feat: Generalize runtime (#1503)

BREAKING CHANGE: The `__alloc` family of built-ins has been split, now being named `__new`. `__renew`, `__newString`, `__newArray` etc. when dealing with managed objects. Furthermore, internal memory layouts of managed objects have changed. As a result, the new `heap.alloc/realloc/free` APIs now allow working with unmanaged heap memory more naturally and do not imply a managed object header anymore, more closely resembling `malloc/realloc/free` in C.

Author: dcodeIO

lib/loader/index.d.ts

@@ -25,10 +25,6 @@ export interface ASUtil {
 
   /** Explicit start function, if requested. */
   _start(): void;
-  /** Allocates a new string in the module's memory and returns a reference (pointer) to it. */
-  __allocString(str: string): number;
-  /** Allocates a new array in the module's memory and returns a reference (pointer) to it. */
-  __allocArray(id: number, values: ArrayLike<number>): number;
 
   /** Copies a string's value from the module's memory. */
   __getString(ptr: number): string;
@@ -85,14 +81,18 @@ export interface ASUtil {
   /** Gets a live view on a Float64Array's values in the module's memory. */
   __getFloat64ArrayView(ptr: number): Float64Array;
 
+  /** Allocates an instance of the class represented by the specified id. */
+  __new(size: number, id: number): number;
+  /** Allocates a new string in the module's memory and returns a reference (pointer) to it. */
+  __newString(str: string): number;
+  /** Allocates a new array in the module's memory and returns a reference (pointer) to it. */
+  __newArray(id: number, values: ArrayLike<number>): number;
   /** Retains a reference to a managed object externally, making sure that it doesn't become collected prematurely. Returns the pointer. */
   __retain(ptr: number): number;
   /** Releases a previously retained reference to a managed object, allowing the runtime to collect it once its reference count reaches zero. */
   __release(ptr: number): void;
   /** Forcefully resets the heap to its initial offset, effectively clearing dynamic memory. Stub runtime only. */
   __reset?(): void;
-  /** Allocates an instance of the class represented by the specified id. */
-  __alloc(size: number, id: number): number;
   /** Tests whether a managed object is an instance of the class represented by the specified base id. */
   __instanceof(ptr: number, baseId: number): boolean;
   /** Forces a cycle collection. Only relevant if objects potentially forming reference cycles are used. */

lib/loader/index.js

@@ -81,7 +81,7 @@ function postInstantiate(extendedExports, instance) {
   const exports = instance.exports;
   const memory = exports.memory;
   const table = exports.table;
-  const alloc = exports["__alloc"];
+  const new_ = exports["__new"];
   const retain = exports["__retain"];
   const rttiBase = exports["__rtti_base"] || ~0; // oob if not present
 
@@ -119,15 +119,15 @@ function postInstantiate(extendedExports, instance) {
   // }
 
   /** Allocates a new string in the module's memory and returns its retained pointer. */
-  function __allocString(str) {
+  function __newString(str) {
     const length = str.length;
-    const ptr = alloc(length << 1, STRING_ID);
+    const ptr = new_(length << 1, STRING_ID);
     const U16 = new Uint16Array(memory.buffer);
     for (var i = 0, p = ptr >>> 1; i < length; ++i) U16[p + i] = str.charCodeAt(i);
     return ptr;
   }
 
-  extendedExports.__allocString = __allocString;
+  extendedExports.__newString = __newString;
 
   /** Reads a string from the module's memory by its pointer. */
   function __getString(ptr) {
@@ -159,16 +159,16 @@ function postInstantiate(extendedExports, instance) {
   }
 
   /** Allocates a new array in the module's memory and returns its retained pointer. */
-  function __allocArray(id, values) {
+  function __newArray(id, values) {
     const info = getArrayInfo(id);
     const align = getValueAlign(info);
     const length = values.length;
-    const buf = alloc(length << align, info & STATICARRAY ? id : ARRAYBUFFER_ID);
+    const buf = new_(length << align, info & STATICARRAY ? id : ARRAYBUFFER_ID);
     let result;
     if (info & STATICARRAY) {
       result = buf;
     } else {
-      const arr = alloc(info & ARRAY ? ARRAY_SIZE : ARRAYBUFFERVIEW_SIZE, id);
+      const arr = new_(info & ARRAY ? ARRAY_SIZE : ARRAYBUFFERVIEW_SIZE, id);
       const U32 = new Uint32Array(memory.buffer);
       U32[arr + ARRAYBUFFERVIEW_BUFFER_OFFSET >>> 2] = retain(buf);
       U32[arr + ARRAYBUFFERVIEW_DATASTART_OFFSET >>> 2] = buf;
@@ -185,7 +185,7 @@ function postInstantiate(extendedExports, instance) {
     return result;
   }
 
-  extendedExports.__allocArray = __allocArray;
+  extendedExports.__newArray = __newArray;
 
   /** Gets a live view on an array's values in the module's memory. Infers the array type from RTTI. */
   function __getArrayView(arr) {

lib/loader/tests/build/default.wasm

@@ -31,7 +31,7 @@ function test(file) {
   // should be able to allocate and work with a new small string
   {
     let str = "Hello world!𤭢";
-    let ref = exports.__retain(exports.__allocString(str));
+    let ref = exports.__retain(exports.__newString(str));
     assert.strictEqual(exports.__getString(ref), str);
     assert.strictEqual(exports.strlen(ref), str.length);
     exports.__release(ref);
@@ -46,7 +46,7 @@ function test(file) {
       ≔ ≕ ≖ ≗ ≘ ≙ ≚ ≛ ≜ ≝ ≞ ≟ ≠ ≡ ≢ ≣ ≤ ≥ ≦ ≧ ≨ ≩ ≪ ≫ ≬ ≭ ≮ ≯
       ≰ ≱ ≲ ≳ ≴ ≵ ≶ ≷ ≸ ≹ ≺ ≻ ≼ ≽ ≾ ≿
     `;
-    let ref = exports.__retain(exports.__allocString(str));
+    let ref = exports.__retain(exports.__newString(str));
     assert.strictEqual(exports.__getString(ref), str);
     assert.strictEqual(exports.strlen(ref), str.length);
     exports.__release(ref);
@@ -55,7 +55,7 @@ function test(file) {
   // should be able to allocate a typed array
   {
     let arr = [1, 2, 3, 4, 5, 0x80000000 | 0];
-    let ref = exports.__retain(exports.__allocArray(exports.INT32ARRAY_ID, arr));
+    let ref = exports.__retain(exports.__newArray(exports.INT32ARRAY_ID, arr));
     assert(exports.__instanceof(ref, exports.INT32ARRAY_ID));
 
     // should be able to get the values of an array
@@ -75,7 +75,7 @@ function test(file) {
   // should be able to allocate a typed array
   {
     let arr = [1, 2, 3, 4, 5, 0x80000000 | 0];
-    let ref = exports.__retain(exports.__allocArray(exports.STATICARRAYI32_ID, arr));
+    let ref = exports.__retain(exports.__newArray(exports.STATICARRAYI32_ID, arr));
     assert(exports.__instanceof(ref, exports.STATICARRAYI32_ID));
 
     // should be able to get the values of an array
@@ -95,21 +95,21 @@ function test(file) {
   /*
   {
     let arrU8Arr = new Uint8Array([0, 1, 2]);
-    let refU8Arr = module.__retain(module.__allocUint8Array(arrU8Arr));
+    let refU8Arr = module.__retain(module.__newUint8Array(arrU8Arr));
     assert(module.__instanceof(refU8Arr, module.UINT8ARRAY_ID));
     assert.deepEqual(module.__getUint8Array(refU8Arr), arrU8Arr);
     module.__release(refU8Arr);
     try { module.__release(refU8Arr); assert(false); } catch (e) {};
 
     let arrU16Arr = new Uint16Array([0, 0x7FFF, 0xFFFF]);
-    let refU16Arr = module.__retain(module.__allocUint16Array(arrU16Arr));
+    let refU16Arr = module.__retain(module.__newUint16Array(arrU16Arr));
     assert(module.__instanceof(refU16Arr, module.UINT16ARRAY_ID));
     assert.deepEqual(module.__getUint16Array(refU16Arr), arrU16Arr);
     module.__release(refU16Arr);
     try { module.__release(refU16Arr); assert(false); } catch (e) {};
 
     let arrI16Arr = new Int16Array([0, -1, -2]);
-    let refI16Arr = module.__retain(module.__allocInt16Array(arrI16Arr));
+    let refI16Arr = module.__retain(module.__newInt16Array(arrI16Arr));
     assert(module.__instanceof(refI16Arr, module.INT16ARRAY_ID));
     assert.deepEqual(module.__getInt16Array(refI16Arr), arrI16Arr);
     module.__release(refI16Arr);
@@ -121,7 +121,7 @@ function test(file) {
   {
     let values = [0, 255, 127];
     let arr = new Uint8Array(values);
-    let ref = exports.__retain(exports.__allocArray(exports.UINT8ARRAY_ID, arr));
+    let ref = exports.__retain(exports.__newArray(exports.UINT8ARRAY_ID, arr));
     assert(exports.__instanceof(ref, exports.UINT8ARRAY_ID));
     assert.deepEqual(exports.__getUint8Array(ref), arr);
     assert.deepEqual(exports.__getUint8ArrayView(ref), arr);
@@ -133,7 +133,7 @@ function test(file) {
   // should be able to distinguish between signed and unsigned for static array layout
   {
     let arr = [0, 255, 127];
-    let ref = exports.__retain(exports.__allocArray(exports.STATICARRAYU8_ID, arr));
+    let ref = exports.__retain(exports.__newArray(exports.STATICARRAYU8_ID, arr));
     assert(exports.__instanceof(ref, exports.STATICARRAYU8_ID));
     assert.deepEqual(exports.__getArray(ref), arr);
     exports.__release(ref);
@@ -144,7 +144,7 @@ function test(file) {
   {
     let values = [0, 0xFFFF, -0x00FF];
     let arr = new Int16Array(values);
-    let ref = exports.__retain(exports.__allocArray(exports.INT16ARRAY_ID, arr));
+    let ref = exports.__retain(exports.__newArray(exports.INT16ARRAY_ID, arr));
     assert(exports.__instanceof(ref, exports.INT16ARRAY_ID));
     assert.deepEqual(exports.__getInt16Array(ref), arr);
     assert.deepEqual(exports.__getInt16ArrayView(ref), arr);
@@ -156,7 +156,7 @@ function test(file) {
   // should be able to distinguish between signed and unsigned for static array layout
   {
     let arr = [0, 0xFFFF, -0x00FF];
-    let ref = exports.__retain(exports.__allocArray(exports.STATICARRAYI16_ID, arr));
+    let ref = exports.__retain(exports.__newArray(exports.STATICARRAYI16_ID, arr));
     assert(exports.__instanceof(ref, exports.STATICARRAYI16_ID));
     assert.deepEqual(exports.__getArray(ref), [0, -1, -255]);
     exports.__release(ref);
@@ -167,7 +167,7 @@ function test(file) {
   {
     let values = [1, -1 >>> 0, 0x80000000];
     let arr = new Uint32Array(values);
-    let ref = exports.__retain(exports.__allocArray(exports.UINT32ARRAY_ID, arr));
+    let ref = exports.__retain(exports.__newArray(exports.UINT32ARRAY_ID, arr));
     assert(exports.__instanceof(ref, exports.UINT32ARRAY_ID));
     assert.deepEqual(exports.__getUint32Array(ref), arr);
     assert.deepEqual(exports.__getUint32ArrayView(ref), arr);
@@ -179,7 +179,7 @@ function test(file) {
   // should be able to distinguish between signed and unsigned with static array layout
   {
     let arr = [1, -1 >>> 0, 0x80000000];
-    let ref = exports.__retain(exports.__allocArray(exports.STATICARRAYU32_ID, arr));
+    let ref = exports.__retain(exports.__newArray(exports.STATICARRAYU32_ID, arr));
     assert(exports.__instanceof(ref, exports.STATICARRAYU32_ID));
     assert.deepEqual(exports.__getArray(ref), arr);
     exports.__release(ref);
@@ -190,7 +190,7 @@ function test(file) {
   {
     let values = [0.0, 1.5, 2.5];
     let arr = new Float32Array(values);
-    let ref = exports.__retain(exports.__allocArray(exports.FLOAT32ARRAY_ID, arr));
+    let ref = exports.__retain(exports.__newArray(exports.FLOAT32ARRAY_ID, arr));
     assert(exports.__instanceof(ref, exports.FLOAT32ARRAY_ID));
     assert.deepEqual(exports.__getFloat32Array(ref), arr);
     assert.deepEqual(exports.__getFloat32ArrayView(ref), arr);
@@ -202,7 +202,7 @@ function test(file) {
   // should be able to distinguish between integer and float static arrays
   {
     let arr = [0.0, 1.5, 2.5];
-    let ref = exports.__retain(exports.__allocArray(exports.STATICARRAYF32_ID, arr));
+    let ref = exports.__retain(exports.__newArray(exports.STATICARRAYF32_ID, arr));
     assert(exports.__instanceof(ref, exports.STATICARRAYF32_ID));
     assert.deepEqual(exports.__getArray(ref), arr);
     exports.__release(ref);
@@ -212,7 +212,7 @@ function test(file) {
   // should be able to work with normal arrays
   {
     let arr = [1, 2, 3, 4, 5];
-    let ref = exports.__retain(exports.__allocArray(exports.ARRAYI32_ID, arr));
+    let ref = exports.__retain(exports.__newArray(exports.ARRAYI32_ID, arr));
     assert(exports.__instanceof(ref, exports.ARRAYI32_ID));
     exports.changeLength(ref, 3);
     assert.deepEqual(exports.__getArray(ref), [1, 2, 3]);
@@ -252,7 +252,7 @@ function test(file) {
 
   // should be able to mutate an array in place using getArrayView
   {
-    let ptr = exports.__retain(exports.__allocArray(exports.FLOAT32ARRAY_ID, [1, 2, 3]));
+    let ptr = exports.__retain(exports.__newArray(exports.FLOAT32ARRAY_ID, [1, 2, 3]));
     let view = exports.__getArrayView(ptr);
     assert.deepEqual(view, new Float32Array([1, 2, 3]));
     exports.modifyFloat32Array(ptr, 0, 4);

lib/loader/tests/build/legacy.wasm

@@ -95,7 +95,7 @@ var loader = (function(exports) {
     const exports = instance.exports;
     const memory = exports.memory;
     const table = exports.table;
-    const alloc = exports["__alloc"];
+    const new_ = exports["__new"];
     const retain = exports["__retain"];
     const rttiBase = exports["__rtti_base"] || ~0; // oob if not present
 
@@ -138,17 +138,17 @@ var loader = (function(exports) {
     /** Allocates a new string in the module's memory and returns its retained pointer. */
 
 
-    function __allocString(str) {
+    function __newString(str) {
       const length = str.length;
-      const ptr = alloc(length << 1, STRING_ID);
+      const ptr = new_(length << 1, STRING_ID);
       const U16 = new Uint16Array(memory.buffer);
 
       for (var i = 0, p = ptr >>> 1; i < length; ++i) U16[p + i] = str.charCodeAt(i);
 
       return ptr;
     }
 
-    extendedExports.__allocString = __allocString;
+    extendedExports.__newString = __newString;
     /** Reads a string from the module's memory by its pointer. */
 
     function __getString(ptr) {
@@ -193,17 +193,17 @@ var loader = (function(exports) {
     /** Allocates a new array in the module's memory and returns its retained pointer. */
 
 
-    function __allocArray(id, values) {
+    function __newArray(id, values) {
       const info = getArrayInfo(id);
       const align = getValueAlign(info);
       const length = values.length;
-      const buf = alloc(length << align, info & STATICARRAY ? id : ARRAYBUFFER_ID);
+      const buf = new_(length << align, info & STATICARRAY ? id : ARRAYBUFFER_ID);
       let result;
 
       if (info & STATICARRAY) {
         result = buf;
       } else {
-        const arr = alloc(info & ARRAY ? ARRAY_SIZE : ARRAYBUFFERVIEW_SIZE, id);
+        const arr = new_(info & ARRAY ? ARRAY_SIZE : ARRAYBUFFERVIEW_SIZE, id);
         const U32 = new Uint32Array(memory.buffer);
         U32[arr + ARRAYBUFFERVIEW_BUFFER_OFFSET >>> 2] = retain(buf);
         U32[arr + ARRAYBUFFERVIEW_DATASTART_OFFSET >>> 2] = buf;
@@ -223,7 +223,7 @@ var loader = (function(exports) {
       return result;
     }
 
-    extendedExports.__allocArray = __allocArray;
+    extendedExports.__newArray = __newArray;
     /** Gets a live view on an array's values in the module's memory. Infers the array type from RTTI. */
 
     function __getArrayView(arr) {

lib/loader/tests/index.js

@@ -9,7 +9,7 @@ const PTR_SIZE = 1 << PTR_SIZE_BITS;
 const PTR_MASK = PTR_SIZE - 1;
 const PTR_VIEW = Uint32Array;
 
-const BLOCK_OVERHEAD = 16;
+const BLOCK_OVERHEAD = PTR_SIZE;
 
 function assert(x) {
   if (!x) throw Error("assertion failed");
@@ -142,9 +142,10 @@ class Rtrace {
 
   /** Obtains information about a block. */
   getBlockInfo(ptr) {
-    var header = new Uint32Array(this.memory.buffer, ptr, 4);
+    var header = new Uint32Array(this.memory.buffer, ptr, 5);
     var mmInfo = header[0];
     var gcInfo = header[1];
+    var gcInfo2 = header[2];
     const mmTags = [ // 0│L│F
       [],
       ["FREE"],
@@ -171,8 +172,9 @@ class Rtrace {
           color: gcColor[gcInfo << 1 >>> 29],
           rc: gcInfo << 4 >>> 4
         },
-        rtId: header[2],
-        rtSize: header[3]
+        gcInfo2,
+        rtId: header[3],
+        rtSize: header[4]
       }
     };
   }

lib/loader/umd/index.js

@@ -607,7 +607,7 @@ export namespace BuiltinNames {
   export const v64x2_load_splat = "~lib/builtins/v64x2.load_splat";
 
   // internals
-  export const heap_base = "~lib/heap/__heap_base";
+  export const heap_base = "~lib/memory/__heap_base";
   export const rtti_base = "~lib/rt/__rtti_base";
   export const visit_globals = "~lib/rt/__visit_globals";
   export const visit_members = "~lib/rt/__visit_members";
@@ -2875,7 +2875,7 @@ function builtin_memory_data(ctx: BuiltinContext): ExpressionRef {
     }
     let buf = new Uint8Array(numElements * elementType.byteSize);
     assert(compiler.writeStaticBuffer(buf, 0, elementType, exprs) == buf.byteLength);
-    offset = compiler.addMemorySegment(buf, align).offset;
+    offset = compiler.addAlignedMemorySegment(buf, align).offset;
   } else { // data(size[, align])
     let arg0 = compiler.compileExpression(operands[0], Type.i32, Constraints.CONV_IMPLICIT);
     let precomp = module.runExpression(arg0, ExpressionRunnerFlags.PreserveSideeffects);
@@ -2904,7 +2904,7 @@ function builtin_memory_data(ctx: BuiltinContext): ExpressionRef {
         return module.unreachable();
       }
     }
-    offset = compiler.addMemorySegment(new Uint8Array(size), align).offset;
+    offset = compiler.addAlignedMemorySegment(new Uint8Array(size), align).offset;
   }
   // FIXME: what if recompiles happen? recompiles are bad.
   compiler.currentType = usizeType;
@@ -8885,7 +8885,7 @@ export function compileRTTI(compiler: Compiler): void {
   }
   assert(off == size);
   var usizeType = program.options.usizeType;
-  var segment = compiler.addMemorySegment(data);
+  var segment = compiler.addAlignedMemorySegment(data);
   if (usizeType.size == 8) {
     let offset = segment.offset;
     module.addGlobal(BuiltinNames.rtti_base, NativeType.I64, false, module.i64(i64_low(offset), i64_high(offset)));

lib/rtrace/index.js

@@ -229,14 +229,18 @@ export namespace CommonNames {
   export const alloc = "__alloc";
   export const realloc = "__realloc";
   export const free = "__free";
+  export const new_ = "__new";
+  export const renew = "__renew";
   export const retain = "__retain";
   export const release = "__release";
   export const collect = "__collect";
   export const typeinfo = "__typeinfo";
   export const instanceof_ = "__instanceof";
   export const visit = "__visit";
-  export const allocBuffer = "__allocBuffer";
-  export const allocArray = "__allocArray";
+  export const newBuffer = "__newBuffer";
+  export const newArray = "__newArray";
+  export const BLOCK = "~lib/rt/common/BLOCK";
+  export const OBJECT = "~lib/rt/common/OBJECT";
 }
 
 // shared