Better fix

[wxWidgets.git] / include / wx / atomic.h

diff --git a/include/wx/atomic.h b/include/wx/atomic.h
index c2cdc6234535d243b5187bcaa8d5065b4de81a1a..829e29bdd34fff719534cad151c8bdec736eb3de 100644 (file)
--- a/include/wx/atomic.h
+++ b/include/wx/atomic.h
@@ -25,46 +25,50 @@
 
 #if wxUSE_THREADS
 
-#if defined(__WXMSW__)
+#if defined(HAVE_GCC_ATOMIC_BUILTINS)
 
-// include standard Windows headers
-#include "wx/msw/wrapwin.h"
+// NB: we intentionally don't use Linux's asm/atomic.h header, because it's
+//     an internal kernel header that doesn't always work in userspace:
+//     http://bugs.mysql.com/bug.php?id=28456
+//     http://golubenco.org/blog/atomic-operations/
 
 inline void wxAtomicInc (wxUint32 &value)
 {
-    InterlockedIncrement ((LONG*)&value);
+    __sync_fetch_and_add(&value, 1);
 }
 
 inline wxUint32 wxAtomicDec (wxUint32 &value)
 {
-    return InterlockedDecrement ((LONG*)&value);
+    return __sync_sub_and_fetch(&value, 1);
 }
 
-#elif defined(__WXMAC__) || defined(__DARWIN__)
 
-#include "libkern/OSAtomic.h"
+#elif defined(__WXMSW__)
+
+// include standard Windows headers
+#include "wx/msw/wrapwin.h"
+
 inline void wxAtomicInc (wxUint32 &value)
 {
-    OSAtomicIncrement32 ((int32_t*)&value);
+    InterlockedIncrement ((LONG*)&value);
 }
 
 inline wxUint32 wxAtomicDec (wxUint32 &value)
 {
-    return OSAtomicDecrement32 ((int32_t*)&value);
+    return InterlockedDecrement ((LONG*)&value);
 }
 
-#elif defined(__LINUX__)
-
-#include <asm/atomic.h>
+#elif defined(__WXMAC__) || defined(__DARWIN__)
 
+#include "libkern/OSAtomic.h"
 inline void wxAtomicInc (wxUint32 &value)
 {
-    atomic_inc ((atomic_t*)&value);
+    OSAtomicIncrement32 ((int32_t*)&value);
 }
 
 inline wxUint32 wxAtomicDec (wxUint32 &value)
 {
-    return atomic_dec_and_test ((atomic_t*)&value) ? 0 : 1;
+    return OSAtomicDecrement32 ((int32_t*)&value);
 }
 
 #elif defined (__SOLARIS__)
@@ -113,6 +117,7 @@ class wxAtomicInt32
 public:
     wxAtomicInt32() { } // non initialized for consistency with basic int type
     wxAtomicInt32(wxInt32 v) : m_value(v) { }
+    wxAtomicInt32(const wxAtomicInt32& a) : m_value(a.m_value) {}
 
     operator wxInt32() const { return m_value; }
     operator volatile wxInt32&() { return m_value; }
@@ -134,8 +139,6 @@ public:
 private:
     volatile wxInt32  m_value;
     wxCriticalSection m_locker;
-
-    DECLARE_NO_COPY_CLASS(wxAtomicInt32)
 };
 
 inline void wxAtomicInc(wxAtomicInt32 &value) { value.Inc(); }