gio/gthreadedsocketservice.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright © 2009 Codethink Limited
   4  * Copyright © 2009 Red Hat, Inc
   5  *
   6  * SPDX-License-Identifier: LGPL-2.1-or-later
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General
  19  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
  20  *
  21  * Authors: Ryan Lortie <desrt@desrt.ca>
  22  *          Alexander Larsson <alexl@redhat.com>
  23  */
  24
  25 /**
  26  * SECTION:gthreadedsocketservice
  27  * @title: GThreadedSocketService
  28  * @short_description: A threaded GSocketService
  29  * @include: gio/gio.h
  30  * @see_also: #GSocketService.
  31  *
  32  * A #GThreadedSocketService is a simple subclass of #GSocketService
  33  * that handles incoming connections by creating a worker thread and
  34  * dispatching the connection to it by emitting the
  35  * #GThreadedSocketService::run signal in the new thread.
  36  *
  37  * The signal handler may perform blocking IO and need not return
  38  * until the connection is closed.
  39  *
  40  * The service is implemented using a thread pool, so there is a
  41  * limited amount of threads available to serve incoming requests.
  42  * The service automatically stops the #GSocketService from accepting
  43  * new connections when all threads are busy.
  44  *
  45  * As with #GSocketService, you may connect to #GThreadedSocketService::run,
  46  * or subclass and override the default handler.
  47  */
  48
  49 #include "config.h"
  50 #include "gsocketconnection.h"
  51 #include "gthreadedsocketservice.h"
  52 #include "glibintl.h"
  53 #include "gmarshal-internal.h"
  54
  55 struct _GThreadedSocketServicePrivate
  56 {
  57   GThreadPool *thread_pool;
  58   int max_threads;
  59   gint job_count;
  60 };
  61
  62 static guint g_threaded_socket_service_run_signal;
  63
  64 G_DEFINE_TYPE_WITH_PRIVATE (GThreadedSocketService,
  65                             g_threaded_socket_service,
  66                             G_TYPE_SOCKET_SERVICE)
  67
  68 typedef enum
  69 {
  70   PROP_MAX_THREADS = 1,
  71 } GThreadedSocketServiceProperty;
  72
  73 G_LOCK_DEFINE_STATIC(job_count);
  74
  75 typedef struct
  76 {
  77   GThreadedSocketService *service;  /* (owned) */
  78   GSocketConnection *connection;  /* (owned) */
  79   GObject *source_object;  /* (owned) (nullable) */
  80 } GThreadedSocketServiceData;
  81
  82 static void
  83 g_threaded_socket_service_data_free (GThreadedSocketServiceData *data)
  84 {
  85   g_clear_object (&data->service);
  86   g_clear_object (&data->connection);
  87   g_clear_object (&data->source_object);
  88   g_slice_free (GThreadedSocketServiceData, data);
  89 }
  90
  91 static void
  92 g_threaded_socket_service_func (gpointer job_data,
  93                                 gpointer user_data)
  94 {
  95   GThreadedSocketServiceData *data = job_data;
  96   gboolean result;
  97
  98   g_signal_emit (data->service, g_threaded_socket_service_run_signal,
  99                  0, data->connection, data->source_object, &result);
 100
 101   G_LOCK (job_count);
 102   if (data->service->priv->job_count-- == data->service->priv->max_threads)
 103     g_socket_service_start (G_SOCKET_SERVICE (data->service));
 104   G_UNLOCK (job_count);
 105
 106   g_threaded_socket_service_data_free (data);
 107 }
 108
 109 static gboolean
 110 g_threaded_socket_service_incoming (GSocketService    *service,
 111                                     GSocketConnection *connection,
 112                                     GObject           *source_object)
 113 {
 114   GThreadedSocketService *threaded;
 115   GThreadedSocketServiceData *data;
 116   GError *local_error = NULL;
 117
 118   threaded = G_THREADED_SOCKET_SERVICE (service);
 119
 120   data = g_slice_new0 (GThreadedSocketServiceData);
 121   data->service = g_object_ref (threaded);
 122   data->connection = g_object_ref (connection);
 123   data->source_object = (source_object != NULL) ? g_object_ref (source_object) : NULL;
 124
 125   G_LOCK (job_count);
 126   if (++threaded->priv->job_count == threaded->priv->max_threads)
 127     g_socket_service_stop (service);
 128   G_UNLOCK (job_count);
 129
 130   if (!g_thread_pool_push (threaded->priv->thread_pool, data, &local_error))
 131     {
 132       g_warning ("Error handling incoming socket: %s", local_error->message);
 133       g_threaded_socket_service_data_free (data);
 134     }
 135
 136   g_clear_error (&local_error);
 137
 138   return FALSE;
 139 }
 140
 141 static void
 142 g_threaded_socket_service_init (GThreadedSocketService *service)
 143 {
 144   service->priv = g_threaded_socket_service_get_instance_private (service);
 145   service->priv->max_threads = 10;
 146 }
 147
 148 static void
 149 g_threaded_socket_service_constructed (GObject *object)
 150 {
 151   GThreadedSocketService *service = G_THREADED_SOCKET_SERVICE (object);
 152
 153   service->priv->thread_pool =
 154     g_thread_pool_new  (g_threaded_socket_service_func,
 155                         NULL,
 156                         service->priv->max_threads,
 157                         FALSE,
 158                         NULL);
 159 }
 160
 161
 162 static void
 163 g_threaded_socket_service_finalize (GObject *object)
 164 {
 165   GThreadedSocketService *service = G_THREADED_SOCKET_SERVICE (object);
 166
 167   /* All jobs in the pool hold a reference to this #GThreadedSocketService, so
 168    * this should only be called once the pool is empty: */
 169   g_thread_pool_free (service->priv->thread_pool, FALSE, FALSE);
 170
 171   G_OBJECT_CLASS (g_threaded_socket_service_parent_class)
 172     ->finalize (object);
 173 }
 174
 175 static void
 176 g_threaded_socket_service_get_property (GObject    *object,
 177                                         guint       prop_id,
 178                                         GValue     *value,
 179                                         GParamSpec *pspec)
 180 {
 181   GThreadedSocketService *service = G_THREADED_SOCKET_SERVICE (object);
 182
 183   switch ((GThreadedSocketServiceProperty) prop_id)
 184     {
 185       case PROP_MAX_THREADS:
 186         g_value_set_int (value, service->priv->max_threads);
 187         break;
 188
 189       default:
 190         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 191     }
 192 }
 193
 194 static void
 195 g_threaded_socket_service_set_property (GObject      *object,
 196                                         guint         prop_id,
 197                                         const GValue *value,
 198                                         GParamSpec   *pspec)
 199 {
 200   GThreadedSocketService *service = G_THREADED_SOCKET_SERVICE (object);
 201
 202   switch ((GThreadedSocketServiceProperty) prop_id)
 203     {
 204       case PROP_MAX_THREADS:
 205         service->priv->max_threads = g_value_get_int (value);
 206         break;
 207
 208       default:
 209         G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 210     }
 211 }
 212
 213
 214 static void
 215 g_threaded_socket_service_class_init (GThreadedSocketServiceClass *class)
 216 {
 217   GObjectClass *gobject_class = G_OBJECT_CLASS (class);
 218   GSocketServiceClass *ss_class = &class->parent_class;
 219
 220   gobject_class->constructed = g_threaded_socket_service_constructed;
 221   gobject_class->finalize = g_threaded_socket_service_finalize;
 222   gobject_class->set_property = g_threaded_socket_service_set_property;
 223   gobject_class->get_property = g_threaded_socket_service_get_property;
 224
 225   ss_class->incoming = g_threaded_socket_service_incoming;
 226
 227   /**
 228    * GThreadedSocketService::run:
 229    * @service: the #GThreadedSocketService.
 230    * @connection: a new #GSocketConnection object.
 231    * @source_object: (nullable): the source_object passed to g_socket_listener_add_address().
 232    *
 233    * The ::run signal is emitted in a worker thread in response to an
 234    * incoming connection. This thread is dedicated to handling
 235    * @connection and may perform blocking IO. The signal handler need
 236    * not return until the connection is closed.
 237    *
 238    * Returns: %TRUE to stop further signal handlers from being called
 239    */
 240   g_threaded_socket_service_run_signal =
 241     g_signal_new (I_("run"), G_TYPE_FROM_CLASS (class), G_SIGNAL_RUN_LAST,
 242                   G_STRUCT_OFFSET (GThreadedSocketServiceClass, run),
 243                   g_signal_accumulator_true_handled, NULL,
 244                   _g_cclosure_marshal_BOOLEAN__OBJECT_OBJECT,
 245                   G_TYPE_BOOLEAN,
 246                   2, G_TYPE_SOCKET_CONNECTION, G_TYPE_OBJECT);
 247   g_signal_set_va_marshaller (g_threaded_socket_service_run_signal,
 248                               G_TYPE_FROM_CLASS (class),
 249                               _g_cclosure_marshal_BOOLEAN__OBJECT_OBJECTv);
 250
 251   g_object_class_install_property (gobject_class, PROP_MAX_THREADS,
 252                                    g_param_spec_int ("max-threads",
 253                                                      P_("Max threads"),
 254                                                      P_("The max number of threads handling clients for this service"),
 255                                                      -1,
 256                                                      G_MAXINT,
 257                                                      10,
 258                                                      G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 259 }
 260
 261 /**
 262  * g_threaded_socket_service_new:
 263  * @max_threads: the maximal number of threads to execute concurrently
 264  *   handling incoming clients, -1 means no limit
 265  *
 266  * Creates a new #GThreadedSocketService with no listeners. Listeners
 267  * must be added with one of the #GSocketListener "add" methods.
 268  *
 269  * Returns: a new #GSocketService.
 270  *
 271  * Since: 2.22
 272  */
 273 GSocketService *
 274 g_threaded_socket_service_new (int max_threads)
 275 {
 276   return g_object_new (G_TYPE_THREADED_SOCKET_SERVICE,
 277                        "max-threads", max_threads,
 278                        NULL);
 279 }