summaryrefslogtreecommitdiff
path: root/src/network/network_gamelist.cpp
blob: dfe07bdbbbecf8260841ae61e1d6df9af94550d4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
/*
 * This file is part of OpenTTD.
 * OpenTTD 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, version 2.
 * OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/**
 * @file network_gamelist.cpp This file handles the GameList
 * Also, it handles the request to a server for data about the server
 */

#include "../stdafx.h"
#include "../debug.h"
#include "../window_func.h"
#include "network_internal.h"
#include "network_udp.h"
#include "network_gamelist.h"
#include <atomic>

#include "../safeguards.h"

NetworkGameList *_network_game_list = nullptr;

/** The games to insert when the GUI thread has time for us. */
static std::atomic<NetworkGameList *> _network_game_delayed_insertion_list(nullptr);

/**
 * Add a new item to the linked gamelist, but do it delayed in the next tick
 * or so to prevent race conditions.
 * @param item the item to add. Will be freed once added.
 */
void NetworkGameListAddItemDelayed(NetworkGameList *item)
{
	item->next = _network_game_delayed_insertion_list.load(std::memory_order_relaxed);
	while (!_network_game_delayed_insertion_list.compare_exchange_weak(item->next, item, std::memory_order_acq_rel)) {}
}

/** Perform the delayed (thread safe) insertion into the game list */
static void NetworkGameListHandleDelayedInsert()
{
	while (true) {
		NetworkGameList *ins_item = _network_game_delayed_insertion_list.load(std::memory_order_relaxed);
		while (ins_item != nullptr && !_network_game_delayed_insertion_list.compare_exchange_weak(ins_item, ins_item->next, std::memory_order_acq_rel)) {}
		if (ins_item == nullptr) break; // No item left.

		NetworkGameList *item = NetworkGameListAddItem(ins_item->address);

		if (item != nullptr) {
			if (StrEmpty(item->info.server_name)) {
				ClearGRFConfigList(&item->info.grfconfig);
				memset(&item->info, 0, sizeof(item->info));
				strecpy(item->info.server_name, ins_item->info.server_name, lastof(item->info.server_name));
				strecpy(item->info.hostname, ins_item->info.hostname, lastof(item->info.hostname));
				item->online = false;
			}
			item->manually |= ins_item->manually;
			if (item->manually) NetworkRebuildHostList();
			UpdateNetworkGameWindow();
		}
		free(ins_item);
	}
}

/**
 * Add a new item to the linked gamelist. If the IP and Port match
 * return the existing item instead of adding it again
 * @param address the address of the to-be added item
 * @return a point to the newly added or already existing item
 */
NetworkGameList *NetworkGameListAddItem(NetworkAddress address)
{
	const char *hostname = address.GetHostname();

	/* Do not query the 'any' address. */
	if (StrEmpty(hostname) ||
			strcmp(hostname, "0.0.0.0") == 0 ||
			strcmp(hostname, "::") == 0) {
		return nullptr;
	}

	NetworkGameList *item, *prev_item;

	prev_item = nullptr;
	for (item = _network_game_list; item != nullptr; item = item->next) {
		if (item->address == address) return item;
		prev_item = item;
	}

	item = CallocT<NetworkGameList>(1);
	item->next = nullptr;
	item->address = address;

	if (prev_item == nullptr) {
		_network_game_list = item;
	} else {
		prev_item->next = item;
	}
	DEBUG(net, 4, "[gamelist] added server to list");

	UpdateNetworkGameWindow();

	return item;
}

/**
 * Remove an item from the gamelist linked list
 * @param remove pointer to the item to be removed
 */
void NetworkGameListRemoveItem(NetworkGameList *remove)
{
	NetworkGameList *prev_item = nullptr;
	for (NetworkGameList *item = _network_game_list; item != nullptr; item = item->next) {
		if (remove == item) {
			if (prev_item == nullptr) {
				_network_game_list = remove->next;
			} else {
				prev_item->next = remove->next;
			}

			/* Remove GRFConfig information */
			ClearGRFConfigList(&remove->info.grfconfig);
			free(remove);
			remove = nullptr;

			DEBUG(net, 4, "[gamelist] removed server from list");
			NetworkRebuildHostList();
			UpdateNetworkGameWindow();
			return;
		}
		prev_item = item;
	}
}

static const uint MAX_GAME_LIST_REQUERY_COUNT  = 10; ///< How often do we requery in number of times per server?
static const uint REQUERY_EVERY_X_GAMELOOPS    = 60; ///< How often do we requery in time?
static const uint REFRESH_GAMEINFO_X_REQUERIES = 50; ///< Refresh the game info itself after REFRESH_GAMEINFO_X_REQUERIES * REQUERY_EVERY_X_GAMELOOPS game loops

/** Requeries the (game) servers we have not gotten a reply from */
void NetworkGameListRequery()
{
	NetworkGameListHandleDelayedInsert();

	static uint8 requery_cnt = 0;

	if (++requery_cnt < REQUERY_EVERY_X_GAMELOOPS) return;
	requery_cnt = 0;

	for (NetworkGameList *item = _network_game_list; item != nullptr; item = item->next) {
		item->retries++;
		if (item->retries < REFRESH_GAMEINFO_X_REQUERIES && (item->online || item->retries >= MAX_GAME_LIST_REQUERY_COUNT)) continue;

		/* item gets mostly zeroed by NetworkUDPQueryServer */
		uint8 retries = item->retries;
		NetworkUDPQueryServer(NetworkAddress(item->address));
		item->retries = (retries >= REFRESH_GAMEINFO_X_REQUERIES) ? 0 : retries;
	}
}

/**
 * Rebuild the GRFConfig's of the servers in the game list as we did
 * a rescan and might have found new NewGRFs.
 */
void NetworkAfterNewGRFScan()
{
	for (NetworkGameList *item = _network_game_list; item != nullptr; item = item->next) {
		/* Reset compatibility state */
		item->info.compatible = item->info.version_compatible;

		for (GRFConfig *c = item->info.grfconfig; c != nullptr; c = c->next) {
			assert(HasBit(c->flags, GCF_COPY));

			const GRFConfig *f = FindGRFConfig(c->ident.grfid, FGCM_EXACT, c->ident.md5sum);
			if (f == nullptr) {
				/* Don't know the GRF, so mark game incompatible and the (possibly)
				 * already resolved name for this GRF (another server has sent the
				 * name of the GRF already. */
				c->name = FindUnknownGRFName(c->ident.grfid, c->ident.md5sum, true);
				c->status = GCS_NOT_FOUND;

				/* If we miss a file, we're obviously incompatible. */
				item->info.compatible = false;
			} else {
				c->filename = f->filename;
				c->name = f->name;
				c->info = f->info;
				c->status = GCS_UNKNOWN;
			}
		}
	}

	InvalidateWindowClassesData(WC_NETWORK_WINDOW);
}