1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
3 /* GIO - GLib Input, Output and Streaming Library
5 * Copyright (C) 2008 Red Hat, Inc.
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General
18 * Public License along with this library; if not, write to the
19 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
20 * Boston, MA 02111-1307, USA.
30 #include "gthreadedresolver.h"
31 #include "gnetworkingprivate.h"
33 #include "gcancellable.h"
34 #include "gsimpleasyncresult.h"
35 #include "gsocketaddress.h"
38 G_DEFINE_TYPE (GThreadedResolver, g_threaded_resolver, G_TYPE_RESOLVER)
40 static void threaded_resolver_thread (gpointer thread_data, gpointer pool_data);
43 g_threaded_resolver_init (GThreadedResolver *gtr)
45 gtr->thread_pool = g_thread_pool_new (threaded_resolver_thread, gtr,
50 finalize (GObject *object)
52 GThreadedResolver *gtr = G_THREADED_RESOLVER (object);
54 g_thread_pool_free (gtr->thread_pool, FALSE, FALSE);
56 G_OBJECT_CLASS (g_threaded_resolver_parent_class)->finalize (object);
59 /* A GThreadedResolverRequest represents a request in progress
60 * (usually, but see case 1). It is refcounted, to make sure that it
61 * doesn't get freed too soon. In particular, it can't be freed until
62 * (a) the resolver thread has finished resolving, (b) the calling
63 * thread has received an answer, and (c) no other thread could be in
64 * the process of trying to cancel it.
68 * 1. Synchronous non-cancellable request: in this case, the request
69 * is simply done in the calling thread, without using
70 * GThreadedResolverRequest at all.
72 * 2. Synchronous cancellable request: A req is created with a GCond,
73 * and 3 refs (for the resolution thread, the calling thread, and
74 * the cancellation signal handler).
76 * a. If the resolution completes successfully, the thread pool
77 * function (threaded_resolver_thread()) will call
78 * g_threaded_resolver_request_complete(), which will detach
79 * the "cancelled" signal handler (dropping one ref on req)
80 * and signal the GCond, and then unref the req. The calling
81 * thread receives the signal from the GCond, processes the
82 * response, and unrefs the req, causing it to be freed.
84 * b. If the resolution is cancelled before completing,
85 * request_cancelled() will call
86 * g_threaded_resolver_request_complete(), which will detach
87 * the signal handler (as above, unreffing the req), set
88 * req->error to indicate that it was cancelled, and signal
89 * the GCond. The calling thread receives the signal from the
90 * GCond, processes the response, and unrefs the req.
91 * Eventually, the resolver thread finishes resolving (or
92 * times out in the resolver) and calls
93 * g_threaded_resolver_request_complete() again, but
94 * _request_complete() does nothing this time since the
95 * request is already complete. The thread pool func then
96 * unrefs the req, causing it to be freed.
98 * 3. Asynchronous request: A req is created with a GSimpleAsyncResult
99 * (and no GCond). The calling thread's ref on req is set up to be
100 * automatically dropped when the async_result is freed. Two
103 * a. If the resolution completes, the thread pool function
104 * (threaded_resolver_thread()) will call
105 * g_threaded_resolver_request_complete(), which will detach
106 * the "cancelled" signal handler (if it was present)
107 * (unreffing the req), queue the async_result to complete in
108 * an idle handler, unref the async_result (which is still
109 * reffed by the idle handler though), and then unref the req.
110 * The main thread then invokes the async_result's callback
111 * and processes the response. When it finishes, the
112 * async_result drops the ref that was taken by
113 * g_simple_async_result_complete_in_idle(), which causes the
114 * async_result to be freed, which causes req to be unreffed
117 * b. If the resolution is cancelled, request_cancelled() will
118 * call g_threaded_resolver_request_complete(), which will
119 * detach the signal handler (as above, unreffing the req) set
120 * req->error to indicate that it was cancelled, and queue and
121 * unref the async_result. The main thread completes the
122 * async_request and unrefs it and the req, as above.
123 * Eventually, the resolver thread finishes resolving (or
124 * times out in the resolver) and calls
125 * g_threaded_resolver_request_complete() again, but
126 * _request_complete() does nothing this time since the
127 * request is already complete. The thread pool func then
128 * unrefs the req, causing it to be freed.
130 * g_threaded_resolver_request_complete() ensures that if the request
131 * completes and cancels "at the same time" that only one of the two
132 * conditions gets processed.
135 typedef struct _GThreadedResolverRequest GThreadedResolverRequest;
136 typedef void (*GThreadedResolverResolveFunc) (GThreadedResolverRequest *, GError **);
137 typedef void (*GThreadedResolverFreeFunc) (GThreadedResolverRequest *);
139 struct _GThreadedResolverRequest {
140 GThreadedResolverResolveFunc resolve_func;
141 GThreadedResolverFreeFunc free_func;
149 GInetAddress *address;
158 GCancellable *cancellable;
165 GSimpleAsyncResult *async_result;
170 static void g_threaded_resolver_request_unref (GThreadedResolverRequest *req);
171 static void request_cancelled (GCancellable *cancellable, gpointer req);
172 static void request_cancelled_disconnect_notify (gpointer req, GClosure *closure);
174 static GThreadedResolverRequest *
175 g_threaded_resolver_request_new (GThreadedResolverResolveFunc resolve_func,
176 GThreadedResolverFreeFunc free_func,
177 GCancellable *cancellable)
179 GThreadedResolverRequest *req;
181 req = g_slice_new0 (GThreadedResolverRequest);
182 req->resolve_func = resolve_func;
183 req->free_func = free_func;
185 /* Initial refcount is 2; one for the caller and one for resolve_func */
188 req->mutex = g_mutex_new ();
189 /* Initially locked; caller must unlock */
190 g_mutex_lock (req->mutex);
195 req->cancellable = g_object_ref (cancellable);
196 g_signal_connect_data (cancellable, "cancelled",
197 G_CALLBACK (request_cancelled), req,
198 request_cancelled_disconnect_notify, 0);
205 g_threaded_resolver_request_unref (GThreadedResolverRequest *req)
209 g_mutex_lock (req->mutex);
210 ref_count = --req->ref_count;
211 g_mutex_unlock (req->mutex);
215 g_mutex_free (req->mutex);
218 g_cond_free (req->cond);
221 g_error_free (req->error);
224 req->free_func (req);
226 /* We don't have to free req->cancellable or req->async_result,
227 * since (if set), they must already have been freed by
228 * request_complete() in order to get here.
231 g_slice_free (GThreadedResolverRequest, req);
235 g_threaded_resolver_request_complete (GThreadedResolverRequest *req,
238 g_mutex_lock (req->mutex);
241 /* The req was cancelled, and now it has finished resolving as
242 * well. But we have nowhere to send the result, so just return.
244 g_mutex_unlock (req->mutex);
248 req->complete = TRUE;
249 g_mutex_unlock (req->mutex);
251 if (req->cancellable)
253 /* Possibly propagate a cancellation error */
254 if (cancelled && !req->error)
255 g_cancellable_set_error_if_cancelled (req->cancellable, &req->error);
257 /* Drop the signal handler's ref on @req */
258 g_signal_handlers_disconnect_by_func (req->cancellable, request_cancelled, req);
259 g_object_unref (req->cancellable);
260 req->cancellable = NULL;
264 g_cond_signal (req->cond);
265 else if (req->async_result)
268 g_simple_async_result_set_from_error (req->async_result, req->error);
269 g_simple_async_result_complete_in_idle (req->async_result);
271 /* Drop our ref on the async_result, which will eventually cause
272 * it to drop its ref on req.
274 g_object_unref (req->async_result);
275 req->async_result = NULL;
280 request_cancelled (GCancellable *cancellable,
283 GThreadedResolverRequest *req = user_data;
285 g_threaded_resolver_request_complete (req, TRUE);
287 /* We can't actually cancel the resolver thread; it will eventually
288 * complete on its own and call request_complete() again, which will
289 * do nothing the second time.
294 request_cancelled_disconnect_notify (gpointer req,
297 g_threaded_resolver_request_unref (req);
301 threaded_resolver_thread (gpointer thread_data,
304 GThreadedResolverRequest *req = thread_data;
306 req->resolve_func (req, &req->error);
307 g_threaded_resolver_request_complete (req, FALSE);
308 g_threaded_resolver_request_unref (req);
312 resolve_sync (GThreadedResolver *gtr,
313 GThreadedResolverRequest *req,
316 if (!req->cancellable || !gtr->thread_pool)
318 req->resolve_func (req, error);
319 g_mutex_unlock (req->mutex);
321 g_threaded_resolver_request_complete (req, FALSE);
322 g_threaded_resolver_request_unref (req);
326 req->cond = g_cond_new ();
327 g_thread_pool_push (gtr->thread_pool, req, &req->error);
329 g_cond_wait (req->cond, req->mutex);
330 g_mutex_unlock (req->mutex);
334 g_propagate_error (error, req->error);
340 resolve_async (GThreadedResolver *gtr,
341 GThreadedResolverRequest *req,
342 GAsyncReadyCallback callback,
346 req->async_result = g_simple_async_result_new (G_OBJECT (gtr),
347 callback, user_data, tag);
348 g_simple_async_result_set_op_res_gpointer (req->async_result, req,
349 (GDestroyNotify)g_threaded_resolver_request_unref);
350 g_thread_pool_push (gtr->thread_pool, req, NULL);
351 g_mutex_unlock (req->mutex);
354 static GThreadedResolverRequest *
355 resolve_finish (GResolver *resolver,
356 GAsyncResult *result,
360 g_return_val_if_fail (g_simple_async_result_is_valid (result, G_OBJECT (resolver), tag), NULL);
362 return g_simple_async_result_get_op_res_gpointer (G_SIMPLE_ASYNC_RESULT (result));
366 do_lookup_by_name (GThreadedResolverRequest *req,
369 struct addrinfo *res = NULL;
372 retval = getaddrinfo (req->u.name.hostname, NULL,
373 &_g_resolver_addrinfo_hints, &res);
374 req->u.name.addresses =
375 _g_resolver_addresses_from_addrinfo (req->u.name.hostname, res, retval, error);
381 lookup_by_name (GResolver *resolver,
382 const gchar *hostname,
383 GCancellable *cancellable,
386 GThreadedResolver *gtr = G_THREADED_RESOLVER (resolver);
387 GThreadedResolverRequest *req;
390 req = g_threaded_resolver_request_new (do_lookup_by_name, NULL, cancellable);
391 req->u.name.hostname = (gchar *)hostname;
392 resolve_sync (gtr, req, error);
394 addresses = req->u.name.addresses;
395 g_threaded_resolver_request_unref (req);
400 free_lookup_by_name (GThreadedResolverRequest *req)
402 g_free (req->u.name.hostname);
403 if (req->u.name.addresses)
404 g_resolver_free_addresses (req->u.name.addresses);
408 lookup_by_name_async (GResolver *resolver,
409 const gchar *hostname,
410 GCancellable *cancellable,
411 GAsyncReadyCallback callback,
414 GThreadedResolver *gtr = G_THREADED_RESOLVER (resolver);
415 GThreadedResolverRequest *req;
417 req = g_threaded_resolver_request_new (do_lookup_by_name, free_lookup_by_name,
419 req->u.name.hostname = g_strdup (hostname);
420 resolve_async (gtr, req, callback, user_data, lookup_by_name_async);
424 lookup_by_name_finish (GResolver *resolver,
425 GAsyncResult *result,
428 GThreadedResolverRequest *req;
431 req = resolve_finish (resolver, result, lookup_by_name_async, error);
432 addresses = req->u.name.addresses;
433 req->u.name.addresses = NULL;
439 do_lookup_by_address (GThreadedResolverRequest *req,
442 struct sockaddr_storage sockaddr;
444 gchar name[NI_MAXHOST];
447 _g_resolver_address_to_sockaddr (req->u.address.address,
448 &sockaddr, &sockaddr_size);
450 retval = getnameinfo ((struct sockaddr *)&sockaddr, sockaddr_size,
451 name, sizeof (name), NULL, 0, NI_NAMEREQD);
452 req->u.address.name = _g_resolver_name_from_nameinfo (req->u.address.address,
453 name, retval, error);
457 lookup_by_address (GResolver *resolver,
458 GInetAddress *address,
459 GCancellable *cancellable,
462 GThreadedResolver *gtr = G_THREADED_RESOLVER (resolver);
463 GThreadedResolverRequest *req;
466 req = g_threaded_resolver_request_new (do_lookup_by_address, NULL, cancellable);
467 req->u.address.address = address;
468 resolve_sync (gtr, req, error);
470 name = req->u.address.name;
471 g_threaded_resolver_request_unref (req);
476 free_lookup_by_address (GThreadedResolverRequest *req)
478 g_object_unref (req->u.address.address);
479 if (req->u.address.name)
480 g_free (req->u.address.name);
484 lookup_by_address_async (GResolver *resolver,
485 GInetAddress *address,
486 GCancellable *cancellable,
487 GAsyncReadyCallback callback,
490 GThreadedResolver *gtr = G_THREADED_RESOLVER (resolver);
491 GThreadedResolverRequest *req;
493 req = g_threaded_resolver_request_new (do_lookup_by_address,
494 free_lookup_by_address,
496 req->u.address.address = g_object_ref (address);
497 resolve_async (gtr, req, callback, user_data, lookup_by_address_async);
501 lookup_by_address_finish (GResolver *resolver,
502 GAsyncResult *result,
505 GThreadedResolverRequest *req;
508 req = resolve_finish (resolver, result, lookup_by_address_async, error);
509 name = req->u.address.name;
510 req->u.address.name = NULL;
516 do_lookup_service (GThreadedResolverRequest *req,
519 #if defined(G_OS_UNIX)
522 #elif defined(G_OS_WIN32)
527 #if defined(G_OS_UNIX)
528 len = res_query (req->u.service.rrname, C_IN, T_SRV, answer, sizeof (answer));
530 req->u.service.targets = _g_resolver_targets_from_res_query (req->u.service.rrname, answer, len, herr, error);
531 #elif defined(G_OS_WIN32)
532 status = DnsQuery_A (req->u.service.rrname, DNS_TYPE_SRV,
533 DNS_QUERY_STANDARD, NULL, &results, NULL);
534 req->u.service.targets = _g_resolver_targets_from_DnsQuery (req->u.service.rrname, status, results, error);
535 DnsRecordListFree (results, DnsFreeRecordList);
540 lookup_service (GResolver *resolver,
542 GCancellable *cancellable,
545 GThreadedResolver *gtr = G_THREADED_RESOLVER (resolver);
546 GThreadedResolverRequest *req;
549 req = g_threaded_resolver_request_new (do_lookup_service, NULL, cancellable);
550 req->u.service.rrname = (char *)rrname;
551 resolve_sync (gtr, req, error);
553 targets = req->u.service.targets;
554 g_threaded_resolver_request_unref (req);
559 free_lookup_service (GThreadedResolverRequest *req)
561 g_free (req->u.service.rrname);
562 if (req->u.service.targets)
563 g_resolver_free_targets (req->u.service.targets);
567 lookup_service_async (GResolver *resolver,
569 GCancellable *cancellable,
570 GAsyncReadyCallback callback,
573 GThreadedResolver *gtr = G_THREADED_RESOLVER (resolver);
574 GThreadedResolverRequest *req;
576 req = g_threaded_resolver_request_new (do_lookup_service,
579 req->u.service.rrname = g_strdup (rrname);
580 resolve_async (gtr, req, callback, user_data, lookup_service_async);
584 lookup_service_finish (GResolver *resolver,
585 GAsyncResult *result,
588 GThreadedResolverRequest *req;
591 req = resolve_finish (resolver, result, lookup_service_async, error);
592 targets = req->u.service.targets;
593 req->u.service.targets = NULL;
599 g_threaded_resolver_class_init (GThreadedResolverClass *threaded_class)
601 GResolverClass *resolver_class = G_RESOLVER_CLASS (threaded_class);
602 GObjectClass *object_class = G_OBJECT_CLASS (threaded_class);
604 resolver_class->lookup_by_name = lookup_by_name;
605 resolver_class->lookup_by_name_async = lookup_by_name_async;
606 resolver_class->lookup_by_name_finish = lookup_by_name_finish;
607 resolver_class->lookup_by_address = lookup_by_address;
608 resolver_class->lookup_by_address_async = lookup_by_address_async;
609 resolver_class->lookup_by_address_finish = lookup_by_address_finish;
610 resolver_class->lookup_service = lookup_service;
611 resolver_class->lookup_service_async = lookup_service_async;
612 resolver_class->lookup_service_finish = lookup_service_finish;
614 object_class->finalize = finalize;