src/tests/system/kernel/wait_test_3.cpp

   1 /*
   2  * Copyright 2007, Axel Dörfler, axeld@pinc-software.de. All rights reserved.
   3  * Distributed under the terms of the MIT License.
   4  */
   5
   6
   7 #include <errno.h>
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <sys/wait.h>
  11 #include <unistd.h>
  12
  13
  14 /*!
  15         waitpid() should wait only once.
  16 */
  17
  18
  19 int
  20 child2()
  21 {
  22         printf("child 2 1. parent id = %ld\n", getppid());
  23         sleep(2);
  24         printf("child 2 2. parent id = %ld\n", getppid());
  25         return 2;
  26 }
  27
  28
  29 //! exits before child 2
  30 int
  31 child1()
  32 {
  33         printf("child 1 process group: %ld\n", getpgrp());
  34
  35         pid_t child = fork();
  36         if (child == 0)
  37                 return child2();
  38
  39         sleep(1);
  40         return 1;
  41 }
  42
  43
  44 int
  45 main()
  46 {
  47         printf("main process group: %ld\n", getpgrp());
  48         pid_t child = fork();
  49         if (child == 0)
  50                 return child1();
  51
  52         pid_t pid;
  53         do {
  54                 int childStatus = -1;
  55                 pid = waitpid(0, &childStatus, 0);
  56                 printf("waitpid() returned %ld (%s), child status %d\n", pid, strerror(errno), childStatus);
  57         } while (pid >= 0);
  58
  59         return 0;
  60 }
  61