compiler/clib/wait.c

   1 /*
   2     Copyright © 2004-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #define DEBUG 0
   7
   8 #include <aros/debug.h>
   9 #include <proto/exec.h>
  10 #include <aros/startup.h>
  11 #include <aros/debug.h>
  12
  13 #include "__arosc_privdata.h"
  14
  15 #include <sys/types.h>
  16 #include <errno.h>
  17
  18 /*****************************************************************************
  19
  20     NAME */
  21 #include <sys/wait.h>
  22
  23         pid_t wait(
  24
  25 /*  SYNOPSIS */
  26         int *status)
  27
  28 /*  FUNCTION
  29         Waits for child process to change state. State change is one of the
  30         following events: child has exited, child was terminated by a signal,
  31         child was stopped by a signal, child was resumed by a signal.
  32
  33         The function stores status of the process that changed state in the
  34         pointer given as status argument.
  35
  36         The following macros can be used to extract information from the
  37         status value:
  38
  39         WIFEXITED(status)    - true if the process has exited
  40         WEXITSTATUS(status)  - exit status of the exited process
  41         WIFSIGNALED(status)  - true if the child process was terminated by a
  42                                signal
  43         WTERMSIG(status)     - number of the signal that caused process
  44                                termination
  45         WIFSTOPPED(status)   - true if the child process was stopped by a
  46                                signal
  47         WSTOPSIG(status)     - number of the signal that caused child process
  48                                stop
  49         WIFCONTINUED(status) - true if the child process was resumed by the
  50                                SIGCONT signal.
  51
  52         Parent process will be suspended until a child changes state. If a
  53         child process has already changed state, function returns immediately.
  54
  55     INPUTS
  56         status - Pointer to int where child return status will be stored or
  57         NULL if you don't want to store status.
  58
  59     RESULT
  60         Process id of the child process on success or -1 on error. If an error
  61         occurred, the global variable errno is set.
  62
  63     NOTES
  64         This function will work only for child processeses notifying parent
  65         process of their death, for example processes created by vfork() call.
  66         If you want to use it for other processes, remember to set the
  67         NP_NotifyOnDeath tag value to TRUE during child process creation.
  68
  69     EXAMPLE
  70
  71     BUGS
  72
  73     SEE ALSO
  74         waitpid()
  75
  76     INTERNALS
  77         Since POSIX signals are not yet implemented, WIFSIGNALED, WIFSTOPPED
  78         and WIFCONTINUED macros always return 0. WIFEXITED always returns 1.
  79
  80         The et_UniqueID field of the ETask structure is used as process id.
  81
  82 ******************************************************************************/
  83 {
  84     pid_t ret = -1;
  85     struct ETask *et;
  86
  87     D(bug("wait()\n"));
  88
  89     et = GetETask(FindTask(NULL));
  90     if(!et)
  91     {
  92         /* only ETasks are fertile */
  93         errno = ECHILD;
  94         return -1;
  95     }
  96
  97     et = (struct ETask *)ChildWait(0);
  98     if (et != (struct ETask *)CHILD_NOTNEW)
  99     {
 100         if(status)
 101         {
 102             *status = et->et_Result1;
 103         }
 104         ret = et->et_UniqueID;
 105         ChildFree(et->et_UniqueID);
 106     }
 107     else
 108         errno = ECHILD;
 109
 110     return ret;
 111 }