From 854a12f68b54a2bc7d320bf5c8d71497a46da44a Mon Sep 17 00:00:00 2001
From: "K. Lange" <klange@toaruos.org>
Date: Tue, 9 Feb 2021 21:34:02 +0900
Subject: [PATCH] Fix up some threading gc stuff before diving into real
 debugging

---
 src/compiler.c  | 16 ----------------
 src/memory.c    |  2 +-
 src/module_os.c |  3 +--
 src/threads.c   | 18 +++++++++++++++++-
 src/vm.c        |  4 ++--
 src/vm.h        | 20 ++++++++++++++++++++
 6 files changed, 41 insertions(+), 22 deletions(-)

diff --git a/src/compiler.c b/src/compiler.c
index 9956489..8b75ed5 100644
--- a/src/compiler.c
+++ b/src/compiler.c
@@ -2612,23 +2612,7 @@ static ParseRule * getRule(KrkTokenType type) {
 }
 
 #ifdef ENABLE_THREADING
-#include <sched.h>
-static void spin_lock(int volatile * lock) {
-	while(__sync_lock_test_and_set(lock, 0x01)) {
-		sched_yield();
-	}
-}
-
-static void spin_unlock(int volatile * lock) {
-	__sync_lock_release(lock);
-}
-
 static volatile int _compilerLock = 0;
-#define _obtain_lock(v) spin_lock(&v);
-#define _release_lock(v) spin_unlock(&v);
-#else
-#define _obtain_lock(v)
-#define _release_lock(v)
 #endif
 
 KrkFunction * krk_compile(const char * src, int newScope, char * fileName) {
diff --git a/src/memory.c b/src/memory.c
index 0cc3403..86561c1 100644
--- a/src/memory.c
+++ b/src/memory.c
@@ -245,7 +245,7 @@ void krk_tableRemoveWhite(KrkTable * table) {
 }
 
 static void markThreadRoots(KrkThreadState * thread) {
-	for (KrkValue * slot = thread->stack; slot < thread->stackTop; ++slot) {
+	for (KrkValue * slot = thread->stack; slot && slot < thread->stackTop; ++slot) {
 		krk_markValue(*slot);
 	}
 	for (KrkUpvalue * upvalue = thread->openUpvalues; upvalue; upvalue = upvalue->next) {
diff --git a/src/module_os.c b/src/module_os.c
index 21a8eba..2662280 100644
--- a/src/module_os.c
+++ b/src/module_os.c
@@ -294,8 +294,7 @@ KrkValue krk_module_onload_os(void) {
 	krk_attachNamedObject(&module->fields, "pardir", (KrkObj*)S(".."));
 	krk_attachNamedObject(&module->fields, "extsep", (KrkObj*)S("."));
 
-	OSError = krk_newClass(S("OSError"), vm.exceptions->baseException);
-	krk_attachNamedObject(&module->fields, "OSError", (KrkObj*)OSError);
+	krk_makeClass(module, &OSError, "OSError", vm.exceptions->baseException);
 	krk_finalizeClass(OSError);
 
 	BIND_FUNC(module,uname);
diff --git a/src/threads.c b/src/threads.c
index 633a7d9..96d0b68 100644
--- a/src/threads.c
+++ b/src/threads.c
@@ -38,13 +38,16 @@ KRK_FUNC(current_thread,{
 #define CURRENT_CTYPE struct Thread *
 #define CURRENT_NAME  self
 
+static volatile int _threadLock = 0;
 static void * _startthread(void * _threadObj) {
 	memset(&krk_currentThread, 0, sizeof(KrkThreadState));
-	/* TODO: Wrap this in a mutex */
+
+	_obtain_lock(_threadLock);
 	if (vm.threads->next) {
 		krk_currentThread.next = vm.threads->next;
 	}
 	vm.threads->next = &krk_currentThread;
+	_release_lock(_threadLock);
 
 	/* Get our run function */
 	struct Thread * self = _threadObj;
@@ -63,6 +66,19 @@ static void * _startthread(void * _threadObj) {
 
 	self->alive = 0;
 
+	/* Remove this thread from the thread pool, its stack is garbage anyway */
+	_obtain_lock(_threadLock);
+	krk_resetStack();
+	KrkThreadState * previous = vm.threads;
+	while (previous) {
+		if (previous->next == &krk_currentThread) {
+			previous->next = krk_currentThread.next;
+			break;
+		}
+		previous = previous->next;
+	}
+	_release_lock(_threadLock);
+
 	return NULL;
 }
 
diff --git a/src/vm.c b/src/vm.c
index 0384dbd..c3d7df7 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -1072,12 +1072,12 @@ static KrkValue krk_setclean(int argc, KrkValue argv[]) {
 }
 
 void krk_initVM(int flags) {
-	vm.globalFlags = flags & 0xF0;
+	vm.globalFlags = flags & 0xFF00;
 	KRK_PAUSE_GC();
 
 	/* Reset current thread */
 	krk_resetStack();
-	krk_currentThread.flags    = flags & 0x0F;
+	krk_currentThread.flags    = flags & 0x00FF;
 	krk_currentThread.module   = NULL;
 	krk_currentThread.watchdog = 0;
 	vm.threads = &krk_currentThread;
diff --git a/src/vm.h b/src/vm.h
index 627dbfc..0ed2ce3 100644
--- a/src/vm.h
+++ b/src/vm.h
@@ -233,3 +233,23 @@ extern int krk_doRecursiveModuleLoad(KrkString * name);
 
 extern KrkValue krk_operator_lt(KrkValue,KrkValue);
 extern KrkValue krk_operator_gt(KrkValue,KrkValue);
+
+#ifdef ENABLE_THREADING
+#include <sched.h>
+static inline void _krk_internal_spin_lock(int volatile * lock) {
+	while(__sync_lock_test_and_set(lock, 0x01)) {
+		sched_yield();
+	}
+}
+
+static inline void _krk_internal_spin_unlock(int volatile * lock) {
+	__sync_lock_release(lock);
+}
+
+#define _obtain_lock(v)  _krk_internal_spin_lock(&v);
+#define _release_lock(v) _krk_internal_spin_unlock(&v);
+#else
+#define _obtain_lock(v)
+#define _release_lock(v)
+#endif
+