1 files changed, 105 insertions, 0 deletions
diff --git a/erts/emulator/drivers/unix/multi_drv.c b/erts/emulator/drivers/unix/multi_drv.c
new file mode 100644
index 0000000000..822c96730c
--- /dev/null
+++ b/erts/emulator/drivers/unix/multi_drv.c
@@ -0,0 +1,105 @@
+/*
+ * %CopyrightBegin%
+ * 
+ * Copyright Ericsson AB 1996-2009. All Rights Reserved.
+ * 
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ * 
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ * 
+ * %CopyrightEnd%
+ */
+
+/* Purpose:    Multidriver interface 
+   This is an example of a driver which allows multiple instances of itself.
+   I.e have one erlang process execute open_port(multi......) and
+   at the same time have an other erlang process open an other port 
+   running multi there as well.
+*/
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include "erl_driver.h"
+#include "sys.h"
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#define MAXCHANNEL 20
+
+static char buf[BUFSIZ];
+
+static ErlDrvData multi_start(ErlDrvPort, char*);
+static int multi_init(void);
+static void multi_stop(ErlDrvData),multi_erlang_read(ErlDrvData, char*, int);
+
+struct driver_entry multi_driver_entry = {
+    multi_init,
+    multi_start,
+    multi_stop,
+    multi_erlang_read,
+    NULL,
+    NULL,
+    "multi"
+};
+
+
+struct channel {
+    ErlDrvPort portno;
+    int channel;
+};
+
+struct channel channels[MAXCHANNEL]; /* Max MAXCHANNEL instances */
+
+static int multi_init(void)
+{
+    memzero(channels,MAXCHANNEL * sizeof(struct channel));
+    return 0;
+}
+
+static ErlDrvData multi_start(ErlDrvPort port, char* buf) 
+{
+    int chan;
+    chan = get_new_channel();
+    channels[port].portno = port;
+    channels[port].channel = chan;
+    fprintf(stderr,"Opening channel %d port is %d\n",chan,port);
+    return (ErlDrvData)port;
+}
+
+
+static int multi_stop(ErlDrvData port)
+{
+    fprintf(stderr,"Closing channel %d\n",channels[port].channel);
+    remove_channel(channels[(int)port].channel);
+}
+
+ 
+static int multi_erlang_read(ErlDrvData port, char* buf, int count)
+{
+    fprintf(stderr,"Writing %d bytes to channel %d\n",
+	    count,
+	    channels[(int)port].channel);
+}
+
+
+/* These two funs are fake */
+
+int get_new_channel() 
+{
+    static int ch = 1;
+    return(ch++);
+}
+
+void remove_channel(int ch)
+{
+}