compiler/clib/wait.c

   1 /*
   2     Copyright © 2004-2009, 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 "etask.h"
  14 #include "__arosc_privdata.h"
  15
  16 #include <sys/types.h>
  17 #include <sys/wait.h>
  18 #include <errno.h>
  19
  20 /*****************************************************************************
  21
  22     NAME */
  23
  24         pid_t wait(
  25
  26 /*  SYNOPSIS */
  27         int *status)
  28
  29 /*  FUNCTION
  30         Waits for child process to change state. State change is one of the
  31         following events: child has exited, child was terminated by a signal,
  32         child was stopped by a signal, child was resumed by a signal.
  33
  34         The function stores status of the process that changed state in the
  35         pointer given as status argument.
  36
  37         The following macros can be used to extract information from the
  38         status value:
  39
  40         WIFEXITED(status)    - true if the process has exited
  41         WEXITSTATUS(status)  - exit status of the exited process
  42         WIFSIGNALED(status)  - true if the child process was terminated by a
  43                                signal
  44         WTERMSIG(status)     - number of the signal that caused process
  45                                termination
  46         WIFSTOPPED(status)   - true if the child process was stopped by a
  47                                signal
  48         WSTOPSIG(status)     - number of the signal that caused child process
  49                                stop
  50         WIFCONTINUED(status) - true if the child process was resumed by the
  51                                SIGCONT signal.
  52
  53         Parent process will be suspended until a child changes state. If a
  54         child process has already changed state, function returns immediately.
  55
  56     INPUTS
  57         status - Pointer to int where child return status will be stored or
  58         NULL if you don't want to store status.
  59
  60     RESULT
  61         Process id of the child process on success or -1 on error. If an error
  62         occurred, the global variable errno is set.
  63
  64     NOTES
  65         This function will work only for child processeses notifying parent
  66         process of their death, for example processes created by vfork() call.
  67         If you want to use it for other processes, remember to set the
  68         NP_NotifyOnDeath tag value to TRUE during child process creation.
  69
  70     EXAMPLE
  71
  72     BUGS
  73
  74     SEE ALSO
  75         waitpid()
  76
  77     INTERNALS
  78         Since POSIX signals are not yet implemented, WIFSIGNALED, WIFSTOPPED
  79         and WIFCONTINUED macros always return 0. WIFEXITED always returns 1.
  80
  81         The et_UniqueID field of the ETask structure is used as process id.
  82
  83 ******************************************************************************/
  84 {
  85     pid_t ret = -1;
  86     struct ETask *et;
  87
  88     D(bug("wait()\n"));
  89
  90     et = GetETask(FindTask(NULL));
  91     if(!et)
  92     {
  93         /* only ETasks are fertile */
  94         errno = ECHILD;
  95         return -1;
  96     }
  97
  98     et = (struct ETask *)ChildWait(0);
  99     if (et != (struct ETask *)CHILD_NOTNEW)
 100     {
 101         if(status)
 102         {
 103             *status = et->et_Result1;
 104         }
 105         ret = et->et_UniqueID;
 106         ChildFree(et->et_UniqueID);
 107     }
 108     else
 109         errno = ECHILD;
 110
 111     return ret;
 112 }