summaryrefslogtreecommitdiff
path: root/src/socketengines/socketengine_poll.cpp
blob: 0c7d41967095da902f7fc4f2ccdb28630501abda (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
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
/*
 * InspIRCd -- Internet Relay Chat Daemon
 *
 *   Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
 *   Copyright (C) 2009 Uli Schlachter <psychon@znc.in>
 *   Copyright (C) 2009 Craig Edwards <craigedwards@brainbox.cc>
 *   Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
 *
 * This file is part of InspIRCd.  InspIRCd 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.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */


#ifndef SOCKETENGINE_POLL
#define SOCKETENGINE_POLL

#include <iostream>
#include <vector>
#include <string>
#include <map>
#include "exitcodes.h"
#include "inspircd.h"
#include "socketengine.h"

#ifndef _WIN32
	#ifndef __USE_XOPEN
    	    #define __USE_XOPEN /* fuck every fucking OS ever made. needed by poll.h to work.*/
	#endif
	#include <poll.h>
	#include <sys/poll.h>
#else
	/* *grumble* */
	#define struct pollfd WSAPOLLFD
	#define poll WSAPoll
#endif

class InspIRCd;

/** A specialisation of the SocketEngine class, designed to use poll().
 */
class PollEngine : public SocketEngine
{
private:
	/** These are used by poll() to hold socket events
	 */
	struct pollfd *events;
	/** This map maps fds to an index in the events array.
	 */
	std::map<int, unsigned int> fd_mappings;
public:
	/** Create a new PollEngine
	 */
	PollEngine();
	/** Delete a PollEngine
	 */
	virtual ~PollEngine();
	virtual bool AddFd(EventHandler* eh, int event_mask);
	virtual void OnSetEvent(EventHandler* eh, int old_mask, int new_mask);
	virtual EventHandler* GetRef(int fd);
	virtual void DelFd(EventHandler* eh);
	virtual int DispatchEvents();
	virtual std::string GetName();
};

#endif

#ifdef BSD
	#include <sys/sysctl.h>
#else
	#include <ulimit.h>
#endif

PollEngine::PollEngine()
{
	CurrentSetSize = 0;
#ifdef BSD
	int mib[2];
	size_t len;

	mib[0] = CTL_KERN;
#ifdef KERN_MAXFILESPERPROC
	mib[1] = KERN_MAXFILESPERPROC;
#else
	mib[1] = KERN_MAXFILES;
#endif
	len = sizeof(MAX_DESCRIPTORS);
	sysctl(mib, 2, &MAX_DESCRIPTORS, &len, NULL, 0);
#else
	int max = ulimit(4, 0);
	if (max > 0)
	{
		MAX_DESCRIPTORS = max;
	}
	else
	{
		ServerInstance->Logs->Log("SOCKET", LOG_DEFAULT, "ERROR: Can't determine maximum number of open sockets: %s", strerror(errno));
		std::cout << "ERROR: Can't determine maximum number of open sockets: " << strerror(errno) << std::endl;
		ServerInstance->Exit(EXIT_STATUS_SOCKETENGINE);
	}
#endif

	ref = new EventHandler* [GetMaxFds()];
	events = new struct pollfd[GetMaxFds()];

	memset(events, 0, GetMaxFds() * sizeof(struct pollfd));
	memset(ref, 0, GetMaxFds() * sizeof(EventHandler*));
}

PollEngine::~PollEngine()
{
	// No destruction required, either.
	delete[] ref;
	delete[] events;
}

static int mask_to_poll(int event_mask)
{
	int rv = 0;
	if (event_mask & (FD_WANT_POLL_READ | FD_WANT_FAST_READ))
		rv |= POLLIN;
	if (event_mask & (FD_WANT_POLL_WRITE | FD_WANT_FAST_WRITE | FD_WANT_SINGLE_WRITE))
		rv |= POLLOUT;
	return rv;
}

bool PollEngine::AddFd(EventHandler* eh, int event_mask)
{
	int fd = eh->GetFd();
	if ((fd < 0) || (fd > GetMaxFds() - 1))
	{
		ServerInstance->Logs->Log("SOCKET",LOG_DEBUG,"AddFd out of range: (fd: %d, max: %d)", fd, GetMaxFds());
		return false;
	}

	if (fd_mappings.find(fd) != fd_mappings.end())
	{
		ServerInstance->Logs->Log("SOCKET",LOG_DEBUG,"Attempt to add duplicate fd: %d", fd);
		return false;
	}

	unsigned int index = CurrentSetSize;

	fd_mappings[fd] = index;
	ref[index] = eh;
	events[index].fd = fd;
	events[index].events = mask_to_poll(event_mask);

	ServerInstance->Logs->Log("SOCKET", LOG_DEBUG,"New file descriptor: %d (%d; index %d)", fd, events[fd].events, index);
	SocketEngine::SetEventMask(eh, event_mask);
	CurrentSetSize++;
	return true;
}

EventHandler* PollEngine::GetRef(int fd)
{
	std::map<int, unsigned int>::iterator it = fd_mappings.find(fd);
	if (it == fd_mappings.end())
		return NULL;
	return ref[it->second];
}

void PollEngine::OnSetEvent(EventHandler* eh, int old_mask, int new_mask)
{
	std::map<int, unsigned int>::iterator it = fd_mappings.find(eh->GetFd());
	if (it == fd_mappings.end())
	{
		ServerInstance->Logs->Log("SOCKET",LOG_DEBUG,"SetEvents() on unknown fd: %d", eh->GetFd());
		return;
	}

	events[it->second].events = mask_to_poll(new_mask);
}

void PollEngine::DelFd(EventHandler* eh)
{
	int fd = eh->GetFd();
	if ((fd < 0) || (fd > MAX_DESCRIPTORS))
	{
		ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "DelFd out of range: (fd: %d, max: %d)", fd, GetMaxFds());
		return;
	}

	std::map<int, unsigned int>::iterator it = fd_mappings.find(fd);
	if (it == fd_mappings.end())
	{
		ServerInstance->Logs->Log("SOCKET",LOG_DEBUG,"DelFd() on unknown fd: %d", fd);
		return;
	}

	unsigned int index = it->second;
	unsigned int last_index = CurrentSetSize - 1;
	int last_fd = events[last_index].fd;

	if (index != last_index)
	{
		// We need to move the last fd we got into this gap (gaps are evil!)

		// So update the mapping for the last fd to its new position
		fd_mappings[last_fd] = index;

		// move last_fd from last_index into index
		events[index].fd = last_fd;
		events[index].events = events[last_index].events;

		ref[index] = ref[last_index];
	}

	// Now remove all data for the last fd we got into out list.
	// Above code made sure this always is right
	fd_mappings.erase(it);
	events[last_index].fd = 0;
	events[last_index].events = 0;
	ref[last_index] = NULL;

	CurrentSetSize--;

	ServerInstance->Logs->Log("SOCKET", LOG_DEBUG, "Remove file descriptor: %d (index: %d) "
			"(Filled gap with: %d (index: %d))", fd, index, last_fd, last_index);
}

int PollEngine::DispatchEvents()
{
	int i = poll(events, CurrentSetSize, 1000);
	int index;
	socklen_t codesize = sizeof(int);
	int errcode;
	int processed = 0;
	ServerInstance->UpdateTime();

	if (i > 0)
	{
		for (index = 0; index < CurrentSetSize && processed != i; index++)
		{
			if (events[index].revents)
				processed++;
			EventHandler* eh = ref[index];
			if (!eh)
				continue;

			if (events[index].revents & POLLHUP)
			{
				eh->HandleEvent(EVENT_ERROR, 0);
				continue;
			}

			if (events[index].revents & POLLERR)
			{
				// Get fd
				int fd = events[index].fd;

				// Get error number
				if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &errcode, &codesize) < 0)
					errcode = errno;
				eh->HandleEvent(EVENT_ERROR, errcode);
				continue;
			}

			if (events[index].revents & POLLIN)
			{
				SetEventMask(eh, eh->GetEventMask() & ~FD_READ_WILL_BLOCK);
				eh->HandleEvent(EVENT_READ);
				if (eh != ref[index])
					// whoops, deleted out from under us
					continue;
			}

			if (events[index].revents & POLLOUT)
			{
				int mask = eh->GetEventMask();
				mask &= ~(FD_WRITE_WILL_BLOCK | FD_WANT_SINGLE_WRITE);
				SetEventMask(eh, mask);
				events[index].events = mask_to_poll(mask);
				eh->HandleEvent(EVENT_WRITE);
			}
		}
	}

	return i;
}

std::string PollEngine::GetName()
{
	return "poll";
}

SocketEngine* CreateSocketEngine()
{
	return new PollEngine;
}