1 files changed, 117 insertions, 0 deletions
diff --git a/src/inc/ipcfunccall.h b/src/inc/ipcfunccall.h
new file mode 100644
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+++ b/src/inc/ipcfunccall.h
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+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+//*****************************************************************************
+// File: IPCFuncCall.h
+//
+// Define class to support a cross process function call. 
+//
+//*****************************************************************************
+
+
+#ifndef _IPCFUNCCALLIMPL_H_
+#define _IPCFUNCCALLIMPL_H_
+
+//-----------------------------------------------------------------------------
+// 1. Handler creates a IPCFuncCallHandler object and inits it with
+// a callback function.
+// 2. Source calls IPCFuncCallSource::DoThreadSafeCall(). This will pause the
+// thread and trigger the callback on the handlers side.
+// 
+// This mechanism is very robust. See the error return codes on 
+// DoThreadSafeCall() for more details.
+//-----------------------------------------------------------------------------
+
+//-----------------------------------------------------------------------------
+// Send the call
+//-----------------------------------------------------------------------------
+class IPCFuncCallSource
+{
+public:
+//.............................................................................
+// Error return codes for members.
+// Our biggest error concerns are timeouts and no handlers. HRESULTS won't
+// help us with these, so we'll have to use our own codes.
+//.............................................................................
+	enum EError
+	{
+	// (Common) the function was called, and we waited for the full duration.
+		Ok,
+
+	// (Common) The function MAY have been called, but we timed out before it 
+	// finished This means either: The function was called, but took too long 
+	// to finish or The handler died on us right after we hooked up to it and 
+	// so the function never even got called.
+		Fail_Timeout_Call,
+
+	// (Common) There was no handler for us to call
+		Fail_NoHandler,
+
+	// (rare) The function was never called. We successfully connected to the handler,
+	// but we timed out waiting for the mutex.
+		Fail_Timeout_Lock,	
+			
+	// (very rare) We were unable to create the mutex to serialize
+		Fail_CreateMutex,
+
+	// (very rare) Catch-all General Failure. 
+		Failed
+		
+	};
+
+
+// Make a call, wrapped in a mutex
+	static EError DoThreadSafeCall();
+
+
+protected:
+	
+};
+
+
+//-----------------------------------------------------------------------------
+// AuxThread Callback
+//-----------------------------------------------------------------------------
+DWORD WINAPI HandlerAuxThreadProc(LPVOID lpParameter);
+
+
+//-----------------------------------------------------------------------------
+// Callback for handler. AuxThread will call this.
+//-----------------------------------------------------------------------------
+typedef void (*HANDLER_CALLBACK)();
+
+//-----------------------------------------------------------------------------
+// Receieves the call. This should be in a different process than the source
+//-----------------------------------------------------------------------------
+class IPCFuncCallHandler
+{
+public:
+    HRESULT InitFCHandler(HANDLER_CALLBACK pfnCallback, HANDLER_CALLBACK pfnCleanupCallback);
+    void TerminateFCHandler();
+    void WaitForShutdown();
+
+    IPCFuncCallHandler();
+    ~IPCFuncCallHandler();
+
+protected:
+    BOOL IsShutdownComplete();
+    void SafeCleanup();
+    HANDLE m_hStartEnum;	// event to notify start call
+    HANDLE m_hDoneEnum;		// event to notify end call
+
+    Volatile<HANDLE> m_hAuxThread;	// thread to listen for m_hStartEnum
+
+    HANDLER_CALLBACK m_pfnCallback;
+    HANDLER_CALLBACK m_pfnCleanupCallback;
+    
+    Volatile<BOOL> m_fShutdownAuxThread; // flag the Aux thread to finish up gracefully
+    HANDLE m_hShutdownThread; // Event to signal the Aux thread to finish up gracefully
+
+    HMODULE m_hCallbackModule; // Hold the module's ref to make sure that the
+                               // aux thread's code doesn't get unmapped.
+// Make auxthread our friend so he can access all our eventing objects
+	friend DWORD WINAPI HandlerAuxThreadProc(LPVOID);
+};
+
+
+#endif // _IPCFUNCCALLIMPL_H_