server/common/logger.C

/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008,2009,2010 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
 * 
 * Deliantra is free software: you can redistribute it and/or modify it under
 * the terms of the Affero GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * 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 Affero GNU General Public License
 * and the GNU General Public License along with this program. If not, see
 * <http://www.gnu.org/licenses/>.
 * 
 * The authors can be reached via e-mail to <support@deliantra.net>
 */

#include <cstdarg>
#include <cstring>

#include <vector>

#include <sys/uio.h>
#include <pthread.h>

#include "global.h"
#include "dynbuf.h"
#include "util.h"

struct logline
{
  struct timeval tv;
  char *buf; // includes PREFIX_LEN garbage bytes
  int len;
  int flags;
};

static SMUTEX(mutex);
static SMUTEX(fdlock);
static SCOND(cond);
static int logfd = STDERR_FILENO;
static int logsync = 1;
static std::vector<logline, slice_allocator<logline> > queue;

int log_setfd (int fd)
{
  SMUTEX_LOCK (fdlock);
  int old = logfd;
  logfd = fd < 0 ? STDERR_FILENO : fd;
  SMUTEX_UNLOCK (fdlock);

  return old;
}

#define PREFIX_LEN sizeof ("0000-00-00 00:00:00.0000+") - 1

static void
log_sync (logline &line)
{
  struct tm lt;
  char pfx [PREFIX_LEN];

  localtime_r (&line.tv.tv_sec, &lt);

  sprintf (pfx, "%04d-%02d-%02d %02d:%02d:%02d.%04d",
    lt.tm_year + 1900,
    lt.tm_mon + 1,
    lt.tm_mday,
    lt.tm_hour,
    lt.tm_min,
    lt.tm_sec,
    (int)(line.tv.tv_usec / 100)
  );

  pfx [PREFIX_LEN - 1] = line.flags & logSync ? '=' : ' ';

  struct iovec iov [2];

  iov [0].iov_base = pfx;
  iov [0].iov_len = PREFIX_LEN;

  char *buf = line.buf;

  if (logsync != 2)
    SMUTEX_LOCK (fdlock);

  while (char *end = strchr (buf, '\n'))
    {
      iov [1].iov_base = buf;
      iov [1].iov_len = end - buf + 1;

      writev (STDERR_FILENO, iov, 2);
      if (logfd != STDERR_FILENO)
        writev (logfd, iov, 2);

      buf = end + 1;

      if (buf == line.buf + line.len)
        break;

      pfx [PREFIX_LEN - 1] = '+';
    }

  if (logsync != 2)
    SMUTEX_UNLOCK (fdlock);

  sfree (line.buf, line.len);
}

static void *
logthread_proc (void *arg)
{
  int idx = 0;

  for (;;)
    {
      logline line;

      SMUTEX_LOCK (mutex);

      while (queue.empty ())
        SCOND_WAIT (cond, mutex);

      line = queue [idx++];

      // this algorithm could result in an ever-increasing vector
      // size if we log faster than we can write, but if that happens
      // we have bigger problems.
      if (idx == queue.size ())
        {
          queue.clear ();
          idx = 0;
        }

      SMUTEX_UNLOCK (mutex);

      log_sync (line);
    }
}

void
log_cleanup ()
{
  logsync = 1;

  for (;;)
    {
      int done;

      SMUTEX_LOCK (mutex);
      done = queue.empty ();
      SMUTEX_UNLOCK (mutex);

      if (done)
        break;

      usleep (10000);
      SMUTEX_LOCK (fdlock);
      SMUTEX_UNLOCK (fdlock);
    }
}

static void
af_child ()
{
  logsync = 2;
}

static struct logthread : thread
{
  logthread ()
  {
    pthread_atfork (0, 0, af_child);
    start (logthread_proc);
    logsync = 0;
  }
} logthread;

void
LOG (int flags, const_utf8_string format, ...)
{
  int level = flags & 15;

  if (level > settings.debug)
    return;

  logline line;
  gettimeofday (&line.tv, 0);

  static dynbuf_text buf;

  va_list ap;
  va_start (ap, format);
  buf.vprintf (format, ap);
  va_end (ap);

  buf << '\n';

  line.buf = buf.linearise ();
  line.len = buf.size ();

  if (line.buf [line.len - 2] == '\n')
    --line.len;

  line.buf = salloc<char> (line.len, line.buf);

  buf.clear ();

  if (logsync)
    flags |= logSync;

  if (flags & logBacktrace)
    {
      line.buf [line.len - 1] = 0;
      log_backtrace (line.buf);
      line.buf [line.len - 1] = '\n';
    }

  line.flags = flags;

  if (line.flags & logSync)
    log_sync (line);
  else
    {
      SMUTEX_LOCK (mutex);
      queue.push_back (line);
      SMUTEX_UNLOCK (mutex);
      SCOND_SIGNAL (cond);
    }
}

static int suspended;

void
log_suspend ()
{
  if (!suspended++)
    {
      LOG (llevDebug, "logging suspended.");
      SMUTEX_LOCK (fdlock);
    }
}

void
log_resume ()
{
  if (!--suspended)
    {
      SMUTEX_UNLOCK (fdlock);
      LOG (llevDebug, "logging resumed.");
    }
}

Revision:	1.24
Committed:	Sun Apr 11 17:27:51 2010 UTC (14 years, 1 month ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.23:	+38 -4 lines
Log Message:	logfile suspend/resume
#	User	Rev	Content
1	elmex	1.1	/*
2	root	1.16	* This file is part of Deliantra, the Roguelike Realtime MMORPG.
3	pippijn	1.11	*
4	root	1.23	* Copyright (©) 2005,2006,2007,2008,2009,2010 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5	pippijn	1.11	*
6	root	1.20	* Deliantra is free software: you can redistribute it and/or modify it under
7			* the terms of the Affero GNU General Public License as published by the
8			* Free Software Foundation, either version 3 of the License, or (at your
9			* option) any later version.
10	pippijn	1.11	*
11	root	1.15	* This program is distributed in the hope that it will be useful,
12			* but WITHOUT ANY WARRANTY; without even the implied warranty of
13			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			* GNU General Public License for more details.
15	pippijn	1.11	*
16	root	1.20	* You should have received a copy of the Affero GNU General Public License
17			* and the GNU General Public License along with this program. If not, see
18			* <http://www.gnu.org/licenses/>.
19	root	1.13	*
20	root	1.16	* The authors can be reached via e-mail to <support@deliantra.net>
21	pippijn	1.11	*/
22	elmex	1.1
23	root	1.12	#include <cstdarg>
24	root	1.17	#include <cstring>
25
26			#include <vector>
27
28			#include <sys/uio.h>
29			#include <pthread.h>
30
31			#include "global.h"
32			#include "dynbuf.h"
33			#include "util.h"
34
35			struct logline
36			{
37			struct timeval tv;
38			char *buf; // includes PREFIX_LEN garbage bytes
39			int len;
40			int flags;
41			};
42
43			static SMUTEX(mutex);
44	root	1.24	static SMUTEX(fdlock);
45	root	1.17	static SCOND(cond);
46			static int logfd = STDERR_FILENO;
47			static int logsync = 1;
48			static std::vector<logline, slice_allocator<logline> > queue;
49
50	root	1.24	int log_setfd (int fd)
51	root	1.17	{
52	root	1.24	SMUTEX_LOCK (fdlock);
53			int old = logfd;
54	root	1.17	logfd = fd < 0 ? STDERR_FILENO : fd;
55	root	1.24	SMUTEX_UNLOCK (fdlock);
56
57			return old;
58	root	1.17	}
59
60			#define PREFIX_LEN sizeof ("0000-00-00 00:00:00.0000+") - 1
61
62			static void
63			log_sync (logline &line)
64			{
65	root	1.18	struct tm lt;
66	root	1.17	char pfx [PREFIX_LEN];
67
68	root	1.18	localtime_r (&line.tv.tv_sec, &lt);
69
70	root	1.17	sprintf (pfx, "%04d-%02d-%02d %02d:%02d:%02d.%04d",
71	root	1.18	lt.tm_year + 1900,
72			lt.tm_mon + 1,
73			lt.tm_mday,
74			lt.tm_hour,
75			lt.tm_min,
76			lt.tm_sec,
77	root	1.17	(int)(line.tv.tv_usec / 100)
78			);
79
80			pfx [PREFIX_LEN - 1] = line.flags & logSync ? '=' : ' ';
81
82			struct iovec iov [2];
83
84			iov [0].iov_base = pfx;
85			iov [0].iov_len = PREFIX_LEN;
86
87			char *buf = line.buf;
88
89	root	1.24	if (logsync != 2)
90			SMUTEX_LOCK (fdlock);
91
92	root	1.17	while (char *end = strchr (buf, '\n'))
93			{
94			iov [1].iov_base = buf;
95			iov [1].iov_len = end - buf + 1;
96
97			writev (STDERR_FILENO, iov, 2);
98			if (logfd != STDERR_FILENO)
99			writev (logfd, iov, 2);
100
101			buf = end + 1;
102
103			if (buf == line.buf + line.len)
104			break;
105
106			pfx [PREFIX_LEN - 1] = '+';
107			}
108
109	root	1.24	if (logsync != 2)
110			SMUTEX_UNLOCK (fdlock);
111
112	root	1.17	sfree (line.buf, line.len);
113			}
114
115			static void *
116			logthread_proc (void *arg)
117			{
118			int idx = 0;
119
120			for (;;)
121			{
122			logline line;
123
124			SMUTEX_LOCK (mutex);
125
126			while (queue.empty ())
127			SCOND_WAIT (cond, mutex);
128
129			line = queue [idx++];
130
131			// this algorithm could result in an ever-increasing vector
132			// size if we log faster than we can write, but if that happens
133			// we have bigger problems.
134			if (idx == queue.size ())
135			{
136			queue.clear ();
137			idx = 0;
138			}
139
140			SMUTEX_UNLOCK (mutex);
141
142			log_sync (line);
143			}
144			}
145
146			void
147			log_cleanup ()
148			{
149			logsync = 1;
150
151			for (;;)
152			{
153			int done;
154
155			SMUTEX_LOCK (mutex);
156			done = queue.empty ();
157			SMUTEX_UNLOCK (mutex);
158
159			if (done)
160			break;
161
162			usleep (10000);
163	root	1.24	SMUTEX_LOCK (fdlock);
164			SMUTEX_UNLOCK (fdlock);
165	root	1.17	}
166			}
167
168			static void
169			af_child ()
170			{
171	root	1.24	logsync = 2;
172	root	1.17	}
173
174			static struct logthread : thread
175			{
176			logthread ()
177			{
178			pthread_atfork (0, 0, af_child);
179			start (logthread_proc);
180			logsync = 0;
181			}
182			} logthread;
183	elmex	1.1
184	root	1.4	void
185	root	1.22	LOG (int flags, const_utf8_string format, ...)
186	elmex	1.1	{
187	root	1.12	int level = flags & 15;
188
189			if (level > settings.debug)
190			return;
191
192	root	1.17	logline line;
193			gettimeofday (&line.tv, 0);
194	root	1.12
195	root	1.17	static dynbuf_text buf;
196	root	1.12
197			va_list ap;
198			va_start (ap, format);
199	root	1.17	buf.vprintf (format, ap);
200	root	1.12	va_end (ap);
201
202	root	1.17	buf << '\n';
203
204			line.buf = buf.linearise ();
205			line.len = buf.size ();
206	root	1.12
207	root	1.17	if (line.buf [line.len - 2] == '\n')
208			--line.len;
209	root	1.14
210	root	1.17	line.buf = salloc<char> (line.len, line.buf);
211
212			buf.clear ();
213
214			if (logsync)
215			flags \|= logSync;
216	root	1.12
217			if (flags & logBacktrace)
218	root	1.17	{
219			line.buf [line.len - 1] = 0;
220			log_backtrace (line.buf);
221			line.buf [line.len - 1] = '\n';
222			}
223
224			line.flags = flags;
225
226			if (line.flags & logSync)
227			log_sync (line);
228			else
229			{
230			SMUTEX_LOCK (mutex);
231			queue.push_back (line);
232			SMUTEX_UNLOCK (mutex);
233			SCOND_SIGNAL (cond);
234			}
235	elmex	1.1	}
236	root	1.17
237	root	1.24	static int suspended;
238
239			void
240			log_suspend ()
241			{
242			if (!suspended++)
243			{
244			LOG (llevDebug, "logging suspended.");
245			SMUTEX_LOCK (fdlock);
246			}
247			}
248
249			void
250			log_resume ()
251			{
252			if (!--suspended)
253			{
254			SMUTEX_UNLOCK (fdlock);
255			LOG (llevDebug, "logging resumed.");
256			}
257			}
258