1 files changed, 46 insertions, 0 deletions

diff --git a/src/common/thunk.h b/src/common/thunk.h
new file mode 100644
index 000000000..c9e6fd39f
--- /dev/null
+++ b/src/common/thunk.h
@@ -0,0 +1,46 @@
+// Copyright 2013 Dolphin Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+#ifndef _THUNK_H_
+#define _THUNK_H_
+
+#include <map>
+
+#include "common.h"
+#include "x64Emitter.h"
+
+// This simple class creates a wrapper around a C/C++ function that saves all fp state
+// before entering it, and restores it upon exit. This is required to be able to selectively
+// call functions from generated code, without inflicting the performance hit and increase
+// of complexity that it means to protect the generated code from this problem.
+
+// This process is called thunking.
+
+// There will only ever be one level of thunking on the stack, plus,
+// we don't want to pollute the stack, so we store away regs somewhere global.
+// NOT THREAD SAFE. This may only be used from the CPU thread.
+// Any other thread using this stuff will be FATAL.
+
+class ThunkManager : public Gen::XCodeBlock
+{
+    std::map<void *, const u8 *> thunks;
+
+    const u8 *save_regs;
+    const u8 *load_regs;
+
+public:
+    ThunkManager() {
+        Init();
+    }
+    ~ThunkManager() {
+        Shutdown();
+    }
+    void *ProtectFunction(void *function, int num_params);
+private:
+    void Init();
+    void Shutdown();
+    void Reset();
+};
+
+#endif // _THUNK_H_