add PK_LOW_MEMORY_MODE

docs/modules/gc.md

@@ -5,4 +5,16 @@ label: gc
 
 ### `gc.collect()`
 
-Invoke the garbage collector.
+Invoke the garbage collector.
+
+### `gc.enable()`
+
+Enable automatic garbage collection.
+
+### `gc.disable()`
+
+Disable automatic garbage collection.
+
+### `gc.isenabled()`
+
+Return `True` if automatic garbage collection is enabled, `False` otherwise.

include/pocketpy/common/utils.h

@@ -45,6 +45,6 @@ typedef struct RefCounted {
     do {                                                                                           \
         if(--(obj)->rc.count == 0) {                                                               \
             (obj)->rc.dtor(obj);                                                                   \
-            free(obj);                                                                             \
+            PK_FREE(obj);                                                                             \
         }                                                                                          \
     } while(0)

include/pocketpy/config.h

@@ -8,6 +8,11 @@
 
 /*************** feature settings ***************/
 
+// Reduce the startup memory usage for embedded systems
+#ifndef PK_LOW_MEMORY_MODE          // can be overridden by cmake
+#define PK_LOW_MEMORY_MODE          0
+#endif
+
 // Whether to compile os-related modules or not
 #ifndef PK_ENABLE_OS                // can be overridden by cmake
 #define PK_ENABLE_OS                1
@@ -15,27 +20,37 @@
 
 // GC min threshold
 #ifndef PK_GC_MIN_THRESHOLD         // can be overridden by cmake
-#define PK_GC_MIN_THRESHOLD         16384
+    #if PK_LOW_MEMORY_MODE
+        #define PK_GC_MIN_THRESHOLD     2048
+    #else
+        #define PK_GC_MIN_THRESHOLD     16384
+    #endif
 #endif
 
-/*************** debug settings ***************/
-// Do not edit the following settings unless you know what you are doing
-#define PK_DEBUG_CEVAL_STEP         0
-#define PK_DEBUG_MEMORY_POOL        0
-#define PK_DEBUG_NO_AUTO_GC         0
-#define PK_DEBUG_GC_STATS           0
-#define PK_DEBUG_COMPILER           0
-
-/*************** internal settings ***************/
+// Memory allocation functions
+#ifndef PK_MALLOC
+#define PK_MALLOC(size)             malloc(size)
+#define PK_REALLOC(ptr, size)       realloc(ptr, size)
+#define PK_FREE(ptr)                free(ptr)
+#endif
 
 // This is the maximum size of the value stack in py_TValue units
 // The actual size in bytes equals `sizeof(py_TValue) * PK_VM_STACK_SIZE`
-#define PK_VM_STACK_SIZE            16384
+#ifndef PK_VM_STACK_SIZE            // can be overridden by cmake
+    #if PK_LOW_MEMORY_MODE
+        #define PK_VM_STACK_SIZE    2048
+    #else
+        #define PK_VM_STACK_SIZE    16384
+    #endif
+#endif
 
 // This is the maximum number of local variables in a function
 // (not recommended to change this)
+#ifndef PK_MAX_CO_VARNAMES          // can be overridden by cmake
 #define PK_MAX_CO_VARNAMES          64
+#endif
 
+/*************** internal settings ***************/
 // This is the maximum character length of a module path
 #define PK_MAX_MODULE_PATH_LEN      63
 
@@ -49,4 +64,4 @@
     #define PK_PLATFORM_SEP '\\'
 #else
     #define PK_PLATFORM_SEP '/'
-#endif
+#endif

include/pocketpy/interpreter/frame.h

@@ -11,11 +11,10 @@ py_TValue* FastLocals__try_get_by_name(py_TValue* locals, const CodeObject* co,
 NameDict* FastLocals__to_namedict(py_TValue* locals, const CodeObject* co);
 
 typedef struct ValueStack {
-    // We allocate extra PK_VM_STACK_SIZE/128 places to keep `_sp` valid when `is_overflow() ==
-    // true`.
     py_TValue* sp;
     py_TValue* end;
-    py_TValue begin[PK_VM_STACK_SIZE + PK_VM_STACK_SIZE / 128];
+    // We allocate extra places to keep `_sp` valid to detect stack overflow
+    py_TValue begin[PK_VM_STACK_SIZE + PK_MAX_CO_VARNAMES * 2];
 } ValueStack;
 
 void ValueStack__ctor(ValueStack* self);

include/pocketpy/interpreter/heap.h

@@ -6,6 +6,8 @@ typedef struct ManagedHeap{
 
     int gc_threshold;
     int gc_counter;
+    bool gc_enabled;
+    
     VM* vm;
 
     void (*gc_on_delete)(VM*, PyObject*);

include/pocketpy/xmacros/smallmap.h

@@ -59,14 +59,14 @@ void METHOD(ctor)(NAME* self) {
 void METHOD(dtor)(NAME* self) { c11_vector__dtor(self); }
 
 NAME* METHOD(new)() {
-    NAME* self = malloc(sizeof(NAME));
+    NAME* self = PK_MALLOC(sizeof(NAME));
     METHOD(ctor)(self);
     return self;
 }
 
 void METHOD(delete)(NAME* self) {
     METHOD(dtor)(self);
-    free(self);
+    PK_FREE(self);
 }
 
 void METHOD(set)(NAME* self, K key, V value) {

src/common/algorithm.c

@@ -1,8 +1,9 @@
 #include "pocketpy/common/algorithm.h"
+#include "pocketpy/config.h"
 #include <string.h>
 #include <stdlib.h>
 
-static bool merge(char* a,
+static bool _stable_sort_merge(char* a,
                   char* a_end,
                   char* b,
                   char* b_end,
@@ -38,19 +39,19 @@ bool c11__stable_sort(void* ptr_,
                       int (*f_lt)(const void* a, const void* b, void* extra),
                       void* extra) {
     // merge sort
-    char *ptr = ptr_, *tmp = malloc(length * elem_size);
+    char *ptr = ptr_, *tmp = PK_MALLOC(length * elem_size);
     for(int seg = 1; seg < length; seg *= 2) {
         for(char* a = ptr; a < ptr + (length - seg) * elem_size; a += 2 * seg * elem_size) {
             char *b = a + seg * elem_size, *a_end = b, *b_end = b + seg * elem_size;
             if(b_end > ptr + length * elem_size) b_end = ptr + length * elem_size;
-            bool ok = merge(a, a_end, b, b_end, tmp, elem_size, f_lt, extra);
+            bool ok = _stable_sort_merge(a, a_end, b, b_end, tmp, elem_size, f_lt, extra);
             if(!ok) {
-                free(tmp);
+                PK_FREE(tmp);
                 return false;
             }
             memcpy(a, tmp, b_end - a);
         }
     }
-    free(tmp);
+    PK_FREE(tmp);
     return true;
 }

src/common/memorypool.c

@@ -136,7 +136,7 @@ static void MemoryPool__ctor(MemoryPool* self) {
 static void* MemoryPool__alloc(MemoryPool* self) {
     MemoryPoolArena* arena;
     if(self->_arenas.length == 0){
-        arena = malloc(sizeof(MemoryPoolArena));
+        arena = PK_MALLOC(sizeof(MemoryPoolArena));
         MemoryPoolArena__ctor(arena);
         LinkedList__push_back(&self->_arenas, (LinkedListNode*)arena);
     } else {
@@ -169,14 +169,14 @@ static void MemoryPool__shrink_to_fit(MemoryPool* self) {
             MemoryPoolArena* arena = (MemoryPoolArena*)node;
             if(MemoryPoolArena__full(arena)) {
                 LinkedList__erase(&self->_arenas, node);
-                free(arena);
+                PK_FREE(arena);
             });
 }
 
 
 static void MemoryPool__dtor(MemoryPool* self) {
-    LinkedList__apply(&self->_arenas, free(node););
-    LinkedList__apply(&self->_empty_arenas, free(node););
+    LinkedList__apply(&self->_arenas, PK_FREE(node););
+    LinkedList__apply(&self->_empty_arenas, PK_FREE(node););
 }
 
 typedef struct FixedMemoryPool {
@@ -195,9 +195,9 @@ static void FixedMemoryPool__ctor(FixedMemoryPool* self, int BlockSize, int Bloc
     self->BlockSize = BlockSize;
     self->BlockCount = BlockCount;
     self->exceeded_bytes = 0;
-    self->data = malloc(BlockSize * BlockCount);
+    self->data = PK_MALLOC(BlockSize * BlockCount);
     self->data_end = self->data + BlockSize * BlockCount;
-    self->_free_list = malloc(sizeof(void*) * BlockCount);
+    self->_free_list = PK_MALLOC(sizeof(void*) * BlockCount);
     self->_free_list_end = self->_free_list;
     for(int i = 0; i < BlockCount; i++) {
         self->_free_list[i] = self->data + i * BlockSize;
@@ -205,8 +205,8 @@ static void FixedMemoryPool__ctor(FixedMemoryPool* self, int BlockSize, int Bloc
 }
 
 static void FixedMemoryPool__dtor(FixedMemoryPool* self) {
-    free(self->_free_list);
-    free(self->data);
+    PK_FREE(self->_free_list);
+    PK_FREE(self->data);
 }
 
 static void* FixedMemoryPool__alloc(FixedMemoryPool* self) {
@@ -215,7 +215,7 @@ static void* FixedMemoryPool__alloc(FixedMemoryPool* self) {
         return *self->_free_list_end;
     } else {
         self->exceeded_bytes += self->BlockSize;
-        return malloc(self->BlockSize);
+        return PK_MALLOC(self->BlockSize);
     }
 }
 
@@ -226,7 +226,7 @@ static void FixedMemoryPool__dealloc(FixedMemoryPool* self, void* p) {
         self->_free_list_end++;
     } else {
         self->exceeded_bytes -= self->BlockSize;
-        free(p);
+        PK_FREE(p);
     }
 }
 

src/common/sourcedata.c

@@ -39,7 +39,7 @@ SourceData_ SourceData__rcnew(const char* source,
                               const char* filename,
                               enum py_CompileMode mode,
                               bool is_dynamic) {
-    SourceData_ self = malloc(sizeof(struct SourceData));
+    SourceData_ self = PK_MALLOC(sizeof(struct SourceData));
     SourceData__ctor(self, source, filename, mode, is_dynamic);
     self->rc.count = 1;
     self->rc.dtor = (void (*)(void*))SourceData__dtor;

src/common/sstream.c

@@ -100,6 +100,7 @@ void c11_sbuf__write_quoted(c11_sbuf* self, c11_sv sv, char quote) {
             case '\b': c11_sbuf__write_cstrn(self, "\\b", 2); break;
             default: {
                 int u8bytes = c11__u8_header(c, true);
+                if(i + u8bytes > sv.size) u8bytes = 0;  // invalid utf8
                 if(u8bytes <= 1) {
                     // not a valid utf8 char, or ascii
                     if(!isprint(c)) {

src/common/str.c

@@ -11,7 +11,7 @@
 c11_string* c11_string__new(const char* data) { return c11_string__new2(data, strlen(data)); }
 
 c11_string* c11_string__new2(const char* data, int size) {
-    c11_string* retval = malloc(sizeof(c11_string) + size + 1);
+    c11_string* retval = PK_MALLOC(sizeof(c11_string) + size + 1);
     c11_string__ctor2(retval, data, size);
     return retval;
 }
@@ -46,12 +46,12 @@ void c11_string__ctor3(c11_string* self, int size) {
 
 c11_string* c11_string__copy(c11_string* self) {
     int total_size = sizeof(c11_string) + self->size + 1;
-    c11_string* retval = malloc(total_size);
+    c11_string* retval = PK_MALLOC(total_size);
     memcpy(retval, self, total_size);
     return retval;
 }
 
-void c11_string__delete(c11_string* self) { free(self); }
+void c11_string__delete(c11_string* self) { PK_FREE(self); }
 
 c11_sv c11_string__sv(c11_string* self) { return (c11_sv){self->data, self->size}; }
 

src/common/strname.c

@@ -13,7 +13,7 @@ static c11_vector /*T=char* */ _r_interned;
 void py_Name__initialize() {
     c11_smallmap_s2n__ctor(&_interned);
     for(int i = 0; i < _r_interned.length; i++) {
-        free(c11__at(char*, &_r_interned, i));
+        PK_FREE(c11__at(char*, &_r_interned, i));
     }
     c11_vector__ctor(&_r_interned, sizeof(c11_sv));
 
@@ -26,7 +26,7 @@ void py_Name__initialize() {
 void py_Name__finalize() {
     // free all char*
     for(int i = 0; i < _r_interned.length; i++) {
-        free(c11__getitem(char*, &_r_interned, i));
+        PK_FREE(c11__getitem(char*, &_r_interned, i));
     }
     c11_smallmap_s2n__dtor(&_interned);
     c11_vector__dtor(&_r_interned);
@@ -41,7 +41,7 @@ py_Name py_namev(c11_sv name) {
     // generate new index
     if(_interned.length > 65530) c11__abort("py_Name index overflow");
     // NOTE: we must allocate the string in the heap so iterators are not invalidated
-    char* p = malloc(name.size + 1);
+    char* p = PK_MALLOC(name.size + 1);
     memcpy(p, name.data, name.size);
     p[name.size] = '\0';
     c11_vector__push(char*, &_r_interned, p);

src/common/vector.c

@@ -3,6 +3,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include "pocketpy/common/utils.h"
+#include "pocketpy/config.h"
 
 void c11_vector__ctor(c11_vector* self, int elem_size) {
     self->data = NULL;
@@ -12,7 +13,7 @@ void c11_vector__ctor(c11_vector* self, int elem_size) {
 }
 
 void c11_vector__dtor(c11_vector* self) {
-    if(self->data) free(self->data);
+    if(self->data) PK_FREE(self->data);
     self->data = NULL;
     self->length = 0;
     self->capacity = 0;
@@ -31,7 +32,7 @@ void c11_vector__reserve(c11_vector* self, int capacity) {
     if(capacity < 4) capacity = 4;
     if(capacity <= self->capacity) return;
     // self->elem_size * capacity may overflow
-    self->data = realloc(self->data, (size_t)self->elem_size * (size_t)capacity);
+    self->data = PK_REALLOC(self->data, (size_t)self->elem_size * (size_t)capacity);
     if(self->data == NULL) c11__abort("c11_vector__reserve(): out of memory");
     self->capacity = capacity;
 }

src/compiler/compiler.c

@@ -464,7 +464,7 @@ void SequenceExpr__dtor(Expr* self_) {
     for(int i = 0; i < self->itemCount; i++) {
         vtdelete(self->items[i]);
     }
-    free(self->items);
+    PK_FREE(self->items);
 }
 
 bool TupleExpr__emit_store(Expr* self_, Ctx* ctx) {
@@ -526,7 +526,7 @@ static SequenceExpr* SequenceExpr__new(int line, const ExprVt* vt, int count, Op
     self->vt = vt;
     self->line = line;
     self->opcode = opcode;
-    self->items = malloc(sizeof(Expr*) * count);
+    self->items = PK_MALLOC(sizeof(Expr*) * count);
     self->itemCount = count;
     return self;
 }
@@ -1318,11 +1318,11 @@ static void Compiler__dtor(Compiler* self) {
     // free tokens
     for(int i = 0; i < self->tokens_length; i++) {
         if(self->tokens[i].value.index == TokenValue_STR) {
-            // free internal string
+            // PK_FREE internal string
             c11_string__delete(self->tokens[i].value._str);
         }
     }
-    free(self->tokens);
+    PK_FREE(self->tokens);
     // free contexts
     c11__foreach(Ctx, &self->contexts, ctx) Ctx__dtor(ctx);
     c11_vector__dtor(&self->contexts);
@@ -1359,7 +1359,7 @@ static NameScope name_scope(Compiler* self) {
 }
 
 Error* SyntaxError(Compiler* self, const char* fmt, ...) {
-    Error* err = malloc(sizeof(Error));
+    Error* err = PK_MALLOC(sizeof(Error));
     err->src = self->src;
     PK_INCREF(self->src);
     Token* t = self->i == self->tokens_length ? prev() : curr();

src/compiler/lexer.c

@@ -186,7 +186,7 @@ static bool is_possible_number_char(char c) {
 
 /******************************/
 static Error* LexerError(Lexer* self, const char* fmt, ...) {
-    Error* err = malloc(sizeof(Error));
+    Error* err = PK_MALLOC(sizeof(Error));
     err->src = self->src;
     PK_INCREF(self->src);
     err->lineno = self->current_line;

src/interpreter/ceval.c

@@ -13,6 +13,14 @@ static bool stack_format_object(VM* self, c11_sv spec);
 #define CHECK_RETURN_FROM_EXCEPT_OR_FINALLY()                                                      \
     if(self->is_curr_exc_handled) py_clearexc(NULL)
 
+#define CHECK_STACK_OVERFLOW()                                                                     \
+    do {                                                                                           \
+        if(self->stack.sp > self->stack.end) {                                                     \
+            py_exception(tp_StackOverflowError, "");                                               \
+            goto __ERROR;                                                                          \
+        }                                                                                          \
+    } while(0)
+
 #define DISPATCH()                                                                                 \
     do {                                                                                           \
         frame->ip++;                                                                               \
@@ -92,7 +100,7 @@ FrameResult VM__run_top_frame(VM* self) {
         pk_print_stack(self, frame, byte);
 #endif
 
-        if(self->is_signal_interrupted){
+        if(self->is_signal_interrupted) {
             self->is_signal_interrupted = false;
             py_exception(tp_KeyboardInterrupt, "");
             goto __ERROR;
@@ -132,15 +140,40 @@ FrameResult VM__run_top_frame(VM* self) {
                 POP();
                 DISPATCH();
             /*****************************************/
-            case OP_LOAD_CONST: PUSH(c11__at(py_TValue, &frame->co->consts, byte.arg)); DISPATCH();
-            case OP_LOAD_NONE: py_newnone(SP()++); DISPATCH();
-            case OP_LOAD_TRUE: py_newbool(SP()++, true); DISPATCH();
-            case OP_LOAD_FALSE: py_newbool(SP()++, false); DISPATCH();
+            case OP_LOAD_CONST: {
+                CHECK_STACK_OVERFLOW();
+                PUSH(c11__at(py_TValue, &frame->co->consts, byte.arg));
+                DISPATCH();
+            }
+            case OP_LOAD_NONE: {
+                CHECK_STACK_OVERFLOW();
+                py_newnone(SP()++);
+                DISPATCH();
+            }
+            case OP_LOAD_TRUE: {
+                CHECK_STACK_OVERFLOW();
+                py_newbool(SP()++, true);
+                DISPATCH();
+            }
+            case OP_LOAD_FALSE: {
+                CHECK_STACK_OVERFLOW();
+                py_newbool(SP()++, false);
+                DISPATCH();
+            }
             /*****************************************/
-            case OP_LOAD_SMALL_INT: py_newint(SP()++, (int16_t)byte.arg); DISPATCH();
+            case OP_LOAD_SMALL_INT: {
+                CHECK_STACK_OVERFLOW();
+                py_newint(SP()++, (int16_t)byte.arg);
+                DISPATCH();
+            }
             /*****************************************/
-            case OP_LOAD_ELLIPSIS: py_newellipsis(SP()++); DISPATCH();
+            case OP_LOAD_ELLIPSIS: {
+                CHECK_STACK_OVERFLOW();
+                py_newellipsis(SP()++);
+                DISPATCH();
+            }
             case OP_LOAD_FUNCTION: {
+                CHECK_STACK_OVERFLOW();
                 FuncDecl_ decl = c11__getitem(FuncDecl_, &frame->co->func_decls, byte.arg);
                 Function* ud = py_newobject(SP(), tp_function, 0, sizeof(Function));
                 Function__ctor(ud, decl, frame->module);
@@ -952,8 +985,12 @@ FrameResult VM__run_top_frame(VM* self) {
                     goto __ERROR;
                 }
 
-                py_Type type =
-                    pk_newtype(py_name2str(name), base, frame->module, NULL, base_ti->is_python, false);
+                py_Type type = pk_newtype(py_name2str(name),
+                                          base,
+                                          frame->module,
+                                          NULL,
+                                          base_ti->is_python,
+                                          false);
                 PUSH(py_tpobject(type));
                 self->__curr_class = TOP();
                 DISPATCH();

src/interpreter/frame.c

@@ -28,14 +28,14 @@ NameDict* FastLocals__to_namedict(py_TValue* locals, const CodeObject* co) {
 }
 
 UnwindTarget* UnwindTarget__new(UnwindTarget* next, int iblock, int offset) {
-    UnwindTarget* self = malloc(sizeof(UnwindTarget));
+    UnwindTarget* self = PK_MALLOC(sizeof(UnwindTarget));
     self->next = next;
     self->iblock = iblock;
     self->offset = offset;
     return self;
 }
 
-void UnwindTarget__delete(UnwindTarget* self) { free(self); }
+void UnwindTarget__delete(UnwindTarget* self) { PK_FREE(self); }
 
 Frame* Frame__new(const CodeObject* co,
                   py_GlobalRef module,

src/interpreter/heap.c

@@ -1,5 +1,6 @@
 #include "pocketpy/interpreter/heap.h"
 #include "pocketpy/common/memorypool.h"
+#include "pocketpy/config.h"
 #include "pocketpy/objects/base.h"
 
 void ManagedHeap__ctor(ManagedHeap* self, VM* vm) {
@@ -8,6 +9,8 @@ void ManagedHeap__ctor(ManagedHeap* self, VM* vm) {
 
     self->gc_threshold = PK_GC_MIN_THRESHOLD;
     self->gc_counter = 0;
+    self->gc_enabled = true;
+
     self->vm = vm;
 
     self->gc_on_delete = NULL;
@@ -27,6 +30,7 @@ void ManagedHeap__dtor(ManagedHeap* self) {
 }
 
 void ManagedHeap__collect_if_needed(ManagedHeap* self) {
+    if(!self->gc_enabled) return;
     if(self->gc_counter < self->gc_threshold) return;
     self->gc_counter = 0;
     ManagedHeap__collect(self);
@@ -91,11 +95,11 @@ PyObject* PyObject__new(py_Type type, int slots, int size) {
     PyObject* self;
     // header + slots + udsize
     size = sizeof(PyObject) + PK_OBJ_SLOTS_SIZE(slots) + size;
-    if(size <= kPoolObjectBlockSize) {
+    if(!PK_LOW_MEMORY_MODE && size <= kPoolObjectBlockSize) {
         self = PoolObject_alloc();
         self->gc_is_large = false;
     } else {
-        self = malloc(size);
+        self = PK_MALLOC(size);
         self->gc_is_large = true;
     }
     self->type = type;

src/interpreter/typeinfo.c

@@ -10,7 +10,7 @@ void TypeList__ctor(TypeList* self) {
 
 void TypeList__dtor(TypeList* self) {
     for (int i = 0; i < self->length; i++) {
-        if(self->chunks[i]) free(self->chunks[i]);
+        if(self->chunks[i]) PK_FREE(self->chunks[i]);
     }
 }
 
@@ -26,7 +26,7 @@ py_TypeInfo* TypeList__emplace(TypeList* self){
     int offset = self->length & (CHUNK_SIZE - 1);
     assert(chunk < 256);
     if(self->chunks[chunk] == NULL){
-        self->chunks[chunk] = malloc(sizeof(py_TypeInfo) * CHUNK_SIZE);
+        self->chunks[chunk] = PK_MALLOC(sizeof(py_TypeInfo) * CHUNK_SIZE);
         memset(self->chunks[chunk], 0, sizeof(py_TypeInfo) * CHUNK_SIZE);
     }
     self->length++;

src/interpreter/vm.c

@@ -17,7 +17,7 @@ static char* pk_default_importfile(const char* path) {
     fseek(f, 0, SEEK_END);
     long size = ftell(f);
     fseek(f, 0, SEEK_SET);
-    char* buffer = malloc(size + 1);
+    char* buffer = PK_MALLOC(size + 1);
     size = fread(buffer, 1, size, f);
     buffer[size] = 0;
     fclose(f);
@@ -572,7 +572,7 @@ void PyObject__delete(PyObject* self) {
     if(ti->dtor) ti->dtor(PyObject__userdata(self));
     if(self->slots == -1) NameDict__dtor(PyObject__dict(self));
     if(self->gc_is_large) {
-        free(self);
+        PK_FREE(self);
     } else {
         PoolObject_dealloc(self);
     }

src/modules/gc.c

@@ -1,8 +1,4 @@
 #include "pocketpy/pocketpy.h"
-
-#include "pocketpy/common/utils.h"
-#include "pocketpy/objects/object.h"
-#include "pocketpy/common/sstream.h"
 #include "pocketpy/interpreter/vm.h"
 
 static bool gc_collect(int argc, py_Ref argv){
@@ -13,8 +9,34 @@ static bool gc_collect(int argc, py_Ref argv){
     return true;
 }
 
+static bool gc_enable(int argc, py_Ref argv){
+    PY_CHECK_ARGC(0);
+    ManagedHeap* heap = &pk_current_vm->heap;
+    heap->gc_enabled = true;
+    py_newnone(py_retval());
+    return true;
+}
+
+static bool gc_disable(int argc, py_Ref argv){
+    PY_CHECK_ARGC(0);
+    ManagedHeap* heap = &pk_current_vm->heap;
+    heap->gc_enabled = false;
+    py_newnone(py_retval());
+    return true;
+}
+
+static bool gc_isenabled(int argc, py_Ref argv){
+    PY_CHECK_ARGC(0);
+    ManagedHeap* heap = &pk_current_vm->heap;
+    py_newbool(py_retval(), heap->gc_enabled);
+    return true;
+}
+
 void pk__add_module_gc() {
     py_Ref mod = py_newmodule("gc");
 
     py_bindfunc(mod, "collect", gc_collect);
+    py_bindfunc(mod, "enable", gc_enable);
+    py_bindfunc(mod, "disable", gc_disable);
+    py_bindfunc(mod, "isenabled", gc_isenabled);
 }

src/modules/os.c

@@ -157,10 +157,10 @@ static bool io_FileIO_read(int argc, py_Ref argv) {
         int actual_size = fread(dst, 1, size, ud->file);
         py_bytes_resize(py_retval(), actual_size);
     } else {
-        void* dst = malloc(size);
+        void* dst = PK_MALLOC(size);
         int actual_size = fread(dst, 1, size, ud->file);
         py_newstrv(py_retval(), (c11_sv){dst, actual_size});
-        free(dst);
+        PK_FREE(dst);
     }
     return true;
 }

src/modules/pickle.c

@@ -41,14 +41,14 @@ typedef struct {
 
 static void PickleObject__ctor(PickleObject* self) {
     self->used_types_length = pk_current_vm->types.length;
-    self->used_types = malloc(self->used_types_length);
+    self->used_types = PK_MALLOC(self->used_types_length);
     memset(self->used_types, 0, self->used_types_length);
     c11_smallmap_p2i__ctor(&self->memo);
     c11_vector__ctor(&self->codes, sizeof(char));
 }
 
 static void PickleObject__dtor(PickleObject* self) {
-    free(self->used_types);
+    PK_FREE(self->used_types);
     c11_smallmap_p2i__dtor(&self->memo);
     c11_vector__dtor(&self->codes);
 }

src/modules/random.c

@@ -225,7 +225,7 @@ static bool Random_choices(int argc, py_Ref argv) {
     if(!py_checktype(py_arg(3), tp_int)) return false;
     py_i64 k = py_toint(py_arg(3));
 
-    py_f64* cum_weights = malloc(sizeof(py_f64) * length);
+    py_f64* cum_weights = PK_MALLOC(sizeof(py_f64) * length);
     if(py_isnone(weights)) {
         for(int i = 0; i < length; i++)
             cum_weights[i] = i + 1;
@@ -233,21 +233,21 @@ static bool Random_choices(int argc, py_Ref argv) {
         py_TValue* w;
         int wlen = pk_arrayview(weights, &w);
         if(wlen == -1) {
-            free(cum_weights);
+            PK_FREE(cum_weights);
             return TypeError("choices(): weights must be a list or tuple");
         }
         if(wlen != length) {
-            free(cum_weights);
+            PK_FREE(cum_weights);
             return ValueError("len(weights) != len(population)");
         }
         if(!py_castfloat(&w[0], &cum_weights[0])) {
-            free(cum_weights);
+            PK_FREE(cum_weights);
             return false;
         }
         for(int i = 1; i < length; i++) {
             py_f64 tmp;
             if(!py_castfloat(&w[i], &tmp)) {
-                free(cum_weights);
+                PK_FREE(cum_weights);
                 return false;
             }
             cum_weights[i] = cum_weights[i - 1] + tmp;
@@ -256,7 +256,7 @@ static bool Random_choices(int argc, py_Ref argv) {
 
     py_f64 total = cum_weights[length - 1];
     if(total <= 0) {
-        free(cum_weights);
+        PK_FREE(cum_weights);
         return ValueError("total of weights must be greater than zero");
     }
 
@@ -269,7 +269,7 @@ static bool Random_choices(int argc, py_Ref argv) {
         py_list_setitem(py_retval(), i, p + index);
     }
 
-    free(cum_weights);
+    PK_FREE(cum_weights);
     return true;
 }
 

src/modules/traceback.c

@@ -8,7 +8,7 @@ static bool traceback_format_exc(int argc, py_Ref argv) {
         py_newnone(py_retval());
     } else {
         py_newstr(py_retval(), s);
-        free(s);
+        PK_FREE(s);
     }
     return true;
 }

src/objects/codeobject.c

@@ -24,7 +24,7 @@ static void FuncDecl__dtor(FuncDecl* self) {
 }
 
 FuncDecl_ FuncDecl__rcnew(SourceData_ src, c11_sv name) {
-    FuncDecl* self = malloc(sizeof(FuncDecl));
+    FuncDecl* self = PK_MALLOC(sizeof(FuncDecl));
     self->rc.count = 1;
     self->rc.dtor = (void (*)(void*))FuncDecl__dtor;
     CodeObject__ctor(&self->code, src, name);

src/objects/namedict.c

@@ -17,11 +17,11 @@ void ModuleDict__ctor(ModuleDict* self, const char* path, py_TValue module) {
 void ModuleDict__dtor(ModuleDict* self) {
     if(self->left) {
         ModuleDict__dtor(self->left);
-        free(self->left);
+        PK_FREE(self->left);
     }
     if(self->right) {
         ModuleDict__dtor(self->right);
-        free(self->right);
+        PK_FREE(self->right);
     }
 }
 
@@ -35,14 +35,14 @@ void ModuleDict__set(ModuleDict* self, const char* key, py_TValue val) {
         if(self->left) {
             ModuleDict__set(self->left, key, val);
         } else {
-            self->left = malloc(sizeof(ModuleDict));
+            self->left = PK_MALLOC(sizeof(ModuleDict));
             ModuleDict__ctor(self->left, key, val);
         }
     } else if(cmp > 0) {
         if(self->right) {
             ModuleDict__set(self->right, key, val);
         } else {
-            self->right = malloc(sizeof(ModuleDict));
+            self->right = PK_MALLOC(sizeof(ModuleDict));
             ModuleDict__ctor(self->right, key, val);
         }
     } else {

src/public/exec.c

@@ -30,7 +30,7 @@ bool _py_compile(CodeObject* out,
         PK_DECREF(src);
 
         PK_DECREF(err->src);
-        free(err);
+        PK_FREE(err);
         return false;
     }
     PK_DECREF(src);

src/public/internal.c

@@ -51,7 +51,7 @@ void py_finalize() {
             // TODO: refactor VM__ctor and VM__dtor
             pk_current_vm = vm;
             VM__dtor(vm);
-            free(vm);
+            PK_FREE(vm);
         }
     }
     pk_current_vm = &pk_default_vm;
@@ -64,7 +64,7 @@ void py_finalize() {
 void py_switchvm(int index) {
     if(index < 0 || index >= 16) c11__abort("invalid vm index");
     if(!pk_all_vm[index]) {
-        pk_current_vm = pk_all_vm[index] = malloc(sizeof(VM));
+        pk_current_vm = pk_all_vm[index] = PK_MALLOC(sizeof(VM));
         memset(pk_current_vm, 0, sizeof(VM));
         VM__ctor(pk_all_vm[index]);
     } else {

src/public/modules.c

@@ -155,7 +155,7 @@ __SUCCESS:
 
     c11_string__delete(filename);
     c11_string__delete(slashed_path);
-    if(need_free) free((void*)data);
+    if(need_free) PK_FREE((void*)data);
     return ok ? 1 : -1;
 }
 

src/public/py_dict.c

@@ -78,7 +78,7 @@ typedef struct {
 static void Dict__ctor(Dict* self, uint32_t capacity, int entries_capacity) {
     self->length = 0;
     self->capacity = capacity;
-    self->indices = malloc(self->capacity * sizeof(DictIndex));
+    self->indices = PK_MALLOC(self->capacity * sizeof(DictIndex));
     memset(self->indices, -1, self->capacity * sizeof(DictIndex));
     c11_vector__ctor(&self->entries, sizeof(DictEntry));
     c11_vector__reserve(&self->entries, entries_capacity);
@@ -87,7 +87,7 @@ static void Dict__ctor(Dict* self, uint32_t capacity, int entries_capacity) {
 static void Dict__dtor(Dict* self) {
     self->length = 0;
     self->capacity = 0;
-    free(self->indices);
+    PK_FREE(self->indices);
     c11_vector__dtor(&self->entries);
 }
 
@@ -154,7 +154,7 @@ __RETRY:
 }
 
 static void Dict__compact_entries(Dict* self) {
-    int* mappings = malloc(self->entries.length * sizeof(int));
+    int* mappings = PK_MALLOC(self->entries.length * sizeof(int));
 
     int n = 0;
     for(int i = 0; i < self->entries.length; i++) {
@@ -176,7 +176,7 @@ static void Dict__compact_entries(Dict* self) {
             self->indices[i]._[j] = mappings[idx];
         }
     }
-    free(mappings);
+    PK_FREE(mappings);
 }
 
 static bool Dict__set(Dict* self, py_TValue* key, py_TValue* val) {
@@ -442,7 +442,7 @@ static bool dict_copy(int argc, py_Ref argv) {
     new_dict->length = self->length;
     new_dict->entries = c11_vector__copy(&self->entries);
     // copy indices
-    new_dict->indices = malloc(new_dict->capacity * sizeof(DictIndex));
+    new_dict->indices = PK_MALLOC(new_dict->capacity * sizeof(DictIndex));
     memcpy(new_dict->indices, self->indices, new_dict->capacity * sizeof(DictIndex));
     return true;
 }

src/public/py_exception.c

@@ -164,7 +164,7 @@ void py_printexc() {
     if(!msg) return;
     pk_current_vm->callbacks.print(msg);
     pk_current_vm->callbacks.print("\n");
-    free(msg);
+    PK_FREE(msg);
 }
 
 static void c11_sbuf__write_exc(c11_sbuf* self, py_Ref exc) {
@@ -218,7 +218,7 @@ char* py_formatexc() {
     }
 
     c11_string* res = c11_sbuf__submit(&ss);
-    char* dup = malloc(res->size + 1);
+    char* dup = PK_MALLOC(res->size + 1);
     memcpy(dup, res->data, res->size);
     dup[res->size] = '\0';
     c11_string__delete(res);