s3-spoolss: make listening asynchronous

This also allows to make each children serve more than one client at the same
time if necessary.

Signed-off-by: Andreas Schneider <asn@samba.org>

diff --git a/source3/printing/spoolssd.c b/source3/printing/spoolssd.c
index e7bee0e0ebd379b9c27d606367c1b55ce09413d4..b4444de52f05d90367ab35d92b34970e4a4ccff6 100644 (file)
--- a/source3/printing/spoolssd.c
+++ b/source3/printing/spoolssd.c
@@ -274,12 +274,11 @@ struct spoolss_children_data {
        struct pf_worker_data *pf;
        int listen_fd;
        int lock_fd;
+
+       bool listening;
 };
 
-static void spoolss_schedule_loop(void *pvt);
-static void spoolss_children_loop(struct tevent_context *ev_ctx,
-                                 struct tevent_immediate *im,
-                                 void *pvt);
+static void spoolss_next_client(void *pvt);
 
 static int spoolss_children_main(struct tevent_context *ev_ctx,
                                 struct pf_worker_data *pf,
@@ -305,11 +304,13 @@ static int spoolss_children_main(struct tevent_context *ev_ctx,
        data->msg_ctx = msg_ctx;
        data->lock_fd = lock_fd;
        data->listen_fd = listen_fd;
-
-       spoolss_schedule_loop(data);
+       data->listening = false;
 
        /* loop until it is time to exit */
        while (pf->status != PF_WORKER_EXITING) {
+               /* try to see if it is time to schedule the next client */
+               spoolss_next_client(data);
+
                ret = tevent_loop_once(ev_ctx);
                if (ret != 0) {
                        DEBUG(0, ("tevent_loop_once() exited with %d: %s\n",
@@ -335,13 +336,22 @@ static void spoolss_client_terminated(void *pvt)
                return;
        }
 
-       spoolss_schedule_loop(pvt);
+       spoolss_next_client(pvt);
 }
 
-static void spoolss_schedule_loop(void *pvt)
+struct spoolss_new_client {
+       struct spoolss_children_data *data;
+       struct sockaddr_un sunaddr;
+       socklen_t addrlen;
+};
+
+static void spoolss_handle_client(struct tevent_req *req);
+
+static void spoolss_next_client(void *pvt)
 {
+       struct tevent_req *req;
        struct spoolss_children_data *data;
-       struct tevent_immediate *im;
+       struct spoolss_new_client *next;
 
        data = talloc_get_type_abort(pvt, struct spoolss_children_data);
 
@@ -354,35 +364,59 @@ static void spoolss_schedule_loop(void *pvt)
                return;
        }
 
-       im = tevent_create_immediate(data);
-       if (!im) {
-               DEBUG(1, ("Failed to create immediate event!\n"));
+       if (data->listening ||
+           data->pf->num_clients >= data->pf->allowed_clients) {
+               /* nothing to do for now we are already listening
+                * or reached the number of clients we are allowed
+                * to handle in parallel */
+               return;
+       }
+
+       next = talloc_zero(data, struct spoolss_new_client);
+       if (!next) {
+               DEBUG(1, ("Out of memory!?\n"));
+               return;
+       }
+       next->data = data;
+       next->addrlen = sizeof(next->sunaddr);
+
+       req = prefork_listen_send(next, data->ev_ctx, data->pf,
+                                 data->lock_fd, data->listen_fd,
+                                 (struct sockaddr *)&next->sunaddr,
+                                 &next->addrlen);
+       if (!req) {
+               DEBUG(1, ("Failed to make listening request!?\n"));
+               talloc_free(next);
                return;
        }
+       tevent_req_set_callback(req, spoolss_handle_client, next);
 
-       tevent_schedule_immediate(im, data->ev_ctx,
-                                 spoolss_children_loop, data);
+       data->listening = true;
 }
 
-static void spoolss_children_loop(struct tevent_context *ev_ctx,
-                                 struct tevent_immediate *im,
-                                 void *pvt)
+static void spoolss_handle_client(struct tevent_req *req)
 {
        struct spoolss_children_data *data;
-       struct sockaddr_un sunaddr;
-       socklen_t addrlen = sizeof(sunaddr);
+       struct spoolss_new_client *client;
        int ret;
        int sd;
 
-       data = talloc_get_type_abort(pvt, struct spoolss_children_data);
+       client = tevent_req_callback_data(req, struct spoolss_new_client);
+       data = client->data;
 
+       ret = prefork_listen_recv(req, &sd);
+
+       /* this will free the request too */
+       talloc_free(client);
+       /* we are done listening */
+       data->listening = false;
 
-       /* FIXME: this call is blocking. */
-       ret = prefork_wait_for_client(data->pf, data->lock_fd, data->listen_fd,
-                                       (struct sockaddr *)(void *)&sunaddr,
-                                       &addrlen, &sd);
        if (ret > 0) {
-               DEBUG(1, ("Failed to accept connection!\n"));
+               DEBUG(1, ("Failed to accept client connection!\n"));
+               /* bail out if we are not serving any other client */
+               if (data->pf->num_clients == 0) {
+                       data->pf->status = PF_WORKER_EXITING;
+               }
                return;
        }
 
@@ -392,7 +426,7 @@ static void spoolss_children_loop(struct tevent_context *ev_ctx,
                return;
        }
 
-       DEBUG(2, ("Spoolss preforked child %d activated!\n",
+       DEBUG(2, ("Spoolss preforked child %d got client connection!\n",
                  (int)(data->pf->pid)));
 
        named_pipe_accept_function(data->ev_ctx, data->msg_ctx,