fork() sequence of execution?

Question

int main () { 

    fork ();     
    fork ();     
    fork (); 

    pf (" hi\n"); 

}

How many times the "hi" will print? What is sequence of execution for fork() ? os:linux compiler:gcc

`fork` can fail, so you cannot be sure of the answer. Read [Advanced Linux Programming](http://advancedlinuxprogramming.com/) which has several chapters explaining that. — Basile Starynkevitch, Jan 08 '15 at 12:10
And by definition `fork` is observably *not* sequential (but usually parallel, it returns twice). — Basile Starynkevitch, Jan 08 '15 at 12:13
Not a duplicate, but relevant: http://stackoverflow.com/a/26716300/2411320 — gsamaras, Jan 08 '15 at 12:56
It is very low quality. A simple search would result answers. — gsamaras, Jan 08 '15 at 12:57

score 0 · Accepted Answer · answered Jan 08 '15 at 12:52

Question 1: How many times the "hi" will print?

                      Due to first Fork
                             |
                   -------------------------
                   |                        |
             Due to second fork         Due to second fork
                   |                          |
          ----------------------            ----------------------------
        |                      |            |                          |
  Due to 3rd fork        Due to 3rd fork   Due to 3rd fork             Due to 3rd fork
        |                      |                |                           |
------------------       ---------------       ----------               ------------
|               |        |             |      |          |               |          |
process-1     process-2   process-3   process-4 pr-5     pr-6         process-7    process-8

So if all fork goes well then total 8 process created so there will be 8 or lesser hi will be there in output

Question 2: What is sequence of execution for fork() ? os:linux compiler:gcc

There is no any guarantee which process will be scheduled first and which one second. Its all depends on Scheduler.

fork() sequence of execution?

1 Answers1