fdev: Introduce fdev for file event handling

This is an effort to keep cutting dependency to systemd.

Change-Id: I9a0c032a1095e297c7f3ac5b67827fda3658b8d9
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

26 files changed, 649 insertions, 133 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 4ef87853..f72d312e 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -42,6 +42,7 @@ ADD_LIBRARY(afb-lib STATIC
 	afb-debug.c
 	afb-evt.c
 	afb-export.c
+	afb-fdev.c
 	afb-hook.c
 	afb-hreq.c
 	afb-hsrv.c
@@ -61,6 +62,9 @@ ADD_LIBRARY(afb-lib STATIC
 	afb-ws.c
 	afb-wsj1.c
 	afb-xreq.c
+	fdev.c
+	fdev-epoll.c
+	fdev-systemd.c
 	jobs.c
 	locale-root.c
 	process-name.c
@@ -96,7 +100,7 @@ INSTALL(TARGETS afs-supervisor
 ###########################################
 # build and install libafbwsc
 ###########################################
-ADD_LIBRARY(afbwsc SHARED afb-ws.c afb-ws-client.c afb-wsj1.c websock.c afb-proto-ws.c jobs-fake.c)
+ADD_LIBRARY(afbwsc SHARED afb-ws.c afb-ws-client.c afb-wsj1.c websock.c afb-proto-ws.c jobs-fake.c fdev.c fdev-systemd.c)
 SET_TARGET_PROPERTIES(afbwsc PROPERTIES
 	VERSION ${LIBAFBWSC_VERSION}
 	SOVERSION ${LIBAFBWSC_SOVERSION})
diff --git a/src/afb-api-ws.c b/src/afb-api-ws.c
index 7fbe5be1..489b43b1 100644
--- a/src/afb-api-ws.c
+++ b/src/afb-api-ws.c
@@ -30,19 +30,19 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 
-#include <systemd/sd-event.h>
+#include "afb-fdev.h"
+#include "afb-systemd.h"
 #include "afb-api.h"
 #include "afb-apiset.h"
-#include "afb-systemd.h"
 #include "afb-stub-ws.h"
 #include "verbose.h"
+#include "fdev.h"
 
 struct api_ws
 {
 	char *path;		/* path of the object for the API */
 	char *api;		/* api name of the interface */
-	int fd;			/* file descriptor */
-	sd_event_source *listensrc; /**< systemd source for server socket */
+	struct fdev *fdev;	/* fdev handler */
 	struct afb_apiset *apiset;
 };
 
@@ -77,7 +77,6 @@ static struct api_ws *api_ws_make(const char *path)
 		goto error2;
 	}
 
-	api->fd = -1;
 	return api;
 
 error2:
@@ -176,7 +175,7 @@ static int api_ws_socket(const char *path, int server)
 
 	/* check for systemd socket */
 	if (0 == strncmp(path, "sd:", 3))
-		fd = systemd_fds_for(path + 3);
+		fd = afb_systemd_fds_for(path + 3);
 	else {
 		/* check for unix socket */
 		if (0 == strncmp(path, "unix:", 5))
@@ -200,6 +199,24 @@ static int api_ws_socket(const char *path, int server)
 	return fd;
 }
 
+static struct fdev *api_ws_socket_fdev(const char *path, int server)
+{
+	int fd;
+	struct fdev *fdev;
+
+	fd = api_ws_socket(path, server);
+	if (fd < 0)
+		fdev = 0;
+	else {
+		fdev = afb_fdev_create(fd);
+		if (!fdev)
+			close(fd);
+	}
+	if (!fdev)
+		ERROR("can't make %s socket for %s", server ? "server" : "client", path);
+	return fdev;
+}
+
 /**********************************************************************************/
 
 int afb_api_ws_add_client(const char *path, struct afb_apiset *apiset, int strong)
@@ -213,27 +230,23 @@ int afb_api_ws_add_client(const char *path, struct afb_apiset *apiset, int stron
 		goto error;
 
 	/* connect to the service */
-	apiws->fd = api_ws_socket(apiws->path, 0);
-	if (apiws->fd < 0) {
-		ERROR("can't connect to ws service %s", apiws->path);
+	apiws->fdev = api_ws_socket_fdev(apiws->path, 0);
+	if (!apiws->fdev)
 		goto error2;
-	}
 
-	stubws = afb_stub_ws_create_client(apiws->fd, apiws->api, apiset);
+	stubws = afb_stub_ws_create_client(apiws->fdev, apiws->api, apiset);
 	if (!stubws) {
 		ERROR("can't setup client ws service to %s", apiws->path);
 		goto error3;
 	}
 	if (afb_stub_ws_client_add(stubws, apiset) < 0) {
 		ERROR("can't add the client to the apiset for service %s", apiws->path);
-		goto error4;
+		goto error3;
 	}
 	free(apiws);
 	return 0;
-error4:
-	afb_stub_ws_unref(stubws);
 error3:
-	close(apiws->fd);
+	afb_stub_ws_unref(stubws);
 error2:
 	free(apiws);
 error:
@@ -250,9 +263,9 @@ int afb_api_ws_add_client_weak(const char *path, struct afb_apiset *apiset)
 	return afb_api_ws_add_client(path, apiset, 0);
 }
 
-static int api_ws_server_accept_client(struct api_ws *apiws, int fd)
+static int api_ws_server_accept_client(struct api_ws *apiws, struct fdev *fdev)
 {
-	return -!afb_stub_ws_create_server(fd, apiws->api, apiws->apiset);
+	return -!afb_stub_ws_create_server(fdev, apiws->api, apiws->apiset);
 }
 
 static void api_ws_server_accept(struct api_ws *apiws)
@@ -260,20 +273,28 @@ static void api_ws_server_accept(struct api_ws *apiws)
 	int rc, fd;
 	struct sockaddr addr;
 	socklen_t lenaddr;
+	struct fdev *fdev;
 
 	lenaddr = (socklen_t)sizeof addr;
-	fd = accept(apiws->fd, &addr, &lenaddr);
-	if (fd >= 0) {
-		rc = api_ws_server_accept_client(apiws, fd);
-		if (rc >= 0)
-			return;
-		close(fd);
+	fd = accept(fdev_fd(apiws->fdev), &addr, &lenaddr);
+	if (fd < 0) {
+		ERROR("can't accept connection to %s: %m", apiws->path);
+	} else {
+		fdev = afb_fdev_create(fd);
+		if (!fdev) {
+			ERROR("can't hold accepted connection to %s: %m", apiws->path);
+			close(fd);
+		} else {
+			rc = api_ws_server_accept_client(apiws, fdev);
+			if (rc < 0)
+				ERROR("can't serve accepted connection to %s: %m", apiws->path);
+		}
 	}
 }
 
 static int api_ws_server_connect(struct api_ws *apiws);
 
-static int api_ws_server_listen_callback(sd_event_source *src, int fd, uint32_t revents, void *closure)
+static void api_ws_server_listen_callback(void *closure, uint32_t revents, struct fdev *fdev)
 {
 	struct api_ws *apiws = closure;
 
@@ -281,42 +302,28 @@ static int api_ws_server_listen_callback(sd_event_source *src, int fd, uint32_t
 		api_ws_server_accept(apiws);
 	if ((revents & EPOLLHUP) != 0)
 		api_ws_server_connect(apiws);
-	return 0;
 }
 
 static void api_ws_server_disconnect(struct api_ws *apiws)
 {
-	if (apiws->listensrc != NULL) {
-		sd_event_source_unref(apiws->listensrc);
-		apiws->listensrc = NULL;
-	}
-	if (apiws->fd >= 0) {
-		close(apiws->fd);
-		apiws->fd = -1;
-	}
+	fdev_unref(apiws->fdev);
+	apiws->fdev = 0;
 }
 
 static int api_ws_server_connect(struct api_ws *apiws)
 {
-	int rc;
-
 	/* ensure disconnected */
 	api_ws_server_disconnect(apiws);
 
 	/* request the service object name */
-	apiws->fd = api_ws_socket(apiws->path, 1);
-	if (apiws->fd < 0)
+	apiws->fdev = api_ws_socket_fdev(apiws->path, 1);
+	if (!apiws->fdev)
 		ERROR("can't create socket %s", apiws->path);
 	else {
 		/* listen for service */
-		rc = sd_event_add_io(afb_systemd_get_event_loop(),
-				&apiws->listensrc, apiws->fd, EPOLLIN,
-				api_ws_server_listen_callback, apiws);
-		if (rc >= 0)
-			return 0;
-		close(apiws->fd);
-		errno = -rc;
-		ERROR("can't add ws object %s", apiws->path);
+		fdev_set_events(apiws->fdev, EPOLLIN);
+		fdev_set_callback(apiws->fdev, api_ws_server_listen_callback, apiws);
+		return 0;
 	}
 	return -1;
 }
diff --git a/src/afb-fdev.c b/src/afb-fdev.c
new file mode 100644
index 00000000..943c2542
--- /dev/null
+++ b/src/afb-fdev.c
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "afb-systemd.h"
+#include "fdev.h"
+#include "fdev-systemd.h"
+
+struct fdev *afb_fdev_create(int fd)
+{
+	return fdev_systemd_create(afb_systemd_get_event_loop(), fd);
+}
+
diff --git a/src/afb-fdev.h b/src/afb-fdev.h
new file mode 100644
index 00000000..0f29a9f3
--- /dev/null
+++ b/src/afb-fdev.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+struct fdev;
+
+extern struct fdev *afb_fdev_create(int fd);
diff --git a/src/afb-proto-ws.c b/src/afb-proto-ws.c
index ce7d75d3..56669e59 100644
--- a/src/afb-proto-ws.c
+++ b/src/afb-proto-ws.c
@@ -38,6 +38,7 @@
 #include "afb-msg-json.h"
 #include "afb-proto-ws.h"
 #include "jobs.h"
+#include "fdev.h"
 
 struct afb_proto_ws;
 
@@ -161,7 +162,7 @@ struct afb_proto_ws
 	int refcount;
 
 	/* file descriptor */
-	int fd;
+	struct fdev *fdev;
 
 	/* resource control */
 	pthread_mutex_t mutex;
@@ -1157,9 +1158,9 @@ static void on_hangup(void *closure)
 		free(cd);
 	}
 
-	if (protows->fd >= 0) {
-		close(protows->fd);
-		protows->fd = -1;
+	if (protows->fdev) {
+		fdev_unref(protows->fdev);
+		protows->fdev = 0;
 		if (protows->on_hangup)
 			protows->on_hangup(protows->closure);
 	}
@@ -1187,7 +1188,7 @@ static const struct afb_ws_itf server_ws_itf =
 
 /*****************************************************/
 
-static struct afb_proto_ws *afb_proto_ws_create(struct sd_event *eloop, int fd, const struct afb_proto_ws_server_itf *itfs, const struct afb_proto_ws_client_itf *itfc, void *closure, const struct afb_ws_itf *itf)
+static struct afb_proto_ws *afb_proto_ws_create(struct fdev *fdev, const struct afb_proto_ws_server_itf *itfs, const struct afb_proto_ws_client_itf *itfc, void *closure, const struct afb_ws_itf *itf)
 {
 	struct afb_proto_ws *protows;
 
@@ -1195,11 +1196,11 @@ static struct afb_proto_ws *afb_proto_ws_create(struct sd_event *eloop, int fd,
 	if (protows == NULL)
 		errno = ENOMEM;
 	else {
-		fcntl(fd, F_SETFD, FD_CLOEXEC);
-		fcntl(fd, F_SETFL, O_NONBLOCK);
-		protows->ws = afb_ws_create(eloop, fd, itf, protows);
+		fcntl(fdev_fd(fdev), F_SETFD, FD_CLOEXEC);
+		fcntl(fdev_fd(fdev), F_SETFL, O_NONBLOCK);
+		protows->ws = afb_ws_create(fdev, itf, protows);
 		if (protows->ws != NULL) {
-			protows->fd = fd;
+			protows->fdev = fdev;
 			protows->refcount = 1;
 			protows->subcalls = NULL;
 			protows->closure = closure;
@@ -1213,14 +1214,14 @@ static struct afb_proto_ws *afb_proto_ws_create(struct sd_event *eloop, int fd,
 	return NULL;
 }
 
-struct afb_proto_ws *afb_proto_ws_create_client(struct sd_event *eloop, int fd, const struct afb_proto_ws_client_itf *itf, void *closure)
+struct afb_proto_ws *afb_proto_ws_create_client(struct fdev *fdev, const struct afb_proto_ws_client_itf *itf, void *closure)
 {
-	return afb_proto_ws_create(eloop, fd, NULL, itf, closure, &proto_ws_client_ws_itf);
+	return afb_proto_ws_create(fdev, NULL, itf, closure, &proto_ws_client_ws_itf);
 }
 
-struct afb_proto_ws *afb_proto_ws_create_server(struct sd_event *eloop, int fd, const struct afb_proto_ws_server_itf *itf, void *closure)
+struct afb_proto_ws *afb_proto_ws_create_server(struct fdev *fdev, const struct afb_proto_ws_server_itf *itf, void *closure)
 {
-	return afb_proto_ws_create(eloop, fd, itf, NULL, closure, &server_ws_itf);
+	return afb_proto_ws_create(fdev, itf, NULL, closure, &server_ws_itf);
 }
 
 void afb_proto_ws_unref(struct afb_proto_ws *protows)
diff --git a/src/afb-proto-ws.h b/src/afb-proto-ws.h
index 103e37ab..cef7eadb 100644
--- a/src/afb-proto-ws.h
+++ b/src/afb-proto-ws.h
@@ -18,7 +18,7 @@
 
 #pragma once
 
-struct sd_event;
+struct fdev;
 struct afb_proto_ws;
 struct afb_proto_ws_call;
 struct afb_proto_ws_subcall;
@@ -47,8 +47,8 @@ struct afb_proto_ws_server_itf
 	void (*on_describe)(void *closure, struct afb_proto_ws_describe *describe);
 };
 
-extern struct afb_proto_ws *afb_proto_ws_create_client(struct sd_event *eloop, int fd, const struct afb_proto_ws_client_itf *itf, void *closure);
-extern struct afb_proto_ws *afb_proto_ws_create_server(struct sd_event *eloop, int fd, const struct afb_proto_ws_server_itf *itf, void *closure);
+extern struct afb_proto_ws *afb_proto_ws_create_client(struct fdev *fdev, const struct afb_proto_ws_client_itf *itf, void *closure);
+extern struct afb_proto_ws *afb_proto_ws_create_server(struct fdev *fdev, const struct afb_proto_ws_server_itf *itf, void *closure);
 
 extern void afb_proto_ws_unref(struct afb_proto_ws *protows);
 extern void afb_proto_ws_addref(struct afb_proto_ws *protows);
diff --git a/src/afb-stub-ws.c b/src/afb-stub-ws.c
index 0049c50c..37607ee0 100644
--- a/src/afb-stub-ws.c
+++ b/src/afb-stub-ws.c
@@ -36,8 +36,6 @@
 
 #include <afb/afb-event.h>
 
-#include "afb-systemd.h"
-
 #include "afb-session.h"
 #include "afb-cred.h"
 #include "afb-api.h"
@@ -48,6 +46,7 @@
 #include "afb-evt.h"
 #include "afb-xreq.h"
 #include "verbose.h"
+#include "fdev.h"
 #include "jobs.h"
 
 struct afb_stub_ws;
@@ -661,7 +660,7 @@ static void on_hangup(void *closure)
 
 /*****************************************************/
 
-static struct afb_stub_ws *afb_stub_ws_create(int fd, const char *apiname, struct afb_apiset *apiset, int client)
+static struct afb_stub_ws *afb_stub_ws_create(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset, int client)
 {
 	struct afb_stub_ws *stubws;
 
@@ -670,10 +669,11 @@ static struct afb_stub_ws *afb_stub_ws_create(int fd, const char *apiname, struc
 		errno = ENOMEM;
 	else {
 		if (client)
-			stubws->proto = afb_proto_ws_create_client(afb_systemd_get_event_loop(), fd, &client_itf, stubws);
+			stubws->proto = afb_proto_ws_create_client(fdev, &client_itf, stubws);
 		else
-			stubws->proto = afb_proto_ws_create_server(afb_systemd_get_event_loop(), fd, &server_itf, stubws);
-		if (stubws->proto != NULL) {
+			stubws->proto = afb_proto_ws_create_server(fdev, &server_itf, stubws);
+
+		if (stubws->proto) {
 			strcpy(stubws->apiname, apiname);
 			stubws->apiset = afb_apiset_addref(apiset);
 			stubws->refcount = 1;
@@ -682,21 +682,22 @@ static struct afb_stub_ws *afb_stub_ws_create(int fd, const char *apiname, struc
 		}
 		free(stubws);
 	}
+	fdev_unref(fdev);
 	return NULL;
 }
 
-struct afb_stub_ws *afb_stub_ws_create_client(int fd, const char *apiname, struct afb_apiset *apiset)
+struct afb_stub_ws *afb_stub_ws_create_client(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset)
 {
-	return afb_stub_ws_create(fd, apiname, apiset, 1);
+	return afb_stub_ws_create(fdev, apiname, apiset, 1);
 }
 
-struct afb_stub_ws *afb_stub_ws_create_server(int fd, const char *apiname, struct afb_apiset *apiset)
+struct afb_stub_ws *afb_stub_ws_create_server(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset)
 {
 	struct afb_stub_ws *stubws;
 
-	stubws = afb_stub_ws_create(fd, apiname, apiset, 0);
+	stubws = afb_stub_ws_create(fdev, apiname, apiset, 0);
 	if (stubws) {
-		stubws->cred = afb_cred_create_for_socket(fd);
+		stubws->cred = afb_cred_create_for_socket(fdev_fd(fdev));
 		stubws->listener = afb_evt_listener_create(&server_evt_itf, stubws);
 		if (stubws->listener != NULL)
 			return stubws;
diff --git a/src/afb-stub-ws.h b/src/afb-stub-ws.h
index 4e07f982..3bb56feb 100644
--- a/src/afb-stub-ws.h
+++ b/src/afb-stub-ws.h
@@ -18,13 +18,14 @@
 
 #pragma once
 
+struct fdev;
 struct afb_stub_ws;
 struct afb_apiset;
 struct afb_api;
 
-extern struct afb_stub_ws *afb_stub_ws_create_client(int fd, const char *apiname, struct afb_apiset *apiset);
+extern struct afb_stub_ws *afb_stub_ws_create_client(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset);
 
-extern struct afb_stub_ws *afb_stub_ws_create_server(int fd, const char *apiname, struct afb_apiset *apiset);
+extern struct afb_stub_ws *afb_stub_ws_create_server(struct fdev *fdev, const char *apiname, struct afb_apiset *apiset);
 
 extern void afb_stub_ws_unref(struct afb_stub_ws *stubws);
 
diff --git a/src/afb-supervision.c b/src/afb-supervision.c
index f41ca18b..0f8a16bb 100644
--- a/src/afb-supervision.c
+++ b/src/afb-supervision.c
@@ -43,6 +43,7 @@
 #include "afs-supervision.h"
 #include "afb-stub-ws.h"
 #include "afb-debug.h"
+#include "afb-fdev.h"
 #include "verbose.h"
 #include "wrap-json.h"
 #include "jobs.h"
@@ -138,6 +139,7 @@ static void try_connect_supervisor()
 	int fd;
 	ssize_t srd;
 	struct afs_supervision_initiator initiator;
+	struct fdev *fdev;
 
 	/* get the mutex */
 	pthread_mutex_lock(&mutex);
@@ -195,10 +197,15 @@ static void try_connect_supervisor()
 	}
 
 	/* make the supervisor link */
-	supervisor = afb_stub_ws_create_server(fd, supervision_apiname, supervision_apiset);
+	fdev = afb_fdev_create(fd);
+	if (!fdev) {
+		ERROR("Creation of fdev failed: %m");
+		goto end2;
+	}
+	supervisor = afb_stub_ws_create_server(fdev, supervision_apiname, supervision_apiset);
 	if (!supervisor) {
 		ERROR("Creation of supervisor failed: %m");
-		goto end2;
+		goto end;
 	}
 	afb_stub_ws_on_hangup(supervisor, on_supervisor_hangup);
 
diff --git a/src/afb-systemd.c b/src/afb-systemd.c
index 575d9f1b..fe47967f 100644
--- a/src/afb-systemd.c
+++ b/src/afb-systemd.c
@@ -80,14 +80,14 @@ static char **fds_names()
 	return names;
 }
 
-int systemd_fds_init()
+int afb_systemd_fds_init()
 {
 	errno = 0;
 	fds_names();
 	return -!!errno;
 }
 
-int systemd_fds_for(const char *name)
+int afb_systemd_fds_for(const char *name)
 {
 	int idx;
 	char **names;
diff --git a/src/afb-systemd.h b/src/afb-systemd.h
index ae8d61b0..bf0c6a9c 100644
--- a/src/afb-systemd.h
+++ b/src/afb-systemd.h
@@ -24,7 +24,7 @@ extern struct sd_event *afb_systemd_get_event_loop();
 extern struct sd_bus *afb_systemd_get_user_bus();
 extern struct sd_bus *afb_systemd_get_system_bus();
 
-extern int systemd_fds_init();
-extern int systemd_fds_for(const char *name);
+extern int afb_systemd_fds_init();
+extern int afb_systemd_fds_for(const char *name);
 
 
diff --git a/src/afb-websock.c b/src/afb-websock.c
index 799b2bd0..e062cf77 100644
--- a/src/afb-websock.c
+++ b/src/afb-websock.c
@@ -30,6 +30,7 @@
 #include "afb-hreq.h"
 #include "afb-websock.h"
 #include "afb-ws-json1.h"
+#include "afb-fdev.h"
 
 /**************** WebSocket connection upgrade ****************************/
 
@@ -94,7 +95,7 @@ static int headerhas(const char *header, const char *needle)
 struct protodef
 {
 	const char *name;
-	void *(*create)(int fd, struct afb_apiset *apiset, struct afb_context *context, void (*cleanup)(void*), void *cleanup_closure);
+	void *(*create)(struct fdev *fdev, struct afb_apiset *apiset, struct afb_context *context, void (*cleanup)(void*), void *cleanup_closure);
 };
 
 static const struct protodef *search_proto(const struct protodef *protodefs, const char *protocols)
@@ -142,11 +143,18 @@ static void upgrade_to_websocket(
 {
 	struct memo_websocket *memo = cls;
 	void *ws;
+	struct fdev *fdev;
 
-	ws = memo->proto->create(sock, memo->apiset, &memo->hreq->xreq.context, close_websocket, urh);
-	if (ws == NULL) {
+	fdev = afb_fdev_create(sock);
+	if (!fdev) {
 		/* TODO */
 		close_websocket(urh);
+	} else {
+		ws = memo->proto->create(fdev, memo->apiset, &memo->hreq->xreq.context, close_websocket, urh);
+		if (ws == NULL) {
+			/* TODO */
+			close_websocket(urh);
+		}
 	}
 	afb_hreq_unref(memo->hreq);
 	free(memo);
diff --git a/src/afb-ws-client.c b/src/afb-ws-client.c
index e1d3277e..7e1a04f1 100644
--- a/src/afb-ws-client.c
+++ b/src/afb-ws-client.c
@@ -29,6 +29,7 @@
 #include <fcntl.h>
 
 #include "afb-wsj1.h"
+#include "fdev-systemd.h"
 
 /**************** WebSocket handshake ****************************/
 
@@ -320,6 +321,7 @@ struct afb_wsj1 *afb_ws_client_connect_wsj1(struct sd_event *eloop, const char *
 	const char *path;
 	struct addrinfo hint, *rai, *iai;
 	struct afb_wsj1 *result;
+	struct fdev *fdev;
 
 	/* scan the uri */
 	rc = parse_uri(uri, &host, &service, &path);
@@ -354,10 +356,13 @@ struct afb_wsj1 *afb_ws_client_connect_wsj1(struct sd_event *eloop, const char *
 			if (rc == 0) {
 				rc = negociate(fd, proto_json1, path, xhost);
 				if (rc == 0) {
-					result = afb_wsj1_create(eloop, fd, itf, closure);
-					if (result != NULL) {
-						fcntl(fd, F_SETFL, O_NONBLOCK);
-						break;
+					fdev = fdev_systemd_create(eloop, fd);
+					if (fdev) {
+						result = afb_wsj1_create(fdev, itf, closure);
+						if (result != NULL) {
+							fcntl(fd, F_SETFL, O_NONBLOCK);
+							break;
+						}
 					}
 				}
 			}
@@ -505,16 +510,18 @@ struct afb_proto_ws *afb_ws_client_connect_api(struct sd_event *eloop, const cha
 {
 	int fd;
 	struct afb_proto_ws *pws;
+	struct fdev *fdev;
 
 	fd = get_socket(uri);
 	if (fd >= 0) {
-		pws = afb_proto_ws_create_client(eloop, fd, itf, closure);
-		if (pws)
-			return pws;
+		fdev = fdev_systemd_create(eloop, fd);
+		if (fdev) {
+			pws = afb_proto_ws_create_client(fdev, itf, closure);
+			if (pws)
+				return pws;
+		}
 		close(fd);
 	}
 	return NULL;
 }
 
-
-
diff --git a/src/afb-ws-json1.c b/src/afb-ws-json1.c
index 0fa13dfd..68565aa2 100644
--- a/src/afb-ws-json1.c
+++ b/src/afb-ws-json1.c
@@ -36,6 +36,7 @@
 #include "afb-context.h"
 #include "afb-evt.h"
 #include "verbose.h"
+#include "fdev.h"
 
 /* predeclaration of structures */
 struct afb_ws_json1;
@@ -99,11 +100,11 @@ static const struct afb_evt_itf evt_itf = {
 ****************************************************************
 ***************************************************************/
 
-struct afb_ws_json1 *afb_ws_json1_create(int fd, struct afb_apiset *apiset, struct afb_context *context, void (*cleanup)(void*), void *cleanup_closure)
+struct afb_ws_json1 *afb_ws_json1_create(struct fdev *fdev, struct afb_apiset *apiset, struct afb_context *context, void (*cleanup)(void*), void *cleanup_closure)
 {
 	struct afb_ws_json1 *result;
 
-	assert(fd >= 0);
+	assert(fdev);
 	assert(context != NULL);
 
 	result = malloc(sizeof * result);
@@ -118,7 +119,7 @@ struct afb_ws_json1 *afb_ws_json1_create(int fd, struct afb_apiset *apiset, stru
 	if (result->session == NULL)
 		goto error2;
 
-	result->wsj1 = afb_wsj1_create(afb_systemd_get_event_loop(), fd, &wsj1_itf, result);
+	result->wsj1 = afb_wsj1_create(fdev, &wsj1_itf, result);
 	if (result->wsj1 == NULL)
 		goto error3;
 
@@ -126,7 +127,7 @@ struct afb_ws_json1 *afb_ws_json1_create(int fd, struct afb_apiset *apiset, stru
 	if (result->listener == NULL)
 		goto error4;
 
-	result->cred = afb_cred_create_for_socket(fd);
+	result->cred = afb_cred_create_for_socket(fdev_fd(fdev));
 	result->apiset = afb_apiset_addref(apiset);
 	return result;
 
@@ -137,7 +138,7 @@ error3:
 error2:
 	free(result);
 error:
-	close(fd);
+	fdev_unref(fdev);
 	return NULL;
 }
 
diff --git a/src/afb-ws-json1.h b/src/afb-ws-json1.h
index 96db1bc6..024dd8c0 100644
--- a/src/afb-ws-json1.h
+++ b/src/afb-ws-json1.h
@@ -20,8 +20,9 @@
 struct afb_ws_json1;
 struct afb_context;
 struct afb_apiset;
+struct fdev;
 
-extern struct afb_ws_json1 *afb_ws_json1_create(int fd, struct afb_apiset *apiset, struct afb_context *context, void (*cleanup)(void*), void *closure);
+extern struct afb_ws_json1 *afb_ws_json1_create(struct fdev *fdev, struct afb_apiset *apiset, struct afb_context *context, void (*cleanup)(void*), void *closure);
 extern struct afb_ws_json1 *afb_ws_json1_addref(struct afb_ws_json1 *ws);
 extern void afb_ws_json1_unref(struct afb_ws_json1 *ws);
 
diff --git a/src/afb-ws.c b/src/afb-ws.c
index c48a5e24..ef73addd 100644
--- a/src/afb-ws.c
+++ b/src/afb-ws.c
@@ -26,12 +26,9 @@
 #include <stdarg.h>
 #include <poll.h>
 
-#include <systemd/sd-event.h>
-
 #include "websock.h"
 #include "afb-ws.h"
-
-#include "afb-common.h"
+#include "fdev.h"
 
 /*
  * declaration of the websock interface for afb-ws
@@ -89,7 +86,7 @@ struct afb_ws
 	const struct afb_ws_itf *itf; /* the callback interface */
 	void *closure;		/* closure when calling the callbacks */
 	struct websock *ws;	/* the websock handler */
-	sd_event_source *evsrc;	/* the event source for the socket */
+	struct fdev *fdev;	/* the fdev for the socket */
 	struct buf buffer;	/* the last read fragment */
 };
 
@@ -123,8 +120,7 @@ static void aws_disconnect(struct afb_ws *ws, int call_on_hangup)
 	struct websock *wsi = ws->ws;
 	if (wsi != NULL) {
 		ws->ws = NULL;
-		sd_event_source_unref(ws->evsrc);
-		ws->evsrc = NULL;
+		fdev_unref(ws->fdev);
 		websock_destroy(wsi);
 		free(ws->buffer.buffer);
 		ws->state = waiting;
@@ -133,13 +129,12 @@ static void aws_disconnect(struct afb_ws *ws, int call_on_hangup)
 	}
 }
 
-static int io_event_callback(sd_event_source *src, int fd, uint32_t revents, void *ws)
+static void fdevcb(void *ws, uint32_t revents, struct fdev *fdev)
 {
 	if ((revents & EPOLLIN) != 0)
 		aws_on_readable(ws);
 	if ((revents & EPOLLHUP) != 0)
 		afb_ws_hangup(ws);
-	return 0;
 }
 
 /*
@@ -151,12 +146,11 @@ static int io_event_callback(sd_event_source *src, int fd, uint32_t revents, voi
  *
  * Returns the handle for the afb_ws created or NULL on error.
  */
-struct afb_ws *afb_ws_create(struct sd_event *eloop, int fd, const struct afb_ws_itf *itf, void *closure)
+struct afb_ws *afb_ws_create(struct fdev *fdev, const struct afb_ws_itf *itf, void *closure)
 {
-	int rc;
 	struct afb_ws *result;
 
-	assert(fd >= 0);
+	assert(fdev);
 
 	/* allocation */
 	result = malloc(sizeof * result);
@@ -164,7 +158,8 @@ struct afb_ws *afb_ws_create(struct sd_event *eloop, int fd, const struct afb_ws
 		goto error;
 
 	/* init */
-	result->fd = fd;
+	result->fdev = fdev;
+	result->fd = fdev_fd(fdev);
 	result->state = waiting;
 	result->itf = itf;
 	result->closure = closure;
@@ -176,19 +171,15 @@ struct afb_ws *afb_ws_create(struct sd_event *eloop, int fd, const struct afb_ws
 	if (result->ws == NULL)
 		goto error2;
 
-	/* creates the evsrc */
-	rc = sd_event_add_io(eloop, &result->evsrc, result->fd, EPOLLIN, io_event_callback, result);
-	if (rc < 0) {
-		errno = -rc;
-		goto error3;
-	}
+	/* finalize */
+	fdev_set_events(fdev, EPOLLIN);
+	fdev_set_callback(fdev, fdevcb, result);
 	return result;
 
-error3:
-	websock_destroy(result->ws);
 error2:
 	free(result);
 error:
+	fdev_unref(fdev);
 	return NULL;
 }
 
diff --git a/src/afb-ws.h b/src/afb-ws.h
index 4b26f0b9..0af236ef 100644
--- a/src/afb-ws.h
+++ b/src/afb-ws.h
@@ -18,7 +18,7 @@
 #pragma once
 
 struct afb_ws;
-struct sd_event;
+struct fdev;
 struct iovec;
 
 struct afb_ws_itf
@@ -30,7 +30,7 @@ struct afb_ws_itf
 	void (*on_hangup) (void *); /* optional, it is safe too call afb_ws_destroy within the callback */
 };
 
-extern struct afb_ws *afb_ws_create(struct sd_event *eloop, int fd, const struct afb_ws_itf *itf, void *closure);
+extern struct afb_ws *afb_ws_create(struct fdev *fdev, const struct afb_ws_itf *itf, void *closure);
 extern void afb_ws_destroy(struct afb_ws *ws);
 extern void afb_ws_hangup(struct afb_ws *ws);
 extern int afb_ws_is_connected(struct afb_ws *ws);
diff --git a/src/afb-wsj1.c b/src/afb-wsj1.c
index be961f51..3876c322 100644
--- a/src/afb-wsj1.c
+++ b/src/afb-wsj1.c
@@ -29,6 +29,7 @@
 
 #include "afb-ws.h"
 #include "afb-wsj1.h"
+#include "fdev.h"
 
 #define CALL 2
 #define RETOK 3
@@ -81,12 +82,11 @@ struct afb_wsj1
 	pthread_mutex_t mutex;
 };
 
-struct afb_wsj1 *afb_wsj1_create(struct sd_event *eloop, int fd, struct afb_wsj1_itf *itf, void *closure)
+struct afb_wsj1 *afb_wsj1_create(struct fdev *fdev, struct afb_wsj1_itf *itf, void *closure)
 {
 	struct afb_wsj1 *result;
 
-	assert(eloop);
-	assert(fd >= 0);
+	assert(fdev);
 	assert(itf);
 	assert(itf->on_call);
 
@@ -103,7 +103,7 @@ struct afb_wsj1 *afb_wsj1_create(struct sd_event *eloop, int fd, struct afb_wsj1
 	if (result->tokener == NULL)
 		goto error2;
 
-	result->ws = afb_ws_create(eloop, fd, &wsj1_itf, result);
+	result->ws = afb_ws_create(fdev, &wsj1_itf, result);
 	if (result->ws == NULL)
 		goto error3;
 
@@ -114,7 +114,7 @@ error3:
 error2:
 	free(result);
 error:
-	close(fd);
+	fdev_unref(fdev);
 	return NULL;
 }
 
diff --git a/src/afb-wsj1.h b/src/afb-wsj1.h
index 7e318f6f..86c7cfdb 100644
--- a/src/afb-wsj1.h
+++ b/src/afb-wsj1.h
@@ -21,7 +21,7 @@ struct afb_wsj1;
 struct afb_wsj1_msg;
 
 struct json_object;
-struct sd_event;
+struct fdev;
 
 /*
  * Interface for callback functions.
@@ -48,13 +48,11 @@ struct afb_wsj1_itf {
 };
 
 /*
- * Creates the afb_wsj1 socket connected to the file descriptor 'fd'
+ * Creates the afb_wsj1 socket connected to the file descriptor 'fdev'
  * and having the callback interface defined by 'itf' for the 'closure'.
- * When the creation is a success, the systemd event loop 'eloop' is
- * used for handling event for 'fd'.
  * Returns the created wsj1 websocket or NULL in case of error.
  */
-extern struct afb_wsj1 *afb_wsj1_create(struct sd_event *eloop, int fd, struct afb_wsj1_itf *itf, void *closure);
+extern struct afb_wsj1 *afb_wsj1_create(struct fdev *fdev, struct afb_wsj1_itf *itf, void *closure);
 
 /*
  * Increases by one the count of reference to 'wsj1'
diff --git a/src/afs-supervisor.c b/src/afs-supervisor.c
index be0cdbf5..1e92b9f3 100644
--- a/src/afs-supervisor.c
+++ b/src/afs-supervisor.c
@@ -45,6 +45,7 @@
 #include "afb-api-so-v2.h"
 #include "afb-api-ws.h"
 #include "afb-apiset.h"
+#include "afb-fdev.h"
 #include "jobs.h"
 #include "verbose.h"
 #include "wrap-json.h"
@@ -193,13 +194,20 @@ static void on_supervised_hangup(struct afb_stub_ws *stub)
 static int make_supervised(int fd, struct afb_cred *cred)
 {
 	struct supervised *s;
+	struct fdev *fdev;
 
 	s = malloc(sizeof *s);
 	if (!s)
 		return -1;
 
+	fdev = afb_fdev_create(fd);
+	if (!fdev) {
+		free(s);
+		return -1;
+	}
+
 	s->cred = cred;
-	s->stub = afb_stub_ws_create_client(fd, supervision_apiname, empty_apiset);
+	s->stub = afb_stub_ws_create_client(fdev, supervision_apiname, empty_apiset);
 	if (!s->stub) {
 		free(s);
 		return -1;
diff --git a/src/fdev-epoll.c b/src/fdev-epoll.c
new file mode 100644
index 00000000..80c037d0
--- /dev/null
+++ b/src/fdev-epoll.c
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <errno.h>
+#include <unistd.h>
+#include <sys/epoll.h>
+
+#define FDEV_PROVIDER
+#include "fdev.h"
+#include "fdev-epoll.h"
+
+#define epollfd(fdev_epoll)  ((int)(intptr_t)fdev_epoll)
+
+static void disable(void *closure, const struct fdev *fdev)
+{
+	struct fdev_epoll *fdev_epoll = closure;
+	epoll_ctl(epollfd(fdev_epoll), EPOLL_CTL_DEL, fdev_fd(fdev), 0);
+}
+
+static void enable(void *closure, const struct fdev *fdev)
+{
+	struct fdev_epoll *fdev_epoll = closure;
+	struct epoll_event event;
+	int rc, fd;
+
+	fd = fdev_fd(fdev);
+	event.events = fdev_events(fdev);
+	event.data.ptr = (void*)fdev;
+	rc = epoll_ctl(epollfd(fdev_epoll), EPOLL_CTL_MOD, fd, &event);
+	if (rc < 0 && errno == ENOENT)
+		epoll_ctl(epollfd(fdev_epoll), EPOLL_CTL_ADD, fd, &event);
+}
+
+static struct fdev_itf itf =
+{
+	.unref = 0,
+	.disable = disable,
+	.enable = enable
+};
+
+struct fdev_epoll *fdev_epoll_create()
+{
+	int fd = epoll_create1(EPOLL_CLOEXEC);
+	if (!fd) {
+		fd = dup(fd);
+		close(0);
+	}
+	return fd < 0 ? 0 : (struct fdev_epoll*)(intptr_t)fd;
+}
+
+void fdev_epoll_destroy(struct fdev_epoll *fdev_epoll)
+{
+	close(epollfd(fdev_epoll));
+}
+
+int fdev_epoll_fd(struct fdev_epoll *fdev_epoll)
+{
+	return epollfd(fdev_epoll);
+}
+
+struct fdev *fdev_epoll_add(struct fdev_epoll *fdev_epoll, int fd)
+{
+	struct fdev *fdev;
+
+	fdev = fdev_create(fd);
+	if (fdev)
+		fdev_set_itf(fdev, &itf, fdev_epoll);
+	return fdev;
+}
+
+void fdev_epoll_wait_and_dispatch(struct fdev_epoll *fdev_epoll, int timeout_ms)
+{
+	struct fdev *fdev;
+	struct epoll_event events[8];
+	int rc, i;
+
+	rc = epoll_wait(epollfd(fdev_epoll), events, sizeof events / sizeof *events, timeout_ms < 0 ? -1 : timeout_ms);
+	for (i = 0 ; i < rc ; i++) {
+		fdev = events[i].data.ptr;
+		fdev_dispatch(fdev, events[i].events);
+	}
+}
+
diff --git a/src/fdev-epoll.h b/src/fdev-epoll.h
new file mode 100644
index 00000000..53d02e72
--- /dev/null
+++ b/src/fdev-epoll.h
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+struct fdev;
+struct fdev_epoll;
+
+extern struct fdev_epoll *fdev_epoll_create();
+extern void fdev_epoll_destroy(struct fdev_epoll *fdev_epoll);
+extern int fdev_epoll_fd(struct fdev_epoll *fdev_epoll);
+extern struct fdev *fdev_epoll_add(struct fdev_epoll *fdev_epoll, int fd);
+extern void fdev_epoll_wait_and_dispatch(struct fdev_epoll *fdev_epoll, int timeout_ms);
+
diff --git a/src/fdev-systemd.c b/src/fdev-systemd.c
new file mode 100644
index 00000000..0f4a03cd
--- /dev/null
+++ b/src/fdev-systemd.c
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <errno.h>
+
+#include <systemd/sd-event.h>
+
+#define FDEV_PROVIDER
+#include "fdev.h"
+#include "fdev-systemd.h"
+
+static int handler(sd_event_source *s, int fd, uint32_t revents, void *userdata)
+{
+	struct fdev *fdev = userdata;
+	fdev_dispatch(fdev, revents);
+	return 0;
+}
+
+static void unref(void *closure)
+{
+	sd_event_source *source = closure;
+	sd_event_source_unref(source);
+}
+
+static void disable(void *closure, const struct fdev *fdev)
+{
+	sd_event_source *source = closure;
+	sd_event_source_set_enabled(source, SD_EVENT_OFF);
+}
+
+static void enable(void *closure, const struct fdev *fdev)
+{
+	sd_event_source *source = closure;
+	sd_event_source_set_io_events(source, fdev_events(fdev));
+	sd_event_source_set_enabled(source, SD_EVENT_ON);
+}
+
+static struct fdev_itf itf =
+{
+	.unref = unref,
+	.disable = disable,
+	.enable = enable
+};
+
+struct fdev *fdev_systemd_create(struct sd_event *eloop, int fd)
+{
+	int rc;
+	sd_event_source *source;
+	struct fdev *fdev;
+
+	fdev = fdev_create(fd);
+	if (fdev) {
+		rc = sd_event_add_io(eloop, &source, fd, 0, handler, fdev);
+		if (rc < 0) {
+			fdev_unref(fdev);
+			fdev = 0;
+			errno = -rc;
+		} else {
+			sd_event_source_set_enabled(source, SD_EVENT_OFF);
+			fdev_set_itf(fdev, &itf, source);
+		}
+	}
+	return fdev;
+}
+
diff --git a/src/fdev-systemd.h b/src/fdev-systemd.h
new file mode 100644
index 00000000..99ea5f1f
--- /dev/null
+++ b/src/fdev-systemd.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+struct fdev;
+struct sd_event;
+
+extern struct fdev *fdev_systemd_create(struct sd_event *eloop, int fd);
diff --git a/src/fdev.c b/src/fdev.c
new file mode 100644
index 00000000..5c31d31b
--- /dev/null
+++ b/src/fdev.c
@@ -0,0 +1,158 @@
+/*
+ * Copyright (C) 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+#define FDEV_PROVIDER
+#include "fdev.h"
+
+struct fdev
+{
+	int fd;
+	uint32_t events;
+	int repeat;
+	unsigned refcount;
+	struct fdev_itf *itf;
+	void *closure_itf;
+	void (*callback)(void*,uint32_t,struct fdev*);
+	void *closure_callback;
+};
+
+struct fdev *fdev_create(int fd)
+{
+	struct fdev *fdev;
+
+	fdev = calloc(1, sizeof *fdev);
+	if (!fdev)
+		errno = ENOMEM;
+	else {
+		fdev->fd = fd;
+		fdev->refcount = 3; /* set autoclose by default */
+		fdev->repeat = -1;
+	}
+	return fdev;
+}
+
+void fdev_set_itf(struct fdev *fdev, struct fdev_itf *itf, void *closure_itf)
+{
+	fdev->itf = itf;
+	fdev->closure_itf = closure_itf;
+}
+
+void fdev_dispatch(struct fdev *fdev, uint32_t events)
+{
+	if (fdev->repeat > 0 && !--fdev->repeat && fdev->itf)
+		fdev->itf->disable(fdev->closure_itf, fdev);
+	if (fdev->callback)
+		fdev->callback(fdev->closure_callback, events, fdev);
+}
+
+struct fdev *fdev_addref(struct fdev *fdev)
+{
+	if (fdev)
+		__atomic_add_fetch(&fdev->refcount, 2, __ATOMIC_RELAXED);
+	return fdev;
+}
+
+void fdev_unref(struct fdev *fdev)
+{
+	if (fdev && __atomic_sub_fetch(&fdev->refcount, 2, __ATOMIC_RELAXED) <= 1) {
+		if (fdev->itf) {
+			fdev->itf->disable(fdev->closure_itf, fdev);
+			fdev->itf->unref(fdev->closure_itf);
+		}
+		if (fdev->refcount)
+			close(fdev->fd);
+		free(fdev);
+	}
+}
+
+int fdev_fd(const struct fdev *fdev)
+{
+	return fdev->fd;
+}
+
+uint32_t fdev_events(const struct fdev *fdev)
+{
+	return fdev->events;
+}
+
+int fdev_repeat(const struct fdev *fdev)
+{
+	return fdev->repeat;
+}
+
+int fdev_autoclose(const struct fdev *fdev)
+{
+	return 1 & fdev->refcount;
+}
+
+static inline int is_active(struct fdev *fdev)
+{
+	return fdev->repeat && fdev->callback;
+}
+
+static inline void update_activity(struct fdev *fdev, int old_active)
+{
+	if (is_active(fdev)) {
+		if (!old_active)
+			fdev->itf->enable(fdev->closure_itf, fdev);
+	} else {
+		if (old_active)
+			fdev->itf->disable(fdev->closure_itf, fdev);
+	}
+}
+
+void fdev_set_callback(struct fdev *fdev, void (*callback)(void*,uint32_t,struct fdev*), void *closure)
+{
+	int oa;
+
+	oa = is_active(fdev);
+	fdev->callback = callback;
+	fdev->closure_callback = closure;
+	update_activity(fdev, oa);
+}
+
+void fdev_set_events(struct fdev *fdev, uint32_t events)
+{
+	if (events != fdev->events) {
+		fdev->events = events;
+		if (is_active(fdev))
+			fdev->itf->enable(fdev->closure_itf, fdev);
+	}
+}
+
+void fdev_set_repeat(struct fdev *fdev, int count)
+{
+	int oa;
+
+	oa = is_active(fdev);
+	fdev->repeat = count;
+	update_activity(fdev, oa);
+}
+
+void fdev_set_autoclose(struct fdev *fdev, int autoclose)
+{
+	if (autoclose)
+		fdev->refcount |= 1;
+	else
+		fdev->refcount &= -2;
+}
+
diff --git a/src/fdev.h b/src/fdev.h
new file mode 100644
index 00000000..9fbcb759
--- /dev/null
+++ b/src/fdev.h
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2018 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <sys/epoll.h>
+
+struct fdev;
+
+#if defined(FDEV_PROVIDER)
+struct fdev_itf
+{
+	void (*unref)(void *closure);
+	void (*disable)(void *closure, const struct fdev *fdev);
+	void (*enable)(void *closure, const struct fdev *fdev);
+};
+
+extern struct fdev *fdev_create(int fd);
+extern void fdev_set_itf(struct fdev *fdev, struct fdev_itf *itf, void *closure_itf);
+extern void fdev_dispatch(struct fdev *fdev, uint32_t events);
+#endif
+
+extern struct fdev *fdev_addref(struct fdev *fdev);
+extern void fdev_unref(struct fdev *fdev);
+
+extern int fdev_fd(const struct fdev *fdev);
+extern uint32_t fdev_events(const struct fdev *fdev);
+extern int fdev_repeat(const struct fdev *fdev);
+extern int fdev_autoclose(const struct fdev *fdev);
+
+extern void fdev_set_callback(struct fdev *fdev, void (*callback)(void*,uint32_t,struct fdev*), void *closure);
+extern void fdev_set_events(struct fdev *fdev, uint32_t events);
+extern void fdev_set_repeat(struct fdev *fdev, int count);
+extern void fdev_set_autoclose(struct fdev *fdev, int autoclose);