Fix broken object modification in thread.

benchmarks/bench-binary-tree-3.b

@@ -0,0 +1,52 @@
+import thread
+
+var start = time()
+
+var N = 21
+
+def make_tree(depth) {
+  if depth <= 0 return [nil, nil]
+  depth -= 1
+  return [make_tree(depth), make_tree(depth)]
+}
+
+def check_tree(node) {
+  var left = node[0], right = node[1]
+  if !left return 1
+  return 1 + check_tree(left) + check_tree(right)
+}
+
+var min_depth = 4
+var max_depth = max(min_depth + 2, N)
+var stretch_depth = max_depth + 1
+
+echo 'stretch tree of depth ${stretch_depth}\t check: ${check_tree(make_tree(stretch_depth))}'
+
+var long_lived_tree = make_tree(max_depth)
+
+var iterations = 2 ** max_depth
+
+var thrds = []
+var lines = []
+iter var depth = min_depth; depth < stretch_depth; depth += 2 {
+  lines.append(nil)
+
+  thrds.append(thread.start(@(_, lines, i, iterations, depth){
+    var check = 0
+    for i in 1..(iterations + 1) {
+      check += check_tree(make_tree(depth))
+    }
+
+    lines[i] = '${iterations}\t trees of depth ${depth}\t check: ${check}'
+  }, [lines, lines.length() - 1, iterations, depth]))
+
+  iterations //= 4
+}
+
+iter var i = 0; i < thrds.length(); i++ {
+  thrds[i].await()
+  echo lines[i]
+}
+
+echo 'long lived tree of depth ${max_depth}\t check: ${check_tree(long_lived_tree)}'
+echo 'Total time taken: ${time() - start}'

benchmarks/bench-binary-tree.b

@@ -13,41 +13,40 @@ class TreeNode {
     self.right = right
   }
 
-  check() {
+  count() {
     if self.left == nil return 1
-    return 1 + self.left.check() + self.right.check()
+    return 1 + self.left.count() + self.right.count()
   }
 }
 
-def bottomUpTree(depth) {
+def tree_with(depth) {
   if depth > 0 {
-    return TreeNode(bottomUpTree(depth - 1), bottomUpTree(depth - 1))
+    return TreeNode(tree_with(depth - 1), tree_with(depth - 1))
   }
   return TreeNode(nil, nil)
 }
 
 def main(n) {
-  var minDepth = 4
-  var maxDepth = max(minDepth + 2, n)
-  var stretchDepth = maxDepth + 1
+  var min_depth = 4
+  var max_depth = max(min_depth + 2, n)
+  var stretch_depth = max_depth + 1
 
-  echo 'stretch tree of depth ${stretchDepth}\t check: ${bottomUpTree(stretchDepth).check()}'
+  echo 'stretch tree of depth ${stretch_depth}\t check: ${tree_with(stretch_depth).count()}'
 
-  var longLivedTree = bottomUpTree(maxDepth)
+  var long_lived_tree = tree_with(max_depth)
 
-  iter var depth = minDepth; depth <= maxDepth; depth += 2 {
-    var check = 0
-    var iterations = 1 << (maxDepth - depth + minDepth)
+  iter var depth = min_depth; depth <= max_depth; depth += 2 {
+    var sum = 0
+    var iterations = 1 << (max_depth - depth + min_depth)
 
     iter var i = 1; i <= iterations; i++ {
-      var tempTree = bottomUpTree(depth)
-      check += tempTree.check()
+      sum += tree_with(depth).count()
     }
 
-    echo '${iterations}\t trees of depth ${depth}\t check: ${check}'
+    echo '${iterations}\t trees of depth ${depth}\t check: ${sum}'
   }
 
-  echo 'long lived tree of depth ${maxDepth}\t check: ${longLivedTree.check()}'
+  echo 'long lived tree of depth ${max_depth}\t check: ${long_lived_tree.count()}'
 }
 
 var start = time()

src/common.h

@@ -95,7 +95,9 @@
 # define LIBRARY_FILE_EXTENSION ".so"
 #endif
 
-#define DEFAULT_GC_START (1024 * 1024)
+//#define DEFAULT_GC_START (1024 * 1024)
+#define DEFAULT_GC_START (1024 * 1024 * 10)
+#define MINIMUM_GC_START (1024 * 1024)
 
 #if defined(_WIN32) && !defined(errno) 
 # define errno (GetLastError())

src/config.h.in

@@ -17,16 +17,18 @@
 #define MAX_USING_CASES 256
 #define MAX_FUNCTION_PARAMETERS 255
 #define FRAMES_MAX 512
-#define ERRORS_MAX 512
+#define ERRORS_MAX 256
 #define NUMBER_FORMAT "%.16g"
 #define MAX_INTERPOLATION_NESTING 8
 #define MAX_EXCEPTION_HANDLERS 16
 
+#define TABLE_MAX_LOAD 0.75
 // Maximum load factor of 12/14
 // see: https://engineering.fb.com/2019/04/25/developer-tools/f14/
-#define TABLE_MAX_LOAD 0.85714286
+// #define TABLE_MAX_LOAD 0.85714286
 
-#define GC_HEAP_GROWTH_FACTOR 1.25
+// #define GC_HEAP_GROWTH_FACTOR 1.25
+#define GC_HEAP_GROWTH_FACTOR 1.5
 
 #define USE_NAN_BOXING 1
 #define PCRE2_CODE_UNIT_WIDTH 8

src/memory.c

@@ -121,7 +121,7 @@ void blacken_object(b_vm *vm, b_obj *object) {
   printf("\n");
 #endif
 
-//  if(object->vm_id != vm->id) return;
+  if(object->vm_id != vm->id) return;
 
   switch (object->type) {
     case OBJ_MODULE: {
@@ -428,6 +428,10 @@ void collect_garbage(b_vm *vm) {
   free_error_stacks(vm);
 
   vm->next_gc = vm->bytes_allocated * GC_HEAP_GROWTH_FACTOR;
+  if(vm->next_gc < MINIMUM_GC_START) {
+    vm->next_gc = MINIMUM_GC_START;
+  }
+
   vm->mark_value = !vm->mark_value;
 
 #if defined(DEBUG_GC) && DEBUG_GC

src/object.c

@@ -27,6 +27,19 @@ b_obj *allocate_object(b_vm *vm, size_t size, b_obj_type type) {
   return object;
 }
 
+void migrate_objects(b_vm *src, b_vm *dest) {
+  if(dest->objects != NULL) {
+    dest->objects->next = src->objects;
+  }
+
+  b_obj *object = src->objects;
+  while (object != NULL) {
+    b_obj *next = object->next;
+    object->vm_id = (int)dest->id;
+    object = next;
+  }
+}
+
 
 b_obj_ptr *new_ptr(b_vm *vm, void *pointer) {
   b_obj_ptr *ptr = ALLOCATE_OBJ(b_obj_ptr, OBJ_PTR);

src/object.h

@@ -284,6 +284,7 @@ static inline bool is_obj_type(b_value v, b_obj_type t) {
   (type *)allocate_object(vm, sizeof(type), obj_type)
 
 b_obj *allocate_object(b_vm *vm, size_t size, b_obj_type type);
+void migrate_objects(b_vm *src, b_vm *dest);
 
 #define ITER_TOOL_PREPARE() \
   int arity = closure->function->arity; \

src/standard/thread.c

@@ -154,6 +154,7 @@ b_vm *copy_vm(b_vm *src, uint64_t id) {
 
   memset(vm, 0, sizeof(b_vm));
 
+  vm->parent_vm = src;
   vm->stack = ALLOCATE(b_value, COPIED_STACK_MIN);
   vm->stack_capacity = COPIED_STACK_MIN;
 
@@ -237,6 +238,11 @@ static b_thread_handle *create_thread_handle(b_vm *vm, b_obj_closure *closure, b
 
 static void free_thread_handle(b_thread_handle *thread) {
   if(thread != NULL && thread->vm != NULL) {
+    // move the surviving items to the parent vm's object list.
+    if(thread->vm->parent_vm != NULL) {
+      migrate_objects(thread->vm, thread->vm->parent_vm);
+    }
+
     free_vm(thread->vm);
 
     thread->vm = NULL;

src/vm.c

@@ -515,6 +515,7 @@ static void init_builtin_methods(b_vm *vm) {
 
 void init_vm(b_vm *vm) {
 
+  vm->parent_vm = NULL;
   vm->stack = ALLOCATE(b_value, STACK_MIN);
   vm->stack_capacity = STACK_MIN;
 
@@ -527,7 +528,7 @@ void init_vm(b_vm *vm) {
   vm->current_frame = NULL;
   vm->root_file = NULL;
   vm->bytes_allocated = 0;
-  vm->next_gc = DEFAULT_GC_START; // default is 1mb. Can be modified via the -g flag.
+  vm->next_gc = DEFAULT_GC_START; // default is 10mb. Can be modified via the -g flag.
   vm->is_repl = false;
   vm->mark_value = true;
   vm->show_warnings = false;

src/vm.h

@@ -82,6 +82,7 @@ struct s_vm {
 
   // id
   uint64_t id;
+  b_vm *parent_vm;
 };
 
 void init_vm(b_vm *vm);