SO Lab 11

lab11.c

// SO IS1 212A LAB05
// Michal Tymejczyk
// tm44537@zut.edu.pl

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <Windows.h>
#include <time.h>
#include <stdbool.h>

HANDLE mutexHandler;

struct thread_args
{
	int length;
	float *args;
};

float sum = 0.0;

DWORD WINAPI create_thread(LPVOID data)
{
	DWORD self = GetCurrentThreadId();

	struct thread_args *args = (struct thread_args *)data;

	fprintf(stdout, "Thread #%ld size=%d\n", self, args->length);

	float fSum = 0.0;
	for (int i = 0; i < args->length; i++)
	{
		fSum = fSum + args->args[i];
	}

	WaitForSingleObject(mutexHandler, INFINITE);
	sum = sum + fSum;
	ReleaseMutex(mutexHandler);

	fprintf(stdout, "Thread #%ld sum=%f\n", self, fSum);

	free(args->args);
	free(args);

	return 0;
}

bool validate(int args_count, int n, int w, char *narray, char *warray)
{
	if (args_count != 3)
	{
		fprintf(stderr, "%s\n", "Error: Args count.");
		return false;
	}

	if ((n <= 0) || (n >= 1000000))
	{
		fprintf(stderr, "%s\n", "Error: Args n <= 0 or n >= 1000000");
		return false;
	}

	if ((w <= 0) || (w >= n))
	{
		fprintf(stderr, "%s\n", "Error: Args are w <= 0 or w >= n!");
		return false;
	}

	if (*narray != '\0' || *warray != '\0')
	{
		fprintf(stderr, "%s\n", "Error: Args aren't integers!");
		return false;
	}

	return true;
}

int main(int argc, char *argv[])
{
	char *narray;
	char *warray;

	int n = strtol(argv[1], &narray, 10);
	int w = strtol(argv[2], &warray, 10);

	bool isValid = validate(argc, n, w, narray, warray);

	if (!isValid)
	{
		return 1;
	}

	mutexHandler = CreateMutex(NULL, FALSE, NULL);

	float t[n];
	srand(time(NULL));

	for (int i = 0; i < n; i++)
	{
		t[i] = 1000.0 * rand() / RAND_MAX;
	}

	DWORD *Thread_ids = malloc(w * sizeof(DWORD));
	HANDLE *Thread_handles = malloc(w * sizeof(HANDLE));

	const int sub_length = n / w;
	const int reminder = n % w;

	struct thread_args *temp_thread_args;

	int sub_index = 0;
	float *temp;

	// Sum with threads
	clock_t timer1;
	timer1 = clock();
	for (int i = 0; i < w; i++)
	{
		if ((i == (w - 1)) && (reminder != 0))
		{
			temp = malloc((sub_length + reminder) * sizeof(t[0]));
			memcpy(temp, &t[sub_index], (sub_length + reminder) * sizeof(t[0]));
		}
		else
		{
			temp = malloc(sub_length * sizeof(t[0]));
			memcpy(temp, &t[sub_index], sub_length * sizeof(t[0]));
		}

		temp_thread_args = malloc(sizeof(*temp_thread_args));

		if ((i == (w - 1)) && (reminder != 0))
		{
			temp_thread_args->length = sub_length + reminder;
		}
		else // no reminder
		{
			temp_thread_args->length = sub_length;
		}

		temp_thread_args->args = temp;

		Thread_handles[i] = CreateThread(NULL, 0, create_thread, temp_thread_args, 0, &Thread_ids[i]);
		sub_index = sub_index + sub_length;
	}

	for (int i = 0; i < w; i++)
	{
		WaitForSingleObject(Thread_handles[i], INFINITE);
		CloseHandle(Thread_handles[i]);
	}
	timer1 = clock() - timer1;

	// Sum without threads
	float sum2 = 0.0;

	clock_t timer2;
	timer2 = clock();
	for (int i = 0; i < n; i++)
	{
		sum2 = sum2 + t[i];
	}
	timer2 = clock() - timer2;

	fprintf(stdout, "Sum with threads: sum=%f, time=%fs\n", sum, (double)timer1 / CLOCKS_PER_SEC);
	fprintf(stdout, "Sum without threads: sum=%f, time=%fs\n", sum2, (double)timer2 / CLOCKS_PER_SEC);

	return 0;
}

// gcc lab11.c -o lab11.exe