server/common/utils.C

/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008,2009 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>
 */

/*
 * General convenience functions for deliantra.
 */

#include <cstdlib>
#include <sys/types.h>
#include <unistd.h>
#include <sys/time.h>
#include <time.h>
#include <signal.h>

#include <global.h>
#include <material.h>
#include <object.h>

#include <sys/time.h>
#include <sys/resource.h>

#include <glib.h>

refcnt_base::refcnt_t refcnt_dummy;
ssize_t slice_alloc;
rand_gen rndm, rmg_rndm;

void
tausworthe_random_generator::seed (uint32_t seed)
{
  state [0] = seed      * 69069U; if (state [0] <   2U) state [0] +=   2U;
  state [1] = state [0] * 69069U; if (state [0] <   8U) state [0] +=   8U;
  state [2] = state [1] * 69069U; if (state [0] <  16U) state [0] +=  16U;
  state [3] = state [2] * 69069U; if (state [0] < 128U) state [0] += 128U;

  for (int i = 11; --i; )
    next ();
}

uint32_t
tausworthe_random_generator::next ()
{
  state [0] = ((state [0] & 0xFFFFFFFEU) << 18U) ^ (((state [0] <<  6U) ^ state [0]) >> 13U);
  state [1] = ((state [1] & 0xFFFFFFF8U) <<  2U) ^ (((state [1] <<  2U) ^ state [1]) >> 27U);
  state [2] = ((state [2] & 0xFFFFFFF0U) <<  7U) ^ (((state [2] << 13U) ^ state [2]) >> 21U);
  state [3] = ((state [3] & 0xFFFFFF80U) << 13U) ^ (((state [3] <<  3U) ^ state [3]) >> 12U);

  return state [0] ^ state [1] ^ state [2] ^ state [3];
}

template<class generator>
uint32_t
random_number_generator<generator>::get_range (uint32_t num)
{
  return (this->next () * (uint64_t)num) >> 32U;
}

// return a number within (min .. max)
template<class generator>
int 
random_number_generator<generator>::get_range (int r_min, int r_max)
{
  return r_min + get_range (max (r_max - r_min + 1, 0));
}

template struct random_number_generator<tausworthe_random_generator>;
template struct random_number_generator<xorshift_random_generator>;

/******************************************************************************/

/* Checks a player-provided string which will become the msg property of
 * an object for dangerous input.
 */
bool 
msg_is_safe (const char *msg)
{
  bool safe = true;

  /* Trying to cheat by getting data into the object */
  if (!strncmp (msg, "endmsg", sizeof ("endmsg") - 1)
      || strstr (msg, "\nendmsg"))
    safe = false;

  /* Trying to make the object talk, and potentially access arbitrary code */
  if (object::msg_has_dialogue (msg))
    safe = false;

  return safe;
}

/////////////////////////////////////////////////////////////////////////////

void
fork_abort (const char *msg)
{
  if (!fork ())
    {
      signal (SIGINT , SIG_IGN);
      signal (SIGTERM, SIG_IGN);
      signal (SIGABRT, SIG_IGN);

      signal (SIGSEGV, SIG_DFL);
      signal (SIGBUS , SIG_DFL);
      signal (SIGILL , SIG_DFL);
      signal (SIGTRAP, SIG_DFL);

      // try to put corefiles into a subdirectory, if existing, to allow
      // an administrator to reduce the I/O load.
      chdir ("cores");

      // try to detach us from as many external dependencies as possible
      // as coredumping can take time by closing all fd's.
      {
        struct rlimit lim;

        if (getrlimit (RLIMIT_NOFILE, &lim))
          lim.rlim_cur = 1024;

        for (int i = 0; i < lim.rlim_cur; ++i)
          close (i);
      }

      {
        sigset_t empty;
        sigemptyset (&empty);
        sigprocmask (SIG_SETMASK, &empty, 0);
      }

      // try to coredump with SIGTRAP
      kill (getpid (), SIGTRAP);
      abort ();
    }

  LOG (llevError, "fork abort: %s\n", msg);
}

void *salloc_ (int n) throw (std::bad_alloc)
{
  void *ptr = g_slice_alloc (n);

  if (!ptr)
    throw std::bad_alloc ();

  slice_alloc += n;
  return ptr;
}

void *salloc_ (int n, void *src) throw (std::bad_alloc)
{
  void *ptr = salloc_ (n);

  if (src)
    memcpy (ptr, src, n);
  else
    memset (ptr, 0, n);

  return ptr;
}

/******************************************************************************/

#if DEBUG_SALLOC

#define MAGIC 0xa1b2c35543deadLL

void *g_slice_alloc (unsigned long size)
{
  unsigned long *p = (unsigned long *) (g_slice_alloc)(size + sizeof (unsigned long));
  *p++ = size ^ MAGIC;
  //fprintf (stderr, "g_slice_alloc %ld %p\n", size, p);//D
  return (void *)p;
}

void *g_slice_alloc0 (unsigned long size)
{
  return memset (g_slice_alloc (size), 0, size);
}

void g_slice_free1 (unsigned long size, void *ptr)
{
  //fprintf (stderr, "g_slice_free %ld %p\n", size, ptr);//D
  if (expect_true (ptr))
    {
      unsigned long *p = (unsigned long *)ptr;
      unsigned long s = *--p ^ MAGIC;

      if (size != (unsigned long)(*p ^ MAGIC))
        {
          LOG (logBacktrace | llevError, "slice free size (%lx) doesn't match alloc size (%lx)\n", size, s);
          abort ();
        }

      *p = MAGIC;

      (g_slice_free1)(s + sizeof (unsigned long), p);
    }
}

#endif

/******************************************************************************/

int
assign (char *dst, const char *src, int maxsize)
{
  if (!src)
    src = "";

  int len = strlen (src);

  if (len >= maxsize)
    {
      if (maxsize <= 4)
        {
          memset (dst, '.', maxsize - 2);
          dst [maxsize - 1] = 0;
        }
      else
        {
          memcpy (dst, src, maxsize - 4);
          memcpy (dst + maxsize - 4, "...", 4);
        }

      len = maxsize;
    }
  else
    memcpy (dst, src, ++len);

  return len;
}

char *
vformat (const char *format, va_list ap)
{
  static dynbuf_text buf; buf.clear ();
  buf.vprintf (format, ap);
  return buf;
}

char *
format (const char *format, ...)
{
  va_list ap;
  va_start (ap, format);
  char *buf = vformat (format, ap);
  va_end (ap);

  return buf;
}

tstamp now ()
{
  struct timeval tv;

  gettimeofday (&tv, 0);
  return tstamp (tv.tv_sec) + tstamp (tv.tv_usec) * tstamp (1e-6);
}

int
similar_direction (int a, int b)
{
  if (!a || !b)
    return 0;

  int diff = (b - a) & 7;
  return diff <= 1 || diff >= 7;
}

/* crc32 0xdebb20e3 table and supplementary functions.  */
extern const uint32_t crc_32_tab[256] =
{
    0x00000000UL, 0x77073096UL, 0xee0e612cUL, 0x990951baUL, 0x076dc419UL,
    0x706af48fUL, 0xe963a535UL, 0x9e6495a3UL, 0x0edb8832UL, 0x79dcb8a4UL,
    0xe0d5e91eUL, 0x97d2d988UL, 0x09b64c2bUL, 0x7eb17cbdUL, 0xe7b82d07UL,
    0x90bf1d91UL, 0x1db71064UL, 0x6ab020f2UL, 0xf3b97148UL, 0x84be41deUL,
    0x1adad47dUL, 0x6ddde4ebUL, 0xf4d4b551UL, 0x83d385c7UL, 0x136c9856UL,
    0x646ba8c0UL, 0xfd62f97aUL, 0x8a65c9ecUL, 0x14015c4fUL, 0x63066cd9UL,
    0xfa0f3d63UL, 0x8d080df5UL, 0x3b6e20c8UL, 0x4c69105eUL, 0xd56041e4UL,
    0xa2677172UL, 0x3c03e4d1UL, 0x4b04d447UL, 0xd20d85fdUL, 0xa50ab56bUL,
    0x35b5a8faUL, 0x42b2986cUL, 0xdbbbc9d6UL, 0xacbcf940UL, 0x32d86ce3UL,
    0x45df5c75UL, 0xdcd60dcfUL, 0xabd13d59UL, 0x26d930acUL, 0x51de003aUL,
    0xc8d75180UL, 0xbfd06116UL, 0x21b4f4b5UL, 0x56b3c423UL, 0xcfba9599UL,
    0xb8bda50fUL, 0x2802b89eUL, 0x5f058808UL, 0xc60cd9b2UL, 0xb10be924UL,
    0x2f6f7c87UL, 0x58684c11UL, 0xc1611dabUL, 0xb6662d3dUL, 0x76dc4190UL,
    0x01db7106UL, 0x98d220bcUL, 0xefd5102aUL, 0x71b18589UL, 0x06b6b51fUL,
    0x9fbfe4a5UL, 0xe8b8d433UL, 0x7807c9a2UL, 0x0f00f934UL, 0x9609a88eUL,
    0xe10e9818UL, 0x7f6a0dbbUL, 0x086d3d2dUL, 0x91646c97UL, 0xe6635c01UL,
    0x6b6b51f4UL, 0x1c6c6162UL, 0x856530d8UL, 0xf262004eUL, 0x6c0695edUL,
    0x1b01a57bUL, 0x8208f4c1UL, 0xf50fc457UL, 0x65b0d9c6UL, 0x12b7e950UL,
    0x8bbeb8eaUL, 0xfcb9887cUL, 0x62dd1ddfUL, 0x15da2d49UL, 0x8cd37cf3UL,
    0xfbd44c65UL, 0x4db26158UL, 0x3ab551ceUL, 0xa3bc0074UL, 0xd4bb30e2UL,
    0x4adfa541UL, 0x3dd895d7UL, 0xa4d1c46dUL, 0xd3d6f4fbUL, 0x4369e96aUL,
    0x346ed9fcUL, 0xad678846UL, 0xda60b8d0UL, 0x44042d73UL, 0x33031de5UL,
    0xaa0a4c5fUL, 0xdd0d7cc9UL, 0x5005713cUL, 0x270241aaUL, 0xbe0b1010UL,
    0xc90c2086UL, 0x5768b525UL, 0x206f85b3UL, 0xb966d409UL, 0xce61e49fUL,
    0x5edef90eUL, 0x29d9c998UL, 0xb0d09822UL, 0xc7d7a8b4UL, 0x59b33d17UL,
    0x2eb40d81UL, 0xb7bd5c3bUL, 0xc0ba6cadUL, 0xedb88320UL, 0x9abfb3b6UL,
    0x03b6e20cUL, 0x74b1d29aUL, 0xead54739UL, 0x9dd277afUL, 0x04db2615UL,
    0x73dc1683UL, 0xe3630b12UL, 0x94643b84UL, 0x0d6d6a3eUL, 0x7a6a5aa8UL,
    0xe40ecf0bUL, 0x9309ff9dUL, 0x0a00ae27UL, 0x7d079eb1UL, 0xf00f9344UL,
    0x8708a3d2UL, 0x1e01f268UL, 0x6906c2feUL, 0xf762575dUL, 0x806567cbUL,
    0x196c3671UL, 0x6e6b06e7UL, 0xfed41b76UL, 0x89d32be0UL, 0x10da7a5aUL,
    0x67dd4accUL, 0xf9b9df6fUL, 0x8ebeeff9UL, 0x17b7be43UL, 0x60b08ed5UL,
    0xd6d6a3e8UL, 0xa1d1937eUL, 0x38d8c2c4UL, 0x4fdff252UL, 0xd1bb67f1UL,
    0xa6bc5767UL, 0x3fb506ddUL, 0x48b2364bUL, 0xd80d2bdaUL, 0xaf0a1b4cUL,
    0x36034af6UL, 0x41047a60UL, 0xdf60efc3UL, 0xa867df55UL, 0x316e8eefUL,
    0x4669be79UL, 0xcb61b38cUL, 0xbc66831aUL, 0x256fd2a0UL, 0x5268e236UL,
    0xcc0c7795UL, 0xbb0b4703UL, 0x220216b9UL, 0x5505262fUL, 0xc5ba3bbeUL,
    0xb2bd0b28UL, 0x2bb45a92UL, 0x5cb36a04UL, 0xc2d7ffa7UL, 0xb5d0cf31UL,
    0x2cd99e8bUL, 0x5bdeae1dUL, 0x9b64c2b0UL, 0xec63f226UL, 0x756aa39cUL,
    0x026d930aUL, 0x9c0906a9UL, 0xeb0e363fUL, 0x72076785UL, 0x05005713UL,
    0x95bf4a82UL, 0xe2b87a14UL, 0x7bb12baeUL, 0x0cb61b38UL, 0x92d28e9bUL,
    0xe5d5be0dUL, 0x7cdcefb7UL, 0x0bdbdf21UL, 0x86d3d2d4UL, 0xf1d4e242UL,
    0x68ddb3f8UL, 0x1fda836eUL, 0x81be16cdUL, 0xf6b9265bUL, 0x6fb077e1UL,
    0x18b74777UL, 0x88085ae6UL, 0xff0f6a70UL, 0x66063bcaUL, 0x11010b5cUL,
    0x8f659effUL, 0xf862ae69UL, 0x616bffd3UL, 0x166ccf45UL, 0xa00ae278UL,
    0xd70dd2eeUL, 0x4e048354UL, 0x3903b3c2UL, 0xa7672661UL, 0xd06016f7UL,
    0x4969474dUL, 0x3e6e77dbUL, 0xaed16a4aUL, 0xd9d65adcUL, 0x40df0b66UL,
    0x37d83bf0UL, 0xa9bcae53UL, 0xdebb9ec5UL, 0x47b2cf7fUL, 0x30b5ffe9UL,
    0xbdbdf21cUL, 0xcabac28aUL, 0x53b39330UL, 0x24b4a3a6UL, 0xbad03605UL,
    0xcdd70693UL, 0x54de5729UL, 0x23d967bfUL, 0xb3667a2eUL, 0xc4614ab8UL,
    0x5d681b02UL, 0x2a6f2b94UL, 0xb40bbe37UL, 0xc30c8ea1UL, 0x5a05df1bUL,
    0x2d02ef8dL
};

void thread::start (void *(*start_routine)(void *), void *arg)
{
  pthread_attr_t attr;

  pthread_attr_init (&attr);
  pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
  pthread_attr_setstacksize (&attr, PTHREAD_STACK_MIN < sizeof (long) * 4096
                                    ? sizeof (long) * 4096 : PTHREAD_STACK_MIN);
#ifdef PTHREAD_SCOPE_PROCESS
  pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS);
#endif

  sigset_t fullsigset, oldsigset;
  sigfillset (&fullsigset);

  pthread_sigmask (SIG_SETMASK, &fullsigset, &oldsigset);

  if (pthread_create (&id, &attr, start_routine, arg))
    cleanup ("unable to create a new thread");

  pthread_sigmask (SIG_SETMASK, &oldsigset, 0);
}

Revision:	1.93
Committed:	Wed Nov 4 00:02:48 2009 UTC (14 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-2_90
Changes since 1.92:	+1 -328 lines
Log Message:	agpl reorganisation
#	Content
1	/*
2	* This file is part of Deliantra, the Roguelike Realtime MMORPG.
3	*
4	* Copyright (©) 2005,2006,2007,2008,2009 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5	*
6	* 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	*
11	* 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	*
16	* 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	*
20	* The authors can be reached via e-mail to <support@deliantra.net>
21	*/
22
23	/*
24	* General convenience functions for deliantra.
25	*/
26
27	#include <cstdlib>
28	#include <sys/types.h>
29	#include <unistd.h>
30	#include <sys/time.h>
31	#include <time.h>
32	#include <signal.h>
33
34	#include <global.h>
35	#include <material.h>
36	#include <object.h>
37
38	#include <sys/time.h>
39	#include <sys/resource.h>
40
41	#include <glib.h>
42
43	refcnt_base::refcnt_t refcnt_dummy;
44	ssize_t slice_alloc;
45	rand_gen rndm, rmg_rndm;
46
47	void
48	tausworthe_random_generator::seed (uint32_t seed)
49	{
50	state [0] = seed * 69069U; if (state [0] < 2U) state [0] += 2U;
51	state [1] = state [0] * 69069U; if (state [0] < 8U) state [0] += 8U;
52	state [2] = state [1] * 69069U; if (state [0] < 16U) state [0] += 16U;
53	state [3] = state [2] * 69069U; if (state [0] < 128U) state [0] += 128U;
54
55	for (int i = 11; --i; )
56	next ();
57	}
58
59	uint32_t
60	tausworthe_random_generator::next ()
61	{
62	state [0] = ((state [0] & 0xFFFFFFFEU) << 18U) ^ (((state [0] << 6U) ^ state [0]) >> 13U);
63	state [1] = ((state [1] & 0xFFFFFFF8U) << 2U) ^ (((state [1] << 2U) ^ state [1]) >> 27U);
64	state [2] = ((state [2] & 0xFFFFFFF0U) << 7U) ^ (((state [2] << 13U) ^ state [2]) >> 21U);
65	state [3] = ((state [3] & 0xFFFFFF80U) << 13U) ^ (((state [3] << 3U) ^ state [3]) >> 12U);
66
67	return state [0] ^ state [1] ^ state [2] ^ state [3];
68	}
69
70	template<class generator>
71	uint32_t
72	random_number_generator<generator>::get_range (uint32_t num)
73	{
74	return (this->next () * (uint64_t)num) >> 32U;
75	}
76
77	// return a number within (min .. max)
78	template<class generator>
79	int
80	random_number_generator<generator>::get_range (int r_min, int r_max)
81	{
82	return r_min + get_range (max (r_max - r_min + 1, 0));
83	}
84
85	template struct random_number_generator<tausworthe_random_generator>;
86	template struct random_number_generator<xorshift_random_generator>;
87
88	/******************************************************************************/
89
90	/* Checks a player-provided string which will become the msg property of
91	* an object for dangerous input.
92	*/
93	bool
94	msg_is_safe (const char *msg)
95	{
96	bool safe = true;
97
98	/* Trying to cheat by getting data into the object */
99	if (!strncmp (msg, "endmsg", sizeof ("endmsg") - 1)
100	\|\| strstr (msg, "\nendmsg"))
101	safe = false;
102
103	/* Trying to make the object talk, and potentially access arbitrary code */
104	if (object::msg_has_dialogue (msg))
105	safe = false;
106
107	return safe;
108	}
109
110	/////////////////////////////////////////////////////////////////////////////
111
112	void
113	fork_abort (const char *msg)
114	{
115	if (!fork ())
116	{
117	signal (SIGINT , SIG_IGN);
118	signal (SIGTERM, SIG_IGN);
119	signal (SIGABRT, SIG_IGN);
120
121	signal (SIGSEGV, SIG_DFL);
122	signal (SIGBUS , SIG_DFL);
123	signal (SIGILL , SIG_DFL);
124	signal (SIGTRAP, SIG_DFL);
125
126	// try to put corefiles into a subdirectory, if existing, to allow
127	// an administrator to reduce the I/O load.
128	chdir ("cores");
129
130	// try to detach us from as many external dependencies as possible
131	// as coredumping can take time by closing all fd's.
132	{
133	struct rlimit lim;
134
135	if (getrlimit (RLIMIT_NOFILE, &lim))
136	lim.rlim_cur = 1024;
137
138	for (int i = 0; i < lim.rlim_cur; ++i)
139	close (i);
140	}
141
142	{
143	sigset_t empty;
144	sigemptyset (&empty);
145	sigprocmask (SIG_SETMASK, &empty, 0);
146	}
147
148	// try to coredump with SIGTRAP
149	kill (getpid (), SIGTRAP);
150	abort ();
151	}
152
153	LOG (llevError, "fork abort: %s\n", msg);
154	}
155
156	void *salloc_ (int n) throw (std::bad_alloc)
157	{
158	void *ptr = g_slice_alloc (n);
159
160	if (!ptr)
161	throw std::bad_alloc ();
162
163	slice_alloc += n;
164	return ptr;
165	}
166
167	void salloc_ (int n, void src) throw (std::bad_alloc)
168	{
169	void *ptr = salloc_ (n);
170
171	if (src)
172	memcpy (ptr, src, n);
173	else
174	memset (ptr, 0, n);
175
176	return ptr;
177	}
178
179	/******************************************************************************/
180
181	#if DEBUG_SALLOC
182
183	#define MAGIC 0xa1b2c35543deadLL
184
185	void *g_slice_alloc (unsigned long size)
186	{
187	unsigned long p = (unsigned long ) (g_slice_alloc)(size + sizeof (unsigned long));
188	*p++ = size ^ MAGIC;
189	//fprintf (stderr, "g_slice_alloc %ld %p\n", size, p);//D
190	return (void *)p;
191	}
192
193	void *g_slice_alloc0 (unsigned long size)
194	{
195	return memset (g_slice_alloc (size), 0, size);
196	}
197
198	void g_slice_free1 (unsigned long size, void *ptr)
199	{
200	//fprintf (stderr, "g_slice_free %ld %p\n", size, ptr);//D
201	if (expect_true (ptr))
202	{
203	unsigned long p = (unsigned long )ptr;
204	unsigned long s = *--p ^ MAGIC;
205
206	if (size != (unsigned long)(*p ^ MAGIC))
207	{
208	LOG (logBacktrace \| llevError, "slice free size (%lx) doesn't match alloc size (%lx)\n", size, s);
209	abort ();
210	}
211
212	*p = MAGIC;
213
214	(g_slice_free1)(s + sizeof (unsigned long), p);
215	}
216	}
217
218	#endif
219
220	/******************************************************************************/
221
222	int
223	assign (char dst, const char src, int maxsize)
224	{
225	if (!src)
226	src = "";
227
228	int len = strlen (src);
229
230	if (len >= maxsize)
231	{
232	if (maxsize <= 4)
233	{
234	memset (dst, '.', maxsize - 2);
235	dst [maxsize - 1] = 0;
236	}
237	else
238	{
239	memcpy (dst, src, maxsize - 4);
240	memcpy (dst + maxsize - 4, "...", 4);
241	}
242
243	len = maxsize;
244	}
245	else
246	memcpy (dst, src, ++len);
247
248	return len;
249	}
250
251	char *
252	vformat (const char *format, va_list ap)
253	{
254	static dynbuf_text buf; buf.clear ();
255	buf.vprintf (format, ap);
256	return buf;
257	}
258
259	char *
260	format (const char *format, ...)
261	{
262	va_list ap;
263	va_start (ap, format);
264	char *buf = vformat (format, ap);
265	va_end (ap);
266
267	return buf;
268	}
269
270	tstamp now ()
271	{
272	struct timeval tv;
273
274	gettimeofday (&tv, 0);
275	return tstamp (tv.tv_sec) + tstamp (tv.tv_usec) * tstamp (1e-6);
276	}
277
278	int
279	similar_direction (int a, int b)
280	{
281	if (!a \|\| !b)
282	return 0;
283
284	int diff = (b - a) & 7;
285	return diff <= 1 \|\| diff >= 7;
286	}
287
288	/* crc32 0xdebb20e3 table and supplementary functions. */
289	extern const uint32_t crc_32_tab[256] =
290	{
291	0x00000000UL, 0x77073096UL, 0xee0e612cUL, 0x990951baUL, 0x076dc419UL,
292	0x706af48fUL, 0xe963a535UL, 0x9e6495a3UL, 0x0edb8832UL, 0x79dcb8a4UL,
293	0xe0d5e91eUL, 0x97d2d988UL, 0x09b64c2bUL, 0x7eb17cbdUL, 0xe7b82d07UL,
294	0x90bf1d91UL, 0x1db71064UL, 0x6ab020f2UL, 0xf3b97148UL, 0x84be41deUL,
295	0x1adad47dUL, 0x6ddde4ebUL, 0xf4d4b551UL, 0x83d385c7UL, 0x136c9856UL,
296	0x646ba8c0UL, 0xfd62f97aUL, 0x8a65c9ecUL, 0x14015c4fUL, 0x63066cd9UL,
297	0xfa0f3d63UL, 0x8d080df5UL, 0x3b6e20c8UL, 0x4c69105eUL, 0xd56041e4UL,
298	0xa2677172UL, 0x3c03e4d1UL, 0x4b04d447UL, 0xd20d85fdUL, 0xa50ab56bUL,
299	0x35b5a8faUL, 0x42b2986cUL, 0xdbbbc9d6UL, 0xacbcf940UL, 0x32d86ce3UL,
300	0x45df5c75UL, 0xdcd60dcfUL, 0xabd13d59UL, 0x26d930acUL, 0x51de003aUL,
301	0xc8d75180UL, 0xbfd06116UL, 0x21b4f4b5UL, 0x56b3c423UL, 0xcfba9599UL,
302	0xb8bda50fUL, 0x2802b89eUL, 0x5f058808UL, 0xc60cd9b2UL, 0xb10be924UL,
303	0x2f6f7c87UL, 0x58684c11UL, 0xc1611dabUL, 0xb6662d3dUL, 0x76dc4190UL,
304	0x01db7106UL, 0x98d220bcUL, 0xefd5102aUL, 0x71b18589UL, 0x06b6b51fUL,
305	0x9fbfe4a5UL, 0xe8b8d433UL, 0x7807c9a2UL, 0x0f00f934UL, 0x9609a88eUL,
306	0xe10e9818UL, 0x7f6a0dbbUL, 0x086d3d2dUL, 0x91646c97UL, 0xe6635c01UL,
307	0x6b6b51f4UL, 0x1c6c6162UL, 0x856530d8UL, 0xf262004eUL, 0x6c0695edUL,
308	0x1b01a57bUL, 0x8208f4c1UL, 0xf50fc457UL, 0x65b0d9c6UL, 0x12b7e950UL,
309	0x8bbeb8eaUL, 0xfcb9887cUL, 0x62dd1ddfUL, 0x15da2d49UL, 0x8cd37cf3UL,
310	0xfbd44c65UL, 0x4db26158UL, 0x3ab551ceUL, 0xa3bc0074UL, 0xd4bb30e2UL,
311	0x4adfa541UL, 0x3dd895d7UL, 0xa4d1c46dUL, 0xd3d6f4fbUL, 0x4369e96aUL,
312	0x346ed9fcUL, 0xad678846UL, 0xda60b8d0UL, 0x44042d73UL, 0x33031de5UL,
313	0xaa0a4c5fUL, 0xdd0d7cc9UL, 0x5005713cUL, 0x270241aaUL, 0xbe0b1010UL,
314	0xc90c2086UL, 0x5768b525UL, 0x206f85b3UL, 0xb966d409UL, 0xce61e49fUL,
315	0x5edef90eUL, 0x29d9c998UL, 0xb0d09822UL, 0xc7d7a8b4UL, 0x59b33d17UL,
316	0x2eb40d81UL, 0xb7bd5c3bUL, 0xc0ba6cadUL, 0xedb88320UL, 0x9abfb3b6UL,
317	0x03b6e20cUL, 0x74b1d29aUL, 0xead54739UL, 0x9dd277afUL, 0x04db2615UL,
318	0x73dc1683UL, 0xe3630b12UL, 0x94643b84UL, 0x0d6d6a3eUL, 0x7a6a5aa8UL,
319	0xe40ecf0bUL, 0x9309ff9dUL, 0x0a00ae27UL, 0x7d079eb1UL, 0xf00f9344UL,
320	0x8708a3d2UL, 0x1e01f268UL, 0x6906c2feUL, 0xf762575dUL, 0x806567cbUL,
321	0x196c3671UL, 0x6e6b06e7UL, 0xfed41b76UL, 0x89d32be0UL, 0x10da7a5aUL,
322	0x67dd4accUL, 0xf9b9df6fUL, 0x8ebeeff9UL, 0x17b7be43UL, 0x60b08ed5UL,
323	0xd6d6a3e8UL, 0xa1d1937eUL, 0x38d8c2c4UL, 0x4fdff252UL, 0xd1bb67f1UL,
324	0xa6bc5767UL, 0x3fb506ddUL, 0x48b2364bUL, 0xd80d2bdaUL, 0xaf0a1b4cUL,
325	0x36034af6UL, 0x41047a60UL, 0xdf60efc3UL, 0xa867df55UL, 0x316e8eefUL,
326	0x4669be79UL, 0xcb61b38cUL, 0xbc66831aUL, 0x256fd2a0UL, 0x5268e236UL,
327	0xcc0c7795UL, 0xbb0b4703UL, 0x220216b9UL, 0x5505262fUL, 0xc5ba3bbeUL,
328	0xb2bd0b28UL, 0x2bb45a92UL, 0x5cb36a04UL, 0xc2d7ffa7UL, 0xb5d0cf31UL,
329	0x2cd99e8bUL, 0x5bdeae1dUL, 0x9b64c2b0UL, 0xec63f226UL, 0x756aa39cUL,
330	0x026d930aUL, 0x9c0906a9UL, 0xeb0e363fUL, 0x72076785UL, 0x05005713UL,
331	0x95bf4a82UL, 0xe2b87a14UL, 0x7bb12baeUL, 0x0cb61b38UL, 0x92d28e9bUL,
332	0xe5d5be0dUL, 0x7cdcefb7UL, 0x0bdbdf21UL, 0x86d3d2d4UL, 0xf1d4e242UL,
333	0x68ddb3f8UL, 0x1fda836eUL, 0x81be16cdUL, 0xf6b9265bUL, 0x6fb077e1UL,
334	0x18b74777UL, 0x88085ae6UL, 0xff0f6a70UL, 0x66063bcaUL, 0x11010b5cUL,
335	0x8f659effUL, 0xf862ae69UL, 0x616bffd3UL, 0x166ccf45UL, 0xa00ae278UL,
336	0xd70dd2eeUL, 0x4e048354UL, 0x3903b3c2UL, 0xa7672661UL, 0xd06016f7UL,
337	0x4969474dUL, 0x3e6e77dbUL, 0xaed16a4aUL, 0xd9d65adcUL, 0x40df0b66UL,
338	0x37d83bf0UL, 0xa9bcae53UL, 0xdebb9ec5UL, 0x47b2cf7fUL, 0x30b5ffe9UL,
339	0xbdbdf21cUL, 0xcabac28aUL, 0x53b39330UL, 0x24b4a3a6UL, 0xbad03605UL,
340	0xcdd70693UL, 0x54de5729UL, 0x23d967bfUL, 0xb3667a2eUL, 0xc4614ab8UL,
341	0x5d681b02UL, 0x2a6f2b94UL, 0xb40bbe37UL, 0xc30c8ea1UL, 0x5a05df1bUL,
342	0x2d02ef8dL
343	};
344
345	void thread::start (void (start_routine)(void ), void arg)
346	{
347	pthread_attr_t attr;
348
349	pthread_attr_init (&attr);
350	pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
351	pthread_attr_setstacksize (&attr, PTHREAD_STACK_MIN < sizeof (long) * 4096
352	? sizeof (long) * 4096 : PTHREAD_STACK_MIN);
353	#ifdef PTHREAD_SCOPE_PROCESS
354	pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS);
355	#endif
356
357	sigset_t fullsigset, oldsigset;
358	sigfillset (&fullsigset);
359
360	pthread_sigmask (SIG_SETMASK, &fullsigset, &oldsigset);
361
362	if (pthread_create (&id, &attr, start_routine, arg))
363	cleanup ("unable to create a new thread");
364
365	pthread_sigmask (SIG_SETMASK, &oldsigset, 0);
366	}
367