Modules/selectmodule.c

   1 /***********************************************************
   2 Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
   3 The Netherlands.
   4
   5                         All Rights Reserved
   6
   7 Permission to use, copy, modify, and distribute this software and its
   8 documentation for any purpose and without fee is hereby granted,
   9 provided that the above copyright notice appear in all copies and that
  10 both that copyright notice and this permission notice appear in
  11 supporting documentation, and that the names of Stichting Mathematisch
  12 Centrum or CWI not be used in advertising or publicity pertaining to
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  15 STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
  16 THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
  17 FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
  18 FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  19 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  20 ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  21 OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  22
  23 ******************************************************************/
  24
  25 /* select - Module containing unix select(2) call */
  26
  27 #include "allobjects.h"
  28 #include "modsupport.h"
  29 #include "ceval.h"
  30
  31 #include <sys/types.h>
  32 #include "myselect.h" /* Also includes mytime.h */
  33
  34 static object *SelectError;
  35
  36 static
  37 list2set(list, set, fd2obj)
  38     object *list;
  39     fd_set *set;
  40     object *fd2obj[FD_SETSIZE];
  41 {
  42     int i, len, v, max = -1;
  43     object *o, *filenomethod, *fno;
  44
  45     FD_ZERO(set);
  46     len = getlistsize(list);
  47     for( i=0; i<len; i++ ) {
  48         o = getlistitem(list, i);
  49         if ( is_intobject(o) ) {
  50             v = getintvalue(o);
  51         } else if ( (filenomethod = getattr(o, "fileno")) != NULL ) {
  52             fno = call_object(filenomethod, NULL);
  53             DECREF(filenomethod);
  54             if ( fno == NULL )
  55                 return -1;
  56             if ( !is_intobject(fno) ) {
  57                 err_badarg();
  58                 DECREF(fno);
  59                 return -1;
  60             }
  61             v = getintvalue(fno);
  62             DECREF(fno);
  63         } else {
  64             err_badarg();
  65             return -1;
  66         }
  67         if ( v < 0 || v >= FD_SETSIZE ) {
  68             err_setstr(ValueError, "filedescriptor out of range in select()");
  69             return -1;
  70         }
  71         if ( v > max ) max = v;
  72         FD_SET(v, set);
  73         XDECREF(fd2obj[v]);
  74         fd2obj[v] = o;
  75     }
  76     return max+1;
  77 }
  78
  79 static object *
  80 set2list(set, max, fd2obj)
  81     fd_set *set;
  82     int max;
  83     object *fd2obj[FD_SETSIZE];
  84 {
  85     int i, num=0;
  86     object *list, *o;
  87
  88     for(i=0; i<max; i++)
  89       if ( FD_ISSET(i,set) )
  90         num++;
  91     list = newlistobject(num);
  92     num = 0;
  93     for(i=0; i<max; i++)
  94       if ( FD_ISSET(i,set) ) {
  95           if ( i > FD_SETSIZE ) {
  96               err_setstr(SystemError,
  97                          "filedescriptor out of range returned in select()");
  98               return NULL;
  99           }
 100           o = fd2obj[i];
 101           if ( o == NULL ) {
 102               err_setstr(SystemError,
 103                          "Bad filedescriptor returned from select()");
 104               return NULL;
 105           }
 106           INCREF(o);
 107           setlistitem(list, num, o);
 108           num++;
 109     }
 110     return list;
 111 }
 112
 113 static object *
 114 select_select(self, args)
 115     object *self;
 116     object *args;
 117 {
 118     object *fd2obj[FD_SETSIZE];
 119     object *ifdlist, *ofdlist, *efdlist;
 120     object *ret, *tout;
 121     fd_set ifdset, ofdset, efdset;
 122     double timeout;
 123     struct timeval tv, *tvp;
 124     int seconds;
 125     int imax, omax, emax, max;
 126     int n;
 127
 128
 129     /* Get args. Looks funny because of optional timeout argument */
 130     if ( getargs(args, "(OOOO)", &ifdlist, &ofdlist, &efdlist, &tout) ) {
 131         if (tout == None)
 132             tvp = (struct timeval *)0;
 133         else {
 134             if (!getargs(tout, "d;timeout must be float or None", &timeout))
 135                     return NULL;
 136             seconds = (int)timeout;
 137             timeout = timeout - (double)seconds;
 138             tv.tv_sec = seconds;
 139             tv.tv_usec = (int)(timeout*1000000.0);
 140             tvp = &tv;
 141         }
 142     } else {
 143         /* Doesn't have 4 args, that means no timeout */
 144         err_clear();
 145         if (!getargs(args, "(OOO)", &ifdlist, &ofdlist, &efdlist) )
 146           return 0;
 147         tvp = (struct timeval *)0;
 148     }
 149     if ( !is_listobject(ifdlist) || !is_listobject(ofdlist) ||
 150         !is_listobject(efdlist) ) {
 151         err_badarg();
 152         return 0;
 153     }
 154
 155     memset((char *)fd2obj, '\0', sizeof(fd2obj));
 156
 157     /* Convert lists to fd_sets, and get maximum fd number */
 158     if( (imax=list2set(ifdlist, &ifdset, fd2obj)) < 0 )
 159       return 0;
 160     if( (omax=list2set(ofdlist, &ofdset, fd2obj)) < 0 )
 161       return 0;
 162     if( (emax=list2set(efdlist, &efdset, fd2obj)) < 0 )
 163       return 0;
 164     max = imax;
 165     if ( omax > max ) max = omax;
 166     if ( emax > max ) max = emax;
 167
 168     BGN_SAVE
 169     n = select(max, &ifdset, &ofdset, &efdset, tvp);
 170     END_SAVE
 171
 172     if ( n < 0 ) {
 173         err_errno(SelectError);
 174         return 0;
 175     }
 176
 177     if ( n == 0 )
 178       imax = omax = emax = 0; /* Speedup hack */
 179
 180     ifdlist = set2list(&ifdset, imax, fd2obj);
 181     ofdlist = set2list(&ofdset, omax, fd2obj);
 182     efdlist = set2list(&efdset, emax, fd2obj);
 183     ret = mkvalue("OOO", ifdlist, ofdlist, efdlist);
 184     XDECREF(ifdlist);
 185     XDECREF(ofdlist);
 186     XDECREF(efdlist);
 187     return ret;
 188 }
 189
 190
 191 static struct methodlist select_methods[] = {
 192     { "select", select_select },
 193     { 0,        0 },
 194 };
 195
 196
 197 void
 198 initselect()
 199 {
 200         object *m, *d;
 201         m = initmodule("select", select_methods);
 202         d = getmoduledict(m);
 203         SelectError = newstringobject("select.error");
 204         if ( SelectError == NULL || dictinsert(d, "error", SelectError) )
 205           fatal("Cannot define select.error");
 206 }