0484 core: add Linux pthread spinlock backend for NSS runtime

include/core/spinlock.h

@@ -0,0 +1,54 @@
+#ifndef MARS_NWE_CORE_SPINLOCK_H
+#define MARS_NWE_CORE_SPINLOCK_H
+
+#include <pthread.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Linux userspace backend for NSS runtime spin locks.
+ *
+ * The imported NSS common-layer headers were written for NetWare/NLM and
+ * Linux-kernel style spinlock APIs.  mars-nwe now targets Linux userspace, so
+ * keep the primitive in libnwcore and map it directly to POSIX pthread
+ * spinlocks instead of carrying a fake NWFS-local shim.
+ */
+typedef pthread_spinlock_t spinlock_t;
+
+static inline void
+spin_lock_init(spinlock_t *lock)
+{
+    (void)pthread_spin_init(lock, PTHREAD_PROCESS_PRIVATE);
+}
+
+static inline void
+spin_lock_destroy(spinlock_t *lock)
+{
+    (void)pthread_spin_destroy(lock);
+}
+
+static inline void
+spin_lock(spinlock_t *lock)
+{
+    (void)pthread_spin_lock(lock);
+}
+
+static inline void
+spin_unlock(spinlock_t *lock)
+{
+    (void)pthread_spin_unlock(lock);
+}
+
+static inline int
+spin_trylock(spinlock_t *lock)
+{
+    return pthread_spin_trylock(lock) == 0;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* MARS_NWE_CORE_SPINLOCK_H */