+++ /dev/null
-/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
-/* dbus-watch.c DBusWatch implementation
- *
- * Copyright (C) 2002, 2003 Red Hat Inc.
- *
- * Licensed under the Academic Free License version 2.1
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- */
-
-#include "dbus-internals.h"
-#include "dbus-watch.h"
-#include "dbus-list.h"
-
-/**
- * @defgroup DBusWatchInternals DBusWatch implementation details
- * @ingroup DBusInternals
- * @brief implementation details for DBusWatch
- *
- * @{
- */
-
-/**
- * Implementation of DBusWatch
- */
-struct DBusWatch
-{
- int refcount; /**< Reference count */
- int fd; /**< File descriptor. */
- unsigned int flags; /**< Conditions to watch. */
-
- DBusWatchHandler handler; /**< Watch handler. */
- void *handler_data; /**< Watch handler data. */
- DBusFreeFunction free_handler_data_function; /**< Free the watch handler data. */
-
- void *data; /**< Application data. */
- DBusFreeFunction free_data_function; /**< Free the application data. */
- unsigned int enabled : 1; /**< Whether it's enabled. */
-};
-
-/**
- * Creates a new DBusWatch. Used to add a file descriptor to be polled
- * by a main loop.
- *
- * @param fd the file descriptor to be watched.
- * @param flags the conditions to watch for on the descriptor.
- * @param enabled the initial enabled state
- * @param handler the handler function
- * @param data data for handler function
- * @param free_data_function function to free the data
- * @returns the new DBusWatch object.
- */
-DBusWatch*
-_dbus_watch_new (int fd,
- unsigned int flags,
- dbus_bool_t enabled,
- DBusWatchHandler handler,
- void *data,
- DBusFreeFunction free_data_function)
-{
- DBusWatch *watch;
-
-#define VALID_WATCH_FLAGS (DBUS_WATCH_WRITABLE | DBUS_WATCH_READABLE)
-
- _dbus_assert ((flags & VALID_WATCH_FLAGS) == flags);
-
- watch = dbus_new0 (DBusWatch, 1);
- if (watch == NULL)
- return NULL;
-
- watch->refcount = 1;
- watch->fd = fd;
- watch->flags = flags;
- watch->enabled = enabled;
-
- watch->handler = handler;
- watch->handler_data = data;
- watch->free_handler_data_function = free_data_function;
-
- return watch;
-}
-
-/**
- * Increments the reference count of a DBusWatch object.
- *
- * @param watch the watch object.
- * @returns the watch object.
- */
-DBusWatch *
-_dbus_watch_ref (DBusWatch *watch)
-{
- watch->refcount += 1;
-
- return watch;
-}
-
-/**
- * Decrements the reference count of a DBusWatch object
- * and finalizes the object if the count reaches zero.
- *
- * @param watch the watch object.
- */
-void
-_dbus_watch_unref (DBusWatch *watch)
-{
- _dbus_assert (watch != NULL);
- _dbus_assert (watch->refcount > 0);
-
- watch->refcount -= 1;
- if (watch->refcount == 0)
- {
- dbus_watch_set_data (watch, NULL, NULL); /* call free_data_function */
-
- if (watch->free_handler_data_function)
- (* watch->free_handler_data_function) (watch->handler_data);
-
- dbus_free (watch);
- }
-}
-
-/**
- * Clears the file descriptor from a now-invalid watch object so that
- * no one tries to use it. This is because a watch may stay alive due
- * to reference counts after the file descriptor is closed.
- * Invalidation makes it easier to catch bugs. It also
- * keeps people from doing dorky things like assuming file descriptors
- * are unique (never recycled).
- *
- * @param watch the watch object.
- */
-void
-_dbus_watch_invalidate (DBusWatch *watch)
-{
- watch->fd = -1;
- watch->flags = 0;
-}
-
-/**
- * Sanitizes the given condition so that it only contains
- * flags that the DBusWatch requested. e.g. if the
- * watch is a DBUS_WATCH_READABLE watch then
- * DBUS_WATCH_WRITABLE will be stripped from the condition.
- *
- * @param watch the watch object.
- * @param condition address of the condition to sanitize.
- */
-void
-_dbus_watch_sanitize_condition (DBusWatch *watch,
- unsigned int *condition)
-{
- if (!(watch->flags & DBUS_WATCH_READABLE))
- *condition &= ~DBUS_WATCH_READABLE;
- if (!(watch->flags & DBUS_WATCH_WRITABLE))
- *condition &= ~DBUS_WATCH_WRITABLE;
-}
-
-
-/**
- * @typedef DBusWatchList
- *
- * Opaque data type representing a list of watches
- * and a set of DBusAddWatchFunction/DBusRemoveWatchFunction.
- * Automatically handles removing/re-adding watches
- * when the DBusAddWatchFunction is updated or changed.
- * Holds a reference count to each watch.
- *
- * Used in the implementation of both DBusServer and
- * DBusClient.
- *
- */
-
-/**
- * DBusWatchList implementation details. All fields
- * are private.
- *
- */
-struct DBusWatchList
-{
- DBusList *watches; /**< Watch objects. */
-
- DBusAddWatchFunction add_watch_function; /**< Callback for adding a watch. */
- DBusRemoveWatchFunction remove_watch_function; /**< Callback for removing a watch. */
- DBusWatchToggledFunction watch_toggled_function; /**< Callback on toggling enablement */
- void *watch_data; /**< Data for watch callbacks */
- DBusFreeFunction watch_free_data_function; /**< Free function for watch callback data */
-};
-
-/**
- * Creates a new watch list. Returns #NULL if insufficient
- * memory exists.
- *
- * @returns the new watch list, or #NULL on failure.
- */
-DBusWatchList*
-_dbus_watch_list_new (void)
-{
- DBusWatchList *watch_list;
-
- watch_list = dbus_new0 (DBusWatchList, 1);
- if (watch_list == NULL)
- return NULL;
-
- return watch_list;
-}
-
-/**
- * Frees a DBusWatchList.
- *
- * @param watch_list the watch list.
- */
-void
-_dbus_watch_list_free (DBusWatchList *watch_list)
-{
- /* free watch_data and removes watches as a side effect */
- _dbus_watch_list_set_functions (watch_list,
- NULL, NULL, NULL, NULL, NULL);
- _dbus_list_foreach (&watch_list->watches,
- (DBusForeachFunction) _dbus_watch_unref,
- NULL);
- _dbus_list_clear (&watch_list->watches);
-
- dbus_free (watch_list);
-}
-
-/**
- * Sets the watch functions. This function is the "backend"
- * for dbus_connection_set_watch_functions() and
- * dbus_server_set_watch_functions().
- *
- * @param watch_list the watch list.
- * @param add_function the add watch function.
- * @param remove_function the remove watch function.
- * @param toggled_function function on toggling enabled flag, or #NULL
- * @param data the data for those functions.
- * @param free_data_function the function to free the data.
- * @returns #FALSE if not enough memory
- *
- */
-dbus_bool_t
-_dbus_watch_list_set_functions (DBusWatchList *watch_list,
- DBusAddWatchFunction add_function,
- DBusRemoveWatchFunction remove_function,
- DBusWatchToggledFunction toggled_function,
- void *data,
- DBusFreeFunction free_data_function)
-{
- /* Add watches with the new watch function, failing on OOM */
- if (add_function != NULL)
- {
- DBusList *link;
-
- link = _dbus_list_get_first_link (&watch_list->watches);
- while (link != NULL)
- {
- DBusList *next = _dbus_list_get_next_link (&watch_list->watches,
- link);
-
-#ifdef DBUS_ENABLE_VERBOSE_MODE
- {
- const char *watch_type;
- int flags;
-
- flags = dbus_watch_get_flags (link->data);
- if ((flags & DBUS_WATCH_READABLE) &&
- (flags & DBUS_WATCH_WRITABLE))
- watch_type = "readwrite";
- else if (flags & DBUS_WATCH_READABLE)
- watch_type = "read";
- else if (flags & DBUS_WATCH_WRITABLE)
- watch_type = "write";
- else
- watch_type = "not read or write";
-
- _dbus_verbose ("Adding a %s watch on fd %d using newly-set add watch function\n",
- watch_type,
- dbus_watch_get_socket (link->data));
- }
-#endif /* DBUS_ENABLE_VERBOSE_MODE */
-
- if (!(* add_function) (link->data, data))
- {
- /* remove it all again and return FALSE */
- DBusList *link2;
-
- link2 = _dbus_list_get_first_link (&watch_list->watches);
- while (link2 != link)
- {
- DBusList *next = _dbus_list_get_next_link (&watch_list->watches,
- link2);
-
- _dbus_verbose ("Removing watch on fd %d using newly-set remove function because initial add failed\n",
- dbus_watch_get_socket (link2->data));
-
- (* remove_function) (link2->data, data);
-
- link2 = next;
- }
-
- return FALSE;
- }
-
- link = next;
- }
- }
-
- /* Remove all current watches from previous watch handlers */
-
- if (watch_list->remove_watch_function != NULL)
- {
- _dbus_verbose ("Removing all pre-existing watches\n");
-
- _dbus_list_foreach (&watch_list->watches,
- (DBusForeachFunction) watch_list->remove_watch_function,
- watch_list->watch_data);
- }
-
- if (watch_list->watch_free_data_function != NULL)
- (* watch_list->watch_free_data_function) (watch_list->watch_data);
-
- watch_list->add_watch_function = add_function;
- watch_list->remove_watch_function = remove_function;
- watch_list->watch_toggled_function = toggled_function;
- watch_list->watch_data = data;
- watch_list->watch_free_data_function = free_data_function;
-
- return TRUE;
-}
-
-/**
- * Adds a new watch to the watch list, invoking the
- * application DBusAddWatchFunction if appropriate.
- *
- * @param watch_list the watch list.
- * @param watch the watch to add.
- * @returns #TRUE on success, #FALSE if no memory.
- */
-dbus_bool_t
-_dbus_watch_list_add_watch (DBusWatchList *watch_list,
- DBusWatch *watch)
-{
- if (!_dbus_list_append (&watch_list->watches, watch))
- return FALSE;
-
- _dbus_watch_ref (watch);
-
- if (watch_list->add_watch_function != NULL)
- {
- _dbus_verbose ("Adding watch on fd %d\n",
- dbus_watch_get_socket (watch));
-
- if (!(* watch_list->add_watch_function) (watch,
- watch_list->watch_data))
- {
- _dbus_list_remove_last (&watch_list->watches, watch);
- _dbus_watch_unref (watch);
- return FALSE;
- }
- }
-
- return TRUE;
-}
-
-/**
- * Removes a watch from the watch list, invoking the
- * application's DBusRemoveWatchFunction if appropriate.
- *
- * @param watch_list the watch list.
- * @param watch the watch to remove.
- */
-void
-_dbus_watch_list_remove_watch (DBusWatchList *watch_list,
- DBusWatch *watch)
-{
- if (!_dbus_list_remove (&watch_list->watches, watch))
- _dbus_assert_not_reached ("Nonexistent watch was removed");
-
- if (watch_list->remove_watch_function != NULL)
- {
- _dbus_verbose ("Removing watch on fd %d\n",
- dbus_watch_get_socket (watch));
-
- (* watch_list->remove_watch_function) (watch,
- watch_list->watch_data);
- }
-
- _dbus_watch_unref (watch);
-}
-
-/**
- * Sets a watch to the given enabled state, invoking the
- * application's DBusWatchToggledFunction if appropriate.
- *
- * @param watch_list the watch list.
- * @param watch the watch to toggle.
- * @param enabled #TRUE to enable
- */
-void
-_dbus_watch_list_toggle_watch (DBusWatchList *watch_list,
- DBusWatch *watch,
- dbus_bool_t enabled)
-{
- enabled = !!enabled;
-
- if (enabled == watch->enabled)
- return;
-
- watch->enabled = enabled;
-
- if (watch_list->watch_toggled_function != NULL)
- {
- _dbus_verbose ("Toggling watch %p on fd %d to %d\n",
- watch, dbus_watch_get_socket (watch), watch->enabled);
-
- (* watch_list->watch_toggled_function) (watch,
- watch_list->watch_data);
- }
-}
-
-/**
- * Sets the handler for the watch.
- *
- * @todo this function only exists because of the weird
- * way connection watches are done, see the note
- * in docs for _dbus_connection_handle_watch().
- *
- * @param watch the watch
- * @param handler the new handler
- * @param data the data
- * @param free_data_function free data with this
- */
-void
-_dbus_watch_set_handler (DBusWatch *watch,
- DBusWatchHandler handler,
- void *data,
- DBusFreeFunction free_data_function)
-{
- if (watch->free_handler_data_function)
- (* watch->free_handler_data_function) (watch->handler_data);
-
- watch->handler = handler;
- watch->handler_data = data;
- watch->free_handler_data_function = free_data_function;
-}
-
-/** @} */
-
-/**
- * @defgroup DBusWatch DBusWatch
- * @ingroup DBus
- * @brief Object representing a file descriptor to be watched.
- *
- * Types and functions related to DBusWatch. A watch represents
- * a file descriptor that the main loop needs to monitor,
- * as in Qt's QSocketNotifier or GLib's g_io_add_watch().
- *
- * Use dbus_connection_set_watch_functions() or dbus_server_set_watch_functions()
- * to be notified when libdbus needs to add or remove watches.
- *
- * @{
- */
-
-/**
- * @typedef DBusWatch
- *
- * Opaque object representing a file descriptor
- * to be watched for changes in readability,
- * writability, or hangup.
- */
-
-/**
- * Deprecated former name of dbus_watch_get_unix_fd().
- *
- * @param watch the DBusWatch object.
- * @returns the file descriptor to watch.
- */
-int
-dbus_watch_get_fd (DBusWatch *watch)
-{
- return dbus_watch_get_unix_fd(watch);
-}
-
-/**
- * Returns a UNIX file descriptor to be watched,
- * which may be a pipe, socket, or other type of
- * descriptor. On UNIX this is preferred to
- * dbus_watch_get_socket() since it works with
- * more kinds of #DBusWatch.
- *
- * Always returns -1 on Windows. On Windows you use
- * dbus_watch_get_socket() to get a Winsock socket to watch.
- *
- * @param watch the DBusWatch object.
- * @returns the file descriptor to watch.
- */
-int
-dbus_watch_get_unix_fd (DBusWatch *watch)
-{
- /* FIXME remove #ifdef and do this on a lower level
- * (watch should have set_socket and set_unix_fd and track
- * which it has, and the transport should provide the
- * appropriate watch type)
- */
-#ifdef DBUS_UNIX
- return watch->fd;
-#else
- return -1;
-#endif
-}
-
-/**
- * Returns a socket to be watched, on UNIX this will return -1 if our
- * transport is not socket-based so dbus_watch_get_unix_fd() is
- * preferred.
- *
- * On Windows, dbus_watch_get_unix_fd() returns -1 but this function
- * returns a Winsock socket (assuming the transport is socket-based,
- * as it always is for now).
- *
- * @param watch the DBusWatch object.
- * @returns the socket to watch.
- */
-int
-dbus_watch_get_socket (DBusWatch *watch)
-{
- return watch->fd;
-}
-
-/**
- * Gets flags from DBusWatchFlags indicating
- * what conditions should be monitored on the
- * file descriptor.
- *
- * The flags returned will only contain DBUS_WATCH_READABLE
- * and DBUS_WATCH_WRITABLE, never DBUS_WATCH_HANGUP or
- * DBUS_WATCH_ERROR; all watches implicitly include a watch
- * for hangups, errors, and other exceptional conditions.
- *
- * @param watch the DBusWatch object.
- * @returns the conditions to watch.
- */
-unsigned int
-dbus_watch_get_flags (DBusWatch *watch)
-{
- _dbus_assert ((watch->flags & VALID_WATCH_FLAGS) == watch->flags);
-
- return watch->flags;
-}
-
-/**
- * Gets data previously set with dbus_watch_set_data()
- * or #NULL if none.
- *
- * @param watch the DBusWatch object.
- * @returns previously-set data.
- */
-void*
-dbus_watch_get_data (DBusWatch *watch)
-{
- return watch->data;
-}
-
-/**
- * Sets data which can be retrieved with dbus_watch_get_data().
- * Intended for use by the DBusAddWatchFunction and
- * DBusRemoveWatchFunction to store their own data. For example with
- * Qt you might store the QSocketNotifier for this watch and with GLib
- * you might store a GSource.
- *
- * @param watch the DBusWatch object.
- * @param data the data.
- * @param free_data_function function to be called to free the data.
- */
-void
-dbus_watch_set_data (DBusWatch *watch,
- void *data,
- DBusFreeFunction free_data_function)
-{
- _dbus_verbose ("Setting watch fd %d data to data = %p function = %p from data = %p function = %p\n",
- dbus_watch_get_socket (watch),
- data, free_data_function, watch->data, watch->free_data_function);
-
- if (watch->free_data_function != NULL)
- (* watch->free_data_function) (watch->data);
-
- watch->data = data;
- watch->free_data_function = free_data_function;
-}
-
-/**
- * Returns whether a watch is enabled or not. If not
- * enabled, it should not be polled by the main loop.
- *
- * @param watch the DBusWatch object
- * @returns #TRUE if the watch is enabled
- */
-dbus_bool_t
-dbus_watch_get_enabled (DBusWatch *watch)
-{
- _dbus_assert (watch != NULL);
- return watch->enabled;
-}
-
-
-/**
- * Called to notify the D-Bus library when a previously-added watch is
- * ready for reading or writing, or has an exception such as a hangup.
- *
- * If this function returns #FALSE, then the file descriptor may still
- * be ready for reading or writing, but more memory is needed in order
- * to do the reading or writing. If you ignore the #FALSE return, your
- * application may spin in a busy loop on the file descriptor until
- * memory becomes available, but nothing more catastrophic should
- * happen.
- *
- * dbus_watch_handle() cannot be called during the
- * DBusAddWatchFunction, as the connection will not be ready to handle
- * that watch yet.
- *
- * It is not allowed to reference a DBusWatch after it has been passed
- * to remove_function.
- *
- * @param watch the DBusWatch object.
- * @param flags the poll condition using #DBusWatchFlags values
- * @returns #FALSE if there wasn't enough memory
- */
-dbus_bool_t
-dbus_watch_handle (DBusWatch *watch,
- unsigned int flags)
-{
-#ifndef DBUS_DISABLE_CHECKS
- if (watch->fd < 0 || watch->flags == 0)
- {
- _dbus_warn_check_failed ("%s: Watch is invalid, it should have been removed\n",
- _DBUS_FUNCTION_NAME);
- return TRUE;
- }
-#endif
-
- _dbus_return_val_if_fail (watch->fd >= 0 /* fails if watch was removed */, TRUE);
-
- _dbus_watch_sanitize_condition (watch, &flags);
-
- if (flags == 0)
- {
- _dbus_verbose ("After sanitization, watch flags on fd %d were 0\n",
- watch->fd);
- return TRUE;
- }
- else
- return (* watch->handler) (watch, flags,
- watch->handler_data);
-}
-
-
-/** @} */
projects / monky / blobdiff