feat: add FreeObj, Slab and spinLockInit

src/spinlock.c

@@ -0,0 +1,40 @@
+#include "spinlock.h"
+#include "ports.h"
+
+void spinLockInit(SpinLock* lock)
+{
+    lock->locked = 0;
+}
+
+uint64 spinLockAcquire(SpinLock* lock)
+{
+    uint64 flags = saveAndDisableInterrupts();
+    while (__atomic_exchange_n(&lock->locked, 1, __ATOMIC_ACQUIRE) != 0) {
+        /* single-core: a lock held across this spin can only be released by
+           an interrupt handler, but interrupts are off -- callers must never
+           acquire a lock they (or a handler nested under them) already hold */
+    }
+    return flags;
+}
+
+bool spinLockTryAcquire(SpinLock* lock, uint64* savedFlags)
+{
+    uint64 flags = saveAndDisableInterrupts();
+    if (__atomic_exchange_n(&lock->locked, 1, __ATOMIC_ACQUIRE) != 0) {
+        restoreInterrupts(flags);
+        return false;
+    }
+    *savedFlags = flags;
+    return true;
+}
+
+void spinLockRelease(SpinLock* lock, uint64 flags)
+{
+    __atomic_store_n(&lock->locked, 0, __ATOMIC_RELEASE);
+    restoreInterrupts(flags);
+}
+
+bool spinLockIsLocked(const SpinLock* lock)
+{
+    return __atomic_load_n(&lock->locked, __ATOMIC_ACQUIRE) != 0;
+}