summaryrefslogtreecommitdiff
path: root/src/socketengines/socketengine_epoll.cpp
blob: 8a5800208f23e6bd872782aebc5fd476c5087158 (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
/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  InspIRCd: (C) 2002-2010 InspIRCd Development Team
 * See: http://wiki.inspircd.org/Credits
 *
 * This program is free but copyrighted software; see
 *            the file COPYING for details.
 *
 * ---------------------------------------------------
 */

#include <vector>
#include <string>
#include <map>
#include "inspircd.h"
#include "exitcodes.h"
#include "socketengine.h"
#include <sys/epoll.h>
#include <ulimit.h>
#define EP_DELAY 5

/** A specialisation of the SocketEngine class, designed to use linux 2.6 epoll().
 */
class EPollEngine : public SocketEngine
{
private:
	/** These are used by epoll() to hold socket events
	 */
	struct epoll_event* events;
	int EngineHandle;
public:
	/** Create a new EPollEngine
	 */
	EPollEngine();
	/** Delete an EPollEngine
	 */
	virtual ~EPollEngine();
	virtual bool AddFd(EventHandler* eh, int event_mask);
	virtual void OnSetEvent(EventHandler* eh, int old_mask, int new_mask);
	virtual void DelFd(EventHandler* eh);
	virtual int DispatchEvents();
	virtual std::string GetName();
};

EPollEngine::EPollEngine()
{
	int max = ulimit(4, 0);
	if (max > 0)
	{
		MAX_DESCRIPTORS = max;
	}
	else
	{
		ServerInstance->Logs->Log("SOCKET", DEFAULT, "ERROR: Can't determine maximum number of open sockets!");
		printf("ERROR: Can't determine maximum number of open sockets!\n");
		ServerInstance->Exit(EXIT_STATUS_SOCKETENGINE);
	}

	// This is not a maximum, just a hint at the eventual number of sockets that may be polled.
	EngineHandle = epoll_create(GetMaxFds() / 4);

	if (EngineHandle == -1)
	{
		ServerInstance->Logs->Log("SOCKET",DEFAULT, "ERROR: Could not initialize socket engine: %s", strerror(errno));
		ServerInstance->Logs->Log("SOCKET",DEFAULT, "ERROR: Your kernel probably does not have the proper features. This is a fatal error, exiting now.");
		printf("ERROR: Could not initialize epoll socket engine: %s\n", strerror(errno));
		printf("ERROR: Your kernel probably does not have the proper features. This is a fatal error, exiting now.\n");
		ServerInstance->Exit(EXIT_STATUS_SOCKETENGINE);
	}

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

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

EPollEngine::~EPollEngine()
{
	this->Close(EngineHandle);
	delete[] ref;
	delete[] events;
}

static int mask_to_epoll(int event_mask)
{
	int rv = 0;
	if (event_mask & (FD_WANT_POLL_READ | FD_WANT_POLL_WRITE | FD_WANT_SINGLE_WRITE))
	{
		// we need to use standard polling on this FD
		if (event_mask & (FD_WANT_POLL_READ | FD_WANT_FAST_READ))
			rv |= EPOLLIN;
		if (event_mask & (FD_WANT_POLL_WRITE | FD_WANT_FAST_WRITE | FD_WANT_SINGLE_WRITE))
			rv |= EPOLLOUT;
	}
	else
	{
		// we can use edge-triggered polling on this FD
		rv = EPOLLET;
		if (event_mask & (FD_WANT_FAST_READ | FD_WANT_EDGE_READ))
			rv |= EPOLLIN;
		if (event_mask & (FD_WANT_FAST_WRITE | FD_WANT_EDGE_WRITE))
			rv |= EPOLLOUT;
	}
	return rv;
}

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

	if (ref[fd])
	{
		ServerInstance->Logs->Log("SOCKET",DEBUG,"Attempt to add duplicate fd: %d", fd);
		return false;
	}

	struct epoll_event ev;
	memset(&ev,0,sizeof(ev));
	ev.events = mask_to_epoll(event_mask);
	ev.data.fd = fd;
	int i = epoll_ctl(EngineHandle, EPOLL_CTL_ADD, fd, &ev);
	if (i < 0)
	{
		ServerInstance->Logs->Log("SOCKET",DEBUG,"Error adding fd: %d to socketengine: %s", fd, strerror(errno));
		return false;
	}

	ServerInstance->Logs->Log("SOCKET",DEBUG,"New file descriptor: %d", fd);

	ref[fd] = eh;
	SocketEngine::SetEventMask(eh, event_mask);
	CurrentSetSize++;
	return true;
}

void EPollEngine::OnSetEvent(EventHandler* eh, int old_mask, int new_mask)
{
	int old_events = mask_to_epoll(old_mask);
	int new_events = mask_to_epoll(new_mask);
	if (old_events != new_events)
	{
		// ok, we actually have something to tell the kernel about
		struct epoll_event ev;
		memset(&ev,0,sizeof(ev));
		ev.events = new_events;
		ev.data.fd = eh->GetFd();
		epoll_ctl(EngineHandle, EPOLL_CTL_MOD, eh->GetFd(), &ev);
	}
}

void EPollEngine::DelFd(EventHandler* eh)
{
	int fd = eh->GetFd();
	if ((fd < 0) || (fd > GetMaxFds() - 1))
	{
		ServerInstance->Logs->Log("SOCKET",DEBUG,"DelFd out of range: (fd: %d, max: %d)", fd, GetMaxFds());
		return;
	}

	struct epoll_event ev;
	memset(&ev,0,sizeof(ev));
	ev.data.fd = fd;
	int i = epoll_ctl(EngineHandle, EPOLL_CTL_DEL, fd, &ev);

	if (i < 0)
	{
		ServerInstance->Logs->Log("SOCKET",DEBUG,"epoll_ctl can't remove socket: %s", strerror(errno));
	}

	ref[fd] = NULL;

	ServerInstance->Logs->Log("SOCKET",DEBUG,"Remove file descriptor: %d", fd);
	CurrentSetSize--;
}

int EPollEngine::DispatchEvents()
{
	socklen_t codesize = sizeof(int);
	int errcode;
	int i = epoll_wait(EngineHandle, events, GetMaxFds() - 1, 1000);
	ServerInstance->UpdateTime();

	TotalEvents += i;

	for (int j = 0; j < i; j++)
	{
		EventHandler* eh = ref[events[j].data.fd];
		if (!eh)
		{
			ServerInstance->Logs->Log("SOCKET",DEBUG,"Got event on unknown fd: %d", events[j].data.fd);
			epoll_ctl(EngineHandle, EPOLL_CTL_DEL, events[j].data.fd, &events[j]);
			continue;
		}
		if (events[j].events & EPOLLHUP)
		{
			ErrorEvents++;
			eh->HandleEvent(EVENT_ERROR, 0);
			continue;
		}
		if (events[j].events & EPOLLERR)
		{
			ErrorEvents++;
			/* Get error number */
			if (getsockopt(events[j].data.fd, SOL_SOCKET, SO_ERROR, &errcode, &codesize) < 0)
				errcode = errno;
			eh->HandleEvent(EVENT_ERROR, errcode);
			continue;
		}
		int mask = eh->GetEventMask();
		if (events[j].events & EPOLLIN)
			mask &= ~FD_READ_WILL_BLOCK;
		if (events[j].events & EPOLLOUT)
		{
			mask &= ~FD_WRITE_WILL_BLOCK;
			if (mask & FD_WANT_SINGLE_WRITE)
			{
				int nm = mask & ~FD_WANT_SINGLE_WRITE;
				OnSetEvent(eh, mask, nm);
				mask = nm;
			}
		}
		SetEventMask(eh, mask);
		if (events[j].events & EPOLLIN)
		{
			ReadEvents++;
			eh->HandleEvent(EVENT_READ);
			if (eh != ref[events[j].data.fd])
				// whoa! we got deleted, better not give out the write event
				continue;
		}
		if (events[j].events & EPOLLOUT)
		{
			WriteEvents++;
			eh->HandleEvent(EVENT_WRITE);
		}
	}

	return i;
}

std::string EPollEngine::GetName()
{
	return "epoll";
}

SocketEngine* CreateSocketEngine()
{
	return new EPollEngine;
}