fix: early update wasm memory for views (#206)

Author: toyobayashi

packages/emnapi/src/memory.ts

@@ -126,8 +126,7 @@ export const emnapiExternalMemory: {
       return view
     }
 
-    const maybeOldWasmMemory = emnapiExternalMemory.isDetachedArrayBuffer(view.buffer) ||
-      ((typeof SharedArrayBuffer === 'function') && (view.buffer instanceof SharedArrayBuffer))
+    const maybeOldWasmMemory = emnapiExternalMemory.isDetachedArrayBuffer(view.buffer) || emnapiExternalMemory.isSharedArrayBuffer(view.buffer)
     if (maybeOldWasmMemory && emnapiExternalMemory.wasmMemoryViewTable.has(view)) {
       const info = emnapiExternalMemory.wasmMemoryViewTable.get(view)!
       const Ctor = info.Ctor

packages/emnapi/src/value/convert2c.ts

@@ -115,7 +115,7 @@ export function napi_get_typedarray_info (
   if (!(ArrayBuffer.isView(jsValue)) && !(jsValue instanceof DataView)) {
     return envObject.setLastError(napi_status.napi_invalid_arg)
   }
-  const v: ArrayBufferView = jsValue
+  let v: ArrayBufferView = jsValue
   if (type) {
     from64('type')
     let t: napi_typedarray_type
@@ -148,13 +148,13 @@ export function napi_get_typedarray_info (
     }
     makeSetValue('type', 0, 't', 'i32')
   }
+  v = emnapiExternalMemory.getOrUpdateMemoryView(v)
   if (length) {
     from64('length')
     makeSetValue('length', 0, 'v.length', SIZE_TYPE)
   }
-  let buffer: ArrayBufferLike
+
   if (data || arraybuffer) {
-    buffer = v.buffer
     if (data) {
       from64('data')
 
@@ -164,7 +164,7 @@ export function napi_get_typedarray_info (
     if (arraybuffer) {
       from64('arraybuffer')
 
-      const ab = emnapiCtx.napiValueFromJsValue(buffer)
+      const ab = emnapiCtx.napiValueFromJsValue(v.buffer)
       makeSetValue('arraybuffer', 0, 'ab', '*')
     }
   }
@@ -213,14 +213,13 @@ export function napi_get_dataview_info (
   if (!(jsValue instanceof DataView)) {
     return envObject.setLastError(napi_status.napi_invalid_arg)
   }
-  const v = jsValue as DataView
+  const v = emnapiExternalMemory.getOrUpdateMemoryView(jsValue as DataView)
   if (byte_length) {
     from64('byte_length')
     makeSetValue('byte_length', 0, 'v.byteLength', SIZE_TYPE)
   }
-  let buffer: ArrayBufferLike
+
   if (data || arraybuffer) {
-    buffer = v.buffer
     if (data) {
       from64('data')
 
@@ -230,7 +229,7 @@ export function napi_get_dataview_info (
     if (arraybuffer) {
       from64('arraybuffer')
 
-      const ab = emnapiCtx.napiValueFromJsValue(buffer)
+      const ab = emnapiCtx.napiValueFromJsValue(v.buffer)
       makeSetValue('arraybuffer', 0, 'ab', '*')
     }
   }

packages/test/CMakeLists.txt

@@ -93,7 +93,7 @@ if(IS_EMSCRIPTEN)
     "-sMAXIMUM_MEMORY=4294967296"
     "-sSAFE_HEAP=1"
     "-sMODULARIZE=1"
-    "-sEXPORTED_RUNTIME_METHODS=['emnapiInit','ExitStatus']"
+    "-sEXPORTED_RUNTIME_METHODS=['emnapiInit','ExitStatus','wasmMemory','growMemory']"
   )
   set(COMMON_EXPORTS_NAPI
     "-sEXPORTED_FUNCTIONS=['_malloc','_free','_napi_register_wasm_v1','_node_api_module_get_api_version_v1','_emnapi_create_env','_emnapi_delete_env']"

packages/test/dataview/dataview.test.js

@@ -5,7 +5,9 @@
 const assert = require('assert')
 const { load } = require('../util')
 
-module.exports = load('dataview').then(test_dataview => {
+const loadPromise = load('dataview')
+
+module.exports = loadPromise.then(test_dataview => {
   // Test for creating dataview with ArrayBuffer
   {
     const buffer = new ArrayBuffer(128)
@@ -43,4 +45,31 @@ module.exports = load('dataview').then(test_dataview => {
       test_dataview.CreateDataView(buffer, 10, 200)
     }, RangeError)
   }
+
+  {
+    const binding = test_dataview
+    const wasmMemory = loadPromise.Module.wasmMemory
+    const before = wasmMemory.buffer
+    const view = binding.CreateDataView(before, 0, 4)
+    if (loadPromise.Module.growMemory) {
+      loadPromise.Module.growMemory(before.byteLength + 65536)
+    } else {
+      wasmMemory.grow(1)
+    }
+
+    const after = wasmMemory.buffer
+    const cloned = binding.CreateDataViewFromJSDataView(view)
+
+    const result = {
+      trackedViewUsesCurrentBuffer: view.buffer === before,
+      bufferIdentityChangedAfterGrow: before !== after,
+      oldBufferLength: before.byteLength,
+      newBufferLength: after.byteLength,
+      returnedViewUsesOldBuffer: cloned.buffer === before,
+      returnedViewUsesNewBuffer: cloned.buffer === after
+    }
+    console.log(result)
+    assert.strictEqual(result.returnedViewUsesOldBuffer, false)
+    assert.strictEqual(result.returnedViewUsesNewBuffer, true)
+  }
 })

packages/test/util.js

@@ -93,6 +93,7 @@ function loadPath (request, options) {
             }
           }
         }).then((source) => {
+          napiModule.wasmMemory = source.instance.exports.memory
           if (process.env.EMNAPI_TEST_4GB) {
             source.instance.exports.malloc(2147483648)
           }
@@ -157,6 +158,7 @@ function loadPath (request, options) {
           }
         }).then(({ instance }) => {
           wasmMemory = instance.exports.memory || sharedMemory
+          napiModule.wasmMemory = wasmMemory
           resolve(napiModule.exports)
         }).catch(reject)
       })