1 files changed, 141 insertions, 0 deletions
diff --git a/include/atomic.h b/include/atomic.h
new file mode 100644
index 00000000..3b5ec24d
--- /dev/null
+++ b/include/atomic.h
@@ -0,0 +1,141 @@
+#ifndef AL_ATOMIC_H
+#define AL_ATOMIC_H
+
+
+typedef void *volatile XchgPtr;
+
+#if defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)) && !defined(__QNXNTO__)
+typedef unsigned int RefCount;
+inline RefCount IncrementRef(volatile RefCount *ptr)
+{ return __sync_add_and_fetch(ptr, 1); }
+inline RefCount DecrementRef(volatile RefCount *ptr)
+{ return __sync_sub_and_fetch(ptr, 1); }
+
+inline int ExchangeInt(volatile int *ptr, int newval)
+{
+    return __sync_lock_test_and_set(ptr, newval);
+}
+inline void *ExchangePtr(XchgPtr *ptr, void *newval)
+{
+    return __sync_lock_test_and_set(ptr, newval);
+}
+inline int CompExchangeInt(volatile int *ptr, int oldval, int newval)
+{
+    return __sync_val_compare_and_swap(ptr, oldval, newval);
+}
+inline void *CompExchangePtr(XchgPtr *ptr, void *oldval, void *newval)
+{
+    return __sync_val_compare_and_swap(ptr, oldval, newval);
+}
+
+#elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
+
+inline unsigned int xaddl(volatile unsigned int *dest, int incr)
+{
+    unsigned int ret;
+    __asm__ __volatile__("lock; xaddl %0,(%1)"
+                         : "=r" (ret)
+                         : "r" (dest), "0" (incr)
+                         : "memory");
+    return ret;
+}
+
+typedef unsigned int RefCount;
+inline RefCount IncrementRef(volatile RefCount *ptr)
+{ return xaddl(ptr, 1)+1; }
+inline RefCount DecrementRef(volatile RefCount *ptr)
+{ return xaddl(ptr, -1)-1; }
+
+inline int ExchangeInt(volatile int *dest, int newval)
+{
+    int ret;
+    __asm__ __volatile__("lock; xchgl %0,(%1)"
+                         : "=r" (ret)
+                         : "r" (dest), "0" (newval)
+                         : "memory");
+    return ret;
+}
+inline void *ExchangePtr(XchgPtr *dest, void *newval)
+{
+    void *ret;
+    __asm__ __volatile__(
+#ifdef __i386__
+                         "lock; xchgl %0,(%1)"
+#else
+                         "lock; xchgq %0,(%1)"
+#endif
+                         : "=r" (ret)
+                         : "r" (dest), "0" (newval)
+                         : "memory"
+    );
+    return ret;
+}
+inline int CompExchangeInt(volatile int *dest, int oldval, int newval)
+{
+    int ret;
+    __asm__ __volatile__("lock; cmpxchgl %2,(%1)"
+                         : "=a" (ret)
+                         : "r" (dest), "r" (newval), "0" (oldval)
+                         : "memory");
+    return ret;
+}
+inline void *CompExchangePtr(XchgPtr *dest, void *oldval, void *newval)
+{
+    void *ret;
+    __asm__ __volatile__(
+#ifdef __i386__
+                         "lock; cmpxchgl %2,(%1)"
+#else
+                         "lock; cmpxchgq %2,(%1)"
+#endif
+                         : "=a" (ret)
+                         : "r" (dest), "r" (newval), "0" (oldval)
+                         : "memory"
+    );
+    return ret;
+}
+
+#elif defined(_WIN32)
+
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+typedef LONG RefCount;
+inline RefCount IncrementRef(volatile RefCount *ptr)
+{ return InterlockedIncrement(ptr); }
+inline RefCount DecrementRef(volatile RefCount *ptr)
+{ return InterlockedDecrement(ptr); }
+
+static_assert(sizeof(LONG)==sizeof(int), "sizeof LONG does not match sizeof int");
+
+inline int ExchangeInt(volatile int *ptr, int newval)
+{
+    union {
+        volatile int *i;
+        volatile LONG *l;
+    } u = { ptr };
+    return InterlockedExchange(u.l, newval);
+}
+inline void *ExchangePtr(XchgPtr *ptr, void *newval)
+{
+    return InterlockedExchangePointer(ptr, newval);
+}
+inline int CompExchangeInt(volatile int *ptr, int oldval, int newval)
+{
+    union {
+        volatile int *i;
+        volatile LONG *l;
+    } u = { ptr };
+    return InterlockedCompareExchange(u.l, newval, oldval);
+}
+inline void *CompExchangePtr(XchgPtr *ptr, void *oldval, void *newval)
+{
+    return InterlockedCompareExchangePointer(ptr, newval, oldval);
+}
+
+#else
+#error "No atomic functions available on this platform!"
+typedef unsigned int RefCount;
+#endif
+
+#endif /* AL_ATOMIC_H */