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authorGuido van Rossum <guido@python.org>1992-06-23 09:07:03 (GMT)
committerGuido van Rossum <guido@python.org>1992-06-23 09:07:03 (GMT)
commited233a56963233bbd646fdac01e55c9fdec50a30 (patch)
tree590cee6874280421f9288568015bf9b30326b8ed /Modules/selectmodule.c
parent5dc8eb0914a6fcea604a6626af9e63120e84b527 (diff)
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Changes for new UNIX-specific built-in module 'select' and new header for
interfaces to variants of select() system call, "myselect.h". This includes adding fileno() methods to files, sockets and stdwin.
Diffstat (limited to 'Modules/selectmodule.c')
-rw-r--r--Modules/selectmodule.c194
1 files changed, 194 insertions, 0 deletions
diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
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+/***********************************************************
+Copyright 1991, 1992 by Stichting Mathematisch Centrum, Amsterdam, The
+Netherlands.
+
+ All Rights Reserved
+
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose and without fee is hereby granted,
+provided that the above copyright notice appear in all copies and that
+both that copyright notice and this permission notice appear in
+supporting documentation, and that the names of Stichting Mathematisch
+Centrum or CWI not be used in advertising or publicity pertaining to
+distribution of the software without specific, written prior permission.
+
+STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
+THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
+FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+******************************************************************/
+
+/* select - Module containing unix select(2) call */
+
+#include "allobjects.h"
+#include "modsupport.h"
+#include "compile.h"
+#include "ceval.h"
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/param.h>
+
+/* XXX Maybe you need to define the FD_* macros here when porting this code */
+
+static object *SelectError;
+
+/* XXX This module should be re-entrant! */
+static object *fd2obj[FD_SETSIZE];
+
+static
+list2set(list, set)
+ object *list;
+ fd_set *set;
+{
+ int i, len, v, max=-1;
+ object *o, *filenomethod, *fno;
+
+ FD_ZERO(set);
+ len = getlistsize(list);
+ for( i=0; i<len; i++ ) {
+ o = getlistitem(list, i);
+ if ( is_intobject(o) ) {
+ v = getintvalue(o);
+ } else if ( (filenomethod = getattr(o, "fileno")) != NULL ) {
+ fno = call_object(filenomethod, NULL);
+ if ( fno == NULL )
+ return -1;
+ if ( !is_intobject(fno) ) {
+ err_badarg();
+ return -1;
+ }
+ v = getintvalue(fno);
+ DECREF(fno);
+ } else {
+ err_badarg();
+ return -1;
+ }
+ if ( v >= FD_SETSIZE ) {
+ err_setstr(SystemError, "FD_SETSIZE too low in select()");
+ return -1;
+ }
+ if ( v > max ) max = v;
+ FD_SET(v, set);
+ fd2obj[v] = o;
+ }
+ return max+1;
+}
+
+static object *
+set2list(set, max)
+ fd_set *set;
+ int max;
+{
+ int i, num=0;
+ object *list, *o;
+
+ for(i=0; i<max; i++)
+ if ( FD_ISSET(i,set) )
+ num++;
+ list = newlistobject(num);
+ num = 0;
+ for(i=0; i<max; i++)
+ if ( FD_ISSET(i,set) ) {
+ if ( i > FD_SETSIZE ) {
+ err_setstr(SystemError, "FD_SETSIZE too low in select()");
+ return NULL;
+ }
+ o = fd2obj[i];
+ if ( o == 0 ) {
+ err_setstr(SystemError,
+ "Bad filedescriptor returned from select()");
+ return NULL;
+ }
+ INCREF(o);
+ setlistitem(list, num, o);
+ num++;
+ }
+ return list;
+}
+
+static object *
+select_select(self, args)
+ object *self;
+ object *args;
+{
+ object *ifdlist, *ofdlist, *efdlist;
+ fd_set ifdset, ofdset, efdset;
+ double timeout;
+ struct timeval tv, *tvp;
+ int seconds;
+ int imax, omax, emax, max;
+ int n;
+
+
+ /* Get args. Looks funny because of optional timeout argument */
+ if ( getargs(args, "(OOOd)", &ifdlist, &ofdlist, &efdlist, &timeout) ) {
+ seconds = (int)timeout;
+ timeout = timeout - (double)seconds;
+ tv.tv_sec = seconds;
+ tv.tv_usec = (int)(timeout*1000000.0);
+ tvp = &tv;
+ } else {
+ /* Doesn't have 4 args, that means no timeout */
+ err_clear();
+ if (!getargs(args, "(OOO)", &ifdlist, &ofdlist, &efdlist) )
+ return 0;
+ tvp = (struct timeval *)0;
+ }
+ if ( !is_listobject(ifdlist) || !is_listobject(ofdlist) ||
+ !is_listobject(efdlist) ) {
+ err_badarg();
+ return 0;
+ }
+
+ bzero((char *)fd2obj, sizeof(fd2obj)); /* Not really needed */
+
+ /* Convert lists to fd_sets, and get maximum fd number */
+ if( (imax=list2set(ifdlist, &ifdset)) < 0 )
+ return 0;
+ if( (omax=list2set(ofdlist, &ofdset)) < 0 )
+ return 0;
+ if( (emax=list2set(efdlist, &efdset)) < 0 )
+ return 0;
+ max = imax;
+ if ( omax > max ) max = omax;
+ if ( emax > max ) max = emax;
+
+ n = select(max, &ifdset, &ofdset, &efdset, tvp);
+
+ if ( n < 0 ) {
+ err_errno(SelectError);
+ return 0;
+ }
+
+ if ( n == 0 )
+ imax = omax = emax = 0; /* Speedup hack */
+
+ ifdlist = set2list(&ifdset, imax);
+ ofdlist = set2list(&ofdset, omax);
+ efdlist = set2list(&efdset, emax);
+
+ return mkvalue("OOO", ifdlist, ofdlist, efdlist);
+}
+
+
+static struct methodlist select_methods[] = {
+ { "select", select_select },
+ { 0, 0 },
+};
+
+
+void
+initselect()
+{
+ object *m, *d;
+ m = initmodule("select", select_methods);
+ d = getmoduledict(m);
+ SelectError = newstringobject("select.error");
+ if ( SelectError == NULL || dictinsert(d, "error", SelectError) )
+ fatal("Cannot define select.error");
+}