compiler/clib/pipe.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 #include <proto/dos.h>
   7 #include <proto/exec.h>
   8 #include <exec/exec.h>
   9
  10 #include <stdlib.h>
  11 #include <unistd.h>
  12 #include <fcntl.h>
  13 #include <stdio.h> /* For snprintf */
  14
  15 #include "__errno.h"
  16 #include "__fdesc.h"
  17
  18 /*****************************************************************************
  19
  20     NAME */
  21
  22         int pipe(
  23
  24 /*  SYNOPSIS */
  25         int *pipedes)
  26
  27 /*  FUNCTION
  28
  29     INPUTS
  30
  31     RESULT
  32
  33     NOTES
  34
  35     EXAMPLE
  36
  37     BUGS
  38
  39     SEE ALSO
  40
  41     INTERNALS
  42
  43 ******************************************************************************/
  44 {
  45     BPTR reader, writer;
  46     fcb *rfcb = NULL, *wfcb = NULL;
  47     fdesc *rdesc = NULL, *wdesc = NULL;
  48     /* PIPE:cpipe-%08x-%d, where %x is the getpid(), %d is the nth pipe */
  49     char pipe_name[5 + 6 + 8 + 1 + 16 + 1];
  50     static int pipeno = 0;
  51
  52     if (!pipedes)
  53     {
  54         errno = EFAULT;
  55
  56         return -1;
  57     }
  58
  59     if (
  60         (rfcb = AllocVec(sizeof(fcb), MEMF_ANY | MEMF_CLEAR)) == NULL ||
  61         (rdesc = __alloc_fdesc()) == NULL ||
  62         (wfcb = AllocVec(sizeof(fcb), MEMF_ANY | MEMF_CLEAR)) == NULL ||
  63         (wdesc = __alloc_fdesc()) == NULL
  64     )
  65     {
  66         if(rfcb)
  67             FreeVec(rfcb);
  68         if(rdesc)
  69             __free_fdesc(rdesc);
  70         if(wfcb)
  71             FreeVec(wfcb);
  72         if(wdesc)
  73             __free_fdesc(wdesc);
  74         errno = ENOMEM;
  75         return -1;
  76     }
  77
  78     /* Get the next pipe number */
  79     Forbid();
  80     pipeno++;
  81     Permit();
  82
  83     snprintf(pipe_name, sizeof(pipe_name), "PIPE:cpipe-%08x-%d",
  84                (unsigned long)getpid(), pipeno);
  85     pipe_name[sizeof(pipe_name)-1] = 0;
  86
  87     writer = Open(pipe_name, MODE_NEWFILE);
  88     if (writer)
  89     {
  90         reader = Open(pipe_name, MODE_OLDFILE);
  91         if (!reader)
  92         {
  93             DeleteFile(pipe_name);
  94             Close(writer);
  95             writer = BNULL;
  96         }
  97     }
  98
  99     if (!writer)
 100     {
 101         errno = IoErr2errno(IoErr());
 102         __free_fdesc(rdesc);
 103         __free_fdesc(wdesc);
 104         return -1;
 105     }
 106
 107     pipedes[0] = __getfdslot(__getfirstfd(0));
 108     rdesc->fdflags = 0;
 109     rdesc->fcb = rfcb;
 110     rdesc->fcb->fh        = reader;
 111     rdesc->fcb->flags     = O_RDONLY;
 112     rdesc->fcb->opencount = 1;
 113     __setfdesc(pipedes[0], rdesc);
 114
 115     pipedes[1] = __getfdslot(__getfirstfd(pipedes[0]));
 116     wdesc->fdflags = 0;
 117     wdesc->fcb = wfcb;
 118     wdesc->fcb->fh        = writer;
 119     wdesc->fcb->flags     = O_WRONLY;
 120     wdesc->fcb->opencount = 1;
 121     __setfdesc(pipedes[1], wdesc);
 122
 123     return 0;
 124 }
 125