fix!: napi_adjust_external_memory no longer grow wasm memory (#207)

Author: toyobayashi

packages/emnapi/src/core/memory.ts

@@ -1,7 +1,6 @@
 /* eslint-disable @typescript-eslint/indent */
 
 import { emnapiCtx } from 'emnapi:shared'
-import { wasmMemory } from 'emscripten:runtime'
 import { from64, makeSetValue } from 'emscripten:parse-tools'
 import { $CHECK_ENV, $CHECK_ARG } from '../macro'
 import { $emnapiSetValueI64 as emnapiSetValueI64 } from '../util'
@@ -16,24 +15,14 @@ export function napi_adjust_external_memory (
   const envObject = emnapiCtx.envStore.get(env)!
   $CHECK_ARG!(envObject, adjusted_value)
 
-  const change_in_bytes_number = Number(change_in_bytes)
-
-  if (change_in_bytes_number < 0) {
-    return envObject.setLastError(napi_status.napi_invalid_arg)
-  }
-
-  const old_size = wasmMemory.buffer.byteLength
-  let new_size = old_size + change_in_bytes_number
-  new_size = new_size + ((65536 - new_size % 65536) % 65536)
-  if (wasmMemory.grow((new_size - old_size + 65535) >> 16) === -1) {
-    return envObject.setLastError(napi_status.napi_generic_failure)
-  }
+  // eslint-disable-next-line prefer-const
+  let adjusted_memory = emnapiCtx.adjustAmountOfExternalAllocatedMemory(change_in_bytes)
 
   from64('adjusted_value')
   if (emnapiCtx.feature.supportBigInt) {
-    makeSetValue('adjusted_value', 0, 'wasmMemory.buffer.byteLength', 'i64')
+    makeSetValue('adjusted_value', 0, 'adjusted_memory', 'i64')
   } else {
-    emnapiSetValueI64(adjusted_value, wasmMemory.buffer.byteLength)
+    emnapiSetValueI64(adjusted_value, Number(adjusted_memory))
   }
 
   return envObject.clearLastError()

packages/emnapi/src/emscripten/memory.ts

@@ -1,14 +1,10 @@
-import { wasmMemory } from 'emscripten:runtime'
+/* eslint-disable @typescript-eslint/indent */
 import { emnapiCtx } from 'emnapi:shared'
 import { from64, makeSetValue } from 'emscripten:parse-tools'
 import { $emnapiSetValueI64 as emnapiSetValueI64 } from '../util'
 import { $CHECK_ENV } from '../macro'
 
-/* eslint-disable @typescript-eslint/indent */
-declare function _emscripten_resize_heap (requested: number): boolean
-
 /**
- * @__deps emscripten_resize_heap
  * @__sig ipjp
  */
 export function napi_adjust_external_memory (
@@ -20,38 +16,28 @@ export function napi_adjust_external_memory (
   $CHECK_ENV!(env)
   const envObject = emnapiCtx.envStore.get(env)!
 
-  let change_in_bytes: number
+  let change_in_bytes: bigint
 
 // #if WASM_BIGINT
   if (!high) return envObject.setLastError(napi_status.napi_invalid_arg)
-  change_in_bytes = Number(low)
+  change_in_bytes = BigInt(low)
 // #else
   if (!adjusted_value) return envObject.setLastError(napi_status.napi_invalid_arg)
-  change_in_bytes = (low >>> 0) + (high * Math.pow(2, 32))
+  change_in_bytes = BigInt(low >>> 0) + (BigInt(high) << BigInt(32))
 // #endif
 
-  if (change_in_bytes < 0) {
-    return envObject.setLastError(napi_status.napi_invalid_arg)
-  }
-
-  if (change_in_bytes > 0) {
-    const old_size = wasmMemory.buffer.byteLength
-    const new_size = old_size + change_in_bytes
-    if (!_emscripten_resize_heap(new_size)) {
-      return envObject.setLastError(napi_status.napi_generic_failure)
-    }
-  }
+  const adjusted_memory = emnapiCtx.adjustAmountOfExternalAllocatedMemory(change_in_bytes)
 
 // #if WASM_BIGINT
   from64('high')
   if (emnapiCtx.feature.supportBigInt) {
-    makeSetValue('high', 0, 'wasmMemory.buffer.byteLength', 'i64')
+    makeSetValue('high', 0, 'adjusted_memory', 'i64')
   } else {
-    emnapiSetValueI64(high, wasmMemory.buffer.byteLength)
+    emnapiSetValueI64(high, Number(adjusted_memory))
   }
 // #else
   from64('adjusted_value')
-  makeSetValue('adjusted_value', 0, 'wasmMemory.buffer.byteLength', 'i64')
+  makeSetValue('adjusted_value', 0, 'adjusted_memory', 'i64')
 // #endif
 
   return envObject.clearLastError()

packages/runtime/src/Context.ts

@@ -24,6 +24,7 @@ import { Reference, ReferenceWithData, ReferenceWithFinalizer, type ReferenceOwn
 import { type IDeferrdValue, Deferred } from './Deferred'
 import { Store } from './Store'
 import { TrackedFinalizer } from './TrackedFinalizer'
+import { ExternalMemory } from './ExternalMemory'
 
 export type CleanupHookCallbackFunction = number | ((arg: number) => void)
 
@@ -110,6 +111,10 @@ class NodejsWaitingRequestCounter {
   }
 }
 
+export interface ContextOptions {
+  onExternalMemoryChange?: (current: bigint, old: bigint, delta: bigint) => any
+}
+
 export class Context {
   private _isStopping = false
   private _canCallIntoJs = true
@@ -122,6 +127,7 @@ export class Context {
   public handleStore = new HandleStore()
   private readonly refCounter?: NodejsWaitingRequestCounter
   private readonly cleanupQueue: CleanupQueue
+  private readonly _externalMemory: ExternalMemory
 
   public feature = {
     supportReflect,
@@ -135,8 +141,9 @@ export class Context {
     MessageChannel: _MessageChannel
   }
 
-  public constructor () {
+  public constructor (options?: ContextOptions) {
     this.cleanupQueue = new CleanupQueue()
+    this._externalMemory = new ExternalMemory(options?.onExternalMemoryChange)
     if (typeof process === 'object' && process !== null && typeof process.once === 'function') {
       this.refCounter = new NodejsWaitingRequestCounter()
       process.once('beforeExit', () => {
@@ -231,7 +238,11 @@ export class Context {
     return Deferred.create(this, value)
   }
 
-  createEnv (
+  public adjustAmountOfExternalAllocatedMemory (changeInBytes: number | bigint): bigint {
+    return this._externalMemory.adjust(changeInBytes)
+  }
+
+  public createEnv (
     filename: string,
     moduleApiVersion: number,
     makeDynCall_vppp: (cb: Ptr) => (a: Ptr, b: Ptr, c: Ptr) => void,
@@ -331,8 +342,8 @@ export class Context {
 
 let defaultContext: Context
 
-export function createContext (): Context {
-  return new Context()
+export function createContext (options?: ContextOptions): Context {
+  return new Context(options)
 }
 
 export function getDefaultContext (): Context {

packages/runtime/src/ExternalMemory.ts

@@ -0,0 +1,27 @@
+const kMaxReasonableBytes = BigInt(1) << BigInt(60)
+const kMinReasonableBytes = -kMaxReasonableBytes
+
+export class ExternalMemory {
+  total: bigint
+  onChange: ((current: bigint, old: bigint, delta: bigint) => any) | null
+
+  constructor (onChange?: (current: bigint, old: bigint, delta: bigint) => any) {
+    this.total = BigInt(0)
+    this.onChange = onChange ?? null
+  }
+
+  adjust (changeInBytes: number | bigint): bigint {
+    changeInBytes = BigInt(changeInBytes)
+    if (!(kMinReasonableBytes <= changeInBytes && changeInBytes < kMaxReasonableBytes)) {
+      throw new RangeError(`changeInBytes ${changeInBytes} is out of reasonable range`)
+    }
+    const old = this.total
+    this.total += changeInBytes
+    const amount = this.total
+    const onChange = this.onChange
+    if (changeInBytes) {
+      onChange?.(amount, old, changeInBytes)
+    }
+    return amount
+  }
+}

packages/runtime/src/index.ts

@@ -1,4 +1,4 @@
-export { createContext, getDefaultContext, Context, type CleanupHookCallbackFunction } from './Context'
+export { createContext, getDefaultContext, Context, type CleanupHookCallbackFunction, type ContextOptions } from './Context'
 export { Deferred, type IDeferrdValue } from './Deferred'
 export { Env, NodeEnv, type IReferenceBinding } from './env'
 export { EmnapiError, NotSupportWeakRefError, NotSupportBufferError } from './errors'