afb-xreq: hide internal addref/unref to xreqs
[src/app-framework-binder.git] / src / afb-xreq.c
index fbed6ed..13deeb0 100644 (file)
@@ -16,7 +16,6 @@
  */
 
 #define _GNU_SOURCE
-#define AFB_BINDING_PRAGMA_NO_VERBOSE_MACRO
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -31,7 +30,7 @@
 #include "afb-xreq.h"
 #include "afb-evt.h"
 #include "afb-msg-json.h"
-#include "afb-subcall.h"
+#include "afb-cred.h"
 #include "afb-hook.h"
 #include "afb-api.h"
 #include "afb-apiset.h"
 
 /******************************************************************************/
 
+static void xreq_finalize(struct afb_xreq *xreq)
+{
+       if (!xreq->replied)
+               afb_xreq_fail(xreq, "error", "no reply");
+       if (xreq->hookflags)
+               afb_hook_xreq_end(xreq);
+       if (xreq->caller)
+               afb_xreq_unhooked_unref(xreq->caller);
+       xreq->queryitf->unref(xreq);
+}
+
+inline void afb_xreq_unhooked_addref(struct afb_xreq *xreq)
+{
+       __atomic_add_fetch(&xreq->refcount, 1, __ATOMIC_RELAXED);
+}
+
+inline void afb_xreq_unhooked_unref(struct afb_xreq *xreq)
+{
+       if (!__atomic_sub_fetch(&xreq->refcount, 1, __ATOMIC_RELAXED))
+               xreq_finalize(xreq);
+}
+
+/******************************************************************************/
+
+static inline struct afb_req to_req(struct afb_xreq *xreq)
+{
+       return (struct afb_req){ .itf = xreq->itf, .closure = xreq };
+}
+
+/******************************************************************************/
+
+struct subcall
+{
+       struct afb_xreq xreq;
+
+       void (*completion)(struct subcall*, int, struct json_object*);
+
+       union {
+               struct {
+                       struct jobloop *jobloop;
+                       struct json_object *result;
+                       int status;
+               };
+               struct {
+                       union {
+                               void (*callback)(void*, int, struct json_object*);
+                               void (*callback2)(void*, int, struct json_object*, struct afb_req);
+                       };
+                       void *closure;
+               };
+       };
+};
+
+static int subcall_subscribe_cb(struct afb_xreq *xreq, struct afb_event event)
+{
+       struct subcall *subcall = CONTAINER_OF_XREQ(struct subcall, xreq);
+
+       return afb_xreq_subscribe(subcall->xreq.caller, event);
+}
+
+static int subcall_unsubscribe_cb(struct afb_xreq *xreq, struct afb_event event)
+{
+       struct subcall *subcall = CONTAINER_OF_XREQ(struct subcall, xreq);
+
+       return afb_xreq_unsubscribe(subcall->xreq.caller, event);
+}
+
+static void subcall_reply_cb(struct afb_xreq *xreq, int status, struct json_object *result)
+{
+       struct subcall *subcall = CONTAINER_OF_XREQ(struct subcall, xreq);
+
+       subcall->completion(subcall, status, result);
+       json_object_put(result);
+       afb_xreq_unhooked_unref(&subcall->xreq);
+}
+
+static void subcall_destroy_cb(struct afb_xreq *xreq)
+{
+       struct subcall *subcall = CONTAINER_OF_XREQ(struct subcall, xreq);
+
+       json_object_put(subcall->xreq.json);
+       afb_cred_unref(subcall->xreq.cred);
+       free(subcall);
+}
+
+const struct afb_xreq_query_itf afb_xreq_subcall_itf = {
+       .reply = subcall_reply_cb,
+       .unref = subcall_destroy_cb,
+       .subscribe = subcall_subscribe_cb,
+       .unsubscribe = subcall_unsubscribe_cb
+};
+
+static struct subcall *subcall_alloc(
+               struct afb_xreq *caller,
+               const char *api,
+               const char *verb,
+               struct json_object *args
+)
+{
+       struct subcall *subcall;
+       size_t lenapi, lenverb;
+       char *copy;
+
+       lenapi = 1 + strlen(api);
+       lenverb = 1 + strlen(verb);
+       subcall = malloc(lenapi + lenverb + sizeof *subcall);
+       if (!subcall)
+               ERROR("out of memory");
+       else {
+               copy = (char*)&subcall[1];
+               memcpy(copy, api, lenapi);
+               api = copy;
+               copy = &copy[lenapi];
+               memcpy(copy, verb, lenverb);
+               verb = copy;
+
+               afb_xreq_init(&subcall->xreq, &afb_xreq_subcall_itf);
+               afb_context_subinit(&subcall->xreq.context, &caller->context);
+               subcall->xreq.cred = afb_cred_addref(caller->cred);
+               subcall->xreq.json = args;
+               subcall->xreq.api = api;
+               subcall->xreq.verb = verb;
+               subcall->xreq.caller = caller;
+               afb_xreq_unhooked_addref(caller);
+       }
+       return subcall;
+}
+
+
+static void subcall_on_reply(struct subcall *subcall, int status, struct json_object *result)
+{
+       subcall->callback(subcall->closure, status, result);
+}
+
+static void subcall_req_on_reply(struct subcall *subcall, int status, struct json_object *result)
+{
+       subcall->callback2(subcall->closure, status, result, to_req(subcall->xreq.caller));
+}
+
+static void subcall_hooked_on_reply(struct subcall *subcall, int status, struct json_object *result)
+{
+       afb_hook_xreq_subcall_result(subcall->xreq.caller, status, result);
+       subcall_on_reply(subcall, status, result);
+}
+
+static void subcall_req_hooked_on_reply(struct subcall *subcall, int status, struct json_object *result)
+{
+       afb_hook_xreq_subcall_req_result(subcall->xreq.caller, status, result);
+       subcall_req_on_reply(subcall, status, result);
+}
+
+static void subcall_reply_direct_cb(void *closure, int status, struct json_object *result)
+{
+       struct afb_xreq *xreq = closure;
+
+       if (xreq->replied) {
+               ERROR("subcall replied more than one time!!");
+               json_object_put(result);
+       } else {
+               xreq->replied = 1;
+               subcall_reply_cb(xreq, status, result);
+       }
+}
+
+static void subcall_process(struct subcall *subcall, void (*completion)(struct subcall*, int, struct json_object*))
+{
+       subcall->completion = completion;
+       if (subcall->xreq.caller->queryitf->subcall) {
+               subcall->xreq.caller->queryitf->subcall(
+                       subcall->xreq.caller, subcall->xreq.api, subcall->xreq.verb,
+                       subcall->xreq.json, subcall_reply_direct_cb, &subcall->xreq);
+       } else {
+               afb_xreq_unhooked_addref(&subcall->xreq);
+               afb_xreq_process(&subcall->xreq, subcall->xreq.caller->apiset);
+       }
+}
+
+static void subcall(struct subcall *subcall, void (*callback)(void*, int, struct json_object*), void *cb_closure)
+{
+       subcall->callback = callback;
+       subcall->closure = cb_closure;
+       subcall_process(subcall, subcall_on_reply);
+}
+
+static void subcall_req(struct subcall *subcall, void (*callback)(void*, int, struct json_object*, struct afb_req), void *cb_closure)
+{
+       subcall->callback2 = callback;
+       subcall->closure = cb_closure;
+       subcall_process(subcall, subcall_req_on_reply);
+}
+
+static void subcall_hooked(struct subcall *subcall, void (*callback)(void*, int, struct json_object*), void *cb_closure)
+{
+       subcall->callback = callback;
+       subcall->closure = cb_closure;
+       subcall_process(subcall, subcall_hooked_on_reply);
+}
+
+static void subcall_req_hooked(struct subcall *subcall, void (*callback)(void*, int, struct json_object*, struct afb_req), void *cb_closure)
+{
+       subcall->callback2 = callback;
+       subcall->closure = cb_closure;
+       subcall_process(subcall, subcall_req_hooked_on_reply);
+}
+
+static void subcall_sync_leave(struct subcall *subcall)
+{
+       struct jobloop *jobloop = __atomic_exchange_n(&subcall->jobloop, NULL, __ATOMIC_RELAXED);
+       if (jobloop)
+               jobs_leave(jobloop);
+}
+
+static void subcall_sync_reply(struct subcall *subcall, int status, struct json_object *result)
+{
+       subcall->status = status;
+       subcall->result = json_object_get(result);
+       subcall_sync_leave(subcall);
+}
+
+static void subcall_sync_enter(int signum, void *closure, struct jobloop *jobloop)
+{
+       struct subcall *subcall = closure;
+
+       if (!signum) {
+               subcall->jobloop = jobloop;
+               subcall->result = NULL;
+               subcall->status = 0;
+               subcall_process(subcall, subcall_sync_reply);
+       } else {
+               subcall->status = -1;
+               subcall_sync_leave(subcall);
+       }
+}
+
+static int subcallsync(struct subcall *subcall, struct json_object **result)
+{
+       int rc;
+
+       afb_xreq_unhooked_addref(&subcall->xreq);
+       rc = jobs_enter(NULL, 0, subcall_sync_enter, subcall);
+       *result = subcall->result;
+       if (rc < 0 || subcall->status < 0) {
+               *result = *result ?: afb_msg_json_internal_error();
+               rc = -1;
+       }
+       afb_xreq_unhooked_unref(&subcall->xreq);
+       return rc;
+}
+
+/******************************************************************************/
+
 static void vinfo(void *first, void *second, const char *fmt, va_list args, void (*fun)(void*,void*,const char*))
 {
        char *info;
@@ -63,10 +313,23 @@ static struct json_object *xreq_json_cb(void *closure)
 static struct afb_arg xreq_get_cb(void *closure, const char *name)
 {
        struct afb_xreq *xreq = closure;
+       struct afb_arg arg;
+       struct json_object *object, *value;
+
        if (xreq->queryitf->get)
-               return xreq->queryitf->get(xreq, name);
-       else
-               return afb_msg_json_get_arg(xreq_json_cb(closure), name);
+               arg = xreq->queryitf->get(xreq, name);
+       else {
+               object = xreq_json_cb(closure);
+               if (json_object_object_get_ex(object, name, &value)) {
+                       arg.name = name;
+                       arg.value = json_object_get_string(value);
+               } else {
+                       arg.name = NULL;
+                       arg.value = NULL;
+               }
+               arg.path = NULL;
+       }
+       return arg;
 }
 
 static void xreq_success_cb(void *closure, struct json_object *obj, const char *info)
@@ -96,7 +359,7 @@ static void xreq_fail_cb(void *closure, const char *status, const char *info)
                if (xreq->queryitf->fail)
                        xreq->queryitf->fail(xreq, status, info);
                else
-                       xreq->queryitf->reply(xreq, 1, afb_msg_json_reply_error(status, info, &xreq->context, NULL));
+                       xreq->queryitf->reply(xreq, -1, afb_msg_json_reply_error(status, info, &xreq->context, NULL));
        }
 }
 
@@ -125,15 +388,13 @@ static void xreq_context_set_cb(void *closure, void *value, void (*free_value)(v
 static void xreq_addref_cb(void *closure)
 {
        struct afb_xreq *xreq = closure;
-       __atomic_add_fetch(&xreq->refcount, 1, __ATOMIC_RELAXED);
+       afb_xreq_unhooked_addref(xreq);
 }
 
 static void xreq_unref_cb(void *closure)
 {
        struct afb_xreq *xreq = closure;
-       if (!__atomic_sub_fetch(&xreq->refcount, 1, __ATOMIC_RELAXED)) {
-               xreq->queryitf->unref(xreq);
-       }
+       afb_xreq_unhooked_unref(xreq);
 }
 
 static void xreq_session_close_cb(void *closure)
@@ -185,85 +446,85 @@ int afb_xreq_unsubscribe(struct afb_xreq *xreq, struct afb_event event)
 static void xreq_subcall_cb(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure)
 {
        struct afb_xreq *xreq = closure;
+       struct subcall *sc;
 
-       if (xreq->queryitf->subcall) {
-               xreq->queryitf->subcall(xreq, api, verb, args, callback, cb_closure);
+       sc = subcall_alloc(xreq, api, verb, args);
+       if (sc == NULL) {
+               if (callback)
+                       callback(cb_closure, 1, afb_msg_json_internal_error());
                json_object_put(args);
        } else {
-               afb_subcall(xreq, api, verb, args, callback, cb_closure);
+               subcall(sc, callback, cb_closure);
        }
 }
 
-struct xreq_sync
+static void xreq_subcall_req_cb(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*, struct afb_req), void *cb_closure)
 {
-       struct afb_xreq *caller;
-       const char *api;
-       const char *verb;
-       struct json_object *args;
-       struct jobloop *jobloop;
-       struct json_object *result;
-       int iserror;
-};
+       struct afb_xreq *xreq = closure;
+       struct subcall *sc;
 
-static void xreq_sync_leave(struct xreq_sync *sync)
-{
-       struct jobloop *jobloop = sync->jobloop;
-       if (jobloop) {
-               sync->jobloop = NULL;
-               jobs_leave(jobloop);
+       sc = subcall_alloc(xreq, api, verb, args);
+       if (sc == NULL) {
+               if (callback)
+                       callback(cb_closure, 1, afb_msg_json_internal_error(), to_req(xreq));
+               json_object_put(args);
+       } else {
+               subcall_req(sc, callback, cb_closure);
        }
 }
 
-static void xreq_sync_reply(void *closure, int iserror, struct json_object *obj)
+
+static int xreq_subcallsync_cb(void *closure, const char *api, const char *verb, struct json_object *args, struct json_object **result)
 {
-       struct xreq_sync *sync = closure;
+       int rc;
+       struct subcall *sc;
+       struct afb_xreq *xreq = closure;
+       struct json_object *resu;
 
-       sync->iserror = iserror;
-       sync->result = json_object_get(obj);
-       xreq_sync_leave(sync);
+       sc = subcall_alloc(xreq, api, verb, args);
+       if (!sc) {
+               rc = -1;
+               resu = afb_msg_json_internal_error();
+               json_object_put(args);
+       } else {
+               rc = subcallsync(sc, &resu);
+       }
+       if (result)
+               *result = resu;
+       else
+               json_object_put(resu);
+       return rc;
 }
 
-static void xreq_sync_enter(int signum, void *closure, struct jobloop *jobloop)
+static void xreq_vverbose_cb(void*closure, int level, const char *file, int line, const char *func, const char *fmt, va_list args)
 {
-       struct xreq_sync *sync = closure;
+       char *p;
+       struct afb_xreq *xreq = closure;
 
-       if (!signum) {
-               sync->jobloop = jobloop;
-               xreq_subcall_cb(sync->caller, sync->api, sync->verb, json_object_get(sync->args), xreq_sync_reply, sync);
-       } else {
-               sync->iserror = 1;
-               xreq_sync_leave(sync);
+       if (!fmt || vasprintf(&p, fmt, args) < 0)
+               vverbose(level, file, line, func, fmt, args);
+       else {
+               verbose(level, file, line, func, "[REQ/API %s] %s", xreq->api, p);
+               free(p);
        }
 }
 
-static int xreq_subcallsync_cb(void *closure, const char *api, const char *verb, struct json_object *args, struct json_object **result)
+static struct afb_stored_req *xreq_store_cb(void *closure)
 {
-       int rc;
-       struct xreq_sync sync;
-       struct afb_xreq *xreq = closure;
-
-       sync.caller = xreq;
-       sync.api = api;
-       sync.verb = verb;
-       sync.args = args;
-       sync.jobloop = NULL;
-       sync.result = NULL;
-       sync.iserror = 1;
-
-       rc = jobs_enter(NULL, 0, xreq_sync_enter, &sync);
-       json_object_put(args);
-       if (rc < 0 || sync.iserror) {
-               *result = sync.result ? : afb_msg_json_internal_error();
-               return 0;
-       }
-       *result = sync.result;
-       return 1;
+       xreq_addref_cb(closure);
+       return closure;
 }
 
-static void xreq_vverbose_cb(void*closure, int level, const char *file, int line, const char *func, const char *fmt, va_list args)
+static int xreq_has_permission_cb(void*closure, const char *permission)
 {
-       /* TODO: improves the implementation. example: on condition make a list of log messages that will be returned */
-       vverbose(level, file, line, func, fmt, args);
+       struct afb_xreq *xreq = closure;
+       return afb_auth_has_permission(xreq, permission);
+}
+
+static char *xreq_get_application_id_cb(void*closure)
+{
+       struct afb_xreq *xreq = closure;
+       return xreq->cred && xreq->cred->id ? strdup(xreq->cred->id) : NULL;
 }
 
 /******************************************************************************/
@@ -331,10 +592,7 @@ static void xreq_hooked_unref_cb(void *closure)
 {
        struct afb_xreq *xreq = closure;
        afb_hook_xreq_unref(xreq);
-       if (!__atomic_sub_fetch(&xreq->refcount, 1, __ATOMIC_RELAXED)) {
-               afb_hook_xreq_end(xreq);
-               xreq->queryitf->unref(xreq);
-       }
+       xreq_unref_cb(closure);
 }
 
 static void xreq_hooked_session_close_cb(void *closure)
@@ -365,35 +623,35 @@ static int xreq_hooked_unsubscribe_cb(void *closure, struct afb_event event)
        return afb_hook_xreq_unsubscribe(xreq, event, r);
 }
 
-struct reply
+static void xreq_hooked_subcall_cb(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure)
 {
-       struct afb_xreq *xreq;
-       void (*callback)(void*, int, struct json_object*);
-       void *closure;
-};
+       struct afb_xreq *xreq = closure;
+       struct subcall *sc;
 
-static void xreq_hooked_subcall_reply_cb(void *closure, int iserror, struct json_object *result)
-{
-       struct reply *reply = closure;
-       
-       afb_hook_xreq_subcall_result(reply->xreq, iserror, result);
-       reply->callback(reply->closure, iserror, result);
-       free(reply);
+       afb_hook_xreq_subcall(xreq, api, verb, args);
+       sc = subcall_alloc(xreq, api, verb, args);
+       if (sc == NULL) {
+               if (callback)
+                       callback(cb_closure, 1, afb_msg_json_internal_error());
+               json_object_put(args);
+       } else {
+               subcall_hooked(sc, callback, cb_closure);
+       }
 }
 
-static void xreq_hooked_subcall_cb(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure)
+static void xreq_hooked_subcall_req_cb(void *closure, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*, struct afb_req), void *cb_closure)
 {
-       struct reply *reply = malloc(sizeof *reply);
        struct afb_xreq *xreq = closure;
-       afb_hook_xreq_subcall(xreq, api, verb, args);
-       if (reply) {
-               reply->xreq = xreq;
-               reply->callback = callback;
-               reply->closure = cb_closure;
-               xreq_subcall_cb(closure, api, verb, args, xreq_hooked_subcall_reply_cb, reply);
+       struct subcall *sc;
+
+       afb_hook_xreq_subcall_req(xreq, api, verb, args);
+       sc = subcall_alloc(xreq, api, verb, args);
+       if (sc == NULL) {
+               if (callback)
+                       callback(cb_closure, 1, afb_msg_json_internal_error(), to_req(xreq));
+               json_object_put(args);
        } else {
-               ERROR("out of memory");
-               xreq_subcall_cb(closure, api, verb, args, callback, cb_closure);
+               subcall_req_hooked(sc, callback, cb_closure);
        }
 }
 
@@ -416,6 +674,28 @@ static void xreq_hooked_vverbose_cb(void*closure, int level, const char *file, i
        va_end(ap);
 }
 
+static struct afb_stored_req *xreq_hooked_store_cb(void *closure)
+{
+       struct afb_xreq *xreq = closure;
+       struct afb_stored_req *r = xreq_store_cb(closure);
+       afb_hook_xreq_store(xreq, r);
+       return r;
+}
+
+static int xreq_hooked_has_permission_cb(void*closure, const char *permission)
+{
+       struct afb_xreq *xreq = closure;
+       int r = xreq_has_permission_cb(closure, permission);
+       return afb_hook_xreq_has_permission(xreq, permission, r);
+}
+
+static char *xreq_hooked_get_application_id_cb(void*closure)
+{
+       struct afb_xreq *xreq = closure;
+       char *r = xreq_get_application_id_cb(closure);
+       return afb_hook_xreq_get_application_id(xreq, r);
+}
+
 /******************************************************************************/
 
 const struct afb_req_itf xreq_itf = {
@@ -435,7 +715,11 @@ const struct afb_req_itf xreq_itf = {
        .unsubscribe = xreq_unsubscribe_cb,
        .subcall = xreq_subcall_cb,
        .subcallsync = xreq_subcallsync_cb,
-       .vverbose = xreq_vverbose_cb
+       .vverbose = xreq_vverbose_cb,
+       .store = xreq_store_cb,
+       .subcall_req = xreq_subcall_req_cb,
+       .has_permission = xreq_has_permission_cb,
+       .get_application_id = xreq_get_application_id_cb
 };
 
 const struct afb_req_itf xreq_hooked_itf = {
@@ -455,16 +739,23 @@ const struct afb_req_itf xreq_hooked_itf = {
        .unsubscribe = xreq_hooked_unsubscribe_cb,
        .subcall = xreq_hooked_subcall_cb,
        .subcallsync = xreq_hooked_subcallsync_cb,
-       .vverbose = xreq_hooked_vverbose_cb
+       .vverbose = xreq_hooked_vverbose_cb,
+       .store = xreq_hooked_store_cb,
+       .subcall_req = xreq_hooked_subcall_req_cb,
+       .has_permission = xreq_hooked_has_permission_cb,
+       .get_application_id = xreq_hooked_get_application_id_cb
 };
 
-static inline struct afb_req to_req(struct afb_xreq *xreq)
+/******************************************************************************/
+
+struct afb_req afb_xreq_unstore(struct afb_stored_req *sreq)
 {
-       return (struct afb_req){ .itf = xreq->hookflags ? &xreq_hooked_itf : &xreq_itf, .closure = xreq };
+       struct afb_xreq *xreq = (struct afb_xreq *)sreq;
+       if (xreq->hookflags)
+               afb_hook_xreq_unstore(xreq);
+       return to_req(xreq);
 }
 
-/******************************************************************************/
-
 struct json_object *afb_xreq_json(struct afb_xreq *xreq)
 {
        return afb_req_json(to_req(xreq));
@@ -477,14 +768,11 @@ void afb_xreq_success(struct afb_xreq *xreq, struct json_object *obj, const char
 
 void afb_xreq_success_f(struct afb_xreq *xreq, struct json_object *obj, const char *info, ...)
 {
-       char *message;
        va_list args;
+
        va_start(args, info);
-       if (info == NULL || vasprintf(&message, info, args) < 0)
-               message = NULL;
+       afb_req_success_v(to_req(xreq), obj, info, args);
        va_end(args);
-       afb_xreq_success(xreq, obj, message);
-       free(message);
 }
 
 void afb_xreq_fail(struct afb_xreq *xreq, const char *status, const char *info)
@@ -494,14 +782,12 @@ void afb_xreq_fail(struct afb_xreq *xreq, const char *status, const char *info)
 
 void afb_xreq_fail_f(struct afb_xreq *xreq, const char *status, const char *info, ...)
 {
-       char *message;
        va_list args;
+
        va_start(args, info);
-       if (info == NULL || vasprintf(&message, info, args) < 0)
-               message = NULL;
+       afb_req_fail_v(to_req(xreq), status, info, args);
        va_end(args);
-       afb_xreq_fail(xreq, status, message);
-       free(message);
+
 }
 
 const char *afb_xreq_raw(struct afb_xreq *xreq, size_t *size)
@@ -605,7 +891,7 @@ static int xreq_session_check_apply_v2(struct afb_xreq *xreq, uint32_t sessionfl
                return -1;
        }
 
-       if (auth && !afb_auth_check(auth, xreq)) {
+       if (auth && !afb_auth_check(xreq, auth)) {
                afb_xreq_fail_f(xreq, "denied", "authorisation refused");
                errno = EPERM;
                return -1;
@@ -642,6 +928,7 @@ void afb_xreq_call_verb_v2(struct afb_xreq *xreq, const struct afb_verb_v2 *verb
 void afb_xreq_init(struct afb_xreq *xreq, const struct afb_xreq_query_itf *queryitf)
 {
        memset(xreq, 0, sizeof *xreq);
+       xreq->itf = &xreq_hooked_itf; /* hook by default */
        xreq->refcount = 1;
        xreq->queryitf = queryitf;
 }
@@ -656,50 +943,102 @@ void afb_xreq_fail_unknown_verb(struct afb_xreq *xreq)
        afb_xreq_fail_f(xreq, "unknown-verb", "verb %s unknown within api %s", xreq->verb, xreq->api);
 }
 
-static void process_sync(struct afb_xreq *xreq)
+static void init_hooking(struct afb_xreq *xreq)
 {
-       struct afb_api api;
-
-       /* init hooking */
        afb_hook_init_xreq(xreq);
        if (xreq->hookflags)
                afb_hook_xreq_begin(xreq);
-
-       /* search the api */
-       if (afb_apiset_get_started(xreq->apiset, xreq->api, &api) < 0) {
-               if (errno == ENOENT)
-                       afb_xreq_fail_f(xreq, "unknown-api", "api %s not found", xreq->api);
-               else
-                       afb_xreq_fail_f(xreq, "bad-api-state", "api %s not started correctly: %m", xreq->api);
-       } else {
-               xreq->context.api_key = api.closure;
-               api.itf->call(api.closure, xreq);
-       }
+       else
+               xreq->itf = &xreq_itf; /* unhook the interface */
 }
 
+/**
+ * job callback for asynchronous and secured processing of the request.
+ */
 static void process_async(int signum, void *arg)
 {
        struct afb_xreq *xreq = arg;
+       const struct afb_api *api;
 
        if (signum != 0) {
+               /* emit the error (assumes that hooking is initialised) */
                afb_xreq_fail_f(xreq, "aborted", "signal %s(%d) caught", strsignal(signum), signum);
        } else {
-               process_sync(xreq);
+               /* init hooking */
+               init_hooking(xreq);
+               /* invoke api call method to process the reqiest */
+               api = (const struct afb_api*)xreq->context.api_key;
+               api->itf->call(api->closure, xreq);
        }
-       afb_xreq_unref(xreq);
+       /* release the request */
+       afb_xreq_unhooked_unref(xreq);
 }
 
+/**
+ * Early request failure of the request 'xreq' with, as usual, 'status' and 'info'
+ * The early failure occurs only in function 'afb_xreq_process' where normally,
+ * the hooking is not initialised. So this "early" failure takes care to initialise
+ * the hooking in first.
+ */
+static void early_failure(struct afb_xreq *xreq, const char *status, const char *info, ...)
+{
+       va_list args;
+
+       /* init hooking */
+       init_hooking(xreq);
+
+       /* send error */
+       va_start(args, info);
+       afb_req_fail_v(to_req(xreq), status, info, args);
+       va_end(args);
+}
+
+/**
+ * Enqueue a job for processing the request 'xreq' using the given 'apiset'.
+ * Errors are reported as request failures.
+ */
 void afb_xreq_process(struct afb_xreq *xreq, struct afb_apiset *apiset)
 {
+       const struct afb_api *api;
+       struct afb_xreq *caller;
+
+       /* lookup at the api */
        xreq->apiset = apiset;
+       api = afb_apiset_lookup_started(apiset, xreq->api, 1);
+       if (!api) {
+               if (errno == ENOENT)
+                       early_failure(xreq, "unknown-api", "api %s not found (for verb %s)", xreq->api, xreq->verb);
+               else
+                       early_failure(xreq, "bad-api-state", "api %s not started correctly: %m", xreq->api);
+               goto end;
+       }
+       xreq->context.api_key = api;
+
+       /* check self locking */
+       if (!api->noconcurrency)
+               api = NULL;
+       else {
+               caller = xreq->caller;
+               while (caller) {
+                       if (caller->context.api_key == api) {
+                               /* noconcurrency lock detected */
+                               ERROR("self-lock detected in call stack for API %s", xreq->api);
+                               early_failure(xreq, "self-locked", "recursive self lock, API %s", xreq->api);
+                               goto end;
+                       }
+                       caller = caller->caller;
+               }
+       }
 
-       afb_xreq_addref(xreq);
-       if (jobs_queue(NULL, afb_apiset_timeout_get(apiset), process_async, xreq) < 0) {
+       /* queue the request job */
+       afb_xreq_unhooked_addref(xreq);
+       if (jobs_queue(api, afb_apiset_timeout_get(apiset), process_async, xreq) < 0) {
                /* TODO: allows or not to proccess it directly as when no threading? (see above) */
                ERROR("can't process job with threads: %m");
-               afb_xreq_fail_f(xreq, "cancelled", "not able to create a job for the task");
-               afb_xreq_unref(xreq);
+               early_failure(xreq, "cancelled", "not able to create a job for the task");
+               afb_xreq_unhooked_unref(xreq);
        }
-       afb_xreq_unref(xreq);
+end:
+       afb_xreq_unhooked_unref(xreq);
 }