From dbf88cc20901ae4f4cdf4892606d3b5d71d839da Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Mon, 18 Nov 2013 14:21:06 +0000
Subject: [PATCH] From Stephan Huber, "minor ios-fixes/-enhancements

* force _OPENTHREADS_ATOMIC_USE_BSD_ATOMIC for IOS device + simulator as the test does not pick the right implementation
* fixed a small compile-bug for iphone-example
* added a check to prevent multiple realization of a GraphicsWindowIOS-object
"
---
 CMakeModules/CheckAtomicOps.cmake             | 199 +++++++++---------
 .../osgviewerIPhone/iphoneViewerAppDelegate.h |   1 -
 src/osgViewer/GraphicsWindowIOS.mm            |   2 +
 3 files changed, 107 insertions(+), 95 deletions(-)

diff --git a/CMakeModules/CheckAtomicOps.cmake b/CMakeModules/CheckAtomicOps.cmake
index e37532f32..a518e6ee8 100644
--- a/CMakeModules/CheckAtomicOps.cmake
+++ b/CMakeModules/CheckAtomicOps.cmake
@@ -1,4 +1,4 @@
-# Check for availability of atomic operations 
+# Check for availability of atomic operations
 # This module defines
 # OPENTHREADS_HAVE_ATOMIC_OPS
 
@@ -15,123 +15,134 @@ IF (OPENTHREADS_ATOMIC_USE_MUTEX)
     SET(_OPENTHREADS_ATOMIC_USE_MUTEX 1)
 
 ELSE()
+    # as the test does not work for IOS hardcode the ATOMIC implementation
+    IF(OSG_BUILD_PLATFORM_IPHONE_SIMULATOR OR OSG_BUILD_PLATFORM_IPHONE)
+       SET(_OPENTHREADS_ATOMIC_USE_GCC_BUILTINS 0)
+       SET(_OPENTHREADS_ATOMIC_USE_MIPOSPRO_BUILTINS 0)
+       SET(_OPENTHREADS_ATOMIC_USE_SUN 0)
+       SET(_OPENTHREADS_ATOMIC_USE_WIN32_INTERLOCKED 0)
+       SET(_OPENTHREADS_ATOMIC_USE_MUTEX 0)
 
-    INCLUDE(CheckCXXSourceRuns)
+       SET(_OPENTHREADS_ATOMIC_USE_BSD_ATOMIC 1)
 
-    # Do step by step checking,
-    CHECK_CXX_SOURCE_RUNS("
-    #include <cstdlib>
+    ELSE()
+       INCLUDE(CheckCXXSourceRuns)
 
-    int main()
-    {
-       unsigned value = 0;
-       void* ptr = &value;
-       __sync_add_and_fetch(&value, 1);
-       __sync_synchronize();
-       __sync_sub_and_fetch(&value, 1);
-       if (!__sync_bool_compare_and_swap(&value, 0, 1))
-          return EXIT_FAILURE;
+       # Do step by step checking,
+       CHECK_CXX_SOURCE_RUNS("
+       #include <cstdlib>
 
-       if (!__sync_bool_compare_and_swap(&ptr, ptr, ptr))
-          return EXIT_FAILURE;
+       int main()
+       {
+          unsigned value = 0;
+          void* ptr = &value;
+          __sync_add_and_fetch(&value, 1);
+          __sync_synchronize();
+          __sync_sub_and_fetch(&value, 1);
+          if (!__sync_bool_compare_and_swap(&value, 0, 1))
+             return EXIT_FAILURE;
 
-       return EXIT_SUCCESS;
-    }
-    " _OPENTHREADS_ATOMIC_USE_GCC_BUILTINS)
+          if (!__sync_bool_compare_and_swap(&ptr, ptr, ptr))
+             return EXIT_FAILURE;
 
-    CHECK_CXX_SOURCE_RUNS("
-    #include <stdlib.h>
+          return EXIT_SUCCESS;
+       }
+       " _OPENTHREADS_ATOMIC_USE_GCC_BUILTINS)
 
-    int main(int, const char**)
-    {
-       unsigned value = 0;
-       void* ptr = &value;
-       __add_and_fetch(&value, 1);
-       __synchronize(value);
-       __sub_and_fetch(&value, 1);
-       if (!__compare_and_swap(&value, 0, 1))
-          return EXIT_FAILURE;
+       CHECK_CXX_SOURCE_RUNS("
+       #include <stdlib.h>
 
-       if (!__compare_and_swap((unsigned long*)&ptr, (unsigned long)ptr, (unsigned long)ptr))
-          return EXIT_FAILURE;
+       int main(int, const char**)
+       {
+          unsigned value = 0;
+          void* ptr = &value;
+          __add_and_fetch(&value, 1);
+          __synchronize(value);
+          __sub_and_fetch(&value, 1);
+          if (!__compare_and_swap(&value, 0, 1))
+             return EXIT_FAILURE;
 
-       return EXIT_SUCCESS;
-    }
-    " _OPENTHREADS_ATOMIC_USE_MIPOSPRO_BUILTINS)
+          if (!__compare_and_swap((unsigned long*)&ptr, (unsigned long)ptr, (unsigned long)ptr))
+             return EXIT_FAILURE;
 
-    CHECK_CXX_SOURCE_RUNS("
-    #include <atomic.h>
-    #include <cstdlib>
+          return EXIT_SUCCESS;
+       }
+       " _OPENTHREADS_ATOMIC_USE_MIPOSPRO_BUILTINS)
 
-    int main(int, const char**)
-    {
-       uint_t value = 0;
-       void* ptr = &value;
-       atomic_inc_uint_nv(&value);
-       membar_consumer();
-       atomic_dec_uint_nv(&value);
-       if (0 != atomic_cas_uint(&value, 0, 1))
-          return EXIT_FAILURE;
+       CHECK_CXX_SOURCE_RUNS("
+       #include <atomic.h>
+       #include <cstdlib>
 
-       if (ptr != atomic_cas_ptr(&ptr, ptr, ptr))
-          return EXIT_FAILURE;
+       int main(int, const char**)
+       {
+          uint_t value = 0;
+          void* ptr = &value;
+          atomic_inc_uint_nv(&value);
+          membar_consumer();
+          atomic_dec_uint_nv(&value);
+          if (0 != atomic_cas_uint(&value, 0, 1))
+             return EXIT_FAILURE;
 
-       return EXIT_SUCCESS;
-    }
-    " _OPENTHREADS_ATOMIC_USE_SUN)
+          if (ptr != atomic_cas_ptr(&ptr, ptr, ptr))
+             return EXIT_FAILURE;
 
-    CHECK_CXX_SOURCE_RUNS("
-    #include <windows.h>
-    #include <intrin.h>
-    #include <cstdlib>
+          return EXIT_SUCCESS;
+       }
+       " _OPENTHREADS_ATOMIC_USE_SUN)
 
-    #pragma intrinsic(_InterlockedAnd)
-    #pragma intrinsic(_InterlockedOr)
-    #pragma intrinsic(_InterlockedXor)
+       CHECK_CXX_SOURCE_RUNS("
+       #include <windows.h>
+       #include <intrin.h>
+       #include <cstdlib>
 
-    int main(int, const char**)
-    {
-       volatile long value = 0;
-       long data = 0;
-       long* volatile ptr = &data;
+       #pragma intrinsic(_InterlockedAnd)
+       #pragma intrinsic(_InterlockedOr)
+       #pragma intrinsic(_InterlockedXor)
 
-       InterlockedIncrement(&value);
-       MemoryBarrier();
-       InterlockedDecrement(&value);
+       int main(int, const char**)
+       {
+          volatile long value = 0;
+          long data = 0;
+          long* volatile ptr = &data;
 
-       if (0 != InterlockedCompareExchange(&value, 1, 0))
-          return EXIT_FAILURE;
+          InterlockedIncrement(&value);
+          MemoryBarrier();
+          InterlockedDecrement(&value);
 
-       if (ptr != InterlockedCompareExchangePointer((PVOID volatile*)&ptr, (PVOID)ptr, (PVOID)ptr))
-          return EXIT_FAILURE;
+          if (0 != InterlockedCompareExchange(&value, 1, 0))
+             return EXIT_FAILURE;
 
-       return EXIT_SUCCESS;
-    }
-    " _OPENTHREADS_ATOMIC_USE_WIN32_INTERLOCKED)
+          if (ptr != InterlockedCompareExchangePointer((PVOID volatile*)&ptr, (PVOID)ptr, (PVOID)ptr))
+             return EXIT_FAILURE;
 
-    CHECK_CXX_SOURCE_RUNS("
-    #include <libkern/OSAtomic.h>
+          return EXIT_SUCCESS;
+       }
+       " _OPENTHREADS_ATOMIC_USE_WIN32_INTERLOCKED)
 
-    int main()
-    {
-      volatile int32_t value = 0;
-      long data = 0;
-      long * volatile ptr = &data;
+       CHECK_CXX_SOURCE_RUNS("
+       #include <libkern/OSAtomic.h>
 
-      OSAtomicIncrement32(&value);
-      OSMemoryBarrier();
-      OSAtomicDecrement32(&value);
-      OSAtomicCompareAndSwapInt(value, 1, &value);
-      OSAtomicCompareAndSwapPtr(ptr, ptr, (void * volatile *)&ptr);
-    }
-    " _OPENTHREADS_ATOMIC_USE_BSD_ATOMIC)
+       int main()
+       {
+         volatile int32_t value = 0;
+         long data = 0;
+         long * volatile ptr = &data;
 
-    IF(NOT _OPENTHREADS_ATOMIC_USE_GCC_BUILTINS AND
-       NOT _OPENTHREADS_ATOMIC_USE_MIPOSPRO_BUILTINS AND
-       NOT _OPENTHREADS_ATOMIC_USE_SUN AND
-       NOT _OPENTHREADS_ATOMIC_USE_WIN32_INTERLOCKED AND
-       NOT _OPENTHREADS_ATOMIC_USE_BSD_ATOMIC)
-               SET(_OPENTHREADS_ATOMIC_USE_MUTEX 1)
+         OSAtomicIncrement32(&value);
+         OSMemoryBarrier();
+         OSAtomicDecrement32(&value);
+         OSAtomicCompareAndSwapInt(value, 1, &value);
+         OSAtomicCompareAndSwapPtr(ptr, ptr, (void * volatile *)&ptr);
+       }
+       " _OPENTHREADS_ATOMIC_USE_BSD_ATOMIC)
+
+       IF(NOT _OPENTHREADS_ATOMIC_USE_GCC_BUILTINS AND
+          NOT _OPENTHREADS_ATOMIC_USE_MIPOSPRO_BUILTINS AND
+          NOT _OPENTHREADS_ATOMIC_USE_SUN AND
+          NOT _OPENTHREADS_ATOMIC_USE_WIN32_INTERLOCKED AND
+          NOT _OPENTHREADS_ATOMIC_USE_BSD_ATOMIC)
+                  SET(_OPENTHREADS_ATOMIC_USE_MUTEX 1)
+       ENDIF()
     ENDIF()
 
 ENDIF()
diff --git a/examples/osgviewerIPhone/iphoneViewerAppDelegate.h b/examples/osgviewerIPhone/iphoneViewerAppDelegate.h
index 25fa77e2c..ddcc4ba59 100644
--- a/examples/osgviewerIPhone/iphoneViewerAppDelegate.h
+++ b/examples/osgviewerIPhone/iphoneViewerAppDelegate.h
@@ -5,7 +5,6 @@
 
 #include <osgDB/ReadFile>
 #include <osg/MatrixTransform>
-#include <osg/CameraNode>
 #include <osgText/Text>
 #include <osgViewer/Viewer>
 
diff --git a/src/osgViewer/GraphicsWindowIOS.mm b/src/osgViewer/GraphicsWindowIOS.mm
index 89b54e977..535b2dc85 100644
--- a/src/osgViewer/GraphicsWindowIOS.mm
+++ b/src/osgViewer/GraphicsWindowIOS.mm
@@ -746,6 +746,8 @@ void GraphicsWindowIOS::init()
 
 bool GraphicsWindowIOS::realizeImplementation()
 {
+    if (_realized) return true;
+    
     NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
     
     BOOL bar_hidden = (_traits->windowDecoration) ? NO: YES;