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, &info, usage_info);
  32
  33         pthread_testcancel();
  34
  35         if (child < 0) {
  36                 // When not getting a child status when WNOHANG was specified, don't
  37                 // fail.
  38                 if (child == B_WOULD_BLOCK && (options & WNOHANG) != 0)
  39                         return 0;
  40                 RETURN_AND_SET_ERRNO(child);
  41         }
  42
  43         // prepare the status
  44         if (_status != NULL) {
  45                 int status;
  46                 switch (info.si_code) {
  47                         case CLD_EXITED:
  48                                 // fill in exit status for WIFEXITED() and WEXITSTATUS()
  49                                 status = info.si_status & 0xff;
  50                                 break;
  51
  52                         case CLD_KILLED:
  53                         case CLD_DUMPED:
  54                                 // fill in signal for WIFSIGNALED() and WTERMSIG()
  55                                 status = (info.si_status << 8) & 0xff00;
  56                                 // if core dumped, set flag for WIFCORED()
  57                                 if (info.si_code == CLD_DUMPED)
  58                                         status |= 0x10000;
  59                                 break;
  60
  61                         case CLD_CONTINUED:
  62                                 // set flag for WIFCONTINUED()
  63                                 status = 0x20000;
  64                                 break;
  65
  66                         case CLD_STOPPED:
  67                                 // fill in signal for WIFSTOPPED() and WSTOPSIG()
  68                                 status = (info.si_status << 16) & 0xff0000;
  69                                 break;
  70
  71                         case CLD_TRAPPED:
  72                                 // we don't do that
  73                         default:
  74                                 // should never get here -- assume exited
  75                                 status = 0;
  76                                 break;
  77                 }
  78
  79                 *_status = status;
  80         }
  81
  82         return child;
  83 }
  84
  85
  86 pid_t
  87 waitpid(pid_t pid, int* _status, int options)
  88 {
  89         return _waitpid(pid, _status, options, NULL);
  90 }
  91
  92
  93 int
  94 waitid(idtype_t idType, id_t id, siginfo_t* info, int options)
  95 {
  96         // translate the idType, id pair to a waitpid() style ID
  97         switch (idType) {
  98                 case P_ALL:
  99                         // any child
 100                         id = -1;
 101                         break;
 102
 103                 case P_PID:
 104                         // the child with the given ID
 105                         if (id <= 0)
 106                                 RETURN_AND_SET_ERRNO_TEST_CANCEL(EINVAL);
 107                         break;
 108
 109                 case P_PGID:
 110                         // any child in the given process group
 111                         if (id <= 1)
 112                                 RETURN_AND_SET_ERRNO_TEST_CANCEL(EINVAL);
 113                         id = -id;
 114                         break;
 115
 116                 default:
 117                         RETURN_AND_SET_ERRNO_TEST_CANCEL(EINVAL);
 118         }
 119
 120         pid_t child = _kern_wait_for_child(id, options, info, NULL);
 121         if (child >= 0 || child == B_WOULD_BLOCK)
 122                 return 0;
 123
 124         RETURN_AND_SET_ERRNO_TEST_CANCEL(child);
 125 }