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IABSD.fr/xenocara/xserver/config/dbus-core.c
matthieu
- xserver/config/dbus-core.c
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/* * Copyright © 2006-2007 Daniel Stone * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. * * Author: Daniel Stone <daniel@fooishbar.org> */ #ifdef HAVE_DIX_CONFIG_H #include <dix-config.h> #endif #include <dbus/dbus.h> #include <sys/select.h> #include "dix.h" #include "os.h" #include "dbus-core.h" /* How often to attempt reconnecting when we get booted off the bus. */ #define RECONNECT_DELAY (10 * 1000) /* in ms */ struct dbus_core_info { int fd; DBusConnection *connection; OsTimerPtr timer; struct dbus_core_hook *hooks; }; static struct dbus_core_info bus_info = { .fd = -1 }; static CARD32 reconnect_timer(OsTimerPtr timer, CARD32 time, void *arg); static void socket_handler(int fd, int ready, void *data) { struct dbus_core_info *info = data; if (info->connection) { do { dbus_connection_read_write_dispatch(info->connection, 0); } while (info->connection && dbus_connection_get_is_connected(info->connection) && dbus_connection_get_dispatch_status(info->connection) == DBUS_DISPATCH_DATA_REMAINS); } } /** * Disconnect (if we haven't already been forcefully disconnected), clean up * after ourselves, and call all registered disconnect hooks. */ static void teardown(void) { struct dbus_core_hook *hook; if (bus_info.timer) { TimerFree(bus_info.timer); bus_info.timer = NULL; } /* We should really have pre-disconnect hooks and run them here, for * completeness. But then it gets awkward, given that you can't * guarantee that they'll be called ... */ if (bus_info.connection) dbus_connection_unref(bus_info.connection); if (bus_info.fd != -1) RemoveNotifyFd(bus_info.fd); bus_info.fd = -1; bus_info.connection = NULL; for (hook = bus_info.hooks; hook; hook = hook->next) { if (hook->disconnect) hook->disconnect(hook->data); } } /** * This is a filter, which only handles the disconnected signal, which * doesn't go to the normal message handling function. This takes * precedence over the message handling function, so have have to be * careful to ignore anything we don't want to deal with here. */ static DBusHandlerResult message_filter(DBusConnection * connection, DBusMessage * message, void *data) { /* If we get disconnected, then take everything down, and attempt to * reconnect immediately (assuming it's just a restart). The * connection isn't valid at this point, so throw it out immediately. */ if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) { DebugF("[dbus-core] disconnected from bus\n"); bus_info.connection = NULL; teardown(); if (bus_info.timer) TimerFree(bus_info.timer); bus_info.timer = TimerSet(NULL, 0, 1, reconnect_timer, NULL); return DBUS_HANDLER_RESULT_HANDLED; } return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; } /** * Attempt to connect to the system bus, and set a filter to deal with * disconnection (see message_filter above). * * @return 1 on success, 0 on failure. */ static int connect_to_bus(void) { DBusError error; struct dbus_core_hook *hook; dbus_error_init(&error); bus_info.connection = dbus_bus_get(DBUS_BUS_SYSTEM, &error); if (!bus_info.connection || dbus_error_is_set(&error)) { LogMessage(X_ERROR, "dbus-core: error connecting to system bus: %s (%s)\n", error.name, error.message); goto err_begin; } /* Thankyou. Really, thankyou. */ dbus_connection_set_exit_on_disconnect(bus_info.connection, FALSE); if (!dbus_connection_get_unix_fd(bus_info.connection, &bus_info.fd)) { ErrorF("[dbus-core] couldn't get fd for system bus\n"); goto err_unref; } if (!dbus_connection_add_filter(bus_info.connection, message_filter, &bus_info, NULL)) { ErrorF("[dbus-core] couldn't add filter: %s (%s)\n", error.name, error.message); goto err_fd; } dbus_error_free(&error); SetNotifyFd(bus_info.fd, socket_handler, X_NOTIFY_READ, &bus_info); for (hook = bus_info.hooks; hook; hook = hook->next) { if (hook->connect) hook->connect(bus_info.connection, hook->data); } return 1; err_fd: bus_info.fd = -1; err_unref: dbus_connection_unref(bus_info.connection); bus_info.connection = NULL; err_begin: dbus_error_free(&error); return 0; } static CARD32 reconnect_timer(OsTimerPtr timer, CARD32 time, void *arg) { if (connect_to_bus()) { TimerFree(bus_info.timer); bus_info.timer = NULL; return 0; } else { return RECONNECT_DELAY; } } int dbus_core_add_hook(struct dbus_core_hook *hook) { struct dbus_core_hook **prev; for (prev = &bus_info.hooks; *prev; prev = &(*prev)->next); hook->next = NULL; *prev = hook; /* If we're already connected, call the connect hook. */ if (bus_info.connection) hook->connect(bus_info.connection, hook->data); return 1; } void dbus_core_remove_hook(struct dbus_core_hook *hook) { struct dbus_core_hook **prev; for (prev = &bus_info.hooks; *prev; prev = &(*prev)->next) { if (*prev == hook) { *prev = hook->next; break; } } } int dbus_core_init(void) { memset(&bus_info, 0, sizeof(bus_info)); bus_info.fd = -1; bus_info.hooks = NULL; if (!connect_to_bus()) bus_info.timer = TimerSet(NULL, 0, 1, reconnect_timer, NULL); return 1; } void dbus_core_fini(void) { teardown(); }