remove thread_tag references (#705)

devkitA64 r29.1 removes  thread_tag from lock struct

Author: WinterMute

nx/include/switch/kernel/mutex.h

@@ -57,7 +57,6 @@ bool mutexIsLockedByCurrentThread(const Mutex* m);
 static inline void rmutexInit(RMutex* m)
 {
     m->lock = 0;
-    m->thread_tag = 0;
     m->counter = 0;
 }
 

nx/source/kernel/mutex.c

@@ -139,20 +139,15 @@ bool mutexIsLockedByCurrentThread(const Mutex* m) {
 }
 
 void rmutexLock(RMutex* m) {
-    if (m->thread_tag != _GetTag()) {
+    if (!mutexIsLockedByCurrentThread(&m->lock)) {
         mutexLock(&m->lock);
-        m->thread_tag = _GetTag();
+        m->counter++;
     }
-
-    m->counter++;
 }
 
 bool rmutexTryLock(RMutex* m) {
-    if (m->thread_tag != _GetTag()) {
-        if (!mutexTryLock(&m->lock)) {
-            return false;
-        }
-        m->thread_tag = _GetTag();
+    if (!mutexIsLockedByCurrentThread(&m->lock)) {
+        return mutexTryLock(&m->lock);
     }
 
     m->counter++;
@@ -161,7 +156,6 @@ bool rmutexTryLock(RMutex* m) {
 
 void rmutexUnlock(RMutex* m) {
     if (--m->counter == 0) {
-        m->thread_tag = 0;
         mutexUnlock(&m->lock);
     }
 }

nx/source/runtime/newlib.c

@@ -108,17 +108,13 @@ int __syscall_cond_wait(_COND_T *cond, _LOCK_T *lock, uint64_t timeout_ns)
 
 int __syscall_cond_wait_recursive(_COND_T *cond, _LOCK_RECURSIVE_T *lock, uint64_t timeout_ns)
 {
-    uint32_t thread_tag_backup = 0;
     if (lock->counter != 1)
         return EBADF;
 
-    thread_tag_backup = lock->thread_tag;
-    lock->thread_tag = 0;
     lock->counter = 0;
 
     int errcode = errno_from_result(condvarWaitTimeout(cond, &lock->lock, timeout_ns));
 
-    lock->thread_tag = thread_tag_backup;
     lock->counter = 1;
 
     return errcode;