agent=]'s [=associated store=] to |store|.
- 1. [=Reset the memory buffer=] of |memaddr|.
+ 1. [=Refresh the memory buffer=] of |memaddr|.
1. Return |ret|.
+
+ The grow(|delta|) method, when invoked, performs the following steps:
+ 1. Let |memaddr| be **this**.\[[Memory]].
+ 1. Return the result of [=grow the memory buffer|growing the memory buffer=] associated with |memaddr| by |delta|.
+
+
Immediately after a WebAssembly [=memory.grow=] instruction executes, perform the following steps:
@@ -685,9 +736,91 @@ Immediately after a WebAssembly [=memory.grow=] instruction executes, perform th
1. Let |frame| be the [=current frame=].
1. Assert: due to validation, |frame|.[=frame/module=].[=moduleinst/memaddrs=][0] exists.
1. Let |memaddr| be the memory address |frame|.[=frame/module=].[=moduleinst/memaddrs=][0].
- 1. [=Reset the memory buffer=] of |memaddr|.
+ 1. [=Refresh the memory buffer=] of |memaddr|.
+
+
+
+ The toFixedLengthBuffer() method, when invoked, performs the following steps:
+ 1. Let |buffer| be **this**.\[[BufferObject]].
+ 1. Let |memaddr| be **this**.\[[Memory]].
+ 1. If |buffer| is an {{ArrayBuffer}},
+ 1. If [=IsFixedLengthArrayBuffer=](|buffer|) is true, return |buffer|.
+ 1. Otherwise,
+ 1. Let |fixedBuffer| be the result of [=create a fixed length memory buffer|creating a fixed length memory buffer=] from |memaddr|.
+ 1. Perform [=!=] [$DetachArrayBuffer$](|buffer|, "WebAssembly.Memory").
+ 1. Set **this**.\[[BufferObject]] to |fixedBuffer|.
+ 1. Return |fixedBuffer|.
+ 1. Otherwise,
+ 1. Let |map| be the [=surrounding agent=]'s associated [=Memory object cache=].
+ 1. Assert: |map|[|memaddr|] [=map/exists=].
+ 1. Let |newMemory| be |map|[|memaddr|].
+ 1. Let |newBufferObject| be |newMemory|.\[[BufferObject]].
+ 1. Set **this**.\[[BufferObject]] to |newBufferObject|.
+ 1. Return |newBufferObject|.
+
+
+
+ The toResizableBuffer() method, when invoked, performs the following steps:
+ 1. Let |buffer| be **this**.\[[BufferObject]].
+ 1. If [=IsFixedLengthArrayBuffer=](|buffer|) is false, return |buffer|.
+ 1. Let |memaddr| be **this**.\[[Memory]].
+ 1. Let |store| be the [=surrounding agent=]'s [=associated store=].
+ 1. Let |memtype| be [=mem_type=](|store|, |memaddr|).
+ 1. If |memtype| has a max,
+ 1. Let |maxsize| be the max value in |memtype|.
+ 1. Otherwise,
+ 1. Let |maxsize| be 65536 × 65536.
+ 1. Let |resizableBuffer| be the result of [=create a resizable memory buffer|creating a resizable memory buffer=] from |memaddr| and |maxsize|.
+ 1. If |buffer| is an {{ArrayBuffer}},
+ 1. Perform [=!=] [$DetachArrayBuffer$](|buffer|, "WebAssembly.Memory").
+ 1. Set **this**.\[[BufferObject]] to |resizableBuffer|.
+ 1. Return |resizableBuffer|.
+
+
+{{ArrayBuffer}} and {{SharedArrayBuffer}} objects returned by a {{Memory}} object must have size that is a multiple of a WebAssembly [=page size=] (the constant 65536). For this reason [=HostResizeArrayBuffer=] and [=HostGrowSharedArrayBuffer=] are redefined as follows.
+
+
+ The abstract operation [=HostResizeArrayBuffer=] takes arguments an {{ArrayBuffer}} |buffer| and |newLength|. It performs the following steps when called.
+
+ 1. If |buffer|.\[[ArrayBufferDetachKey]] is "WebAssembly.Memory",
+ 1. Let |map| be the [=surrounding agent=]'s associated [=Memory object cache=].
+ 1. Assert: |buffer| is the \[[BufferObject]] of exactly one value in |map|.
+ 1. [=map/iterate|For each=] |memaddr| → |mem| in |map|,
+ 1. If [=SameValue=](mem.\[[BufferObject]], |buffer|) is true,
+ 1. Assert: |buffer|.\[[ArrayBufferByteLength]] modulo 65536 is 0.
+ 1. Let |lengthDelta| be |newLength| - |buffer|.\[[ArrayBufferByteLength]].
+ 1. If |lengthDelta| < 0 or |lengthDelta| modulo 65536 is not 0,
+ 1. Throw a {{RangeError}} exception.
+ 1. Let |delta| be |lengthDelta| ÷ 65536.
+ 1. [=grow the memory buffer|Grow the memory buffer=] associated with |memaddr| by |delta|.
+ 1. Return handled.
+ 1. Otherwise, return unhandled.
+
+ The abstract operation [=HostGrowSharedArrayBuffer=] takes arguments a {{SharedArrayBuffer}} |buffer| and |newLength|. It performs the following steps when called.
+
+ 1. Let |map| be the [=surrounding agent=]'s associated [=Memory object cache=].
+ 1. Assert: |buffer| is the \[[BufferObject]] of exactly one value in |map|.
+ 1. [=map/iterate|For each=] |memaddr| → |mem| in |map|,
+ 1. If [=SameValue=](mem.\[[BufferObject]], |buffer|) is true,
+ 1. Assert: |buffer|.\[[ArrayBufferByteLength]] modulo 65536 is 0.
+ 1. Let |lengthDelta| be |newLength| - |buffer|.\[[ArrayBufferByteLength]].
+ 1. If |lengthDelta| < 0 or |lengthDelta| modulo 65536 is not 0,
+ 1. Throw a {{RangeError}} exception.
+ 1. Let |delta| be |lengthDelta| ÷ 65536.
+ 1. [=grow the memory buffer|Grow the memory buffer=] associated with |memaddr| by |delta|.
+ 1. If |newLength| < |buffer|.\[[ArrayBufferByteLength]] or |newLength| > |buffer|.\[[ArrayBufferMaxByteLength]], throw a {{RangeError}} exception.
+ 1. Let |agentRecord| be the surrounding agent's [=Agent Record=].
+ 1. Let |isLittleEndian| be |agentRecord|.\[[LittleEndian]] .
+ 1. Let |event| be an implementation defined [=ReadModifyWriteSharedMemory=] event, whose \[[Order]] is "SeqCst", \[[Payload]] is [Ā§NumericToRawBytes$](Bigint, |newLength|, |isLittleEndian|), \[[Block]] is |buffer|.\[[ArrayBufferByteLengthData]], \[[ByteIndex]] is 0, and \[[ElementSize]] is 8.
+ 1. Let |eventsRecord| be the [=Agent Events Record|EventsRecord=] in |agentRecord|.\[[CandidateExecution]].\[[EventsRecords]] that corresponds to the surrounding agent's signifier |agentRecord|.\[[Signifier]].
+ 1. Append |event| to |eventsRecord|.\[[EventsList]].
+ 1. Return handled.
+
+
+Note: (TODO) Check the error case of memory.grow on the Wasm side.
+
The getter of the buffer attribute of {{Memory}} perfoms the following steps: