Category: Computer Science

// James Pate Williams, Jr. (c) 10/04/2022
// Second version, no longer dependent on
// a global object
#include <windows.h>
#include <synchapi.h>
#include <chrono>
#include <iostream>
#include <vector>
using namespace std::chrono;
using namespace std;

// https://learn.microsoft.com/en-us/windows/win32/procthread/creating-threads
// https://www.geeksforgeeks.org/measure-execution-time-function-cpp/

long long counter;

class Test
{
public:
	inline void CountUp(
		HANDLE mutex,
		long long number)
	{
		counter = 0;

		for (long long i = 0; i < number; i++)
		{
			counter++;
		}

		ReleaseMutex(mutex);
	}
};

typedef struct Data
{
	long long number;
	DWORD dwWaitMS;
	Test* test;
} DATA, *PDATA;

DWORD WINAPI ThreadCode(LPVOID lpParam)
{
	Data* pData = (Data*)lpParam;
	HANDLE mutex = CreateMutex(NULL, FALSE, NULL);

	if (mutex != NULL)
	{
		pData->test->CountUp(
			mutex, pData->number);

		DWORD err = WaitForSingleObject(mutex, pData->dwWaitMS);
		CloseHandle(mutex);
	}

	return 0;
}

int main()
{
	long long number = 1000000000000;

	for (DWORD dwWaitMS = 30000;
		dwWaitMS <= 240000; dwWaitMS += 30000)
	{
		cout << "Number  = " << number << endl;
		cout << "Wait MS = " << dwWaitMS << endl;

		DWORD dwThreadId;
		Data* pData = new Data;

		pData->number = number;
		pData->dwWaitMS = dwWaitMS;
		pData->test = new Test();
		counter = 0;
		
		HANDLE hThread = NULL;

		hThread = CreateThread(
					NULL,			    // default security attributes
					0,					// use default stack size  
					ThreadCode,			// thread function name
					pData,				// argument to thread function 
					0,			        // use default creation flags 
					& dwThreadId);		// returns the thread identifier

		if (hThread != NULL)
		{
			auto start = high_resolution_clock::now();
			WaitForSingleObject(hThread, dwWaitMS);
			auto stop = high_resolution_clock::now();
			auto duration = duration_cast<milliseconds>(stop - start);
			double runtime = (double)duration.count() / 1.0e3;

			cout << "Counter = " << counter << endl;
			cout << "Runtime = " << runtime << endl;
			
			CloseHandle(hThread);
		}
	}
	return 0;
}

Number  = 1000000000000
Wait MS = 30000
Counter = 19226393400
Runtime = 30.006
Number  = 1000000000000
Wait MS = 60000
Counter = 7248012054
Runtime = 60.003
Number  = 1000000000000
Wait MS = 90000
Counter = 5264969696
Runtime = 90.011
Number  = 1000000000000
Wait MS = 120000
Counter = 10312016711
Runtime = 120
Number  = 1000000000000
Wait MS = 150000
Counter = 15342215540
Runtime = 150.011
Number  = 1000000000000
Wait MS = 180000
Counter = 20399182381
Runtime = 180
Number  = 1000000000000
Wait MS = 210000
Counter = 25358449910
Runtime = 210.009
Number  = 1000000000000
Wait MS = 240000
Counter = 30917682739
Runtime = 240.017

C:\Users\james\source\repos\MutexTest\Debug\MutexTest.exe (process 49516) exited with code 0.
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