diff --git a/include/pocketpy/common/smallmap.h b/include/pocketpy/common/smallmap.h
index 26f3ccea..74556202 100644
--- a/include/pocketpy/common/smallmap.h
+++ b/include/pocketpy/common/smallmap.h
@@ -20,8 +20,8 @@
 
 #define SMALLMAP_T__HEADER
 #define K c11_sv
-#define V py_Name
-#define NAME c11_smallmap_v2n
+#define V int
+#define NAME c11_smallmap_v2d
 #define less(a, b)      (c11_sv__cmp((a), (b)) <  0)
 #define equal(a, b)     (c11_sv__cmp((a), (b)) == 0)
 #include "pocketpy/xmacros/smallmap.h"
diff --git a/include/pocketpy/interpreter/name.h b/include/pocketpy/interpreter/name.h
deleted file mode 100644
index e69de29b..00000000
diff --git a/include/pocketpy/interpreter/vm.h b/include/pocketpy/interpreter/vm.h
index 00381d7a..78065bed 100644
--- a/include/pocketpy/interpreter/vm.h
+++ b/include/pocketpy/interpreter/vm.h
@@ -1,12 +1,12 @@
 #pragma once
 
 #include "pocketpy/common/memorypool.h"
+#include "pocketpy/common/name.h"
 #include "pocketpy/objects/codeobject.h"
 #include "pocketpy/pocketpy.h"
 #include "pocketpy/interpreter/heap.h"
 #include "pocketpy/interpreter/frame.h"
 #include "pocketpy/interpreter/typeinfo.h"
-#include "pocketpy/interpreter/name.h"
 #include "pocketpy/interpreter/line_profiler.h"
 #include <time.h>
 
@@ -49,6 +49,8 @@ typedef struct VM {
     py_TValue reg[8];  // users' registers
     void* ctx;         // user-defined context
 
+    NameDict cached_names;
+
     py_StackRef curr_class;
     py_StackRef curr_decl_based_function;
     TraceInfo trace_info;
@@ -56,7 +58,6 @@ typedef struct VM {
     LineProfiler line_profiler;
     py_TValue vectorcall_buffer[PK_MAX_CO_VARNAMES];
 
-    InternedNames names;
     FixedMemoryPool pool_frame;
     ManagedHeap heap;
     ValueStack stack;  // put `stack` at the end for better cache locality
diff --git a/include/pocketpy/pocketpy.h b/include/pocketpy/pocketpy.h
index 4762d707..93c68986 100644
--- a/include/pocketpy/pocketpy.h
+++ b/include/pocketpy/pocketpy.h
@@ -237,13 +237,13 @@ PK_API py_Name py_name(const char*);
 /// Convert a name to a null-terminated string.
 PK_API const char* py_name2str(py_Name);
 /// Convert a name to a python `str` object with cache.
-PK_API py_GlobalRef py_name2ref(py_Name);
+PK_API py_ItemRef py_name2ref(py_Name);
 /// Convert a `c11_sv` to a name.
 PK_API py_Name py_namev(c11_sv);
 /// Convert a name to a `c11_sv`.
 PK_API c11_sv py_name2sv(py_Name);
-/// Check if the name matches the two underscores pattern. e.g. `__init__`, `__str__`, etc.
-PK_API bool py_ismagicname(py_Name);
+
+#define py_ismagicname(name) (true)
 
 /************* Meta Operations *************/
 
diff --git a/src/common/name.c b/src/common/name.c
index 191d9480..2c479131 100644
--- a/src/common/name.c
+++ b/src/common/name.c
@@ -1,25 +1,96 @@
 #include "pocketpy/common/name.h"
+#include "pocketpy/common/str.h"
+#include "pocketpy/pocketpy.h"
 #include <stdatomic.h>
 
-typedef struct InternedEntry InternedEntry;
-typedef struct InternedEntry{
-    InternedEntry* prev;
-    InternedEntry* next;
-    py_i64 hash;
-    int size;       // size of the data excluding the null-terminator
-    char data[];    // null-terminated data
-} InternedEntry;
+typedef struct NameBucket NameBucket;
 
-typedef struct {
-    InternedEntry* table[1 << 16];
+typedef struct NameBucket {
+    NameBucket* next;
+    uint64_t hash;
+    int size;     // size of the data excluding the null-terminator
+    char data[];  // null-terminated data
+} NameBucket;
+
+static struct {
+    NameBucket* table[0x10000];
     atomic_bool lock;
-} InternedNames;
+} pk_string_table;
+
+#define MAGIC_METHOD(x) py_Name x;
+#include "pocketpy/xmacros/magics.h"
+#undef MAGIC_METHOD
 
 void pk_names_initialize() {
-
+#define MAGIC_METHOD(x) x = py_name(#x);
+#include "pocketpy/xmacros/magics.h"
+#undef MAGIC_METHOD
 }
 
-
 void pk_names_finalize() {
-    
+    for(int i = 0; i < 0x10000; i++) {
+        NameBucket* p = pk_string_table.table[i];
+        while(p) {
+            NameBucket* next = p->next;
+            PK_FREE(p);
+            p = next;
+        }
+        pk_string_table.table[i] = NULL;
+    }
+}
+
+py_Name py_namev(c11_sv name) {
+    while(atomic_exchange(&pk_string_table.lock, true)) {
+        // busy-wait until the lock is released
+    }
+    uint64_t hash = c11_sv__hash(name);
+    int index = hash & 0xFFFF;
+    NameBucket* p = pk_string_table.table[index];
+    bool found = false;
+    while(p) {
+        c11_sv p_sv = {p->data, p->size};
+        if(p->hash == hash && c11__sveq(p_sv, name)) {
+            found = true;
+            break;
+        } else {
+            p = p->next;
+        }
+    }
+    if(found) {
+        atomic_store(&pk_string_table.lock, false);
+        return (py_Name)p;
+    }
+
+    // generate new index
+    NameBucket* entry = PK_MALLOC(sizeof(NameBucket) + name.size + 1);
+    entry->next = NULL;
+    entry->hash = hash;
+    entry->size = name.size;
+    memcpy(entry->data, name.data, name.size);
+    entry->data[name.size] = '\0';
+    if(p == NULL) {
+        pk_string_table.table[index] = entry;
+    } else {
+        assert(p->next == NULL);
+        p->next = entry;
+    }
+    atomic_store(&pk_string_table.lock, false);
+    return (py_Name)entry;
+}
+
+c11_sv py_name2sv(py_Name index) {
+    NameBucket* p = (NameBucket*)index;
+    return (c11_sv){p->data, p->size};
+}
+
+py_Name py_name(const char* name) {
+    c11_sv sv;
+    sv.data = name;
+    sv.size = strlen(name);
+    return py_namev(sv);
+}
+
+const char* py_name2str(py_Name index) {
+    NameBucket* p = (NameBucket*)index;
+    return p->data;
 }
\ No newline at end of file
diff --git a/src/common/smallmap.c b/src/common/smallmap.c
index fa017811..228fd42f 100644
--- a/src/common/smallmap.c
+++ b/src/common/smallmap.c
@@ -16,8 +16,8 @@
 
 #define SMALLMAP_T__SOURCE
 #define K c11_sv
-#define V py_Name
-#define NAME c11_smallmap_v2n
+#define V int
+#define NAME c11_smallmap_v2d
 #define less(a, b)      (c11_sv__cmp((a), (b)) <  0)
 #define equal(a, b)     (c11_sv__cmp((a), (b)) == 0)
 #include "pocketpy/xmacros/smallmap.h"
diff --git a/src/compiler/compiler.c b/src/compiler/compiler.c
index 4ca7785e..c557630b 100644
--- a/src/compiler/compiler.c
+++ b/src/compiler/compiler.c
@@ -1,5 +1,6 @@
 #include "pocketpy/compiler/compiler.h"
 #include "pocketpy/common/vector.h"
+#include "pocketpy/common/name.h"
 #include "pocketpy/compiler/lexer.h"
 #include "pocketpy/objects/base.h"
 #include "pocketpy/objects/codeobject.h"
@@ -63,7 +64,7 @@ typedef struct Ctx {
     bool is_compiling_class;
     c11_vector /*T=Expr_p*/ s_expr;
     c11_smallmap_n2d global_names;
-    c11_smallmap_v2n co_consts_string_dedup_map;    // this stores 0-based index instead of pointer
+    c11_smallmap_v2d co_consts_string_dedup_map;  // this stores 0-based index instead of pointer
 } Ctx;
 
 typedef struct Expr Expr;
@@ -1076,7 +1077,7 @@ static void Ctx__ctor(Ctx* self, CodeObject* co, FuncDecl* func, int level) {
     self->is_compiling_class = false;
     c11_vector__ctor(&self->s_expr, sizeof(Expr*));
     c11_smallmap_n2d__ctor(&self->global_names);
-    c11_smallmap_v2n__ctor(&self->co_consts_string_dedup_map);
+    c11_smallmap_v2d__ctor(&self->co_consts_string_dedup_map);
 }
 
 static void Ctx__dtor(Ctx* self) {
@@ -1087,11 +1088,11 @@ static void Ctx__dtor(Ctx* self) {
     c11_vector__dtor(&self->s_expr);
     c11_smallmap_n2d__dtor(&self->global_names);
     // free the dedup map
-    c11__foreach(c11_smallmap_v2n_KV, &self->co_consts_string_dedup_map, p_kv) {
+    c11__foreach(c11_smallmap_v2d_KV, &self->co_consts_string_dedup_map, p_kv) {
         const char* p = p_kv->key.data;
         PK_FREE((void*)p);
     }
-    c11_smallmap_v2n__dtor(&self->co_consts_string_dedup_map);
+    c11_smallmap_v2d__dtor(&self->co_consts_string_dedup_map);
 }
 
 static int Ctx__prepare_loop_divert(Ctx* self, int line, bool is_break) {
@@ -1200,9 +1201,7 @@ static int Ctx__add_varname(Ctx* self, py_Name name) {
     return CodeObject__add_varname(self->co, name);
 }
 
-static int Ctx__add_name(Ctx* self, py_Name name) {
-    return CodeObject__add_name(self->co, name);
-}
+static int Ctx__add_name(Ctx* self, py_Name name) { return CodeObject__add_name(self->co, name); }
 
 static int Ctx__add_const_string(Ctx* self, c11_sv key) {
     if(key.size > 100) {
@@ -1211,7 +1210,7 @@ static int Ctx__add_const_string(Ctx* self, c11_sv key) {
         int index = self->co->consts.length - 1;
         return index;
     }
-    uintptr_t* val = c11_smallmap_v2n__try_get(&self->co_consts_string_dedup_map, key);
+    int* val = c11_smallmap_v2d__try_get(&self->co_consts_string_dedup_map, key);
     if(val) {
         return *val;
     } else {
@@ -1222,7 +1221,7 @@ static int Ctx__add_const_string(Ctx* self, c11_sv key) {
         char* new_buf = PK_MALLOC(key.size + 1);
         memcpy(new_buf, key.data, key.size);
         new_buf[key.size] = 0;
-        c11_smallmap_v2n__set(&self->co_consts_string_dedup_map,
+        c11_smallmap_v2d__set(&self->co_consts_string_dedup_map,
                               (c11_sv){new_buf, key.size},
                               index);
         return index;
@@ -2376,7 +2375,7 @@ static Error* compile_function(Compiler* self, int decorators) {
             }
         }
 
-        Ctx__emit_(ctx(), OP_STORE_CLASS_ATTR, decl_name, prev()->line);
+        Ctx__emit_(ctx(), OP_STORE_CLASS_ATTR, Ctx__add_name(ctx(), decl_name), prev()->line);
     } else {
         NameExpr* e = NameExpr__new(prev()->line, decl_name, name_scope(self));
         vtemit_store((Expr*)e, ctx());
@@ -2404,7 +2403,7 @@ static Error* compile_class(Compiler* self, int decorators) {
     } else {
         Ctx__s_emit_top(ctx());  // []
     }
-    Ctx__emit_(ctx(), OP_BEGIN_CLASS, name, BC_KEEPLINE);
+    Ctx__emit_(ctx(), OP_BEGIN_CLASS, Ctx__add_name(ctx(), name), BC_KEEPLINE);
 
     c11__foreach(Ctx, &self->contexts, it) {
         if(it->is_compiling_class) return SyntaxError(self, "nested class is not allowed");
@@ -2788,7 +2787,10 @@ static Error* compile_stmt(Compiler* self) {
                         NameExpr* ne = (NameExpr*)Ctx__s_top(ctx());
                         int index = Ctx__add_const_string(ctx(), type_hint);
                         Ctx__emit_(ctx(), OP_LOAD_CONST, index, BC_KEEPLINE);
-                        Ctx__emit_(ctx(), OP_ADD_CLASS_ANNOTATION, Ctx__add_name(ctx(), ne->name), BC_KEEPLINE);
+                        Ctx__emit_(ctx(),
+                                   OP_ADD_CLASS_ANNOTATION,
+                                   Ctx__add_name(ctx(), ne->name),
+                                   BC_KEEPLINE);
                     }
                 }
             }
diff --git a/src/interpreter/name.c b/src/interpreter/name.c
deleted file mode 100644
index 529e3dcc..00000000
--- a/src/interpreter/name.c
+++ /dev/null
@@ -1,67 +0,0 @@
-#include "pocketpy/interpreter/name.h"
-#include "pocketpy/interpreter/vm.h"
-
-#define MAGIC_METHOD(x) py_Name x;
-#include "pocketpy/xmacros/magics.h"
-#undef MAGIC_METHOD
-
-void InternedNames__ctor(InternedNames* self) {
-    c11_smallmap_v2n__ctor(&self->interned);
-
-    // initialize all magic names
-#define MAGIC_METHOD(x) x = py_name(#x);
-#include "pocketpy/xmacros/magics.h"
-#undef MAGIC_METHOD
-}
-
-void InternedNames__dtor(InternedNames* self) {
-    for(int i = 0; i < self->interned.length; i++) {
-        c11_smallmap_v2n_KV* kv = c11__at(c11_smallmap_v2n_KV, &self->interned, i);
-        PK_FREE((void*)kv->value);
-    }
-    c11_smallmap_v2n__dtor(&self->interned);
-}
-
-py_Name py_name(const char* name) {
-    c11_sv sv;
-    sv.data = name;
-    sv.size = strlen(name);
-    return py_namev(sv);
-}
-
-py_Name py_namev(c11_sv name) {
-    InternedNames* self = &pk_current_vm->names;
-    py_Name index = c11_smallmap_v2n__get(&self->interned, name, 0);
-    if(index != 0) return index;
-    // generate new index
-    InternedEntry* p = PK_MALLOC(sizeof(InternedEntry) + name.size + 1);
-    p->size = name.size;
-    memcpy(p->data, name.data, name.size);
-    p->data[name.size] = '\0';
-    memset(&p->obj, 0, sizeof(py_TValue));
-    index = (py_Name)p;
-    // save to _interned
-    c11_smallmap_v2n__set(&self->interned, (c11_sv){p->data, name.size}, index);
-    return index;
-}
-
-const char* py_name2str(py_Name index) {
-    InternedEntry* p = (InternedEntry*)index;
-    return p->data;
-}
-
-c11_sv py_name2sv(py_Name index) {
-    InternedEntry* p = (InternedEntry*)index;
-    return (c11_sv){p->data, p->size};
-}
-
-py_GlobalRef py_name2ref(py_Name index) {
-    InternedEntry* p = (InternedEntry*)index;
-    if(p->obj.type == tp_nil) {
-        c11_sv sv;
-        sv.data = p->data;
-        sv.size = p->size;
-        py_newstrv(&p->obj, sv);
-    }
-    return &p->obj;
-}
diff --git a/src/interpreter/vm.c b/src/interpreter/vm.c
index 135f395b..3afe0c70 100644
--- a/src/interpreter/vm.c
+++ b/src/interpreter/vm.c
@@ -65,7 +65,6 @@ static void py_TypeInfo__ctor(py_TypeInfo* self,
 
 void VM__ctor(VM* self) {
     self->top_frame = NULL;
-    InternedNames__ctor(&self->names);
 
     ModuleDict__ctor(&self->modules, "", *py_NIL());
     TypeList__ctor(&self->types);
@@ -97,6 +96,7 @@ void VM__ctor(VM* self) {
 
     ManagedHeap__ctor(&self->heap);
     ValueStack__ctor(&self->stack);
+    NameDict__ctor(&self->cached_names, PK_INST_ATTR_LOAD_FACTOR);
 
     /* Init Builtin Types */
     // 0: unused
@@ -274,7 +274,7 @@ void VM__dtor(VM* self) {
     TypeList__dtor(&self->types);
     FixedMemoryPool__dtor(&self->pool_frame);
     ValueStack__dtor(&self->stack);
-    InternedNames__dtor(&self->names);
+    NameDict__dtor(&self->cached_names);
 }
 
 void VM__push_frame(VM* self, py_Frame* frame) {
@@ -666,13 +666,6 @@ void ManagedHeap__mark(ManagedHeap* self) {
     for(int i = 0; i < c11__count_array(vm->reg); i++) {
         pk__mark_value(&vm->reg[i]);
     }
-    // mark interned names
-    for(int i = 0; i < vm->names.interned.length; i++) {
-        c11_smallmap_v2n_KV* kv = c11__at(c11_smallmap_v2n_KV, &vm->names.interned, i);
-        InternedEntry* entry = (InternedEntry*)kv->value;
-        pk__mark_value(&entry->obj);
-    }
-
     /*****************************/
     while(p_stack->length > 0) {
         PyObject* obj = c11_vector__back(PyObject*, p_stack);
@@ -842,4 +835,16 @@ int py_replinput(char* buf, int max_size) {
 
     buf[size] = '\0';
     return size;
+}
+
+py_Ref py_name2ref(py_Name name) {
+    assert(name != NULL);
+    NameDict* d = &pk_current_vm->cached_names;
+    py_Ref res = NameDict__try_get(d, name);
+    if(res != NULL) return res;
+    // not found, create a new one
+    py_TValue tmp;
+    py_newstrv(&tmp, py_name2sv(name));
+    NameDict__set(d, name, &tmp);
+    return NameDict__try_get(d, name);
 }
\ No newline at end of file
diff --git a/src/modules/dis.c b/src/modules/dis.c
index 85c7fc68..cc750b09 100644
--- a/src/modules/dis.c
+++ b/src/modules/dis.c
@@ -99,11 +99,31 @@ static bool disassemble(CodeObject* co) {
                     pk_sprintf(&ss, " (%s)", decl->code.name->data);
                     break;
                 }
-                case OP_BINARY_OP: {
-                    py_Name name = byte.arg & 0xFF;
-                    pk_sprintf(&ss, " (%s)", pk_op2str(name));
-                    break;
-                }
+#define CASE_BINARY_OP(label, op, rop)                                                             \
+    case label: {                                                                                  \
+        pk_sprintf(&ss, " (%s)", pk_op2str(op));                                                   \
+        break;                                                                                     \
+    }
+                    CASE_BINARY_OP(OP_BINARY_ADD, __add__, __radd__)
+                    CASE_BINARY_OP(OP_BINARY_SUB, __sub__, __rsub__)
+                    CASE_BINARY_OP(OP_BINARY_MUL, __mul__, __rmul__)
+                    CASE_BINARY_OP(OP_BINARY_TRUEDIV, __truediv__, __rtruediv__)
+                    CASE_BINARY_OP(OP_BINARY_FLOORDIV, __floordiv__, __rfloordiv__)
+                    CASE_BINARY_OP(OP_BINARY_MOD, __mod__, __rmod__)
+                    CASE_BINARY_OP(OP_BINARY_POW, __pow__, __rpow__)
+                    CASE_BINARY_OP(OP_BINARY_LSHIFT, __lshift__, 0)
+                    CASE_BINARY_OP(OP_BINARY_RSHIFT, __rshift__, 0)
+                    CASE_BINARY_OP(OP_BINARY_AND, __and__, 0)
+                    CASE_BINARY_OP(OP_BINARY_OR, __or__, 0)
+                    CASE_BINARY_OP(OP_BINARY_XOR, __xor__, 0)
+                    CASE_BINARY_OP(OP_BINARY_MATMUL, __matmul__, 0)
+                    CASE_BINARY_OP(OP_COMPARE_LT, __lt__, __gt__)
+                    CASE_BINARY_OP(OP_COMPARE_LE, __le__, __ge__)
+                    CASE_BINARY_OP(OP_COMPARE_EQ, __eq__, __eq__)
+                    CASE_BINARY_OP(OP_COMPARE_NE, __ne__, __ne__)
+                    CASE_BINARY_OP(OP_COMPARE_GT, __gt__, __lt__)
+                    CASE_BINARY_OP(OP_COMPARE_GE, __ge__, __le__)
+#undef CASE_BINARY_OP
             }
         } while(0);
 
diff --git a/src/modules/pkpy.c b/src/modules/pkpy.c
index 45d75ff1..1edd036c 100644
--- a/src/modules/pkpy.c
+++ b/src/modules/pkpy.c
@@ -160,7 +160,7 @@ static void
 static bool _pk_compute_thread_flags[16];
 
 static void c11_ComputeThread__dtor(c11_ComputeThread* self) {
-    if(!self->is_done) {
+    if(!atomic_load(&self->is_done)) {
         c11__abort("ComputeThread(%d) is not done yet!! But the object was deleted.",
                    self->vm_index);
     }
@@ -187,7 +187,7 @@ static bool ComputeThread__new__(int argc, py_Ref argv) {
     c11_ComputeThread* self =
         py_newobject(py_retval(), py_totype(argv), 0, sizeof(c11_ComputeThread));
     self->vm_index = 0;
-    self->is_done = true;
+    atomic_store(&self->is_done, true);
     self->last_retval_data = NULL;
     self->last_retval_size = 0;
     self->last_error = NULL;
@@ -217,15 +217,16 @@ static bool ComputeThread__init__(int argc, py_Ref argv) {
 static bool ComputeThread_is_done(int argc, py_Ref argv) {
     PY_CHECK_ARGC(1);
     c11_ComputeThread* self = py_touserdata(argv);
-    py_newbool(py_retval(), self->is_done);
+    py_newbool(py_retval(), atomic_load(&self->is_done));
     return true;
 }
 
 static bool ComputeThread_wait_for_done(int argc, py_Ref argv) {
     PY_CHECK_ARGC(1);
     c11_ComputeThread* self = py_touserdata(argv);
-    while(!self->is_done)
+    while(!atomic_load(&self->is_done)) {
         c11_thrd_yield();
+    }
     py_newnone(py_retval());
     return true;
 }
@@ -233,7 +234,7 @@ static bool ComputeThread_wait_for_done(int argc, py_Ref argv) {
 static bool ComputeThread_last_error(int argc, py_Ref argv) {
     PY_CHECK_ARGC(1);
     c11_ComputeThread* self = py_touserdata(argv);
-    if(!self->is_done) return OSError("thread is not done yet");
+    if(!atomic_load(&self->is_done)) return OSError("thread is not done yet");
     if(self->last_error) {
         py_newstr(py_retval(), self->last_error);
     } else {
@@ -245,7 +246,7 @@ static bool ComputeThread_last_error(int argc, py_Ref argv) {
 static bool ComputeThread_last_retval(int argc, py_Ref argv) {
     PY_CHECK_ARGC(1);
     c11_ComputeThread* self = py_touserdata(argv);
-    if(!self->is_done) return OSError("thread is not done yet");
+    if(!atomic_load(&self->is_done)) return OSError("thread is not done yet");
     if(self->last_retval_data == NULL) return ValueError("no retval available");
     return py_pickle_loads(self->last_retval_data, self->last_retval_size);
 }
@@ -273,12 +274,12 @@ static c11_thrd_retval_t ComputeThreadJob_call(void* arg) {
     unsigned char* retval_data = py_tobytes(py_retval(), &retval_size);
     self->last_retval_data = c11_memdup(retval_data, retval_size);
     self->last_retval_size = retval_size;
-    self->is_done = true;
+    atomic_store(&self->is_done, true);
     return (c11_thrd_retval_t)0;
 
 __ERROR:
     self->last_error = py_formatexc();
-    self->is_done = true;
+    atomic_store(&self->is_done, true);
     py_clearexc(p0);
     py_newnone(py_retval());
     return (c11_thrd_retval_t)0;
@@ -296,12 +297,12 @@ static c11_thrd_retval_t ComputeThreadJob_exec(void* arg) {
     unsigned char* retval_data = py_tobytes(py_retval(), &retval_size);
     self->last_retval_data = c11_memdup(retval_data, retval_size);
     self->last_retval_size = retval_size;
-    self->is_done = true;
+    atomic_store(&self->is_done, true);
     return (c11_thrd_retval_t)0;
 
 __ERROR:
     self->last_error = py_formatexc();
-    self->is_done = true;
+    atomic_store(&self->is_done, true);
     py_clearexc(p0);
     return (c11_thrd_retval_t)0;
 }
@@ -309,7 +310,7 @@ __ERROR:
 static bool ComputeThread_submit_exec(int argc, py_Ref argv) {
     PY_CHECK_ARGC(2);
     c11_ComputeThread* self = py_touserdata(py_arg(0));
-    if(!self->is_done) return OSError("thread is not done yet");
+    if(!atomic_load(&self->is_done)) return OSError("thread is not done yet");
     PY_CHECK_ARG_TYPE(1, tp_str);
     const char* source = py_tostr(py_arg(1));
     /**************************/
@@ -319,10 +320,10 @@ static bool ComputeThread_submit_exec(int argc, py_Ref argv) {
     job->mode = EXEC_MODE;
     c11_ComputeThread__reset_job(self, job, ComputeThreadJobExec__dtor);
     /**************************/
-    self->is_done = false;
+    atomic_store(&self->is_done, false);
     bool ok = c11_thrd_create(&self->thread, ComputeThreadJob_exec, job);
     if(!ok) {
-        self->is_done = true;
+        atomic_store(&self->is_done, true);
         return OSError("thrd_create() failed");
     }
     py_newnone(py_retval());
@@ -332,7 +333,7 @@ static bool ComputeThread_submit_exec(int argc, py_Ref argv) {
 static bool ComputeThread_submit_eval(int argc, py_Ref argv) {
     PY_CHECK_ARGC(2);
     c11_ComputeThread* self = py_touserdata(py_arg(0));
-    if(!self->is_done) return OSError("thread is not done yet");
+    if(!atomic_load(&self->is_done)) return OSError("thread is not done yet");
     PY_CHECK_ARG_TYPE(1, tp_str);
     const char* source = py_tostr(py_arg(1));
     /**************************/
@@ -342,10 +343,10 @@ static bool ComputeThread_submit_eval(int argc, py_Ref argv) {
     job->mode = EVAL_MODE;
     c11_ComputeThread__reset_job(self, job, ComputeThreadJobExec__dtor);
     /**************************/
-    self->is_done = false;
+    atomic_store(&self->is_done, false);
     bool ok = c11_thrd_create(&self->thread, ComputeThreadJob_exec, job);
     if(!ok) {
-        self->is_done = true;
+        atomic_store(&self->is_done, true);
         return OSError("thrd_create() failed");
     }
     py_newnone(py_retval());
@@ -355,7 +356,7 @@ static bool ComputeThread_submit_eval(int argc, py_Ref argv) {
 static bool ComputeThread_submit_call(int argc, py_Ref argv) {
     PY_CHECK_ARGC(4);
     c11_ComputeThread* self = py_touserdata(py_arg(0));
-    if(!self->is_done) return OSError("thread is not done yet");
+    if(!atomic_load(&self->is_done)) return OSError("thread is not done yet");
     PY_CHECK_ARG_TYPE(1, tp_str);
     PY_CHECK_ARG_TYPE(2, tp_tuple);
     PY_CHECK_ARG_TYPE(3, tp_dict);
@@ -379,10 +380,10 @@ static bool ComputeThread_submit_call(int argc, py_Ref argv) {
     job->kwargs_size = kwargs_size;
     c11_ComputeThread__reset_job(self, job, ComputeThreadJobCall__dtor);
     /**************************/
-    self->is_done = false;
+    atomic_store(&self->is_done, false);
     bool ok = c11_thrd_create(&self->thread, ComputeThreadJob_call, job);
     if(!ok) {
-        self->is_done = true;
+        atomic_store(&self->is_done, true);
         return OSError("thrd_create() failed");
     }
     py_newnone(py_retval());
@@ -392,8 +393,8 @@ static bool ComputeThread_submit_call(int argc, py_Ref argv) {
 static bool c11_ComputeThread__exec_blocked(c11_ComputeThread* self,
                                             const char* source,
                                             enum py_CompileMode mode) {
-    if(!self->is_done) return OSError("thread is not done yet");
-    self->is_done = false;
+    if(!atomic_load(&self->is_done)) return OSError("thread is not done yet");
+    atomic_store(&self->is_done, false);
     char* err = NULL;
     int old_vm_index = py_currentvm();
     py_switchvm(self->vm_index);
@@ -405,14 +406,14 @@ static bool c11_ComputeThread__exec_blocked(c11_ComputeThread* self,
     unsigned char* retval_data = py_tobytes(py_retval(), &retval_size);
     py_switchvm(old_vm_index);
     bool ok = py_pickle_loads(retval_data, retval_size);
-    self->is_done = true;
+    atomic_store(&self->is_done, true);
     return ok;
 
 __ERROR:
     err = py_formatexc();
     py_clearexc(p0);
     py_switchvm(old_vm_index);
-    self->is_done = true;
+    atomic_store(&self->is_done, true);
     RuntimeError("c11_ComputeThread__exec_blocked() failed:\n%s", err);
     PK_FREE(err);
     return false;
@@ -454,7 +455,7 @@ static void pk_ComputeThread__register(py_Ref mod) {
     py_bindmethod(type, "eval", ComputeThread_eval);
 }
 
-static void pkpy_configmacros_add(py_Ref dict, const char* key, int val){
+static void pkpy_configmacros_add(py_Ref dict, const char* key, int val) {
     assert(dict->type == tp_dict);
     py_TValue tmp;
     py_newint(&tmp, val);
diff --git a/src/public/internal.c b/src/public/internal.c
index cd7c5945..5a2912fc 100644
--- a/src/public/internal.c
+++ b/src/public/internal.c
@@ -3,6 +3,7 @@
 #include "pocketpy/pocketpy.h"
 
 #include "pocketpy/common/utils.h"
+#include "pocketpy/common/name.h"
 #include "pocketpy/interpreter/vm.h"
 
 _Thread_local VM* pk_current_vm;
@@ -18,6 +19,8 @@ void py_initialize() {
         return;
     }
 
+    pk_names_initialize();
+
     // check endianness
     int x = 1;
     bool is_little_endian = *(char*)&x == 1;
@@ -62,6 +65,8 @@ void py_finalize() {
     pk_current_vm = &pk_default_vm;
     VM__dtor(&pk_default_vm);
     pk_current_vm = NULL;
+
+    pk_names_finalize();
 }
 
 void py_switchvm(int index) {