How to resolve this warning : 33 16 C:\Users\prcm\Documents\mutex.cpp [Error] 'sleep'

[Prashanth CM]

Hi ,

I am getting this error for a gcc compiler

33 16 C:\Users\prcm\Documents\mutex.cpp [Error] 'sleep' was not declared in this scope


I have included <unistd.h> as well but still i see the error.

How to resolve this?

#include <stdio.h>
#include <pthread.h>
#include <stdint.h>
#include <unistd.h>
 
#define NUM 5
 
pthread_mutex_t mutex;
 
void* thread_f(void* par){
        //int id = (int) par;    
        int id = (intptr_t)par;
    /*sleep waiting for the lock*/
    pthread_mutex_lock(&mutex);
        printf("Thread %d starting to work!\n",id);
    pthread_mutex_unlock(&mutex);
        return NULL;
}
 
int main(){
        pthread_t threads[NUM];
        int i;
 
    /*initialize and lock mutex*/
    pthread_mutex_init(&mutex, NULL);
    pthread_mutex_lock(&mutex);
 
        for (i=0;i<NUM;i++){
                pthread_create(&threads[i],NULL,thread_f,(void *)i);
        }
 
        printf("Everyone wait...\n");
        sleep(1);
        printf("Now go!\n");
    /*wake one thread*/
    pthread_mutex_unlock(&mutex);
 
    /*give the threads time to complete their tasks*/
        sleep(1);
 
    printf("Main is quitting...\n");
        return 0;
}
 

[weaknessforcats]

Have you added libc.lib to your linker library list?

Also, some implementations, like Windows, use Sleep and not sleep.

[invention]

I guess, you need to include stdlib.h as well.