/* -*-c++-*-
*
- * Copyright (C) 2005-2006 Mathias Froehlich
+ * Copyright (C) 2005-2009,2011 Mathias Froehlich
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
*
*/
-#include "SGAtomic.hxx"
+#ifdef HAVE_CONFIG_H
+# include <simgear_config.h>
+#endif
-#if defined(SGATOMIC_USE_GCC4_BUILTINS) && defined(__i386__)
+#include "SGAtomic.hxx"
-// Usually the apropriate functions are inlined by gcc.
-// But if gcc is called with something aequivalent to -march=i386,
-// it will not assume that there is a lock instruction and instead
-// calls this pair of functions. We will provide them here in this case.
-// Note that this assembler code will not work on a i386 chip anymore.
-// But I hardly believe that we can assume to run at least on a i486 ...
+#if defined(SGATOMIC_USE_LIBRARY_FUNCTIONS)
-extern "C" {
+#if defined(_WIN32)
+# include <windows.h>
+#elif defined(GCC_ATOMIC_BUILTINS_FOUND)
+#elif defined(__GNUC__) && defined(__i386__)
+#elif defined(SGATOMIC_USE_MUTEX)
+# include <simgear/threads/SGGuard.hxx>
+#else
+# error
+#endif
-unsigned __sync_sub_and_fetch_4(volatile void *ptr, unsigned value)
+unsigned
+SGAtomic::operator++()
{
- register volatile unsigned* mem = reinterpret_cast<volatile unsigned*>(ptr);
- register unsigned result;
- __asm__ __volatile__("lock; xadd{l} {%0,%1|%1,%0}"
- : "=r" (result), "=m" (*mem)
- : "0" (-value), "m" (*mem)
- : "memory");
- return result;
+#if defined(_WIN32)
+ return InterlockedIncrement(reinterpret_cast<long volatile*>(&mValue));
+#elif defined(GCC_ATOMIC_BUILTINS_FOUND)
+ return __sync_add_and_fetch(&mValue, 1);
+#elif defined(__GNUC__) && defined(__i386__)
+ register volatile unsigned* mem = reinterpret_cast<volatile unsigned*>(&mValue);
+ register unsigned result;
+ __asm__ __volatile__("lock; xadd{l} {%0,%1|%1,%0}"
+ : "=r" (result), "=m" (*mem)
+ : "0" (1), "m" (*mem)
+ : "memory");
+ return result + 1;
+#else
+ SGGuard<SGMutex> lock(mMutex);
+ return ++mValue;
+#endif
}
-unsigned __sync_add_and_fetch_4(volatile void *ptr, unsigned value)
+unsigned
+SGAtomic::operator--()
{
- register volatile unsigned* mem = reinterpret_cast<volatile unsigned*>(ptr);
- register unsigned result;
- __asm__ __volatile__("lock; xadd{l} {%0,%1|%1,%0}"
- : "=r" (result), "=m" (*mem)
- : "0" (value), "m" (*mem)
- : "memory");
- return result;
+#if defined(_WIN32)
+ return InterlockedDecrement(reinterpret_cast<long volatile*>(&mValue));
+#elif defined(GCC_ATOMIC_BUILTINS_FOUND)
+ return __sync_sub_and_fetch(&mValue, 1);
+#elif defined(__GNUC__) && defined(__i386__)
+ register volatile unsigned* mem = reinterpret_cast<volatile unsigned*>(&mValue);
+ register unsigned result;
+ __asm__ __volatile__("lock; xadd{l} {%0,%1|%1,%0}"
+ : "=r" (result), "=m" (*mem)
+ : "0" (-1), "m" (*mem)
+ : "memory");
+ return result - 1;
+#else
+ SGGuard<SGMutex> lock(mMutex);
+ return --mValue;
+#endif
}
-void __sync_synchronize()
+SGAtomic::operator unsigned() const
{
- __asm__ __volatile__("": : : "memory");
+#if defined(_WIN32)
+ return static_cast<unsigned const volatile &>(mValue);
+#elif defined(GCC_ATOMIC_BUILTINS_FOUND)
+ __sync_synchronize();
+ return mValue;
+#elif defined(__GNUC__) && defined(__i386__)
+ __asm__ __volatile__("": : : "memory");
+ return mValue;
+#else
+ SGGuard<SGMutex> lock(mMutex);
+ return mValue;
+#endif
}
-} // extern "C"
+bool
+SGAtomic::compareAndExchange(unsigned oldValue, unsigned newValue)
+{
+#if defined(_WIN32)
+ long volatile* lvPtr = reinterpret_cast<long volatile*>(&mValue);
+ return oldValue == InterlockedCompareExchange(lvPtr, newValue, oldValue);
+#elif defined(GCC_ATOMIC_BUILTINS_FOUND)
+ return __sync_bool_compare_and_swap(&mValue, oldValue, newValue);
+#elif defined(__GNUC__) && defined(__i386__)
+ register volatile unsigned* mem = reinterpret_cast<volatile unsigned*>(&mValue);
+ unsigned before;
+ __asm__ __volatile__("lock; cmpxchg{l} {%1,%2|%1,%2}"
+ : "=a"(before)
+ : "q"(newValue), "m"(*mem), "0"(oldValue)
+ : "memory");
+ return before == oldValue;
+#else
+ SGGuard<SGMutex> lock(mMutex);
+ if (mValue != oldValue)
+ return false;
+ mValue = newValue;
+ return true;
+#endif
+}
#endif