From 6ef472beb240d01b8e681735e5c0d4f15a64b0ad Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?P=C5=99emysl=20Janouch?= Date: Sat, 25 Apr 2015 00:36:02 +0200 Subject: [PATCH] degesch: remove cyclic dependency Between users and channels. --- degesch.c | 74 ++++++++++++++++++++++++++----------------------------- 1 file changed, 35 insertions(+), 39 deletions(-) diff --git a/degesch.c b/degesch.c index 12850ed..d624731 100644 --- a/degesch.c +++ b/degesch.c @@ -101,12 +101,6 @@ static struct config_item g_config_table[] = return false; \ BLOCK_END -struct user; -static void user_unref (struct user *self); - -struct channel; -static void channel_unref (struct channel *self); - // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - // We need a few reference countable objects with support @@ -144,8 +138,6 @@ struct user_channel { LIST_HEADER (struct user_channel) - // FIXME: this should be a weak reference to destroy a cycle - struct channel *channel; ///< Reference to channel }; @@ -159,7 +151,8 @@ user_channel_new (void) static void user_channel_destroy (struct user_channel *self) { - channel_unref (self->channel); + // The "channel" reference is weak and this object should get + // destroyed whenever the user stops being in the channel. free (self); } @@ -227,8 +220,10 @@ channel_user_destroy (struct channel_user *self) // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -// We keep references to channels in their users and buffers, -// and weak references in the name lookup table. +// We keep references to channels in their buffers, +// and weak references in their users and the name lookup table. + +// XXX: this doesn't really have to be reference countable struct channel { @@ -259,8 +254,8 @@ channel_destroy (struct channel *self) free (self->name); free (self->mode); free (self->topic); - LIST_FOR_EACH (struct channel_user, iter, self->users) - channel_user_destroy (iter); + // Owner has to make sure we have no users by now + hard_assert (!self->users); str_vector_free (&self->names_buf); free (self); } @@ -1327,11 +1322,31 @@ irc_get_or_make_user_buffer (struct app_context *ctx, const char *nickname) return buffer; } +static void +irc_channel_unlink_user + (struct channel *channel, struct channel_user *channel_user) +{ + // First destroy the user's weak references to the channel + struct user *user = channel_user->user; + LIST_FOR_EACH (struct user_channel, iter, user->channels) + if (iter->channel == channel) + { + LIST_UNLINK (user->channels, iter); + user_channel_destroy (iter); + } + + // Then just unlink the user from the channel + LIST_UNLINK (channel->users, channel_user); + channel_user_destroy (channel_user); +} + static void irc_channel_on_destroy (void *object, void *user_data) { struct channel *channel = object; struct app_context *ctx = user_data; + LIST_FOR_EACH (struct channel_user, iter, channel->users) + irc_channel_unlink_user (channel, iter); str_map_set (&ctx->irc_channels, channel->name, NULL); } @@ -1351,21 +1366,11 @@ irc_make_channel (struct app_context *ctx, char *name) } static void -irc_unlink_user_from_channel (struct user *user, struct channel *channel) +irc_remove_user_from_channel (struct user *user, struct channel *channel) { - // The order is important here as the channel can hold the last reference - LIST_FOR_EACH (struct user_channel, iter, user->channels) - if (iter->channel == channel) - { - LIST_UNLINK (user->channels, iter); - user_channel_destroy (iter); - } LIST_FOR_EACH (struct channel_user, iter, channel->users) if (iter->user == user) - { - LIST_UNLINK (channel->users, iter); - channel_user_destroy (iter); - } + irc_channel_unlink_user (channel, iter); } // --- Supporting code --------------------------------------------------------- @@ -1945,7 +1950,7 @@ irc_handle_join (struct app_context *ctx, const struct irc_message *msg) // Link the user with the channel struct user_channel *user_channel = user_channel_new (); - user_channel->channel = channel_ref (channel); + user_channel->channel = channel; LIST_PREPEND (user->channels, user_channel); struct channel_user *channel_user = channel_user_new (); @@ -1985,7 +1990,7 @@ irc_handle_kick (struct app_context *ctx, const struct irc_message *msg) // It would be is weird for this to be false if (user && channel) - irc_unlink_user_from_channel (user, channel); + irc_remove_user_from_channel (user, channel); if (buffer) { @@ -2106,7 +2111,7 @@ irc_handle_part (struct app_context *ctx, const struct irc_message *msg) // It would be is weird for this to be false if (user && channel) - irc_unlink_user_from_channel (user, channel); + irc_remove_user_from_channel (user, channel); if (buffer) { @@ -2202,17 +2207,8 @@ irc_handle_quit (struct app_context *ctx, const struct irc_message *msg) buffer_send (ctx, buffer, BUFFER_LINE_QUIT, 0, msg->prefix, message, ""); - // Unlink the user from the channel - struct channel *channel = iter->channel; - LIST_FOR_EACH (struct channel_user, iter, channel->users) - if (iter->user == user) - { - LIST_UNLINK (channel->users, iter); - channel_user_destroy (iter); - } - - LIST_UNLINK (user->channels, iter); - user_channel_destroy (iter); + // This destroys "iter" which doesn't matter to us + irc_remove_user_from_channel (user, iter->channel); } }