+# if defined (_POSIX_SPIN_LOCKS) && ((_POSIX_SPIN_LOCKS - 0) > 0)
+typedef pthread_spinlock_t vlc_spinlock_t;
+
+/**
+ * Initializes a spinlock.
+ */
+static inline int vlc_spin_init (vlc_spinlock_t *spin)
+{
+ return pthread_spin_init (spin, PTHREAD_PROCESS_PRIVATE);
+}
+
+/**
+ * Acquires a spinlock.
+ */
+static inline void vlc_spin_lock (vlc_spinlock_t *spin)
+{
+ pthread_spin_lock (spin);
+}
+
+/**
+ * Releases a spinlock.
+ */
+static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
+{
+ pthread_spin_unlock (spin);
+}
+
+/**
+ * Deinitializes a spinlock.
+ */
+static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
+{
+ pthread_spin_destroy (spin);
+}
+
+#elif defined( WIN32 )
+
+typedef CRITICAL_SECTION vlc_spinlock_t;
+
+/**
+ * Initializes a spinlock.
+ */
+static inline int vlc_spin_init (vlc_spinlock_t *spin)
+{
+ return !InitializeCriticalSectionAndSpinCount(spin, 4000);
+}
+
+/**
+ * Acquires a spinlock.
+ */
+static inline void vlc_spin_lock (vlc_spinlock_t *spin)
+{
+ EnterCriticalSection(spin);
+}
+
+/**
+ * Releases a spinlock.
+ */
+static inline void vlc_spin_unlock (vlc_spinlock_t *spin)
+{
+ LeaveCriticalSection(spin);
+}
+
+/**
+ * Deinitializes a spinlock.
+ */
+static inline void vlc_spin_destroy (vlc_spinlock_t *spin)
+{
+ DeleteCriticalSection(spin);
+}
+
+#else
+
+/* Fallback to plain mutexes if spinlocks are not available */
+typedef vlc_mutex_t vlc_spinlock_t;
+
+static inline int vlc_spin_init (vlc_spinlock_t *spin)
+{
+ return vlc_mutex_init (spin);
+}
+
+# define vlc_spin_lock vlc_mutex_lock
+# define vlc_spin_unlock vlc_mutex_unlock
+# define vlc_spin_destroy vlc_mutex_destroy
+#endif
+
+/**
+ * Issues a full memory barrier.
+ */
+#if defined (__APPLE__)
+# include <libkern/OSAtomic.h> /* OSMemoryBarrier() */
+#endif
+static inline void barrier (void)
+{
+#if defined (__GNUC__) && (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)
+ __sync_synchronize ();
+#elif defined(__APPLE__)
+ OSMemoryBarrier ();
+#elif defined(__powerpc__)
+ asm volatile ("sync":::"memory");
+#elif defined(__i386__)
+ asm volatile ("mfence":::"memory");
+#elif defined (LIBVLC_USE_PTHREAD)
+ static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;
+ pthread_mutex_lock (&lock);
+ pthread_mutex_unlock (&lock);