Rename heap to memory; Allocator strategies

Author: dcodeIO

bin/asc.js

@@ -105,8 +105,8 @@ function checkDiagnostics(parser) {
 }
 
 // Include standard library
+var stdlibDir = path.join(__dirname, "..", "std", "assembly");
 if (!args.noLib) {
-  var stdlibDir = path.join(__dirname, "..", "std", "assembly");
   var notIoTime = 0;
   readTime += measure(() => {
     glob.sync("*.ts", { cwd: stdlibDir }).forEach(file => {
@@ -156,7 +156,10 @@ args._.forEach(filename => {
   while ((nextPath = parser.nextFile()) != null) {
     try {
       readTime += measure(() => {
-        nextText = fs.readFileSync(nextPath + ".ts", { encoding: "utf8" });
+        if (nextPath.starsWith("std:"))
+          nextText = fs.readFileSync(stdlibDir + "/" + nextPath.substring(4) + ".ts", { encoding: "utf8" });
+        else
+          nextText = fs.readFileSync(nextPath + ".ts", { encoding: "utf8" });
       });
       ++readCount;
     } catch (e) {

std/assembly/heap.ts renamed to std/assembly/memory.ts

@@ -1,24 +1,4 @@
-const ALIGN_LOG2: usize = 3;
-const ALIGN_SIZE: usize = 1 << ALIGN_LOG2;
-const ALIGN_MASK: usize = ALIGN_SIZE - 1;
-
-var HEAP_OFFSET: usize = HEAP_BASE; // HEAP_BASE is a constant generated by the compiler
-
-export function allocate_memory(size: usize): usize {
-  if (!size) return 0;
-  var len: i32 = current_memory();
-  if (HEAP_OFFSET + size > <usize>len << 16)
-    if(grow_memory(max<i32>(<i32>ceil<f64>(<f64>size / 65536), len * 2 - len)) < 0)
-      unreachable();
-  var ptr: usize = HEAP_OFFSET;
-  if ((HEAP_OFFSET += size) & ALIGN_MASK) // align next offset
-    HEAP_OFFSET = (HEAP_OFFSET | ALIGN_MASK) + 1;
-  return ptr;
-}
-
-export function free_memory(ptr: usize): void {
-  // just a big chunk of non-disposable memory for now
-}
+import "std:memory/arena";
 
 function copy_memory(dest: usize, src: usize, n: usize): void {
   // based on musl's implementation of memcpy

std/assembly/memory/arena.ts

@@ -0,0 +1,30 @@
+// An simple arena allocator that provides a `clear_memory` function to reset
+// everything to the initial state. A user must have to make sure that there
+// a no more references to cleared memory.
+
+const ALIGN_LOG2: usize = 3;
+const ALIGN_SIZE: usize = 1 << ALIGN_LOG2;
+const ALIGN_MASK: usize = ALIGN_SIZE - 1;
+
+var HEAP_OFFSET: usize = HEAP_BASE; // generated by the compiler
+
+export function allocate_memory(size: usize): usize {
+  if (!size) return 0;
+  var len: i32 = current_memory();
+  if (HEAP_OFFSET + size > <usize>len << 16)
+    if(grow_memory(max<i32>(<i32>ceil<f64>(<f64>size / 65536), len * 2 - len)) < 0)
+      unreachable();
+  var ptr: usize = HEAP_OFFSET;
+  if ((HEAP_OFFSET += size) & ALIGN_MASK) // align next offset
+    HEAP_OFFSET = (HEAP_OFFSET | ALIGN_MASK) + 1;
+  set_memory(ptr, 0, size);
+  return ptr;
+}
+
+export function free_memory(ptr: usize): void {
+  // nop
+}
+
+export function clear_memory(): void {
+  HEAP_OFFSET = HEAP_BASE;
+}

tests/compiler.js

@@ -15,7 +15,8 @@ var ElementKind = require("../src/program").ElementKind;
 var isCreate = process.argv[2] === "--create";
 var filter = process.argv.length > 2 && !isCreate ? "**/" + process.argv[2] + ".ts" : "**/*.ts";
 
-var stdFiles = glob.sync("*.ts", { cwd: __dirname + "/../std/assembly" });
+var stdDir = __dirname + "/../std/assembly";
+var stdFiles = glob.sync("*.ts", { cwd: stdDir });
 
 var success = 0;
 var failures = 0;
@@ -42,7 +43,10 @@ glob.sync(filter, { cwd: __dirname + "/compiler" }).forEach(filename => {
   while ((nextFile = parser.nextFile()) !== null) {
     var nextSourceText;
     try {
-      nextSourceText = fs.readFileSync(path.join(__dirname, "compiler", nextFile + ".ts"), { encoding: "utf8" });
+      if (nextFile.startsWith("std:"))
+        nextSourceText = fs.readFileSync(path.join(stdDir, nextFile.substring(4) + ".ts"), { encoding: "utf8" });
+      else
+        nextSourceText = fs.readFileSync(path.join(__dirname, "compiler", nextFile + ".ts"), { encoding: "utf8" });
     } catch (e) {
       nextSourceText = fs.readFileSync(path.join(__dirname, "compiler", nextFile, "index.ts"), { encoding: "utf8" });
     }