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degesch: unfuck reference counting 

We really needed weak references for the name map.
This commit is contained in:
Přemysl Eric Janouch 2015-04-21 00:04:34 +02:00
parent 3cfe01e3a7
commit 0a87e43aff
1 changed files with 65 additions and 42 deletions
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107
degesch.c
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@ -103,6 +103,9 @@ static struct config_item g_config_table[] =
static void user_unref (void *p);
static void channel_unref (void *p);
/// Callback just before a reference counted object is destroyed
typedef void (*destroy_cb_fn) (void *object, void *user_data);
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
struct user_channel
@ -130,12 +133,15 @@ user_channel_destroy (void *p)
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// We keep references to user information in channels and buffers,
// as well as in the name lookup table.
// and weak references in the name lookup table.
struct user
{
size_t ref_count; ///< Reference count
destroy_cb_fn on_destroy; ///< To remove any weak references
void *user_data; ///< User data for callbacks
// TODO: eventually a reference to the server
char *nickname; ///< Literal nickname
@ -156,6 +162,9 @@ user_new (void)
static void
user_destroy (struct user *self)
{
if (self->on_destroy)
self->on_destroy (self, self->user_data);
free (self->nickname);
LIST_FOR_EACH (struct user_channel, iter, self->channels)
user_channel_destroy (iter);
@ -212,6 +221,9 @@ struct channel
{
size_t ref_count; ///< Reference count
destroy_cb_fn on_destroy; ///< To remove any weak references
void *user_data; ///< User data for callbacks
// TODO: eventually a reference to the server
char *name; ///< Channel name
@ -230,9 +242,11 @@ channel_new (void)
}
static void
channel_destroy (void *p)
channel_destroy (struct channel *self)
{
struct channel *self = p;
if (self->on_destroy)
self->on_destroy (self, self->user_data);
free (self->name);
free (self->mode);
free (self->topic);
@ -409,8 +423,6 @@ struct app_context
// maybe also broadcast all buffers about the disconnection event
// TODO: when getting connected again, rejoin all current channels
// FIXME: these should only have weak references, so that we don't have
// to watch all places where they might get unref-ed
struct str_map irc_users; ///< IRC user data
struct str_map irc_channels; ///< IRC channel data
struct str_map irc_buffer_map; ///< Maps IRC identifiers to buffers
@ -480,10 +492,8 @@ app_context_init (struct app_context *self)
self->irc_ready = false;
str_map_init (&self->irc_users);
self->irc_users.free = user_unref;
self->irc_users.key_xfrm = irc_strxfrm;
str_map_init (&self->irc_channels);
self->irc_channels.free = channel_unref;
self->irc_channels.key_xfrm = irc_strxfrm;
str_map_init (&self->irc_buffer_map);
self->irc_buffer_map.key_xfrm = irc_strxfrm;
@ -1057,13 +1067,6 @@ buffer_remove (struct app_context *ctx, struct buffer *buffer)
}
#endif // RL_READLINE_VERSION
// Get rid of the channel, as well as the users,
// if the buffer was the last thing keeping them alive
if (buffer->channel && buffer->channel->ref_count == 2)
str_map_set (&ctx->irc_channels, buffer->channel->name, NULL);
if (buffer->user && buffer->user->ref_count == 2)
str_map_set (&ctx->irc_users, buffer->user->nickname, NULL);
// And make sure to unlink the buffer from "irc_buffer_map"
if (buffer->channel)
str_map_set (&ctx->irc_buffer_map, buffer->channel->name, NULL);
@ -1284,6 +1287,50 @@ init_buffers (struct app_context *ctx)
// --- Users, channels ---------------------------------------------------------
static void
irc_user_on_destroy (void *object, void *user_data)
{
struct user *user = object;
struct app_context *ctx = user_data;
str_map_set (&ctx->irc_users, user->nickname, NULL);
}
struct user *
irc_make_user (struct app_context *ctx, char *nickname)
{
hard_assert (!str_map_find (&ctx->irc_users, nickname));
struct user *user = user_new ();
user->on_destroy = irc_user_on_destroy;
user->user_data = ctx;
user->nickname = nickname;
str_map_set (&ctx->irc_users, user->nickname, user);
return user;
}
static void
irc_channel_on_destroy (void *object, void *user_data)
{
struct channel *channel = object;
struct app_context *ctx = user_data;
str_map_set (&ctx->irc_channels, channel->name, NULL);
}
struct channel *
irc_make_channel (struct app_context *ctx, char *name)
{
hard_assert (!str_map_find (&ctx->irc_channels, name));
struct channel *channel = channel_new ();
channel->on_destroy = irc_channel_on_destroy;
channel->user_data = ctx;
channel->name = name;
channel->mode = xstrdup ("");
channel->topic = NULL;
str_map_set (&ctx->irc_channels, channel->name, channel);
return channel;
}
// --- Supporting code ---------------------------------------------------------
static char *
@ -1833,11 +1880,7 @@ irc_handle_join (struct app_context *ctx, const struct irc_message *msg)
// We've joined a new channel
if (!channel && irc_is_this_us (ctx, msg->prefix))
{
channel = channel_new ();
channel->name = xstrdup (target);
channel->mode = xstrdup ("");
channel->topic = NULL;
str_map_set (&ctx->irc_channels, channel->name, channel);
channel = irc_make_channel (ctx, xstrdup (target));
buffer = buffer_new ();
buffer->type = BUFFER_CHANNEL;
@ -1857,11 +1900,7 @@ irc_handle_join (struct app_context *ctx, const struct irc_message *msg)
char *nickname = irc_cut_nickname (msg->prefix);
struct user *user = str_map_find (&ctx->irc_users, nickname);
if (!user)
{
user = user_new ();
user->nickname = nickname;
str_map_set (&ctx->irc_users, user->nickname, user);
}
user = irc_make_user (ctx, nickname);
else
free (nickname);
@ -2041,11 +2080,7 @@ irc_handle_privmsg (struct app_context *ctx, const struct irc_message *msg)
char *nickname = irc_cut_nickname (msg->prefix);
struct user *user = str_map_find (&ctx->irc_users, nickname);
if (!user)
{
user = user_new ();
user->nickname = xstrdup (nickname);
str_map_set (&ctx->irc_users, user->nickname, user);
}
user = irc_make_user (ctx, xstrdup (nickname));
// Open a new buffer for the user
buffer = buffer_new ();
@ -2120,15 +2155,6 @@ irc_handle_quit (struct app_context *ctx, const struct irc_message *msg)
LIST_UNLINK (user->channels, iter);
user_channel_destroy (iter);
}
// If it's the last reference, there's no reason for the user to stay.
// Note that when the user has their own buffer, it still keeps a reference
// and we don't have to care about removing them from "irc_buffer_map".
if (user->ref_count == 1)
{
hard_assert (!user->channels);
str_map_set (&ctx->irc_users, user->nickname, NULL);
}
}
static void
@ -2912,10 +2938,7 @@ irc_connect (struct app_context *ctx, struct error **e)
irc_send (ctx, "USER %s 8 * :%s", username, realname);
// XXX: maybe we should wait for the first message from the server
ctx->irc_user = user_new ();
ctx->irc_user->nickname = xstrdup (nickname);
str_map_set (&ctx->irc_users, nickname, user_ref (ctx->irc_user));
ctx->irc_user = irc_make_user (ctx, xstrdup (nickname));
ctx->irc_user_mode = xstrdup ("");
ctx->irc_user_host = NULL;
return true;