pthread_create Error in Visual Studio

Question

Hi I'm using Visual Studio 2010 and having trouble getting this barber shop program to work.

I get this error

pthread_create : cannot convert parameter 3 from void *(__cdecl *)(void) to void *(__cdecl *)(void *)

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <Windows.h>
#define seats 6

void *customerMaker();
void *barberShop();
void *waitingRoom();
void checkQueue();

pthread_mutex_t queue_mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_t wait_mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_mutex_t sleep_mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t barberSleep_cond = PTHREAD_COND_INITIALIZER;
pthread_cond_t barberWorking_cond = PTHREAD_COND_INITIALIZER;

int returnTime=5,current=0, sleeping=0, iseed;

int main(int argc, char *argv[])
{
iseed=time(NULL);
srand(iseed);
//declare barber thread;
pthread_t barber,customerM,timer_thread;
pthread_attr_t barberAttr, timerAttr;
pthread_attr_t customerMAttr;

//define barber, and cutomerMaker default attributes
pthread_attr_init(&timerAttr);
pthread_attr_init(&barberAttr);
pthread_attr_init(&customerMAttr);

printf("\n");

//create cutomerMaker
pthread_create(&customerM,&customerMAttr,customerMaker,NULL);

//create barber
pthread_create(&barber,&barberAttr,barberShop,NULL);

pthread_join(barber,NULL);
pthread_join(customerM,NULL);

return 0;
}

void *customerMaker()
{
int i=0;
printf("*Customer Maker Created*\n\n");
fflush(stdout);
pthread_t customer[seats+1];
pthread_attr_t customerAttr[seats+1];
while(i<(seats+1))
{
i++;
pthread_attr_init(&customerAttr[i]);
while(rand()%2!=1)
{
Sleep(1);
}
pthread_create(&customer[i],&customerAttr[i],waitingRoom,NULL);
}
pthread_exit(0);
}

void *waitingRoom()
{
//take seat
pthread_mutex_lock(&queue_mutex);
checkQueue();

Sleep(returnTime);
waitingRoom();
}

void *barberShop()
{
int loop=0;
printf("The barber has opened the store.\n");
fflush(stdout);
while(loop==0)
{
if(current==0)
{
printf("\tThe shop is empty, barber is sleeping.\n");
fflush(stdout);
pthread_mutex_lock(&sleep_mutex);
sleeping=1;
pthread_cond_wait(&barberSleep_cond,&sleep_mutex);
sleeping=0;
pthread_mutex_unlock(&sleep_mutex);
printf("\t\t\t\tBarber wakes up.\n");
fflush(stdout);
}
else
{
printf("\t\t\tBarber begins cutting hair.\n");
fflush(stdout);
Sleep((rand()%20)/5);
current--;
printf("\t\t\t\tHair cut complete, customer leaving store.\n");
pthread_cond_signal(&barberWorking_cond);
}
}
pthread_exit(0);
}

void checkQueue()
{
current++;
printf("\tCustomer has arrived in the waiting room.\t\t\t\t\t\t\t%d Customers in store.\n",current);
fflush(stdout);
printf("\t\tCustomer checking chairs.\n");
fflush(stdout);
if(current<seats)
{
if(sleeping==1)
{
printf("\t\t\tBarber is sleeping, customer wakes him.\n");
fflush(stdout);
pthread_cond_signal(&barberSleep_cond);
}
printf("\t\tCustomer takes a seat.\n");
fflush(stdout);
pthread_mutex_unlock(&queue_mutex);
pthread_mutex_lock(&wait_mutex);
pthread_cond_wait(&barberWorking_cond,&wait_mutex);
pthread_mutex_unlock(&wait_mutex);
return;
}
if(current>=seats)
{
printf("\t\tAll chairs full, leaving store.\n");
fflush(stdout);
current--;
pthread_mutex_unlock(&queue_mutex);
return;
}
}

Answer 1

waitingRoom must accept a pointer parameter. See the pthread_create documentation .