WinRT: made the skeleton C++11 thread implementation use .cpp files, …

…not .c

VisualC/SDL/SDL_VS2012_WinRT.vcxproj

@@ -91,9 +91,9 @@
     <ClCompile Include="..\..\src\stdlib\SDL_string.c" />
     <ClCompile Include="..\..\src\thread\generic\SDL_syssem.c" />
     <ClCompile Include="..\..\src\thread\SDL_thread.c" />
-    <ClCompile Include="..\..\src\thread\stdcpp\SDL_syscond.c" />
-    <ClCompile Include="..\..\src\thread\stdcpp\SDL_sysmutex.c" />
-    <ClCompile Include="..\..\src\thread\stdcpp\SDL_systhread.c" />
+    <ClCompile Include="..\..\src\thread\stdcpp\SDL_syscond.cpp" />
+    <ClCompile Include="..\..\src\thread\stdcpp\SDL_sysmutex.cpp" />
+    <ClCompile Include="..\..\src\thread\stdcpp\SDL_systhread.cpp" />
     <ClCompile Include="..\..\src\timer\dummy\SDL_systimer.c" />
     <ClCompile Include="..\..\src\timer\SDL_timer.c" />
     <ClCompile Include="..\..\src\video\dummy\SDL_nullevents.c" />

src/thread/stdcpp/SDL_syscond.c → src/thread/stdcpp/SDL_syscond.cpp

@@ -38,6 +38,7 @@ struct SDL_cond
 };
 
 /* Create a condition variable */
+extern "C"
 SDL_cond *
 SDL_CreateCond(void)
 {
@@ -60,6 +61,7 @@ SDL_CreateCond(void)
 }
 
 /* Destroy a condition variable */
+extern "C"
 void
 SDL_DestroyCond(SDL_cond * cond)
 {
@@ -78,6 +80,7 @@ SDL_DestroyCond(SDL_cond * cond)
 }
 
 /* Restart one of the threads that are waiting on the condition variable */
+extern "C"
 int
 SDL_CondSignal(SDL_cond * cond)
 {
@@ -103,6 +106,7 @@ SDL_CondSignal(SDL_cond * cond)
 }
 
 /* Restart all threads that are waiting on the condition variable */
+extern "C"
 int
 SDL_CondBroadcast(SDL_cond * cond)
 {
@@ -158,6 +162,7 @@ Thread B:
     SDL_CondSignal(cond);
     SDL_UnlockMutex(lock);
  */
+extern "C"
 int
 SDL_CondWaitTimeout(SDL_cond * cond, SDL_mutex * mutex, Uint32 ms)
 {
@@ -214,6 +219,7 @@ SDL_CondWaitTimeout(SDL_cond * cond, SDL_mutex * mutex, Uint32 ms)
 }
 
 /* Wait on the condition variable forever */
+extern "C"
 int
 SDL_CondWait(SDL_cond * cond, SDL_mutex * mutex)
 {

src/thread/stdcpp/SDL_sysmutex.c → src/thread/stdcpp/SDL_sysmutex.cpp

@@ -34,6 +34,7 @@ struct SDL_mutex
 };
 
 /* Create a mutex */
+extern "C"
 SDL_mutex *
 SDL_CreateMutex(void)
 {
@@ -57,6 +58,7 @@ SDL_CreateMutex(void)
 }
 
 /* Free the mutex */
+extern "C"
 void
 SDL_DestroyMutex(SDL_mutex * mutex)
 {
@@ -69,6 +71,7 @@ SDL_DestroyMutex(SDL_mutex * mutex)
 }
 
 /* Lock the semaphore */
+extern "C"
 int
 SDL_mutexP(SDL_mutex * mutex)
 {
@@ -100,6 +103,7 @@ SDL_mutexP(SDL_mutex * mutex)
 }
 
 /* Unlock the mutex */
+extern "C"
 int
 SDL_mutexV(SDL_mutex * mutex)
 {

src/thread/stdcpp/SDL_systhread.c → src/thread/stdcpp/SDL_systhread.cpp

@@ -22,34 +22,41 @@
 
 /* Thread management routines for SDL */
 
+extern "C" {
 #include "SDL_thread.h"
 #include "../SDL_systhread.h"
+}
 
+extern "C"
 int
 SDL_SYS_CreateThread(SDL_Thread * thread, void *args)
 {
     SDL_SetError("Threads are not supported on this platform");
     return (-1);
 }
 
+extern "C"
 void
 SDL_SYS_SetupThread(const char *name)
 {
     return;
 }
 
+extern "C"
 SDL_threadID
 SDL_ThreadID(void)
 {
     return (0);
 }
 
+extern "C"
 int
 SDL_SYS_SetThreadPriority(SDL_ThreadPriority priority)
 {
     return (0);
 }
 
+extern "C"
 void
 SDL_SYS_WaitThread(SDL_Thread * thread)
 {