Added a README file regarding WinRT support

To note, this file is currently formatted with CRLF line endings, rather than
LF, to allow the file to be viewed with Notepad.

src/thread/stdcpp/SDL_sysmutex.cpp

@@ -0,0 +1,111 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2014 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "../../SDL_internal.h"
+
+extern "C" {
+#include "SDL_thread.h"
+#include "SDL_systhread_c.h"
+#include "SDL_log.h"
+}
+
+#include <system_error>
+
+#include "SDL_sysmutex_c.h"
+#include <Windows.h>
+
+
+/* Create a mutex */
+extern "C"
+SDL_mutex *
+SDL_CreateMutex(void)
+{
+    /* Allocate and initialize the mutex */
+    try {
+        SDL_mutex * mutex = new SDL_mutex;
+        return mutex;
+    } catch (std::system_error & ex) {
+        SDL_SetError("unable to create a C++ mutex: code=%d; %s", ex.code(), ex.what());
+        return NULL;
+    } catch (std::bad_alloc &) {
+        SDL_OutOfMemory();
+        return NULL;
+    }
+}
+
+/* Free the mutex */
+extern "C"
+void
+SDL_DestroyMutex(SDL_mutex * mutex)
+{
+    if (mutex) {
+        delete mutex;
+    }
+}
+
+/* Lock the semaphore */
+extern "C"
+int
+SDL_mutexP(SDL_mutex * mutex)
+{
+    if (mutex == NULL) {
+        SDL_SetError("Passed a NULL mutex");
+        return -1;
+    }
+
+    try {
+        mutex->cpp_mutex.lock();
+        return 0;
+    } catch (std::system_error & ex) {
+        SDL_SetError("unable to lock a C++ mutex: code=%d; %s", ex.code(), ex.what());
+        return -1;
+    }
+}
+
+/* TryLock the mutex */
+int
+SDL_TryLockMutex(SDL_mutex * mutex)
+{
+    int retval = 0;
+    if (mutex == NULL) {
+        return SDL_SetError("Passed a NULL mutex");
+    }
+
+    if (mutex->cpp_mutex.try_lock() == false) {
+        retval = SDL_MUTEX_TIMEDOUT;
+    }
+    return retval;
+}
+
+/* Unlock the mutex */
+extern "C"
+int
+SDL_mutexV(SDL_mutex * mutex)
+{
+    if (mutex == NULL) {
+        SDL_SetError("Passed a NULL mutex");
+        return -1;
+    }
+
+    mutex->cpp_mutex.unlock();
+    return 0;
+}
+
+/* vi: set ts=4 sw=4 expandtab: */