I'm trying to solve the dining philosophers problem and each time it's printing that only 2 are eating. Each thread I created was a philosopher and each section was a fork and according to the algorithm, each time we send a philosopher we try to get his forks(for the first it's fork1 and fork2) and the forks are the critical sections. Any idea on How to fix this? Here's my code:
#include <windows.h>
#include <stdio.h>
#include <tchar.h>
#include <tchar.h>
#include <iostream>
#include <chrono>//To check runtime(it was also asked but I know how to do this)
#include <thread>
using namespace std;
CRITICAL_SECTION ghCARITICALSection1;
CRITICAL_SECTION ghCARITICALSection2;
//Same for the rest
DWORD WINAPI func(int* phiphilosopher)
{
if (1 == *phiphilosopher)
{
if (TryEnterCriticalSection(&ghCARITICALSection1)) {
if (TryEnterCriticalSection(&ghCARITICALSection2)) {
cout << "1 is eating..."<< endl;
for (int i = 0; i < 1000000; i++)
{
i = i;
}
LeaveCriticalSection(&ghCARITICALSection2);
}
LeaveCriticalSection(&ghCARITICALSection1);
}
}
//Same for the rest but with all the numbers increased and on the 5th we check 5 and 1
And that's the main:
int main()
{
int philosopher1 = 1;
int* philosopher1ptr = &philosopher1;
//Same for the rest
InitializeCriticalSection(&ghCARITICALSection1);
InitializeCriticalSection(&ghCARITICALSection2);
//Same for the rest
HANDLE WINAPI th1 = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)func, philosopher1ptr, 0, NULL);
//Same for the rest
WaitForSingleObject(th1, INFINITE);
//Same for the rest
}
probably two of the threads or more accessing to the same criticalSection and overlap eachother. try adding timer between each creation of a thread.
HANDLE WINAPI th1 = CreateThread(...);
std::this_thread::sleep_for(std::chrono::milliseconds(100));
HANDLE WINAPI th2 = CreateThread(...);