NamedSharedMemoryExample1.cpp

// CONSOLE 1 - creator of the named shared memory block

#include <iostream>
#include <windows.h>
#include <conio.h>

struct MyData {
	int i;
	float f;
	char c;
	bool b;
	double d;
};

int main() {
	
	MyData myData = { 99, 7.56f, 'A', true, 69.42 };

	// open a named shared memory block
	HANDLE fileHandle = CreateFileMapping(INVALID_HANDLE_VALUE, // a handle to an existing virtual file, or invalid
										  nullptr, // optional security attributes
										  PAGE_READWRITE, // read/write access control
										  0, sizeof(MyData), // size of the memory block, 
										  L"MySharedMemory");

	if (fileHandle == nullptr) {
		std::cout << "Could not create file mapping object: " << GetLastError() << std::endl;
		return 1;
	}

	// map the memory from the shared block to a pointer we can manipulate
	MyData* data = (MyData*)MapViewOfFile(fileHandle,
								 FILE_MAP_ALL_ACCESS,
								 0,
								 0,
								 sizeof(MyData));

	if (data == nullptr) {
		std::cout << "Could not map view of file: " << GetLastError() << std::endl;
		CloseHandle(fileHandle);
		return 1;
	}

	// write to the memory block
	*data = myData;

	// wait for a keypress to close
	_getch();

	// unmap the memory block since we're done with it
	UnmapViewOfFile(data);

	// close the shared file
	CloseHandle(fileHandle);

	return 0;
}