src/tests/libs/bsd/wait4_test.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 <inttypes.h>
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <sys/resource.h>
  12 #define _BSD_SOURCE
  13 #include <sys/wait.h>
  14 #include <unistd.h>
  15
  16
  17 /*!
  18         wait() should wait only once. If any argument is given, waitpid() should return
  19         an error (and errno to ECHILD), since there is no child with that process group ID.
  20 */
  21
  22
  23 int
  24 child2()
  25 {
  26         sleep(2);
  27         return 2;
  28 }
  29
  30
  31 //! exits before child 2
  32 int
  33 child1()
  34 {
  35         setpgrp();
  36                 // put us into a new process group
  37
  38         pid_t child = fork();
  39         if (child == 0)
  40                 return child2();
  41
  42         sleep(1);
  43         return 1;
  44 }
  45
  46
  47 int
  48 main(int argc, char** argv)
  49 {
  50         bool waitForGroup = argc > 1;
  51
  52         pid_t child = fork();
  53         if (child == 0)
  54                 return child1();
  55
  56         struct rusage usage;
  57         pid_t pid;
  58         do {
  59                 memset(&usage, 0, sizeof(usage));
  60                 int childStatus = -1;
  61                 pid = wait4(-1, &childStatus, 0, &usage);
  62                 printf("wait4() returned %" PRId32 " (%s), child status %" PRId32
  63                         ", kernel: %ld.%06" PRId32 " user: %ld.%06" PRId32 "\n",
  64                         pid, strerror(errno), childStatus, usage.ru_stime.tv_sec,
  65                         usage.ru_stime.tv_usec, usage.ru_utime.tv_sec,
  66                         usage.ru_utime.tv_usec);
  67         } while (pid >= 0);
  68
  69         return 0;
  70 }
  71