Centralized thread cancellation in processor_t

This ensures that no threads are active when plugins and the rest of the
daemon are unloaded.

callback_job_t was simplified a lot in the process as its main
functionality is now contained in processor_t.  The parent-child
relationships were abandoned as these were only needed to simplify job
cancellation.

31 files changed, 261 insertions, 475 deletions

diff --git a/src/charon-nm/nm/nm_backend.c b/src/charon-nm/nm/nm_backend.c
index 19382a028..19d095935 100644
--- a/src/charon-nm/nm/nm_backend.c
+++ b/src/charon-nm/nm/nm_backend.c
@@ -67,6 +67,22 @@ static job_requeue_t run(nm_backend_t *this)
 	return JOB_REQUEUE_NONE;
 }
 
+/**
+ * Cancel the GLib Main Event Loop
+ */
+static bool cancel(nm_backend_t *this)
+{
+	if (this->loop)
+	{
+		if (g_main_loop_is_running(this->loop))
+		{
+			g_main_loop_quit(this->loop);
+		}
+		g_main_loop_unref(this->loop);
+	}
+	return TRUE;
+}
+
 /*
  * see header file
  */
@@ -78,14 +94,6 @@ void nm_backend_deinit()
 	{
 		return;
 	}
-	if (this->loop)
-	{
-		if (g_main_loop_is_running(this->loop))
-		{
-			g_main_loop_quit(this->loop);
-		}
-		g_main_loop_unref(this->loop);
-	}
 	if (this->plugin)
 	{
 		g_object_unref(this->plugin);
@@ -132,8 +140,8 @@ bool nm_backend_init()
 	charon->keep_cap(charon, CAP_DAC_OVERRIDE);
 
 	lib->processor->queue_job(lib->processor,
-				(job_t*)callback_job_create_with_prio((callback_job_cb_t)run,
-										this, NULL, NULL, JOB_PRIO_CRITICAL));
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)run, this,
+				NULL, (callback_job_cancel_t)cancel, JOB_PRIO_CRITICAL));
 	return TRUE;
 }
 
diff --git a/src/libcharon/daemon.c b/src/libcharon/daemon.c
index 60a32339d..8a4b3906f 100644
--- a/src/libcharon/daemon.c
+++ b/src/libcharon/daemon.c
@@ -113,6 +113,10 @@ static void destroy(private_daemon_t *this)
 	{
 		this->public.sender->flush(this->public.sender);
 	}
+
+	/* cancel all threads and wait for their termination */
+	lib->processor->cancel(lib->processor);
+
 	DESTROY_IF(this->public.receiver);
 #ifdef ME
 	DESTROY_IF(this->public.connect_manager);
@@ -120,7 +124,6 @@ static void destroy(private_daemon_t *this)
 #endif /* ME */
 	/* make sure the cache is clear before unloading plugins */
 	lib->credmgr->flush_cache(lib->credmgr, CERT_ANY);
-	/* unload plugins to release threads */
 	lib->plugins->unload(lib->plugins);
 #ifdef CAPABILITIES_LIBCAP
 	cap_free(this->caps);
diff --git a/src/libcharon/network/receiver.c b/src/libcharon/network/receiver.c
index 1e00eb239..f0cb0b2d1 100644
--- a/src/libcharon/network/receiver.c
+++ b/src/libcharon/network/receiver.c
@@ -55,11 +55,6 @@ struct private_receiver_t {
 	receiver_t public;
 
 	/**
-	 * Threads job receiving packets
-	 */
-	callback_job_t *job;
-
-	/**
 	 * current secret to use for cookie calculation
 	 */
 	char secret[SECRET_LENGTH];
@@ -393,8 +388,6 @@ static job_requeue_t receive_packets(private_receiver_t *this)
 	status = charon->socket->receive(charon->socket, &packet);
 	if (status == NOT_SUPPORTED)
 	{
-		/* the processor destroys this job  */
-		this->job = NULL;
 		return JOB_REQUEUE_NONE;
 	}
 	else if (status != SUCCESS)
@@ -504,10 +497,6 @@ static job_requeue_t receive_packets(private_receiver_t *this)
 METHOD(receiver_t, destroy, void,
 	private_receiver_t *this)
 {
-	if (this->job)
-	{
-		this->job->cancel(this->job);
-	}
 	this->rng->destroy(this->rng);
 	this->hasher->destroy(this->hasher);
 	free(this);
@@ -568,9 +557,9 @@ receiver_t *receiver_create()
 	this->rng->get_bytes(this->rng, SECRET_LENGTH, this->secret);
 	memcpy(this->secret_old, this->secret, SECRET_LENGTH);
 
-	this->job = callback_job_create_with_prio((callback_job_cb_t)receive_packets,
-										this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)receive_packets,
+			this, NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
 	return &this->public;
 }
diff --git a/src/libcharon/network/sender.c b/src/libcharon/network/sender.c
index dc2641f7f..75635d2e3 100644
--- a/src/libcharon/network/sender.c
+++ b/src/libcharon/network/sender.c
@@ -39,11 +39,6 @@ struct private_sender_t {
 	sender_t public;
 
 	/**
-	 * Sender threads job.
-	 */
-	callback_job_t *job;
-
-	/**
 	 * The packets are stored in a linked list
 	 */
 	linked_list_t *list;
@@ -164,7 +159,6 @@ METHOD(sender_t, flush, void,
 METHOD(sender_t, destroy, void,
 	private_sender_t *this)
 {
-	this->job->cancel(this->job);
 	this->list->destroy_offset(this->list, offsetof(packet_t, destroy));
 	this->got->destroy(this->got);
 	this->sent->destroy(this->sent);
@@ -189,8 +183,6 @@ sender_t * sender_create()
 		.mutex = mutex_create(MUTEX_TYPE_DEFAULT),
 		.got = condvar_create(CONDVAR_TYPE_DEFAULT),
 		.sent = condvar_create(CONDVAR_TYPE_DEFAULT),
-		.job = callback_job_create_with_prio((callback_job_cb_t)send_packets,
-										this, NULL, NULL, JOB_PRIO_CRITICAL),
 		.send_delay = lib->settings->get_int(lib->settings,
 								"%s.send_delay", 0, charon->name),
 		.send_delay_type = lib->settings->get_int(lib->settings,
@@ -201,7 +193,9 @@ sender_t * sender_create()
 								"%s.send_delay_response", TRUE, charon->name),
 	);
 
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)send_packets,
+			this, NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
 	return &this->public;
 }
diff --git a/src/libcharon/plugins/android/android_service.c b/src/libcharon/plugins/android/android_service.c
index f4e7e5097..6ca7407ca 100644
--- a/src/libcharon/plugins/android/android_service.c
+++ b/src/libcharon/plugins/android/android_service.c
@@ -42,11 +42,6 @@ struct private_android_service_t {
 	ike_sa_t *ike_sa;
 
 	/**
-	 * job that handles requests from the Android control socket
-	 */
-	callback_job_t *job;
-
-	/**
 	 * android credentials
 	 */
 	android_creds_t *creds;
@@ -384,9 +379,9 @@ android_service_t *android_service_create(android_creds_t *creds)
 	}
 
 	charon->bus->add_listener(charon->bus, &this->public.listener);
-	this->job = callback_job_create((callback_job_cb_t)initiate, this,
-									NULL, NULL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create((callback_job_cb_t)initiate, this,
+									NULL, NULL));
 
 	return &this->public;
 }
diff --git a/src/libcharon/plugins/dhcp/dhcp_socket.c b/src/libcharon/plugins/dhcp/dhcp_socket.c
index 091d91c2d..b4e9af788 100644
--- a/src/libcharon/plugins/dhcp/dhcp_socket.c
+++ b/src/libcharon/plugins/dhcp/dhcp_socket.c
@@ -105,11 +105,6 @@ struct private_dhcp_socket_t {
 	 * DHCP server address, or broadcast
 	 */
 	host_t *dst;
-
-	/**
-	 * Callback job receiving DHCP responses
-	 */
-	callback_job_t *job;
 };
 
 /**
@@ -613,10 +608,6 @@ static job_requeue_t receive_dhcp(private_dhcp_socket_t *this)
 METHOD(dhcp_socket_t, destroy, void,
 	private_dhcp_socket_t *this)
 {
-	if (this->job)
-	{
-		this->job->cancel(this->job);
-	}
 	while (this->waiting)
 	{
 		this->condvar->signal(this->condvar);
@@ -761,9 +752,9 @@ dhcp_socket_t *dhcp_socket_create()
 		return NULL;
 	}
 
-	this->job = callback_job_create_with_prio((callback_job_cb_t)receive_dhcp,
-									this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)receive_dhcp,
+			this, NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
 	return &this->public;
 }
diff --git a/src/libcharon/plugins/duplicheck/duplicheck_notify.c b/src/libcharon/plugins/duplicheck/duplicheck_notify.c
index b86f1ef3d..3da640efe 100644
--- a/src/libcharon/plugins/duplicheck/duplicheck_notify.c
+++ b/src/libcharon/plugins/duplicheck/duplicheck_notify.c
@@ -43,11 +43,6 @@ struct private_duplicheck_notify_t {
 	duplicheck_notify_t public;
 
 	/**
-	 * Callback job dispatching connections
-	 */
-	callback_job_t *job;
-
-	/**
 	 * Mutex to lock list
 	 */
 	mutex_t *mutex;
@@ -167,10 +162,6 @@ METHOD(duplicheck_notify_t, destroy, void,
 	enumerator_t *enumerator;
 	uintptr_t fd;
 
-	if (this->job)
-	{
-		this->job->cancel(this->job);
-	}
 	enumerator = this->connected->create_enumerator(this->connected);
 	while (enumerator->enumerate(enumerator, &fd))
 	{
@@ -203,9 +194,9 @@ duplicheck_notify_t *duplicheck_notify_create()
 		destroy(this);
 		return NULL;
 	}
-	this->job = callback_job_create_with_prio((callback_job_cb_t)receive,
-									this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)receive, this,
+				NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
 	return &this->public;
 }
diff --git a/src/libcharon/plugins/eap_radius/eap_radius_dae.c b/src/libcharon/plugins/eap_radius/eap_radius_dae.c
index 967c731bf..80da99a0f 100644
--- a/src/libcharon/plugins/eap_radius/eap_radius_dae.c
+++ b/src/libcharon/plugins/eap_radius/eap_radius_dae.c
@@ -53,11 +53,6 @@ struct private_eap_radius_dae_t {
 	int fd;
 
 	/**
-	 * Listen job
-	 */
-	callback_job_t *job;
-
-	/**
 	 * RADIUS shared secret for DAE exchanges
 	 */
 	chunk_t secret;
@@ -481,10 +476,6 @@ static bool open_socket(private_eap_radius_dae_t *this)
 METHOD(eap_radius_dae_t, destroy, void,
 	private_eap_radius_dae_t *this)
 {
-	if (this->job)
-	{
-		this->job->cancel(this->job);
-	}
 	if (this->fd != -1)
 	{
 		close(this->fd);
@@ -538,9 +529,9 @@ eap_radius_dae_t *eap_radius_dae_create(eap_radius_accounting_t *accounting)
 		return NULL;
 	}
 
-	this->job = callback_job_create_with_prio((callback_job_cb_t)receive,
-										this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)receive,
+			this, NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
 	return &this->public;
 }
diff --git a/src/libcharon/plugins/farp/farp_spoofer.c b/src/libcharon/plugins/farp/farp_spoofer.c
index 587a3a74e..52b037c19 100644
--- a/src/libcharon/plugins/farp/farp_spoofer.c
+++ b/src/libcharon/plugins/farp/farp_spoofer.c
@@ -45,11 +45,6 @@ struct private_farp_spoofer_t {
 	farp_listener_t *listener;
 
 	/**
-	 * Callback job to read ARP requests
-	 */
-	callback_job_t *job;
-
-	/**
 	 * RAW socket for ARP requests
 	 */
 	int skt;
@@ -135,7 +130,6 @@ static job_requeue_t receive_arp(private_farp_spoofer_t *this)
 METHOD(farp_spoofer_t, destroy, void,
 	private_farp_spoofer_t *this)
 {
-	this->job->cancel(this->job);
 	close(this->skt);
 	free(this);
 }
@@ -189,9 +183,9 @@ farp_spoofer_t *farp_spoofer_create(farp_listener_t *listener)
 		return NULL;
 	}
 
-	this->job = callback_job_create_with_prio((callback_job_cb_t)receive_arp,
-									this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)receive_arp,
+			this, NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
 	return &this->public;
 }
diff --git a/src/libcharon/plugins/ha/ha_ctl.c b/src/libcharon/plugins/ha/ha_ctl.c
index 9c99807ed..32f7d04d9 100644
--- a/src/libcharon/plugins/ha/ha_ctl.c
+++ b/src/libcharon/plugins/ha/ha_ctl.c
@@ -48,11 +48,6 @@ struct private_ha_ctl_t {
 	 * Resynchronization message cache
 	 */
 	ha_cache_t *cache;
-
-	/**
-	 * FIFO reader thread
-	 */
-	callback_job_t *job;
 };
 
 /**
@@ -105,7 +100,6 @@ static job_requeue_t dispatch_fifo(private_ha_ctl_t *this)
 METHOD(ha_ctl_t, destroy, void,
 	private_ha_ctl_t *this)
 {
-	this->job->cancel(this->job);
 	free(this);
 }
 
@@ -141,9 +135,9 @@ ha_ctl_t *ha_ctl_create(ha_segments_t *segments, ha_cache_t *cache)
 			 strerror(errno));
 	}
 
-	this->job = callback_job_create_with_prio((callback_job_cb_t)dispatch_fifo,
-										this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)dispatch_fifo,
+			this, NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 	return &this->public;
 }
 
diff --git a/src/libcharon/plugins/ha/ha_dispatcher.c b/src/libcharon/plugins/ha/ha_dispatcher.c
index de5253b37..98055fa7e 100644
--- a/src/libcharon/plugins/ha/ha_dispatcher.c
+++ b/src/libcharon/plugins/ha/ha_dispatcher.c
@@ -58,11 +58,6 @@ struct private_ha_dispatcher_t {
 	 * HA enabled pool
 	 */
 	ha_attribute_t *attr;
-
-	/**
-	 * Dispatcher job
-	 */
-	callback_job_t *job;
 };
 
 /**
@@ -1032,7 +1027,6 @@ static job_requeue_t dispatch(private_ha_dispatcher_t *this)
 METHOD(ha_dispatcher_t, destroy, void,
 	private_ha_dispatcher_t *this)
 {
-	this->job->cancel(this->job);
 	free(this);
 }
 
@@ -1056,9 +1050,9 @@ ha_dispatcher_t *ha_dispatcher_create(ha_socket_t *socket,
 		.kernel = kernel,
 		.attr = attr,
 	);
-	this->job = callback_job_create_with_prio((callback_job_cb_t)dispatch,
-										this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)dispatch, this,
+				NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
 	return &this->public;
 }
diff --git a/src/libcharon/plugins/ha/ha_segments.c b/src/libcharon/plugins/ha/ha_segments.c
index f947970b5..01792624c 100644
--- a/src/libcharon/plugins/ha/ha_segments.c
+++ b/src/libcharon/plugins/ha/ha_segments.c
@@ -62,11 +62,6 @@ struct private_ha_segments_t {
 	condvar_t *condvar;
 
 	/**
-	 * Job checking for heartbeats
-	 */
-	callback_job_t *job;
-
-	/**
 	 * Total number of ClusterIP segments
 	 */
 	u_int count;
@@ -82,6 +77,11 @@ struct private_ha_segments_t {
 	u_int node;
 
 	/**
+	 * Are we checking for heartbeats?
+	 */
+	bool heartbeat_active;
+
+	/**
 	 * Interval we send hearbeats
 	 */
 	int heartbeat_delay;
@@ -237,7 +237,7 @@ METHOD(listener_t, alert_hook, bool,
 {
 	if (alert == ALERT_SHUTDOWN_SIGNAL)
 	{
-		if (this->job)
+		if (this->heartbeat_active)
 		{
 			DBG1(DBG_CFG, "HA heartbeat active, dropping all segments");
 			deactivate(this, 0, TRUE);
@@ -269,7 +269,7 @@ static job_requeue_t watchdog(private_ha_segments_t *this)
 		DBG1(DBG_CFG, "no heartbeat received, taking all segments");
 		activate(this, 0, TRUE);
 		/* disable heartbeat detection util we get one */
-		this->job = NULL;
+		this->heartbeat_active = FALSE;
 		return JOB_REQUEUE_NONE;
 	}
 	return JOB_REQUEUE_DIRECT;
@@ -280,9 +280,10 @@ static job_requeue_t watchdog(private_ha_segments_t *this)
  */
 static void start_watchdog(private_ha_segments_t *this)
 {
-	this->job = callback_job_create_with_prio((callback_job_cb_t)watchdog,
-									this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	this->heartbeat_active = TRUE;
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)watchdog, this,
+				NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 }
 
 METHOD(ha_segments_t, handle_status, void,
@@ -312,10 +313,10 @@ METHOD(ha_segments_t, handle_status, void,
 		}
 	}
 
-	this->mutex->unlock(this->mutex);
 	this->condvar->signal(this->condvar);
+	this->mutex->unlock(this->mutex);
 
-	if (!this->job)
+	if (!this->heartbeat_active)
 	{
 		DBG1(DBG_CFG, "received heartbeat, reenabling watchdog");
 		start_watchdog(this);
@@ -361,10 +362,6 @@ METHOD(ha_segments_t, is_active, bool,
 METHOD(ha_segments_t, destroy, void,
 	private_ha_segments_t *this)
 {
-	if (this->job)
-	{
-		this->job->cancel(this->job);
-	}
 	this->mutex->destroy(this->mutex);
 	this->condvar->destroy(this->condvar);
 	free(this);
diff --git a/src/libcharon/plugins/maemo/maemo_service.c b/src/libcharon/plugins/maemo/maemo_service.c
index 0e834918e..b5f50f1c6 100644
--- a/src/libcharon/plugins/maemo/maemo_service.c
+++ b/src/libcharon/plugins/maemo/maemo_service.c
@@ -431,8 +431,10 @@ static job_requeue_t run(private_maemo_service_t *this)
 	return JOB_REQUEUE_NONE;
 }
 
-METHOD(maemo_service_t, destroy, void,
-	   private_maemo_service_t *this)
+/**
+ * Cancel the GLib Main Event Loop
+ */
+static bool cancel(private_maemo_service_t *this)
 {
 	if (this->loop)
 	{
@@ -442,6 +444,12 @@ METHOD(maemo_service_t, destroy, void,
 		}
 		g_main_loop_unref(this->loop);
 	}
+	return TRUE;
+}
+
+METHOD(maemo_service_t, destroy, void,
+	   private_maemo_service_t *this)
+{
 	if (this->context)
 	{
 		osso_rpc_unset_cb_f(this->context,
@@ -510,8 +518,8 @@ maemo_service_t *maemo_service_create()
 	}
 
 	lib->processor->queue_job(lib->processor,
-				(job_t*)callback_job_create_with_prio((callback_job_cb_t)run,
-										this, NULL, NULL, JOB_PRIO_CRITICAL));
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)run, this,
+				NULL, (callback_job_cancel_t)cancel, JOB_PRIO_CRITICAL));
 
 	return &this->public;
 }
diff --git a/src/libcharon/plugins/smp/smp.c b/src/libcharon/plugins/smp/smp.c
index 7fdbdbae4..870f0a022 100644
--- a/src/libcharon/plugins/smp/smp.c
+++ b/src/libcharon/plugins/smp/smp.c
@@ -49,11 +49,6 @@ struct private_smp_t {
 	 * XML unix socket fd
 	 */
 	int socket;
-
-	/**
-	 * job accepting stroke messages
-	 */
-	callback_job_t *job;
 };
 
 ENUM(ike_sa_state_lower_names, IKE_CREATED, IKE_DELETING,
@@ -704,7 +699,8 @@ static job_requeue_t dispatch(private_smp_t *this)
 
 	fdp = malloc_thing(int);
 	*fdp = fd;
-	job = callback_job_create((callback_job_cb_t)process, fdp, free, this->job);
+	job = callback_job_create((callback_job_cb_t)process, fdp, free,
+							  (callback_job_cancel_t)return_false);
 	lib->processor->queue_job(lib->processor, (job_t*)job);
 
 	return JOB_REQUEUE_DIRECT;
@@ -719,7 +715,6 @@ METHOD(plugin_t, get_name, char*,
 METHOD(plugin_t, destroy, void,
 	private_smp_t *this)
 {
-	this->job->cancel(this->job);
 	close(this->socket);
 	free(this);
 }
@@ -775,9 +770,9 @@ plugin_t *smp_plugin_create()
 		return NULL;
 	}
 
-	this->job = callback_job_create_with_prio((callback_job_cb_t)dispatch,
-										this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)dispatch, this,
+				NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
 	return &this->public.plugin;
 }
diff --git a/src/libcharon/plugins/stroke/stroke_socket.c b/src/libcharon/plugins/stroke/stroke_socket.c
index daf244e74..e2865a640 100644
--- a/src/libcharon/plugins/stroke/stroke_socket.c
+++ b/src/libcharon/plugins/stroke/stroke_socket.c
@@ -64,16 +64,6 @@ struct private_stroke_socket_t {
 	int socket;
 
 	/**
-	 * job accepting stroke messages
-	 */
-	callback_job_t *receiver;
-
-	/**
-	 * job handling stroke messages
-	 */
-	callback_job_t *handler;
-
-	/**
 	 * queued stroke commands
 	 */
 	linked_list_t *commands;
@@ -702,7 +692,7 @@ static job_requeue_t handle(private_stroke_socket_t *this)
 	this->handling++;
 	thread_cleanup_pop(TRUE);
 	job = callback_job_create_with_prio((callback_job_cb_t)process, ctx,
-			(void*)stroke_job_context_destroy, this->handler, JOB_PRIO_HIGH);
+			(void*)stroke_job_context_destroy, NULL, JOB_PRIO_HIGH);
 	lib->processor->queue_job(lib->processor, (job_t*)job);
 	return JOB_REQUEUE_DIRECT;
 }
@@ -787,8 +777,6 @@ static bool open_socket(private_stroke_socket_t *this)
 METHOD(stroke_socket_t, destroy, void,
 	private_stroke_socket_t *this)
 {
-	this->handler->cancel(this->handler);
-	this->receiver->cancel(this->receiver);
 	this->commands->destroy_function(this->commands, (void*)stroke_job_context_destroy);
 	this->condvar->destroy(this->condvar);
 	this->mutex->destroy(this->mutex);
@@ -843,13 +831,13 @@ stroke_socket_t *stroke_socket_create()
 	charon->backends->add_backend(charon->backends, &this->config->backend);
 	hydra->attributes->add_provider(hydra->attributes, &this->attribute->provider);
 
-	this->receiver = callback_job_create_with_prio((callback_job_cb_t)receive,
-										this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->receiver);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)receive, this,
+				NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
-	this->handler = callback_job_create_with_prio((callback_job_cb_t)handle,
-										this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->handler);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)handle, this,
+				NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
 	return &this->public;
 }
diff --git a/src/libcharon/plugins/tnc_pdp/tnc_pdp.c b/src/libcharon/plugins/tnc_pdp/tnc_pdp.c
index c5509a245..7e2e667f9 100644
--- a/src/libcharon/plugins/tnc_pdp/tnc_pdp.c
+++ b/src/libcharon/plugins/tnc_pdp/tnc_pdp.c
@@ -67,11 +67,6 @@ struct private_tnc_pdp_t {
 	int ipv6;
 
 	/**
-	 * Callback job dispatching commands
-	 */
-	callback_job_t *job;
-
-	/**
 	 * RADIUS shared secret
 	 */
 	chunk_t secret;
@@ -546,10 +541,6 @@ static job_requeue_t receive(private_tnc_pdp_t *this)
 METHOD(tnc_pdp_t, destroy, void,
 	private_tnc_pdp_t *this)
 {
-	if (this->job)
-	{
-		this->job->cancel(this->job);
-	}
 	if (this->ipv4)
 	{
 		close(this->ipv4);
@@ -639,9 +630,9 @@ tnc_pdp_t *tnc_pdp_create(u_int16_t port)
 	}
 	DBG1(DBG_IKE, "eap method %N selected", eap_type_names, this->type);
 
-	this->job = callback_job_create_with_prio((callback_job_cb_t)receive,
-										this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)receive, this,
+				NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
 	return &this->public;
 }
diff --git a/src/libcharon/plugins/uci/uci_control.c b/src/libcharon/plugins/uci/uci_control.c
index 87d0f8603..53221b786 100644
--- a/src/libcharon/plugins/uci/uci_control.c
+++ b/src/libcharon/plugins/uci/uci_control.c
@@ -42,11 +42,6 @@ struct private_uci_control_t {
 	 * Public part
 	 */
 	uci_control_t public;
-
-	/**
-	 * Job
-	 */
-	callback_job_t *job;
 };
 
 /**
@@ -269,7 +264,6 @@ static job_requeue_t receive(private_uci_control_t *this)
 METHOD(uci_control_t, destroy, void,
 	private_uci_control_t *this)
 {
-	this->job->cancel(this->job);
 	unlink(FIFO_FILE);
 	free(this);
 }
@@ -295,9 +289,10 @@ uci_control_t *uci_control_create()
 	}
 	else
 	{
-		this->job = callback_job_create_with_prio((callback_job_cb_t)receive,
-										this, NULL, NULL, JOB_PRIO_CRITICAL);
-		lib->processor->queue_job(lib->processor, (job_t*)this->job);
+		lib->processor->queue_job(lib->processor,
+			(job_t*)callback_job_create_with_prio((callback_job_cb_t)receive,
+							this, NULL, (callback_job_cancel_t)return_false,
+							JOB_PRIO_CRITICAL));
 	}
 	return &this->public;
 }
diff --git a/src/libcharon/plugins/whitelist/whitelist_control.c b/src/libcharon/plugins/whitelist/whitelist_control.c
index 202c9a418..0c20bd1aa 100644
--- a/src/libcharon/plugins/whitelist/whitelist_control.c
+++ b/src/libcharon/plugins/whitelist/whitelist_control.c
@@ -49,11 +49,6 @@ struct private_whitelist_control_t {
 	 * Whitelist unix socket file descriptor
 	 */
 	int socket;
-
-	/**
-	 * Callback job dispatching commands
-	 */
-	callback_job_t *job;
 };
 
 /**
@@ -200,7 +195,6 @@ static job_requeue_t receive(private_whitelist_control_t *this)
 METHOD(whitelist_control_t, destroy, void,
 	private_whitelist_control_t *this)
 {
-	this->job->cancel(this->job);
 	close(this->socket);
 	free(this);
 }
@@ -225,9 +219,9 @@ whitelist_control_t *whitelist_control_create(whitelist_listener_t *listener)
 		return NULL;
 	}
 
-	this->job = callback_job_create_with_prio((callback_job_cb_t)receive,
-										this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)receive, this,
+				NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
 	return &this->public;
 }
diff --git a/src/libcharon/sa/ikev2/connect_manager.c b/src/libcharon/sa/ikev2/connect_manager.c
index a8366e953..75bb8f7ea 100644
--- a/src/libcharon/sa/ikev2/connect_manager.c
+++ b/src/libcharon/sa/ikev2/connect_manager.c
@@ -919,8 +919,10 @@ static void update_checklist_state(private_connect_manager_t *this,
 			 &checklist->connect_id);
 
 		callback_data_t *data = callback_data_create(this, checklist->connect_id);
-		job_t *job = (job_t*)callback_job_create((callback_job_cb_t)initiator_finish, data, (callback_job_cleanup_t)callback_data_destroy, NULL);
-		lib->scheduler->schedule_job_ms(lib->scheduler, job, ME_WAIT_TO_FINISH);
+		lib->scheduler->schedule_job_ms(lib->scheduler,
+				(job_t*)callback_job_create((callback_job_cb_t)initiator_finish,
+					data, (callback_job_cleanup_t)callback_data_destroy, NULL),
+				ME_WAIT_TO_FINISH);
 		checklist->is_finishing = TRUE;
 	}
 
@@ -1007,8 +1009,12 @@ retransmit_end:
  */
 static void queue_retransmission(private_connect_manager_t *this, check_list_t *checklist, endpoint_pair_t *pair)
 {
-	callback_data_t *data = retransmit_data_create(this, checklist->connect_id, pair->id);
-	job_t *job = (job_t*)callback_job_create((callback_job_cb_t)retransmit, data, (callback_job_cleanup_t)callback_data_destroy, NULL);
+	callback_data_t *data;
+	job_t *job;
+
+	data = retransmit_data_create(this, checklist->connect_id, pair->id);
+	job = (job_t*)callback_job_create((callback_job_cb_t)retransmit, data,
+						(callback_job_cleanup_t)callback_data_destroy, NULL);
 
 	u_int32_t retransmission = pair->retransmitted + 1;
 	u_int32_t rto = ME_INTERVAL;
@@ -1155,10 +1161,12 @@ static job_requeue_t sender(callback_data_t *data)
 /**
  * Schedules checks for a checklist (time in ms)
  */
-static void schedule_checks(private_connect_manager_t *this, check_list_t *checklist, u_int32_t time)
+static void schedule_checks(private_connect_manager_t *this,
+							check_list_t *checklist, u_int32_t time)
 {
 	callback_data_t *data = callback_data_create(this, checklist->connect_id);
-	checklist->sender = (job_t*)callback_job_create((callback_job_cb_t)sender, data, (callback_job_cleanup_t)callback_data_destroy, NULL);
+	checklist->sender = (job_t*)callback_job_create((callback_job_cb_t)sender,
+					data, (callback_job_cleanup_t)callback_data_destroy, NULL);
 	lib->scheduler->schedule_job_ms(lib->scheduler, checklist->sender, time);
 }
 
@@ -1210,12 +1218,15 @@ static void finish_checks(private_connect_manager_t *this, check_list_t *checkli
 		if (get_initiated_by_ids(this, checklist->initiator.id,
 				checklist->responder.id, &initiated) == SUCCESS)
 		{
+			callback_job_t *job;
+
 			remove_checklist(this, checklist);
 			remove_initiated(this, initiated);
 
 			initiate_data_t *data = initiate_data_create(checklist, initiated);
-			job_t *job = (job_t*)callback_job_create((callback_job_cb_t)initiate_mediated, data, (callback_job_cleanup_t)initiate_data_destroy, NULL);
-			lib->processor->queue_job(lib->processor, job);
+			job = callback_job_create((callback_job_cb_t)initiate_mediated,
+					data, (callback_job_cleanup_t)initiate_data_destroy, NULL);
+			lib->processor->queue_job(lib->processor, (job_t*)job);
 			return;
 		}
 		else
diff --git a/src/libhydra/plugins/kernel_klips/kernel_klips_ipsec.c b/src/libhydra/plugins/kernel_klips/kernel_klips_ipsec.c
index ceff8cdc9..b8d44d686 100644
--- a/src/libhydra/plugins/kernel_klips/kernel_klips_ipsec.c
+++ b/src/libhydra/plugins/kernel_klips/kernel_klips_ipsec.c
@@ -138,11 +138,6 @@ struct private_kernel_klips_ipsec_t
 	linked_list_t *ipsec_devices;
 
 	/**
-	 * job receiving PF_KEY events
-	 */
-	callback_job_t *job;
-
-	/**
 	 * mutex to lock access to the PF_KEY socket
 	 */
 	mutex_t *mutex_pfkey;
@@ -2552,10 +2547,6 @@ METHOD(kernel_ipsec_t, bypass_socket, bool,
 METHOD(kernel_ipsec_t, destroy, void,
 	private_kernel_klips_ipsec_t *this)
 {
-	if (this->job)
-	{
-		this->job->cancel(this->job);
-	}
 	if (this->socket > 0)
 	{
 		close(this->socket);
@@ -2639,9 +2630,9 @@ kernel_klips_ipsec_t *kernel_klips_ipsec_create()
 		return NULL;
 	}
 
-	this->job = callback_job_create_with_prio((callback_job_cb_t)receive_events,
-									this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	lib->processor->queue_job(lib->processor,
+		(job_t*)callback_job_create_with_prio((callback_job_cb_t)receive_events,
+			this, NULL, (callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 
 	return &this->public;
 }
diff --git a/src/libhydra/plugins/kernel_netlink/kernel_netlink_ipsec.c b/src/libhydra/plugins/kernel_netlink/kernel_netlink_ipsec.c
index 63f8894a3..b46450c38 100644
--- a/src/libhydra/plugins/kernel_netlink/kernel_netlink_ipsec.c
+++ b/src/libhydra/plugins/kernel_netlink/kernel_netlink_ipsec.c
@@ -269,11 +269,6 @@ struct private_kernel_netlink_ipsec_t {
 	hashtable_t *sas;
 
 	/**
-	 * Job receiving netlink events
-	 */
-	callback_job_t *job;
-
-	/**
 	 * Netlink xfrm socket (IPsec)
 	 */
 	netlink_socket_t *socket_xfrm;
@@ -2618,10 +2613,6 @@ METHOD(kernel_ipsec_t, destroy, void,
 	enumerator_t *enumerator;
 	policy_entry_t *policy;
 
-	if (this->job)
-	{
-		this->job->cancel(this->job);
-	}
 	if (this->socket_xfrm_events > 0)
 	{
 		close(this->socket_xfrm_events);
@@ -2730,9 +2721,10 @@ kernel_netlink_ipsec_t *kernel_netlink_ipsec_create()
 			destroy(this);
 			return NULL;
 		}
-		this->job = callback_job_create_with_prio((callback_job_cb_t)receive_events,
-											this, NULL, NULL, JOB_PRIO_CRITICAL);
-		lib->processor->queue_job(lib->processor, (job_t*)this->job);
+		lib->processor->queue_job(lib->processor,
+			(job_t*)callback_job_create_with_prio(
+					(callback_job_cb_t)receive_events, this, NULL,
+					(callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 	}
 
 	return &this->public;
diff --git a/src/libhydra/plugins/kernel_netlink/kernel_netlink_net.c b/src/libhydra/plugins/kernel_netlink/kernel_netlink_net.c
index 2f2167adf..fc59c8abe 100644
--- a/src/libhydra/plugins/kernel_netlink/kernel_netlink_net.c
+++ b/src/libhydra/plugins/kernel_netlink/kernel_netlink_net.c
@@ -254,11 +254,6 @@ struct private_kernel_netlink_net_t {
 	linked_list_t *ifaces;
 
 	/**
-	 * job receiving netlink events
-	 */
-	callback_job_t *job;
-
-	/**
 	 * netlink rt socket (routing)
 	 */
 	netlink_socket_t *socket;
@@ -1794,10 +1789,6 @@ METHOD(kernel_net_t, destroy, void,
 		manage_rule(this, RTM_DELRULE, AF_INET6, this->routing_table,
 					this->routing_table_prio);
 	}
-	if (this->job)
-	{
-		this->job->cancel(this->job);
-	}
 	if (this->socket_events > 0)
 	{
 		close(this->socket_events);
@@ -1923,9 +1914,10 @@ kernel_netlink_net_t *kernel_netlink_net_create()
 			return NULL;
 		}
 
-		this->job = callback_job_create_with_prio((callback_job_cb_t)receive_events,
-											this, NULL, NULL, JOB_PRIO_CRITICAL);
-		lib->processor->queue_job(lib->processor, (job_t*)this->job);
+		lib->processor->queue_job(lib->processor,
+			(job_t*)callback_job_create_with_prio(
+					(callback_job_cb_t)receive_events, this, NULL,
+					(callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 	}
 
 	if (init_address_list(this) != SUCCESS)
diff --git a/src/libhydra/plugins/kernel_pfkey/kernel_pfkey_ipsec.c b/src/libhydra/plugins/kernel_pfkey/kernel_pfkey_ipsec.c
index c39ebbd9a..dfe10f93f 100644
--- a/src/libhydra/plugins/kernel_pfkey/kernel_pfkey_ipsec.c
+++ b/src/libhydra/plugins/kernel_pfkey/kernel_pfkey_ipsec.c
@@ -173,11 +173,6 @@ struct private_kernel_pfkey_ipsec_t
 	bool install_routes;
 
 	/**
-	 * job receiving PF_KEY events
-	 */
-	callback_job_t *job;
-
-	/**
 	 * mutex to lock access to the PF_KEY socket
 	 */
 	mutex_t *mutex_pfkey;
@@ -2496,10 +2491,6 @@ METHOD(kernel_ipsec_t, bypass_socket, bool,
 METHOD(kernel_ipsec_t, destroy, void,
 	private_kernel_pfkey_ipsec_t *this)
 {
-	if (this->job)
-	{
-		this->job->cancel(this->job);
-	}
 	if (this->socket > 0)
 	{
 		close(this->socket);
@@ -2592,9 +2583,10 @@ kernel_pfkey_ipsec_t *kernel_pfkey_ipsec_create()
 			return NULL;
 		}
 
-		this->job = callback_job_create_with_prio((callback_job_cb_t)receive_events,
-											this, NULL, NULL, JOB_PRIO_CRITICAL);
-		lib->processor->queue_job(lib->processor, (job_t*)this->job);
+		lib->processor->queue_job(lib->processor,
+			(job_t*)callback_job_create_with_prio(
+					(callback_job_cb_t)receive_events, this, NULL,
+					(callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 	}
 
 	return &this->public;
diff --git a/src/libhydra/plugins/kernel_pfroute/kernel_pfroute_net.c b/src/libhydra/plugins/kernel_pfroute/kernel_pfroute_net.c
index bd6941754..918fdd3c7 100644
--- a/src/libhydra/plugins/kernel_pfroute/kernel_pfroute_net.c
+++ b/src/libhydra/plugins/kernel_pfroute/kernel_pfroute_net.c
@@ -120,11 +120,6 @@ struct private_kernel_pfroute_net_t
 	linked_list_t *ifaces;
 
 	/**
-	 * job receiving PF_ROUTE events
-	 */
-	callback_job_t *job;
-
-	/**
 	 * mutex to lock access to the PF_ROUTE socket
 	 */
 	mutex_t *mutex_pfroute;
@@ -648,10 +643,6 @@ static status_t init_address_list(private_kernel_pfroute_net_t *this)
 METHOD(kernel_net_t, destroy, void,
 	private_kernel_pfroute_net_t *this)
 {
-	if (this->job)
-	{
-		this->job->cancel(this->job);
-	}
 	if (this->socket > 0)
 	{
 		close(this->socket);
@@ -718,9 +709,10 @@ kernel_pfroute_net_t *kernel_pfroute_net_create()
 			return NULL;
 		}
 
-		this->job = callback_job_create_with_prio((callback_job_cb_t)receive_events,
-											this, NULL, NULL, JOB_PRIO_CRITICAL);
-		lib->processor->queue_job(lib->processor, (job_t*)this->job);
+		lib->processor->queue_job(lib->processor,
+			(job_t*)callback_job_create_with_prio(
+					(callback_job_cb_t)receive_events, this, NULL,
+					(callback_job_cancel_t)return_false, JOB_PRIO_CRITICAL));
 	}
 
 	if (init_address_list(this) != SUCCESS)
diff --git a/src/libstrongswan/plugins/pkcs11/pkcs11_manager.c b/src/libstrongswan/plugins/pkcs11/pkcs11_manager.c
index 5b321b26e..83c383671 100644
--- a/src/libstrongswan/plugins/pkcs11/pkcs11_manager.c
+++ b/src/libstrongswan/plugins/pkcs11/pkcs11_manager.c
@@ -61,8 +61,6 @@ typedef struct {
 	char *path;
 	/* loaded library */
 	pkcs11_library_t *lib;
-	/* event dispatcher job */
-	callback_job_t *job;
 } lib_entry_t;
 
 /**
@@ -70,10 +68,6 @@ typedef struct {
  */
 static void lib_entry_destroy(lib_entry_t *entry)
 {
-	if (entry->job)
-	{
-		entry->job->cancel(entry->job);
-	}
 	entry->lib->destroy(entry->lib);
 	free(entry);
 }
@@ -202,14 +196,6 @@ static job_requeue_t dispatch_slot_events(lib_entry_t *entry)
 }
 
 /**
- * End dispatching, unset job
- */
-static void end_dispatch(lib_entry_t *entry)
-{
-	entry->job = NULL;
-}
-
-/**
  * Get the slot list of a library
  */
 static CK_SLOT_ID_PTR get_slot_list(pkcs11_library_t *p11, CK_ULONG *out)
@@ -384,9 +370,9 @@ pkcs11_manager_t *pkcs11_manager_create(pkcs11_manager_token_event_t cb,
 	while (enumerator->enumerate(enumerator, &entry))
 	{
 		query_slots(entry);
-		entry->job = callback_job_create_with_prio((void*)dispatch_slot_events,
-						 entry, (void*)end_dispatch, NULL, JOB_PRIO_CRITICAL);
-		lib->processor->queue_job(lib->processor, (job_t*)entry->job);
+		lib->processor->queue_job(lib->processor,
+			(job_t*)callback_job_create_with_prio((void*)dispatch_slot_events,
+						entry, NULL, (void*)return_false, JOB_PRIO_CRITICAL));
 	}
 	enumerator->destroy(enumerator);
 
diff --git a/src/libstrongswan/processing/jobs/callback_job.c b/src/libstrongswan/processing/jobs/callback_job.c
index 86d5228bf..a5ddc8ff6 100644
--- a/src/libstrongswan/processing/jobs/callback_job.c
+++ b/src/libstrongswan/processing/jobs/callback_job.c
@@ -51,42 +51,9 @@ struct private_callback_job_t {
 	callback_job_cleanup_t cleanup;
 
 	/**
-	 * thread of the job, if running
+	 * cancel function
 	 */
-	thread_t *thread;
-
-	/**
-	 * mutex to access private job data
-	 */
-	mutex_t *mutex;
-
-	/**
-	 * list of associated child jobs
-	 */
-	linked_list_t *children;
-
-	/**
-	 * parent of this job, or NULL
-	 */
-	private_callback_job_t *parent;
-
-	/**
-	 * TRUE if the job got canceled
-	 */
-	bool canceled;
-
-	/**
-	 * condvar to synchronize the cancellation/destruction of the job
-	 */
-	condvar_t *destroyable;
-
-	/**
-	 * semaphore to synchronize the termination of the assigned thread.
-	 *
-	 * separately created during cancellation, so that we can wait on it
-	 * without risking that it gets destroyed too early during destruction.
-	 */
-	semaphore_t *terminated;
+	callback_job_cancel_t cancel;
 
 	/**
 	 * Priority of this job
@@ -94,131 +61,26 @@ struct private_callback_job_t {
 	job_priority_t prio;
 };
 
-/**
- * unregister a child from its parent, if any.
- * note: this->mutex has to be locked
- */
-static void unregister(private_callback_job_t *this)
-{
-	if (this->parent)
-	{
-		this->parent->mutex->lock(this->parent->mutex);
-		if (this->parent->canceled && !this->canceled)
-		{
-			/* if the parent has been canceled but we have not yet, we do not
-			 * unregister until we got canceled by the parent. */
-			this->parent->mutex->unlock(this->parent->mutex);
-			this->destroyable->wait(this->destroyable, this->mutex);
-			this->parent->mutex->lock(this->parent->mutex);
-		}
-		this->parent->children->remove(this->parent->children, this, NULL);
-		this->parent->mutex->unlock(this->parent->mutex);
-		this->parent = NULL;
-	}
-}
-
 METHOD(job_t, destroy, void,
 	private_callback_job_t *this)
 {
-	this->mutex->lock(this->mutex);
-	unregister(this);
 	if (this->cleanup)
 	{
 		this->cleanup(this->data);
 	}
-	if (this->terminated)
-	{
-		this->terminated->post(this->terminated);
-	}
-	this->children->destroy(this->children);
-	this->destroyable->destroy(this->destroyable);
-	this->mutex->unlock(this->mutex);
-	this->mutex->destroy(this->mutex);
 	free(this);
 }
 
-METHOD(callback_job_t, cancel, void,
+METHOD(job_t, execute, job_requeue_t,
 	private_callback_job_t *this)
 {
-	callback_job_t *child;
-	semaphore_t *terminated = NULL;
-
-	this->mutex->lock(this->mutex);
-	this->canceled = TRUE;
-	/* terminate children */
-	while (this->children->get_first(this->children, (void**)&child) == SUCCESS)
-	{
-		this->mutex->unlock(this->mutex);
-		child->cancel(child);
-		this->mutex->lock(this->mutex);
-	}
-	if (this->thread)
-	{
-		/* terminate the thread, if there is currently one executing the job.
-		 * we wait for its termination using a semaphore */
-		this->thread->cancel(this->thread);
-		terminated = this->terminated = semaphore_create(0);
-	}
-	else
-	{
-		/* if the job is currently queued, it gets terminated later.
-		 * we can't wait, because it might not get executed at all.
-		 * we also unregister the queued job manually from its parent (the
-		 * others get unregistered during destruction) */
-		unregister(this);
-	}
-	this->destroyable->signal(this->destroyable);
-	this->mutex->unlock(this->mutex);
-
-	if (terminated)
-	{
-		terminated->wait(terminated);
-		terminated->destroy(terminated);
-	}
+	return this->callback(this->data);
 }
 
-METHOD(job_t, execute, job_requeue_t,
+METHOD(job_t, cancel, bool,
 	private_callback_job_t *this)
 {
-	bool requeue = FALSE;
-
-	this->mutex->lock(this->mutex);
-	this->thread = thread_current();
-	this->mutex->unlock(this->mutex);
-
-	while (TRUE)
-	{
-		this->mutex->lock(this->mutex);
-		if (this->canceled)
-		{
-			this->mutex->unlock(this->mutex);
-			break;
-		}
-		this->mutex->unlock(this->mutex);
-		switch (this->callback(this->data))
-		{
-			case JOB_REQUEUE_DIRECT:
-				continue;
-			case JOB_REQUEUE_FAIR:
-			{
-				requeue = TRUE;
-				break;
-			}
-			case JOB_REQUEUE_NONE:
-			default:
-			{
-				break;
-			}
-		}
-		break;
-	}
-	this->mutex->lock(this->mutex);
-	this->thread = NULL;
-	this->mutex->unlock(this->mutex);
-	/* manually create a cancellation point to avoid that a canceled thread
-	 * goes back into the thread pool at all */
-	thread_cancellation_point();
-	return requeue ? JOB_REQUEUE_FAIR : JOB_REQUEUE_NONE;
+	return this->cancel(this->data);
 }
 
 METHOD(job_t, get_priority, job_priority_t,
@@ -231,8 +93,8 @@ METHOD(job_t, get_priority, job_priority_t,
  * Described in header.
  */
 callback_job_t *callback_job_create_with_prio(callback_job_cb_t cb, void *data,
-					callback_job_cleanup_t cleanup, callback_job_t *parent,
-					job_priority_t prio)
+				callback_job_cleanup_t cleanup, callback_job_cancel_t cancel,
+				job_priority_t prio)
 {
 	private_callback_job_t *this;
 
@@ -243,24 +105,17 @@ callback_job_t *callback_job_create_with_prio(callback_job_cb_t cb, void *data,
 				.get_priority = _get_priority,
 				.destroy = _destroy,
 			},
-			.cancel = _cancel,
 		},
-		.mutex = mutex_create(MUTEX_TYPE_DEFAULT),
 		.callback = cb,
 		.data = data,
 		.cleanup = cleanup,
-		.children = linked_list_create(),
-		.parent = (private_callback_job_t*)parent,
-		.destroyable = condvar_create(CONDVAR_TYPE_DEFAULT),
+		.cancel = cancel,
 		.prio = prio,
 	);
 
-	/* register us at parent */
-	if (parent)
+	if (cancel)
 	{
-		this->parent->mutex->lock(this->parent->mutex);
-		this->parent->children->insert_last(this->parent->children, this);
-		this->parent->mutex->unlock(this->parent->mutex);
+		this->public.job.cancel = _cancel;
 	}
 
 	return &this->public;
@@ -271,8 +126,8 @@ callback_job_t *callback_job_create_with_prio(callback_job_cb_t cb, void *data,
  */
 callback_job_t *callback_job_create(callback_job_cb_t cb, void *data,
 									callback_job_cleanup_t cleanup,
-									callback_job_t *parent)
+									callback_job_cancel_t cancel)
 {
-	return callback_job_create_with_prio(cb, data, cleanup, parent,
+	return callback_job_create_with_prio(cb, data, cleanup, cancel,
 										 JOB_PRIO_MEDIUM);
 }
diff --git a/src/libstrongswan/processing/jobs/callback_job.h b/src/libstrongswan/processing/jobs/callback_job.h
index ebe5c9c2b..6f2e39eb8 100644
--- a/src/libstrongswan/processing/jobs/callback_job.h
+++ b/src/libstrongswan/processing/jobs/callback_job.h
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2012 Tobias Brunner
  * Copyright (C) 2007-2011 Martin Willi
  * Copyright (C) 2011 revosec AG
  * Hochschule fuer Technik Rapperswil
@@ -46,11 +47,22 @@ typedef job_requeue_t (*callback_job_cb_t)(void *data);
  * to supply to the constructor.
  *
  * @param data			param supplied to job
- * @return				requeing policy how to requeue the job
  */
 typedef void (*callback_job_cleanup_t)(void *data);
 
 /**
+ * Cancellation function to use for the callback job.
+ *
+ * Optional function to be called when a job has to be canceled.
+ *
+ * See job_t.cancel() for details on the return value.
+ *
+ * @param data			param supplied to job
+ * @return				TRUE if canceled, FALSE to explicitly cancel the thread
+ */
+typedef bool (*callback_job_cancel_t)(void *data);
+
+/**
  * Class representing an callback Job.
  *
  * This is a special job which allows a simple callback function to
@@ -64,14 +76,6 @@ struct callback_job_t {
 	 */
 	job_t job;
 
-	/**
-	 * Cancel the job's thread and wait for its termination.
-	 *
-	 * This only works reliably for jobs that always use JOB_REQUEUE_FAIR or
-	 * JOB_REQUEUE_DIRECT, otherwise the job may already be destroyed when
-	 * cancel is called.
-	 */
-	void (*cancel)(callback_job_t *this);
 };
 
 /**
@@ -79,19 +83,20 @@ struct callback_job_t {
  *
  * The cleanup function is called when the job gets destroyed to destroy
  * the associated data.
- * If parent is not NULL, the specified job gets an association. Whenever
- * the parent gets cancelled (or runs out), all of its children are cancelled,
- * too.
+ *
+ * The cancel function is optional and should only be provided if the callback
+ * function calls potentially blocking functions and/or always returns
+ * JOB_REQUEUE_DIRECT.
  *
  * @param cb				callback to call from the processor
  * @param data				user data to supply to callback
  * @param cleanup			destructor for data on destruction, or NULL
- * @param parent			parent of this job
+ * @param cancel			function to cancel the job, or NULL
  * @return					callback_job_t object
  */
 callback_job_t *callback_job_create(callback_job_cb_t cb, void *data,
 									callback_job_cleanup_t cleanup,
-									callback_job_t *parent);
+									callback_job_cancel_t cancel);
 
 /**
  * Creates a callback job, with priority.
@@ -101,12 +106,12 @@ callback_job_t *callback_job_create(callback_job_cb_t cb, void *data,
  * @param cb				callback to call from the processor
  * @param data				user data to supply to callback
  * @param cleanup			destructor for data on destruction, or NULL
- * @param parent			parent of this job
+ * @param cancel			function to cancel the job, or NULL
  * @param prio				job priority
  * @return					callback_job_t object
  */
 callback_job_t *callback_job_create_with_prio(callback_job_cb_t cb, void *data,
-					callback_job_cleanup_t cleanup, callback_job_t *parent,
-					job_priority_t prio);
+				callback_job_cleanup_t cleanup, callback_job_cancel_t cancel,
+				job_priority_t prio);
 
 #endif /** CALLBACK_JOB_H_ @}*/
diff --git a/src/libstrongswan/processing/jobs/job.h b/src/libstrongswan/processing/jobs/job.h
index c3e640065..43bb5430e 100644
--- a/src/libstrongswan/processing/jobs/job.h
+++ b/src/libstrongswan/processing/jobs/job.h
@@ -103,6 +103,26 @@ struct job_t {
 	job_requeue_t (*execute) (job_t *this);
 
 	/**
+	 * Cancel a job.
+	 *
+	 * Implementing this method is optional.  It allows potentially blocking
+	 * jobs to be canceled during shutdown.
+	 *
+	 * If no special action is to be taken simply return FALSE then the thread
+	 * executing the job will be canceled.  If TRUE is returned the job is
+	 * expected to return from execute() itself (i.e. the thread won't be
+	 * canceled explicitly and can still be joined later).
+	 * Jobs that return FALSE have to make sure they provide the appropriate
+	 * cancellation points.
+	 *
+	 * @note Regular jobs that do not block MUST NOT implement this method.
+	 * @note This method could be called even before execute() has been called.
+	 *
+	 * @return			FALSE to cancel the thread, TRUE if canceled otherwise
+	 */
+	bool (*cancel)(job_t *this);
+
+	/**
 	 * Get the priority of a job.
 	 *
 	 * @return			job priority
@@ -117,7 +137,7 @@ struct job_t {
 	 *
 	 * Use the status of a job to decide what to do during destruction.
 	 */
-	void (*destroy) (job_t *this);
+	void (*destroy)(job_t *this);
 };
 
 #endif /** JOB_H_ @}*/
diff --git a/src/libstrongswan/processing/processor.c b/src/libstrongswan/processing/processor.c
index 69838aa13..0f0c192d2 100644
--- a/src/libstrongswan/processing/processor.c
+++ b/src/libstrongswan/processing/processor.c
@@ -88,7 +88,6 @@ struct private_processor_t {
 	condvar_t *thread_terminated;
 };
 
-
 /**
  * Worker thread
  */
@@ -222,26 +221,38 @@ static void process_jobs(worker_thread_t *worker)
 					{
 						break;
 					}
+					else if (!worker->job->cancel)
+					{	/* only allow cancelable jobs to requeue directly */
+						requeue = JOB_REQUEUE_FAIR;
+						break;
+					}
 				}
 				thread_cleanup_pop(FALSE);
 				this->mutex->lock(this->mutex);
 				this->working_threads[i]--;
-				switch (requeue)
+				if (worker->job->status == JOB_STATUS_CANCELED)
+				{	/* job was canceled via a custom cancel() method or did not
+					 * use JOB_REQUEUE_TYPE_DIRECT */
+					worker->job->destroy(worker->job);
+				}
+				else
 				{
-					case JOB_REQUEUE_NONE:
-						worker->job->status = JOB_STATUS_DONE;
-						worker->job->destroy(worker->job);
-						break;
-					case JOB_REQUEUE_FAIR:
-						worker->job->status = JOB_STATUS_QUEUED;
-						this->jobs[i]->insert_last(this->jobs[i], worker->job);
-						this->job_added->signal(this->job_added);
-						break;
-					case JOB_REQUEUE_SCHEDULED:
-						worker->job->status = JOB_STATUS_QUEUED;
-						/* fall-through */
-					default:
-						break;
+					switch (requeue)
+					{
+						case JOB_REQUEUE_NONE:
+							worker->job->status = JOB_STATUS_DONE;
+							worker->job->destroy(worker->job);
+							break;
+						case JOB_REQUEUE_FAIR:
+							worker->job->status = JOB_STATUS_QUEUED;
+							this->jobs[i]->insert_last(this->jobs[i],
+													   worker->job);
+							this->job_added->signal(this->job_added);
+							break;
+						case JOB_REQUEUE_SCHEDULED:
+						default:
+							break;
+					}
 				}
 				break;
 			}
@@ -364,14 +375,29 @@ METHOD(processor_t, set_threads, void,
 	this->mutex->unlock(this->mutex);
 }
 
-METHOD(processor_t, destroy, void,
+METHOD(processor_t, cancel, void,
 	private_processor_t *this)
 {
+	enumerator_t *enumerator;
 	worker_thread_t *worker;
-	int i;
 
-	set_threads(this, 0);
 	this->mutex->lock(this->mutex);
+	this->desired_threads = 0;
+	/* cancel potentially blocking jobs */
+	enumerator = this->threads->create_enumerator(this->threads);
+	while (enumerator->enumerate(enumerator, (void**)&worker))
+	{
+		if (worker->job && worker->job->cancel)
+		{
+			worker->job->status = JOB_STATUS_CANCELED;
+			if (!worker->job->cancel(worker->job))
+			{	/* job requests to be canceled explicitly, otherwise we assume
+				 * the thread terminates itself and can be joined */
+				worker->thread->cancel(worker->thread);
+			}
+		}
+	}
+	enumerator->destroy(enumerator);
 	while (this->total_threads > 0)
 	{
 		this->job_added->broadcast(this->job_added);
@@ -384,6 +410,14 @@ METHOD(processor_t, destroy, void,
 		free(worker);
 	}
 	this->mutex->unlock(this->mutex);
+}
+
+METHOD(processor_t, destroy, void,
+	private_processor_t *this)
+{
+	int i;
+
+	cancel(this);
 	this->thread_terminated->destroy(this->thread_terminated);
 	this->job_added->destroy(this->job_added);
 	this->mutex->destroy(this->mutex);
@@ -411,6 +445,7 @@ processor_t *processor_create()
 			.get_job_load = _get_job_load,
 			.queue_job = _queue_job,
 			.set_threads = _set_threads,
+			.cancel = _cancel,
 			.destroy = _destroy,
 		},
 		.threads = linked_list_create(),
diff --git a/src/libstrongswan/processing/processor.h b/src/libstrongswan/processing/processor.h
index 05e88a2cf..94860f5d3 100644
--- a/src/libstrongswan/processing/processor.h
+++ b/src/libstrongswan/processing/processor.h
@@ -1,4 +1,5 @@
 /*
+ * Copyright (C) 2012 Tobias Brunner
  * Copyright (C) 2005-2007 Martin Willi
  * Copyright (C) 2005 Jan Hutter
  * Hochschule fuer Technik Rapperswil
@@ -78,14 +79,21 @@ struct processor_t {
 	 *
 	 * If the number of threads is smaller than number of currently running
 	 * threads, thread count is decreased. Use 0 to disable the processor.
-	 * This call blocks if it decreases thread count until threads have
-	 * terminated, so make sure there are not too many blocking jobs.
+	 *
+	 * This call does not block and wait for threads to terminate if the number
+	 * of threads is reduced.  Instead use cancel() for that during shutdown.
 	 *
 	 * @param count			number of threads to allocate
 	 */
 	void (*set_threads)(processor_t *this, u_int count);
 
 	/**
+	 * Sets the number of threads to 0 and cancels all blocking jobs, then waits
+	 * for all threads to be terminated.
+	 */
+	void (*cancel)(processor_t *this);
+
+	/**
 	 * Destroy a processor object.
 	 */
 	void (*destroy) (processor_t *processor);
diff --git a/src/libstrongswan/processing/scheduler.c b/src/libstrongswan/processing/scheduler.c
index 979a7139f..c97dbc4be 100644
--- a/src/libstrongswan/processing/scheduler.c
+++ b/src/libstrongswan/processing/scheduler.c
@@ -68,11 +68,6 @@ struct private_scheduler_t {
 	 scheduler_t public;
 
 	/**
-	 * Job which queues scheduled jobs to the processor.
-	 */
-	callback_job_t *job;
-
-	/**
 	 * The heap in which the events are stored.
 	 */
 	event_t **heap;
@@ -309,7 +304,6 @@ METHOD(scheduler_t, destroy, void,
 	private_scheduler_t *this)
 {
 	event_t *event;
-	this->job->cancel(this->job);
 	this->condvar->destroy(this->condvar);
 	this->mutex->destroy(this->mutex);
 	while ((event = remove_event(this)) != NULL)
@@ -326,6 +320,7 @@ METHOD(scheduler_t, destroy, void,
 scheduler_t * scheduler_create()
 {
 	private_scheduler_t *this;
+	callback_job_t *job;
 
 	INIT(this,
 		.public = {
@@ -342,9 +337,9 @@ scheduler_t * scheduler_create()
 
 	this->heap = (event_t**)calloc(this->heap_size + 1, sizeof(event_t*));
 
-	this->job = callback_job_create_with_prio((callback_job_cb_t)schedule,
-										this, NULL, NULL, JOB_PRIO_CRITICAL);
-	lib->processor->queue_job(lib->processor, (job_t*)this->job);
+	job = callback_job_create_with_prio((callback_job_cb_t)schedule, this,
+										NULL, return_false, JOB_PRIO_CRITICAL);
+	lib->processor->queue_job(lib->processor, (job_t*)job);
 
 	return &this->public;
 }