src/tests/system/kernel/wait_test_4.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         wait() should wait only once. If any argument is given, waitpid() should return
  16         an error (and errno to ECHILD), since there is no child with that process group ID.
  17 */
  18
  19
  20 int
  21 child2()
  22 {
  23         sleep(3);
  24         return 2;
  25 }
  26
  27
  28 //! exits before child 2
  29 int
  30 child1()
  31 {
  32         pid_t child = fork();
  33         if (child == 0)
  34                 return child2();
  35
  36         sleep(1);
  37         setpgrp();
  38                 // put us into a new process group
  39         sleep(1);
  40         return 1;
  41 }
  42
  43
  44 int
  45 main(int argc, char** argv)
  46 {
  47         bool waitForGroup = argc > 1;
  48
  49         pid_t child = fork();
  50         if (child == 0)
  51                 return child1();
  52
  53         pid_t pid;
  54         do {
  55                 int childStatus = -1;
  56                 if (waitForGroup)
  57                         pid = waitpid(0, &childStatus, 0);
  58                 else
  59                         pid = wait(&childStatus);
  60                 printf("wait() returned %ld (%s), child status %d\n",
  61                         pid, strerror(errno), childStatus);
  62         } while (pid >= 0);
  63
  64         return 0;
  65 }
  66