Fix invalid reference counts after internal realloc, see #672

Previously realloc falsely copied the RC of the old block and missed to inform rtrace of the implicit free
AssemblyScript · Jun 17, 2019 · 49edefc · 49edefc
1 parent f48f3c9
commit 49edefc
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Showing 35 changed files with 794 additions and 747 deletions.
diff --git a/src/builtins.ts b/src/builtins.ts
@@ -4060,14 +4060,14 @@ export function compileVisitMembers(compiler: Compiler): void {
     assert(id == lastId++);
 
     let visitImpl: Element | null;
+    let code = new Array<ExpressionRef>();
 
     // if a library element, check if it implements a custom traversal function
     if (instance.isDeclaredInLibrary && (visitImpl = instance.lookupInSelf("__visit_impl"))) {
       assert(visitImpl.kind == ElementKind.FUNCTION_PROTOTYPE);
       let visitFunc = program.resolver.resolveFunction(<FunctionPrototype>visitImpl, null);
-      let block: RelooperBlockRef;
       if (!visitFunc || !compiler.compileFunction(visitFunc)) {
-        block = relooper.addBlock(
+        code.push(
           module.unreachable()
         );
       } else {
@@ -4078,26 +4078,16 @@ export function compileVisitMembers(compiler: Compiler): void {
           visitSig.returnType == Type.void &&
           visitSig.thisType == instance.type
         );
-        let callExpr = module.call(visitFunc.internalName, [
-          module.local_get(0, nativeSizeType), // ref
-          module.local_get(1, NativeType.I32)  // cookie
-        ], NativeType.None);
-        block = relooper.addBlock(
-          instance.base
-            ? callExpr // branch will be added later
-            : module.block(null, [
-                callExpr,
-                module.return()
-              ])
+        code.push(
+          module.call(visitFunc.internalName, [
+            module.local_get(0, nativeSizeType), // ref
+            module.local_get(1, NativeType.I32)  // cookie
+          ], NativeType.None)
         );
       }
-      relooper.addBranchForSwitch(outer, block, [ id ]);
-      blocks.push(block);
 
-    // otherwise generate one
+    // otherwise generate traversal logic for own fields
     } else {
-      // traverse references assigned to own fields
-      let code = new Array<ExpressionRef>();
       let members = instance.members;
       if (members) {
         for (let member of members.values()) {
@@ -4127,13 +4117,13 @@ export function compileVisitMembers(compiler: Compiler): void {
           }
         }
       }
-      if (!instance.base) code.push(module.return());
-      let block = relooper.addBlock(
-        flatten(module, code, NativeType.None)
-      );
-      relooper.addBranchForSwitch(outer, block, [ id ]);
-      blocks.push(block);
     }
+    if (!instance.base) code.push(module.return());
+    let block = relooper.addBlock(
+      flatten(module, code, NativeType.None)
+    );
+    relooper.addBranchForSwitch(outer, block, [ id ]);
+    blocks.push(block);
   }
   for (let [id, instance] of managedClasses) {
     let base = instance.base;

diff --git a/std/assembly/rt/pure.ts b/std/assembly/rt/pure.ts
@@ -23,7 +23,7 @@ import { onincrement, ondecrement, onfree, onalloc } from "./rtrace";
 // @ts-ignore: decorator
 @inline const COLOR_MASK: u32 = ((1 << COLOR_BITS) - 1) << COLOR_SHIFT;
 // @ts-ignore: decorator
-@inline const REFCOUNT_MASK: u32 = (1 << COLOR_SHIFT) - 1;
+@inline export const REFCOUNT_MASK: u32 = (1 << COLOR_SHIFT) - 1;
 
 // ╒════════╤═══════════════════ Colors ═══════════════════════════╕
 // │ Color  │ Meaning                                              │

diff --git a/std/assembly/rt/tlsf.ts b/std/assembly/rt/tlsf.ts
@@ -1,5 +1,6 @@
 import { AL_BITS, AL_MASK, DEBUG, BLOCK, BLOCK_OVERHEAD, BLOCK_MAXSIZE } from "rt/common";
 import { onfree, onalloc } from "./rtrace";
+import { REFCOUNT_MASK } from "./pure";
 
 /////////////////////// The TLSF (Two-Level Segregate Fit) memory allocator ///////////////////////
 //                             see: http://www.gii.upv.es/tlsf/
@@ -490,7 +491,12 @@ export function allocateBlock(root: Root, size: usize): Block {
 export function reallocateBlock(root: Root, block: Block, size: usize): Block {
   var payloadSize = prepareSize(size);
   var blockInfo = block.mmInfo;
-  if (DEBUG) assert(!(blockInfo & FREE)); // must be used
+  if (DEBUG) {
+    assert(
+      !(blockInfo & FREE) &&           // must be used
+      !(block.gcInfo & ~REFCOUNT_MASK) // not buffered or != BLACK
+    );
+  }
 
   // possibly split and update runtime size if it still fits
   if (payloadSize <= (blockInfo & ~TAGS_MASK)) {
@@ -517,11 +523,11 @@ export function reallocateBlock(root: Root, block: Block, size: usize): Block {
 
   // otherwise move the block
   var newBlock = allocateBlock(root, size);
-  newBlock.gcInfo = block.gcInfo;
   newBlock.rtId = block.rtId;
   memory.copy(changetype<usize>(newBlock) + BLOCK_OVERHEAD, changetype<usize>(block) + BLOCK_OVERHEAD, size);
   block.mmInfo = blockInfo | FREE;
   insertBlock(root, block);
+  if (isDefined(ASC_RTRACE)) onfree(block);
   return newBlock;
 }
 

diff --git a/tests/compiler/rc/global-init.optimized.wat b/tests/compiler/rc/global-init.optimized.wat
@@ -94,7 +94,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 276
+   i32.const 277
    i32.const 13
    call $~lib/builtins/abort
    unreachable
@@ -116,7 +116,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 278
+   i32.const 279
    i32.const 13
    call $~lib/builtins/abort
    unreachable
@@ -161,7 +161,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 291
+   i32.const 292
    i32.const 13
    call $~lib/builtins/abort
    unreachable
@@ -258,7 +258,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 204
+   i32.const 205
    i32.const 13
    call $~lib/builtins/abort
    unreachable
@@ -272,7 +272,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 206
+   i32.const 207
    i32.const 13
    call $~lib/builtins/abort
    unreachable
@@ -345,7 +345,7 @@
    if
     i32.const 0
     i32.const 88
-    i32.const 227
+    i32.const 228
     i32.const 15
     call $~lib/builtins/abort
     unreachable
@@ -402,7 +402,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 242
+   i32.const 243
    i32.const 13
    call $~lib/builtins/abort
    unreachable
@@ -417,7 +417,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 243
+   i32.const 244
    i32.const 13
    call $~lib/builtins/abort
    unreachable
@@ -467,7 +467,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 259
+   i32.const 260
    i32.const 13
    call $~lib/builtins/abort
    unreachable
@@ -541,7 +541,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 531
+   i32.const 537
    i32.const 2
    call $~lib/builtins/abort
    unreachable
@@ -599,7 +599,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 385
+   i32.const 386
    i32.const 4
    call $~lib/builtins/abort
    unreachable
@@ -616,7 +616,7 @@
    if
     i32.const 0
     i32.const 88
-    i32.const 395
+    i32.const 396
     i32.const 15
     call $~lib/builtins/abort
     unreachable
@@ -644,7 +644,7 @@
    if
     i32.const 0
     i32.const 88
-    i32.const 407
+    i32.const 408
     i32.const 4
     call $~lib/builtins/abort
     unreachable
@@ -781,7 +781,7 @@
   if
    i32.const 232
    i32.const 88
-   i32.const 447
+   i32.const 448
    i32.const 29
    call $~lib/builtins/abort
    unreachable
@@ -856,7 +856,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 337
+   i32.const 338
    i32.const 13
    call $~lib/builtins/abort
    unreachable
@@ -908,7 +908,7 @@
     if
      i32.const 0
      i32.const 88
-     i32.const 350
+     i32.const 351
      i32.const 17
      call $~lib/builtins/abort
      unreachable
@@ -978,7 +978,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 364
+   i32.const 365
    i32.const 13
    call $~lib/builtins/abort
    unreachable
@@ -1064,7 +1064,7 @@
    if
     i32.const 0
     i32.const 88
-    i32.const 477
+    i32.const 478
     i32.const 15
     call $~lib/builtins/abort
     unreachable
@@ -1079,7 +1079,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 479
+   i32.const 480
    i32.const 13
    call $~lib/builtins/abort
    unreachable
@@ -1302,7 +1302,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 561
+   i32.const 567
    i32.const 13
    call $~lib/builtins/abort
    unreachable
@@ -1318,7 +1318,7 @@
   if
    i32.const 0
    i32.const 88
-   i32.const 562
+   i32.const 568
    i32.const 2
    call $~lib/builtins/abort
    unreachable