Index: uspace/lib/c/generic/loc.c
===================================================================
--- uspace/lib/c/generic/loc.c	(revision 15f3c3fbb3cd87db466db2f9b1379fe5b0794299)
+++ uspace/lib/c/generic/loc.c	(revision 15f3c3fbb3cd87db466db2f9b1379fe5b0794299)
@@ -0,0 +1,521 @@
+/*
+ * Copyright (c) 2007 Josef Cejka
+ * Copyright (c) 2009 Jiri Svoboda
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <str.h>
+#include <ipc/services.h>
+#include <ns.h>
+#include <ipc/loc.h>
+#include <loc.h>
+#include <fibril_synch.h>
+#include <async.h>
+#include <errno.h>
+#include <malloc.h>
+#include <bool.h>
+
+static FIBRIL_MUTEX_INITIALIZE(loc_supp_block_mutex);
+static FIBRIL_MUTEX_INITIALIZE(loc_cons_block_mutex);
+
+static FIBRIL_MUTEX_INITIALIZE(loc_supplier_mutex);
+static FIBRIL_MUTEX_INITIALIZE(loc_consumer_mutex);
+
+static async_sess_t *loc_supp_block_sess = NULL;
+static async_sess_t *loc_cons_block_sess = NULL;
+
+static async_sess_t *loc_supplier_sess = NULL;
+static async_sess_t *loc_consumer_sess = NULL;
+
+static void clone_session(fibril_mutex_t *mtx, async_sess_t *src,
+    async_sess_t **dst)
+{
+	fibril_mutex_lock(mtx);
+	
+	if ((*dst == NULL) && (src != NULL))
+		*dst = src;
+	
+	fibril_mutex_unlock(mtx);
+}
+
+/** Start an async exchange on the loc session (blocking).
+ *
+ * @param iface Location service interface to choose
+ *
+ * @return New exchange.
+ *
+ */
+async_exch_t *loc_exchange_begin_blocking(loc_interface_t iface)
+{
+	switch (iface) {
+	case LOC_PORT_SUPPLIER:
+		fibril_mutex_lock(&loc_supp_block_mutex);
+		
+		while (loc_supp_block_sess == NULL) {
+			clone_session(&loc_supplier_mutex, loc_supplier_sess,
+			    &loc_supp_block_sess);
+			
+			if (loc_supp_block_sess == NULL)
+				loc_supp_block_sess =
+				    service_connect_blocking(EXCHANGE_SERIALIZE,
+				    SERVICE_LOC, LOC_PORT_SUPPLIER, 0);
+		}
+		
+		fibril_mutex_unlock(&loc_supp_block_mutex);
+		
+		clone_session(&loc_supplier_mutex, loc_supp_block_sess,
+		    &loc_supplier_sess);
+		
+		return async_exchange_begin(loc_supp_block_sess);
+	case LOC_PORT_CONSUMER:
+		fibril_mutex_lock(&loc_cons_block_mutex);
+		
+		while (loc_cons_block_sess == NULL) {
+			clone_session(&loc_consumer_mutex, loc_consumer_sess,
+			    &loc_cons_block_sess);
+			
+			if (loc_cons_block_sess == NULL)
+				loc_cons_block_sess =
+				    service_connect_blocking(EXCHANGE_SERIALIZE,
+				    SERVICE_LOC, LOC_PORT_CONSUMER, 0);
+		}
+		
+		fibril_mutex_unlock(&loc_cons_block_mutex);
+		
+		clone_session(&loc_consumer_mutex, loc_cons_block_sess,
+		    &loc_consumer_sess);
+		
+		return async_exchange_begin(loc_cons_block_sess);
+	default:
+		return NULL;
+	}
+}
+
+/** Start an async exchange on the loc session.
+ *
+ * @param iface Location service interface to choose
+ *
+ * @return New exchange.
+ *
+ */
+async_exch_t *loc_exchange_begin(loc_interface_t iface)
+{
+	switch (iface) {
+	case LOC_PORT_SUPPLIER:
+		fibril_mutex_lock(&loc_supplier_mutex);
+		
+		if (loc_supplier_sess == NULL)
+			loc_supplier_sess =
+			    service_connect(EXCHANGE_SERIALIZE, SERVICE_LOC,
+			    LOC_PORT_SUPPLIER, 0);
+		
+		fibril_mutex_unlock(&loc_supplier_mutex);
+		
+		if (loc_supplier_sess == NULL)
+			return NULL;
+		
+		return async_exchange_begin(loc_supplier_sess);
+	case LOC_PORT_CONSUMER:
+		fibril_mutex_lock(&loc_consumer_mutex);
+		
+		if (loc_consumer_sess == NULL)
+			loc_consumer_sess =
+			    service_connect(EXCHANGE_SERIALIZE, SERVICE_LOC,
+			    LOC_PORT_CONSUMER, 0);
+		
+		fibril_mutex_unlock(&loc_consumer_mutex);
+		
+		if (loc_consumer_sess == NULL)
+			return NULL;
+		
+		return async_exchange_begin(loc_consumer_sess);
+	default:
+		return NULL;
+	}
+}
+
+/** Finish an async exchange on the loc session.
+ *
+ * @param exch Exchange to be finished.
+ *
+ */
+void loc_exchange_end(async_exch_t *exch)
+{
+	async_exchange_end(exch);
+}
+
+/** Register new driver with loc. */
+int loc_server_register(const char *name, async_client_conn_t conn)
+{
+	async_exch_t *exch = loc_exchange_begin_blocking(LOC_PORT_SUPPLIER);
+	
+	ipc_call_t answer;
+	aid_t req = async_send_2(exch, LOC_SERVER_REGISTER, 0, 0, &answer);
+	sysarg_t retval = async_data_write_start(exch, name, str_size(name));
+	
+	loc_exchange_end(exch);
+	
+	if (retval != EOK) {
+		async_wait_for(req, NULL);
+		return retval;
+	}
+	
+	async_set_client_connection(conn);
+	
+	exch = loc_exchange_begin(LOC_PORT_SUPPLIER);
+	async_connect_to_me(exch, 0, 0, 0, NULL, NULL);
+	loc_exchange_end(exch);
+	
+	async_wait_for(req, &retval);
+	return retval;
+}
+
+/** Register new device.
+ *
+ * The @p interface is used when forwarding connection to the driver.
+ * If not 0, the first argument is the interface and the second argument
+ * is the service ID.
+ *
+ * When the interface is zero (default), the first argument is directly
+ * the handle (to ensure backward compatibility).
+ *
+ * @param      fqdn      Fully qualified device name.
+ * @param[out] handle    Handle to the created instance of device.
+ * @param      interface Interface when forwarding.
+ *
+ */
+int loc_service_register_with_iface(const char *fqdn,
+    service_id_t *handle, sysarg_t interface)
+{
+	async_exch_t *exch = loc_exchange_begin_blocking(LOC_PORT_SUPPLIER);
+	
+	ipc_call_t answer;
+	aid_t req = async_send_2(exch, LOC_SERVICE_REGISTER, interface, 0,
+	    &answer);
+	sysarg_t retval = async_data_write_start(exch, fqdn, str_size(fqdn));
+	
+	loc_exchange_end(exch);
+	
+	if (retval != EOK) {
+		async_wait_for(req, NULL);
+		return retval;
+	}
+	
+	async_wait_for(req, &retval);
+	
+	if (retval != EOK) {
+		if (handle != NULL)
+			*handle = -1;
+		
+		return retval;
+	}
+	
+	if (handle != NULL)
+		*handle = (service_id_t) IPC_GET_ARG1(answer);
+	
+	return retval;
+}
+
+/** Register new device.
+ *
+ * @param fqdn   Fully qualified device name.
+ * @param handle Output: Handle to the created instance of device.
+ *
+ */
+int loc_service_register(const char *fqdn, service_id_t *handle)
+{
+	return loc_service_register_with_iface(fqdn, handle, 0);
+}
+
+int loc_service_get_id(const char *fqdn, service_id_t *handle,
+    unsigned int flags)
+{
+	async_exch_t *exch;
+	
+	if (flags & IPC_FLAG_BLOCKING)
+		exch = loc_exchange_begin_blocking(LOC_PORT_CONSUMER);
+	else {
+		exch = loc_exchange_begin(LOC_PORT_CONSUMER);
+		if (exch == NULL)
+			return errno;
+	}
+	
+	ipc_call_t answer;
+	aid_t req = async_send_2(exch, LOC_SERVICE_GET_ID, flags, 0,
+	    &answer);
+	sysarg_t retval = async_data_write_start(exch, fqdn, str_size(fqdn));
+	
+	loc_exchange_end(exch);
+	
+	if (retval != EOK) {
+		async_wait_for(req, NULL);
+		return retval;
+	}
+	
+	async_wait_for(req, &retval);
+	
+	if (retval != EOK) {
+		if (handle != NULL)
+			*handle = (service_id_t) -1;
+		
+		return retval;
+	}
+	
+	if (handle != NULL)
+		*handle = (service_id_t) IPC_GET_ARG1(answer);
+	
+	return retval;
+}
+
+int loc_namespace_get_id(const char *name, service_id_t *handle,
+    unsigned int flags)
+{
+	async_exch_t *exch;
+	
+	if (flags & IPC_FLAG_BLOCKING)
+		exch = loc_exchange_begin_blocking(LOC_PORT_CONSUMER);
+	else {
+		exch = loc_exchange_begin(LOC_PORT_CONSUMER);
+		if (exch == NULL)
+			return errno;
+	}
+	
+	ipc_call_t answer;
+	aid_t req = async_send_2(exch, LOC_NAMESPACE_GET_ID, flags, 0,
+	    &answer);
+	sysarg_t retval = async_data_write_start(exch, name, str_size(name));
+	
+	loc_exchange_end(exch);
+	
+	if (retval != EOK) {
+		async_wait_for(req, NULL);
+		return retval;
+	}
+	
+	async_wait_for(req, &retval);
+	
+	if (retval != EOK) {
+		if (handle != NULL)
+			*handle = (service_id_t) -1;
+		
+		return retval;
+	}
+	
+	if (handle != NULL)
+		*handle = (service_id_t) IPC_GET_ARG1(answer);
+	
+	return retval;
+}
+
+loc_object_type_t loc_id_probe(service_id_t handle)
+{
+	async_exch_t *exch = loc_exchange_begin_blocking(LOC_PORT_CONSUMER);
+	
+	sysarg_t type;
+	int retval = async_req_1_1(exch, LOC_ID_PROBE, handle, &type);
+	
+	loc_exchange_end(exch);
+	
+	if (retval != EOK)
+		return LOC_OBJECT_NONE;
+	
+	return (loc_object_type_t) type;
+}
+
+async_sess_t *loc_service_connect(exch_mgmt_t mgmt, service_id_t handle,
+    unsigned int flags)
+{
+	async_sess_t *sess;
+	
+	if (flags & IPC_FLAG_BLOCKING)
+		sess = service_connect_blocking(mgmt, SERVICE_LOC,
+		    LOC_CONNECT_TO_SERVICE, handle);
+	else
+		sess = service_connect(mgmt, SERVICE_LOC,
+		    LOC_CONNECT_TO_SERVICE, handle);
+	
+	return sess;
+}
+
+int loc_null_create(void)
+{
+	async_exch_t *exch = loc_exchange_begin_blocking(LOC_PORT_CONSUMER);
+	
+	sysarg_t null_id;
+	int retval = async_req_0_1(exch, LOC_NULL_CREATE, &null_id);
+	
+	loc_exchange_end(exch);
+	
+	if (retval != EOK)
+		return -1;
+	
+	return (int) null_id;
+}
+
+void loc_null_destroy(int null_id)
+{
+	async_exch_t *exch = loc_exchange_begin_blocking(LOC_PORT_CONSUMER);
+	async_req_1_0(exch, LOC_NULL_DESTROY, (sysarg_t) null_id);
+	loc_exchange_end(exch);
+}
+
+static size_t loc_count_namespaces_internal(async_exch_t *exch)
+{
+	sysarg_t count;
+	int retval = async_req_0_1(exch, LOC_GET_NAMESPACE_COUNT, &count);
+	if (retval != EOK)
+		return 0;
+	
+	return count;
+}
+
+static size_t loc_count_services_internal(async_exch_t *exch,
+    service_id_t ns_handle)
+{
+	sysarg_t count;
+	int retval = async_req_1_1(exch, LOC_GET_SERVICE_COUNT, ns_handle,
+	    &count);
+	if (retval != EOK)
+		return 0;
+	
+	return count;
+}
+
+size_t loc_count_namespaces(void)
+{
+	async_exch_t *exch = loc_exchange_begin_blocking(LOC_PORT_CONSUMER);
+	size_t size = loc_count_namespaces_internal(exch);
+	loc_exchange_end(exch);
+	
+	return size;
+}
+
+size_t loc_count_services(service_id_t ns_handle)
+{
+	async_exch_t *exch = loc_exchange_begin_blocking(LOC_PORT_CONSUMER);
+	size_t size = loc_count_services_internal(exch, ns_handle);
+	loc_exchange_end(exch);
+	
+	return size;
+}
+
+size_t loc_get_namespaces(loc_sdesc_t **data)
+{
+	/* Loop until namespaces read succesful */
+	while (true) {
+		async_exch_t *exch = loc_exchange_begin_blocking(LOC_PORT_CONSUMER);
+		size_t count = loc_count_namespaces_internal(exch);
+		loc_exchange_end(exch);
+		
+		if (count == 0)
+			return 0;
+		
+		loc_sdesc_t *devs = (loc_sdesc_t *) calloc(count, sizeof(loc_sdesc_t));
+		if (devs == NULL)
+			return 0;
+		
+		exch = loc_exchange_begin(LOC_PORT_CONSUMER);
+		
+		ipc_call_t answer;
+		aid_t req = async_send_0(exch, LOC_GET_NAMESPACES, &answer);
+		int rc = async_data_read_start(exch, devs, count * sizeof(loc_sdesc_t));
+		
+		loc_exchange_end(exch);
+		
+		if (rc == EOVERFLOW) {
+			/*
+			 * Number of namespaces has changed since
+			 * the last call of LOC_GET_NAMESPACE_COUNT
+			 */
+			free(devs);
+			continue;
+		}
+		
+		if (rc != EOK) {
+			async_wait_for(req, NULL);
+			free(devs);
+			return 0;
+		}
+		
+		sysarg_t retval;
+		async_wait_for(req, &retval);
+		
+		if (retval != EOK)
+			return 0;
+		
+		*data = devs;
+		return count;
+	}
+}
+
+size_t loc_get_services(service_id_t ns_handle, loc_sdesc_t **data)
+{
+	/* Loop until devices read succesful */
+	while (true) {
+		async_exch_t *exch = loc_exchange_begin_blocking(LOC_PORT_CONSUMER);
+		size_t count = loc_count_services_internal(exch, ns_handle);
+		loc_exchange_end(exch);
+		
+		if (count == 0)
+			return 0;
+		
+		loc_sdesc_t *devs = (loc_sdesc_t *) calloc(count, sizeof(loc_sdesc_t));
+		if (devs == NULL)
+			return 0;
+		
+		exch = loc_exchange_begin(LOC_PORT_CONSUMER);
+		
+		ipc_call_t answer;
+		aid_t req = async_send_1(exch, LOC_GET_SERVICES, ns_handle, &answer);
+		int rc = async_data_read_start(exch, devs, count * sizeof(loc_sdesc_t));
+		
+		loc_exchange_end(exch);
+		
+		if (rc == EOVERFLOW) {
+			/*
+			 * Number of services has changed since
+			 * the last call of LOC_GET_SERVICE_COUNT
+			 */
+			free(devs);
+			continue;
+		}
+		
+		if (rc != EOK) {
+			async_wait_for(req, NULL);
+			free(devs);
+			return 0;
+		}
+		
+		sysarg_t retval;
+		async_wait_for(req, &retval);
+		
+		if (retval != EOK)
+			return 0;
+		
+		*data = devs;
+		return count;
+	}
+}
