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POWhy aren't my processes running concurrently?
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copied!<p>My questions are:</p> <p>1.) How can I get the parent process to always die last? I get that this isn't being accomplished because the parent is the first pid that gets ran, but I don't know how to change it.</p> <p>2.) How do I get my child processes to execute at the same time like his? I've even bumped the number up really high to see if it was just a coincidence, but it appears to not be.</p> <p>EDIT: SOLUTIONS</p> <p>1.) added wait(NULL) twice in inner Default<br> 2.) was happening. used sleep(1) to prove it.</p> <p>My code is as follows</p> <pre><code>#include <stdio.h> int main() { int pid, i; pid = fork(); switch(pid) { case -1: // error printf("Fork error"); break; case 0: // child process printf("First child is born, my pid is %d\n", getpid()); for(i=1; i<10; i++) printf("First child executes iteration %d\n", i); printf("First child dies quietly.\n"); break; default: // parent process printf("Parent process is born, my pid is %d\n", getpid()); pid = fork(); switch(pid) { case -1: // error printf("Fork error"); break; case 0: // child process printf("Second child is born, my pid is %d\n", getpid()); for(i=1; i<10; i++) printf("Second child executes iteration %d\n", i); printf("Second child dies quietly.\n"); break; default: // parent process printf("Parent process dies quietly."); } } return 0; } </code></pre> <p>My output always looks like this:</p> <pre> Parent process is born, my pid is 7847 First child is born, my pid is 7848 First child executes iteration: 1 First child executes iteration: 2 First child executes iteration: 3 First child executes iteration: 4 First child executes iteration: 5 First child executes iteration: 6 First child executes iteration: 7 First child executes iteration: 8 First child executes iteration: 9 First child executes iteration: 10 First child dies quietly. Parent process dies quietly. Second child is born, my pid is 7849 Second child executes iteration 1 Second child executes iteration 2 Second child executes iteration 3 Second child executes iteration 4 Second child executes iteration 5 Second child executes iteration 6 Second child executes iteration 7 Second child executes iteration 8 Second child executes iteration 9 Second child executes iteration 10 Second child dies quietly. </pre> <p>My assignment is:</p> <p>Write a C program ("procs.c") that creates three processes: a parent process that creates two child processes.</p> <p>The first child should do the following:</p> <ul> <li><p>display "First child is born, my pid is ..."</p></li> <li><p>display ten times the message "First child executes iteration X", where X is the number of the iteration</p></li> <li><p>display "First child dies quietly."</p></li> </ul> <p>The second child should do the following:</p> <ul> <li><p>display "Second child is born, my pid is ..."</p></li> <li><p>display ten times the message "Second child executes iteration X", where X is the number of the iteration</p></li> <li><p>display "Second child dies quietly."</p></li> </ul> <p>The parent process should do the following:</p> <ul> <li><p>display "Parent process is born, my pid is ..."</p></li> <li><p>create the first child</p></li> <li><p>create the second child</p></li> <li><p>display "Parent process dies quietly."</p></li> </ul> <p>Compile the program using gcc and name the executable "procs". Execute the program several times and notice how the output of the two children interlace.</p> <p>A possible output of this program is:</p> <pre> nova> ./procs Parent process is born, my pid is 7847 First child is born, my pid is 7848 First child executes iteration: 1 First child executes iteration: 2 First child executes iteration: 3 First child executes iteration: 4 First child executes iteration: 5 Second child is born, my pid is 7849 Second child executes iteration 1 Second child executes iteration 2 Second child executes iteration 3 First child executes iteration: 6 Second child executes iteration 4 Second child executes iteration 5 Second child executes iteration 6 First child executes iteration: 7 Second child executes iteration 7 Second child executes iteration 8 Second child executes iteration 9 Second child executes iteration 10 Second child dies quietly. First child executes iteration: 8 First child executes iteration: 9 First child executes iteration: 10 First child dies quietly. Parent process dies quietly. </pre>

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