src/system/libroot/posix/sys/wait.cpp

   1 /*
   2  * Copyright 2011, Ingo Weinhold, ingo_weinhold@gmx.de.
   3  * Copyright 2004-2007, Axel Dörfler, axeld@pinc-software.de.
   4  * All rights reserved.
   5  * Distributed under the terms of the MIT License.
   6  */
   7
   8 #include <sys/wait.h>
   9
  10 #include <errno.h>
  11 #include <pthread.h>
  12
  13 #include <syscall_utils.h>
  14
  15 #include <errno_private.h>
  16 #include <syscalls.h>
  17 #include <thread_defs.h>
  18
  19
  20 pid_t
  21 wait(int* _status)
  22 {
  23         return waitpid(-1, _status, 0);
  24 }
  25
  26 extern "C" pid_t
  27 _waitpid(pid_t pid, int* _status, int options, team_usage_info *usage_info)
  28 {
  29         // wait
  30         siginfo_t info;
  31         pid_t child = _kern_wait_for_child(pid, options | WEXITED, &info,
  32                 usage_info);
  33
  34         pthread_testcancel();
  35
  36         if (child < 0) {
  37                 // When not getting a child status when WNOHANG was specified, don't
  38                 // fail.
  39                 if (child == B_WOULD_BLOCK && (options & WNOHANG) != 0)
  40                         return 0;
  41                 RETURN_AND_SET_ERRNO(child);
  42         }
  43
  44         // prepare the status
  45         if (_status != NULL) {
  46                 int status;
  47                 switch (info.si_code) {
  48                         case CLD_EXITED:
  49                                 // fill in exit status for WIFEXITED() and WEXITSTATUS()
  50                                 status = info.si_status & 0xff;
  51                                 break;
  52
  53                         case CLD_KILLED:
  54                         case CLD_DUMPED:
  55                                 // fill in signal for WIFSIGNALED() and WTERMSIG()
  56                                 status = (info.si_status << 8) & 0xff00;
  57                                 // if core dumped, set flag for WIFCORED()
  58                                 if (info.si_code == CLD_DUMPED)
  59                                         status |= 0x10000;
  60                                 break;
  61
  62                         case CLD_CONTINUED:
  63                                 // set flag for WIFCONTINUED()
  64                                 status = 0x20000;
  65                                 break;
  66
  67                         case CLD_STOPPED:
  68                                 // fill in signal for WIFSTOPPED() and WSTOPSIG()
  69                                 status = (info.si_status << 16) & 0xff0000;
  70                                 break;
  71
  72                         case CLD_TRAPPED:
  73                                 // we don't do that
  74                         default:
  75                                 // should never get here -- assume exited
  76                                 status = 0;
  77                                 break;
  78                 }
  79
  80                 *_status = status;
  81         }
  82
  83         return child;
  84 }
  85
  86
  87 pid_t
  88 waitpid(pid_t pid, int* _status, int options)
  89 {
  90         return _waitpid(pid, _status, options, NULL);
  91 }
  92
  93
  94 int
  95 waitid(idtype_t idType, id_t id, siginfo_t* info, int options)
  96 {
  97         // translate the idType, id pair to a waitpid() style ID
  98         switch (idType) {
  99                 case P_ALL:
 100                         // any child
 101                         id = -1;
 102                         break;
 103
 104                 case P_PID:
 105                         // the child with the given ID
 106                         if (id <= 0)
 107                                 RETURN_AND_SET_ERRNO_TEST_CANCEL(EINVAL);
 108                         break;
 109
 110                 case P_PGID:
 111                         // any child in the given process group
 112                         if (id <= 1)
 113                                 RETURN_AND_SET_ERRNO_TEST_CANCEL(EINVAL);
 114                         id = -id;
 115                         break;
 116
 117                 default:
 118                         RETURN_AND_SET_ERRNO_TEST_CANCEL(EINVAL);
 119         }
 120
 121         pid_t child = _kern_wait_for_child(id, options, info, NULL);
 122         if (child >= 0 || child == B_WOULD_BLOCK)
 123                 return 0;
 124
 125         RETURN_AND_SET_ERRNO_TEST_CANCEL(child);
 126 }