Fork() | OS

Question

int doWork(){
       fork();
       fork();
       printf("Hello world!\n");
}
int main() {
       doWork();
       printf("Hello world!\n");
       exit(0);
}

Answer 1

Basically it’ll execute 8 times printf() , 4 times in doWork and 4 times in main function.
main func calls doWork(),
doWork executes like this , exactly like this.


http://web.stanford.edu/~hhli/CS110Notes/CS110NotesCollection/Topic%202%20Multiprocessing%20(1).html


Practical implementation of your program fetches the below result. (GNU- GCC —7.5.0)


The number in bubbles are PIDs and L1 , L2 are 1^st and 2^nd forks , and L3 the line 3 ,i.e , printf in doWork()

If there are n forks then total processes = child processes + main-parent process = ( (2^n)-1 ) +1 = 2^n

Comments

Thank you @rd8794