Made improvements to threading

Some memory issues sorted and you should be able to return a number from
a function without it segfaulting, now.

stdlib/thread.c

@@ -3,6 +3,7 @@
 #include <string.h>
 #include "comet.h"
 #include "comet_stdlib.h"
+#include "cometlib.h"
 #ifdef WIN32
 #include <Windows.h>
 #include <conio.h>
@@ -36,16 +37,21 @@ void thread_constructor(void *instanceData)
 void *thread_runner(void *arg)
 {
     ThreadData *data = (ThreadData *)arg;
-    return AS_OBJ(call_function(data->self, data->start_routine, 1, &data->arg));
+    return (void *)(uintptr_t)call_function(data->self, data->start_routine, 1, &data->arg);
 }
 
-VALUE thread_start(VM *vm, VALUE self, int UNUSED(arg_count), VALUE *arguments)
+VALUE thread_start(VM *vm, VALUE self, int arg_count, VALUE *arguments)
 {
     ThreadData *data = GET_NATIVE_INSTANCE_DATA(ThreadData, self);
     data->self = self;
     data->start_routine = arguments[0];
-    data->arg = arguments[1];
+    data->arg = arg_count > 1 ? arguments[1] : NIL_VAL;
     int status = 0;
+    if (callable_p(vm, 1, arguments) == FALSE_VAL)
+    {
+        throw_exception_native(vm, "ArgumentException", "The first argument to Thread::start was not callable");
+        return NIL_VAL;
+    }
 #ifdef WIN32
     data->thread_handle = CreateThread(NULL, 0, &thread_runner, data, 0, &data->thread_id);
     status = data->thread_handle == NULL ? -1 : 0;
@@ -94,6 +100,6 @@ void thread_mark_contents(VALUE self)
 void init_thread(VM *vm)
 {
     VALUE klass = defineNativeClass(vm, "Thread", thread_constructor, NULL, NULL, CLS_THREAD, sizeof(ThreadData), true);
-    defineNativeMethod(vm, klass, &thread_start, "start", 2, false);
+    defineNativeMethod(vm, klass, &thread_start, "start", 1, false);
     defineNativeMethod(vm, klass, &thread_join, "join", 0, false);
 }

test_scripts/socket_threads.cmt

@@ -9,6 +9,7 @@ function client(arg)
     print(contents)
     client.write("This is from the client")
     client.close()
+    sleep(0.5)
 }
 
 var server = Socket(SOCKET_TYPE.TCP, ADDRESS_FAMILY.IPv6)

vmlib/mem.c

@@ -243,6 +243,11 @@ static void blackenObject(Obj *object)
         markValue(((ObjUpvalue *)object)->closed);
         break;
     case OBJ_NATIVE_METHOD:
+    {
+        ObjNativeMethod *method = (ObjNativeMethod *)object;
+        markValue(method->name);
+        break;
+    }
     case OBJ_NATIVE:
         break;
     }

vmlib/vm.c

@@ -1135,6 +1135,7 @@ VALUE call_function(VALUE receiver, VALUE method, int arg_count, VALUE *argument
     {
         push(frame, arguments[i]);
     }
+    closeUpvalues(frame, NULL);
     if (IS_BOUND_METHOD(method) || IS_CLOSURE(method) || IS_FUNCTION(method))
     {
         if (callValue(frame, method, arg_count) && run(frame) == INTERPRET_OK)