diff --git a/examples/twoway/introspecting.c b/examples/twoway/introspecting.c
new file mode 100644
index 0000000000000000000000000000000000000000..dee04cab049192b77fa40425d612e079e21b1b69
--- /dev/null
+++ b/examples/twoway/introspecting.c
@@ -0,0 +1,220 @@
+/*
+ introspecting.c -- LabComm example of a twoway stacked introspection
+ reader/writer.
+
+ Copyright 2013 Anders Blomdell <anders.blomdell@control.lth.se>
+
+ This file is part of LabComm.
+
+ LabComm is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ LabComm is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "labcomm_private.h"
+#include "introspecting.h"
+#include "gen/introspecting_messages.h"
+
+struct introspecting_private {
+ struct introspecting introspecting;
+ struct labcomm_encoder *encoder;
+ int encoder_initialized;
+ struct labcomm_decoder *decoder;
+ int decoder_initialized;
+ struct labcomm_reader_action_context reader_action_context;
+ struct labcomm_writer_action_context writer_action_context;
+ LABCOMM_SIGNATURE_ARRAY_DEF(introspection,
+ struct introspection {
+ int has_got_response;
+ int has_handler;
+ });
+};
+
+static void handles_signature(
+ introspecting_messages_handles_signature *value,
+ void * context)
+{
+ fprintf(stderr, "### %s %x %s\n", __FUNCTION__, value->index, value->name);
+/*
+ struct introspecting_private *introspecting = context;
+ struct introspection *introspection;
+
+ introspection = LABCOMM_SIGNATURE_ARRAY_REF(introspecting->introspection,
+ struct introspection,
+ value->index);
+
+ introspection->has_handler = value->has_handler;
+*/
+}
+
+static int wrap_reader_alloc(
+ struct labcomm_reader *r,
+ struct labcomm_reader_action_context *action_context,
+ struct labcomm_decoder *decoder,
+ char *labcomm_version)
+{
+ int result;
+ struct introspecting_private *introspecting = action_context->context;
+
+ fprintf(stderr, "%s %s\n", __FILE__, __FUNCTION__);
+ /* Stash away decoder for later use */
+ introspecting->decoder = decoder;
+ result = labcomm_reader_alloc(r, action_context->next,
+ decoder, labcomm_version);
+ labcomm_decoder_register_introspecting_messages_handles_signature(
+ introspecting->decoder, handles_signature, introspecting);
+ introspecting->decoder_initialized = 1;
+ return result;
+}
+
+static int wrap_reader_start(
+ struct labcomm_reader *r,
+ struct labcomm_reader_action_context *action_context,
+ int index, struct labcomm_signature *signature,
+ void *value)
+{
+ struct introspecting_private *introspecting = action_context->context;
+
+ if (value == NULL && introspecting->decoder_initialized) {
+ introspecting_messages_handles_signature handles_signature;
+
+ handles_signature.index = index;
+ handles_signature.name = signature->name;
+ handles_signature.signature.n_0 = signature->size;
+ handles_signature.signature.a = signature->signature;
+ labcomm_encode_introspecting_messages_handles_signature(
+ introspecting->encoder, &handles_signature);
+ }
+ return labcomm_reader_start(r, action_context->next, index, signature, value);
+}
+
+ void encode_handles_signature(
+ struct labcomm_encoder *encoder,
+ void *context)
+{
+ struct labcomm_signature *signature = context;
+ introspecting_messages_handles_signature handles_signature;
+ int index = 0;
+
+ fprintf(stderr, "## Handles %x %s\n", index, signature->name);
+ handles_signature.index = index;
+ handles_signature.name = signature->name;
+ handles_signature.signature.n_0 = signature->size;
+ handles_signature.signature.a = signature->signature;
+
+ labcomm_encode_introspecting_messages_handles_signature(
+ NULL, &handles_signature);
+}
+
+struct labcomm_reader_action introspecting_reader_action = {
+ .alloc = wrap_reader_alloc,
+ .free = NULL,
+ .start = wrap_reader_start,
+ .end = NULL,
+ .fill = NULL,
+ .ioctl = NULL
+};
+
+static void register_signatures(struct labcomm_encoder *encoder,
+ void *context)
+{
+ labcomm_encoder_register_introspecting_messages_handles_signature(
+ encoder);
+}
+
+static int wrap_writer_alloc(
+ struct labcomm_writer *w,
+ struct labcomm_writer_action_context *action_context,
+ struct labcomm_encoder *encoder, char *labcomm_version,
+ labcomm_encoder_enqueue enqueue)
+{
+ int result;
+ struct introspecting_private *introspecting = action_context->context;
+
+ fprintf(stderr, "%s %s\n", __FILE__, __FUNCTION__);
+ /* Stash away encoder for later use */
+ introspecting->encoder = encoder;
+ result = labcomm_writer_alloc(w, action_context->next,
+ encoder, labcomm_version, enqueue);
+ enqueue(encoder, register_signatures, NULL);
+ return result;
+}
+
+static int wrap_writer_start(
+ struct labcomm_writer *w,
+ struct labcomm_writer_action_context *action_context,
+ int index, struct labcomm_signature *signature,
+ void *value)
+{
+// struct introspecting_private *introspecting = action_context->context;
+
+ fprintf(stderr, "%s %p\n", __FUNCTION__, value);
+ return labcomm_writer_start(w, action_context->next, index, signature, value);
+}
+
+struct labcomm_writer_action introspecting_writer_action = {
+ .alloc = wrap_writer_alloc,
+ .free = NULL,
+ .start = wrap_writer_start,
+ .end = NULL,
+ .flush = NULL,
+ .ioctl = NULL
+};
+
+extern struct introspecting *introspecting_new(
+ struct labcomm_reader *reader,
+ struct labcomm_writer *writer,
+ struct labcomm_lock *lock)
+{
+ struct introspecting_private *result;
+
+ result = malloc(sizeof(*result));
+ if (result == NULL) {
+ goto out_fail;
+ }
+
+ /* Wrap reader and writer */
+ result->reader_action_context.next = reader->action_context;
+ result->reader_action_context.action = &introspecting_reader_action;
+ result->reader_action_context.context = result;
+ reader->action_context = &result->reader_action_context;
+
+ result->writer_action_context.next = writer->action_context;
+ result->writer_action_context.action = &introspecting_writer_action;
+ result->writer_action_context.context = result;
+ writer->action_context = &result->writer_action_context;
+
+ /* Init visible result struct */
+ result->introspecting.reader = reader;
+ result->introspecting.writer = writer;
+
+ /* Init other fields */
+ result->encoder = NULL;
+ result->encoder_initialized = 0;
+ result->decoder = NULL;
+ result->decoder_initialized = 0;
+ result->lock = lock;
+ LABCOMM_SIGNATURE_ARRAY_INIT(result->introspection, struct introspection);
+
+ goto out_ok;
+
+out_fail:
+ return NULL;
+
+out_ok:
+ return &result->introspecting;
+}
+
+
diff --git a/examples/twoway/introspecting.h b/examples/twoway/introspecting.h
new file mode 100644
index 0000000000000000000000000000000000000000..9c168274d41c626250e16e2615e974991262417d
--- /dev/null
+++ b/examples/twoway/introspecting.h
@@ -0,0 +1,43 @@
+/*
+ introspecting.h -- LabComm example of a twoway stacked introspection
+ reader/writer.
+
+ Copyright 2013 Anders Blomdell <anders.blomdell@control.lth.se>
+
+ This file is part of LabComm.
+
+ LabComm is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ LabComm is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __INTROSPECTING_H__
+#define __INTROSPECTING_H__
+
+#include <labcomm.h>
+#include <labcomm_ioctl.h>
+#include <labcomm_fd_reader.h>
+#include <labcomm_fd_writer.h>
+
+struct introspecting {
+ struct labcomm_reader *reader;
+ struct labcomm_writer *writer;
+};
+
+extern struct introspecting *introspecting_new(
+ struct labcomm_reader *reader,
+ struct labcomm_writer *writer,
+ struct labcomm_lock *lock);
+
+#define HAS_SIGNATURE LABCOMM_IOS('i',2)
+
+#endif