EV/schmorp.h

#ifndef SCHMORP_PERL_H_
#define SCHMORP_PERL_H_

/* WARNING
 * This header file is a shared resource between many modules.
 */

#include <signal.h>
#include <errno.h>

#ifndef _WIN32
# include <poll.h>
#endif

/* useful stuff, used by schmorp mostly */

#include "patchlevel.h"

#define PERL_VERSION_ATLEAST(a,b,c)                             \
  (PERL_REVISION > (a)                                          \
   || (PERL_REVISION == (a)                                     \
       && (PERL_VERSION > (b)                                   \
           || (PERL_VERSION == (b) && PERL_SUBVERSION >= (c)))))

#if !PERL_VERSION_ATLEAST (5,6,0)
# ifndef PL_ppaddr
#  define PL_ppaddr ppaddr
# endif
# ifndef call_sv
#  define call_sv perl_call_sv
# endif
# ifndef get_sv
#  define get_sv perl_get_sv
# endif
# ifndef get_cv
#  define get_cv perl_get_cv
# endif
# ifndef IS_PADGV
#  define IS_PADGV(v) 0
# endif
# ifndef IS_PADCONST
#  define IS_PADCONST(v) 0
# endif
#endif

/* 5.11 */
#ifndef CxHASARGS
# define CxHASARGS(cx) (cx)->blk_sub.hasargs
#endif

/* 5.10.0 */
#ifndef SvREFCNT_inc_NN
# define SvREFCNT_inc_NN(sv) SvREFCNT_inc (sv)
#endif

/* 5.8.8 */
#ifndef GV_NOTQUAL
# define GV_NOTQUAL 0
#endif
#ifndef newSV
# define newSV(l) NEWSV(0,l)
#endif
#ifndef CvISXSUB_on
# define CvISXSUB_on(cv) (void)cv
#endif
#ifndef CvISXSUB
# define CvISXSUB(cv) (CvXSUB (cv) ? TRUE : FALSE)
#endif
#ifndef Newx
# define Newx(ptr,nitems,type) New (0,ptr,nitems,type)
#endif

/* 5.8.7 */
#ifndef SvRV_set
# define SvRV_set(s,v) SvRV(s) = (v)
#endif

static int
s_signum (SV *sig)
{
#ifndef SIG_SIZE
  /* kudos to Slaven Rezic for the idea */
  static char sig_size [] = { SIG_NUM };
# define SIG_SIZE (sizeof (sig_size) + 1)
#endif
  dTHX;
  int signum;

  SvGETMAGIC (sig);

  for (signum = 1; signum < SIG_SIZE; ++signum)
    if (strEQ (SvPV_nolen (sig), PL_sig_name [signum]))
      return signum;

  signum = SvIV (sig);

  if (signum > 0 && signum < SIG_SIZE)
    return signum;

  return -1;
}

static int
s_signum_croak (SV *sig)
{
  int signum = s_signum (sig);

  if (signum < 0)
    {
      dTHX;
      croak ("%s: invalid signal name or number", SvPV_nolen (sig));
    }

  return signum;
}

static int
s_fileno (SV *fh, int wr)
{
  dTHX;
  SvGETMAGIC (fh);

  if (SvROK (fh))
    {
      fh = SvRV (fh);
      SvGETMAGIC (fh);
    }

  if (SvTYPE (fh) == SVt_PVGV)
    return PerlIO_fileno (wr ? IoOFP (sv_2io (fh)) : IoIFP (sv_2io (fh)));

  if (SvOK (fh) && (SvIV (fh) >= 0) && (SvIV (fh) < 0x7fffffffL))
    return SvIV (fh);

  return -1;
}

static int
s_fileno_croak (SV *fh, int wr)
{
  int fd = s_fileno (fh, wr);

  if (fd < 0)
    {
      dTHX;
      croak ("%s: illegal fh argument, either not an OS file or read/write mode mismatch", SvPV_nolen (fh));
    }

  return fd;
}

static SV *
s_get_cv (SV *cb_sv)
{
  dTHX;
  HV *st;
  GV *gvp;

  return (SV *)sv_2cv (cb_sv, &st, &gvp, 0);
}

static SV *
s_get_cv_croak (SV *cb_sv)
{
  SV *cv = s_get_cv (cb_sv);

  if (!cv)
    {
      dTHX;
      croak ("%s: callback must be a CODE reference or another callable object", SvPV_nolen (cb_sv));
    }

  return cv;
}

/*****************************************************************************/
/* gensub: simple closure generation utility */

#define S_GENSUB_ARG CvXSUBANY (cv).any_ptr

/* create a closure from XS, returns a code reference */
/* the arg can be accessed via GENSUB_ARG from the callback */
/* the callback must use dXSARGS/XSRETURN */
static SV *
s_gensub (pTHX_ void (*xsub)(pTHX_ CV *), void *arg)
{
  CV *cv = (CV *)newSV (0);

  sv_upgrade ((SV *)cv, SVt_PVCV);

  CvANON_on (cv);
  CvISXSUB_on (cv);
  CvXSUB (cv) = xsub;
  S_GENSUB_ARG = arg;

  return newRV_noinc ((SV *)cv);
}

/*****************************************************************************/
/* portable pipe/socketpair */

#ifdef USE_SOCKETS_AS_HANDLES
# define S_TO_HANDLE(x) ((HANDLE)win32_get_osfhandle (x))
#else
# define S_TO_HANDLE(x) ((HANDLE)x)
#endif

#ifdef _WIN32
/* taken almost verbatim from libev's ev_win32.c */
/* oh, the humanity! */
static int
s_pipe (int filedes [2])
{
  dTHX;

  struct sockaddr_in addr = { 0 };
  int addr_size = sizeof (addr);
  struct sockaddr_in adr2;
  int adr2_size = sizeof (adr2);
  SOCKET listener;
  SOCKET sock [2] = { -1, -1 };

  if ((listener = socket (AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET) 
    return -1;

  addr.sin_family = AF_INET;
  addr.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
  addr.sin_port = 0;

  if (bind (listener, (struct sockaddr *)&addr, addr_size))
    goto fail;

  if (getsockname (listener, (struct sockaddr *)&addr, &addr_size))
    goto fail;

  if (listen (listener, 1))
    goto fail;

  if ((sock [0] = socket (AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET) 
    goto fail;

  if (connect (sock [0], (struct sockaddr *)&addr, addr_size))
    goto fail;

  if ((sock [1] = accept (listener, 0, 0)) < 0)
    goto fail;

  /* windows vista returns fantasy port numbers for getpeername.
   * example for two interconnected tcp sockets:
   *
   * (Socket::unpack_sockaddr_in getsockname $sock0)[0] == 53364
   * (Socket::unpack_sockaddr_in getpeername $sock0)[0] == 53363
   * (Socket::unpack_sockaddr_in getsockname $sock1)[0] == 53363
   * (Socket::unpack_sockaddr_in getpeername $sock1)[0] == 53365
   *
   * wow! tridirectional sockets!
   *
   * this way of checking ports seems to work:
   */
  if (getpeername (sock [0], (struct sockaddr *)&addr, &addr_size))
    goto fail;

  if (getsockname (sock [1], (struct sockaddr *)&adr2, &adr2_size))
    goto fail;

  errno = WSAEINVAL;
  if (addr_size != adr2_size
      || addr.sin_addr.s_addr != adr2.sin_addr.s_addr /* just to be sure, I mean, it's windows */
      || addr.sin_port        != adr2.sin_port)
    goto fail;

  closesocket (listener);

#ifdef USE_SOCKETS_AS_HANDLES
  /* when select isn't winsocket, we also expect socket, connect, accept etc.
   * to work on fds */
  filedes [0] = sock [0];
  filedes [1] = sock [1];
#else
  filedes [0] = _open_osfhandle (sock [0], 0);
  filedes [1] = _open_osfhandle (sock [1], 0);
#endif

  return 0;

fail:
  closesocket (listener);

  if (sock [0] != INVALID_SOCKET) closesocket (sock [0]);
  if (sock [1] != INVALID_SOCKET) closesocket (sock [1]);

  return -1;
}

#define s_socketpair(domain,type,protocol,filedes) s_pipe (filedes)

static int
s_fd_blocking (int fd, int blocking)
{
  u_long nonblocking = !blocking;

  return ioctlsocket ((SOCKET)S_TO_HANDLE (fd), FIONBIO, &nonblocking);
}

#define s_fd_prepare(fd) s_fd_blocking (fd, 0)

#else

#define s_socketpair(domain,type,protocol,filedes) socketpair (domain, type, protocol, filedes)
#define s_pipe(filedes) pipe (filedes)

static int
s_fd_blocking (int fd, int blocking)
{
  return fcntl (fd, F_SETFL, blocking ? 0 : O_NONBLOCK);
}

static int
s_fd_prepare (int fd)
{
  return s_fd_blocking (fd, 0)
         || fcntl (fd, F_SETFD, FD_CLOEXEC);
}

#endif

#if __linux && (__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 7))
/* our minimum requirement is glibc 2.7 which has the stub, but not the header */
# include <stdint.h>
# ifdef __cplusplus
extern "C" {
# endif
  int eventfd (unsigned int initval, int flags);
# ifdef __cplusplus
}
# endif
#else
# define eventfd(initval,flags) -1
#endif

typedef struct {
  int fd[2]; /* read, write fd, might be equal */
  int len; /* write length (1 pipe/socket, 8 eventfd) */
} s_epipe;

static int
s_epipe_new (s_epipe *epp)
{
  s_epipe ep;

  ep.fd [0] = ep.fd [1] = eventfd (0, 0);

  if (ep.fd [0] >= 0)
    {
      s_fd_prepare (ep.fd [0]);
      ep.len = 8;
    }
  else
    {
      if (s_pipe (ep.fd))
        return -1;

      if (s_fd_prepare (ep.fd [0])
          || s_fd_prepare (ep.fd [1]))
        {
           dTHX;

           close (ep.fd [0]);
           close (ep.fd [1]);
           return -1;
        }

      ep.len = 1;
    }

  *epp = ep;
  return 0;
}

static void
s_epipe_destroy (s_epipe *epp)
{
  dTHX;

  close (epp->fd [0]);

  if (epp->fd [1] != epp->fd [0])
    close (epp->fd [1]);

  epp->len = 0;
}

static void
s_epipe_signal (s_epipe *epp)
{
#ifdef _WIN32
  /* perl overrides send with a function that crashes in other threads.
   * unfortunately, it overrides it with an argument-less macro, so
   * there is no way to force usage of the real send function.
   * incompetent windows programmers - is this redundant?
   */
  DWORD dummy;
  WriteFile (S_TO_HANDLE (epp->fd [1]), (LPCVOID)&dummy, 1, &dummy, 0);
#else
  static uint64_t counter = 1;
  /* some modules accept fd's from outside, support eventfd here */
  if (write (epp->fd [1], &counter, epp->len) < 0
      && errno == EINVAL
      && epp->len != 8)
    write (epp->fd [1], &counter, (epp->len = 8));
#endif
}

static void
s_epipe_drain (s_epipe *epp)
{
  dTHX;
  char buf [9];

#ifdef _WIN32
  recv (epp->fd [0], buf, sizeof (buf), 0);
#else
  read (epp->fd [0], buf, sizeof (buf));
#endif
}

/* like new, but dups over old */
static int
s_epipe_renew (s_epipe *epp)
{
  dTHX;
  s_epipe epn;

  if (epp->fd [1] != epp->fd [0])
    close (epp->fd [1]);

  if (s_epipe_new (&epn))
    return -1;

  if (epp->len)
    {
      if (dup2 (epn.fd [0], epp->fd [0]) < 0)
        croak ("unable to dup over old event pipe"); /* should not croak */

      if (epp->fd [1] != epp->fd [0])
        close (epn.fd [0]);

      epn.fd [0] = epp->fd [0];
    }

  *epp = epn;

  return 0;
}

#define s_epipe_fd(epp) ((epp)->fd [0])

static int
s_epipe_wait (s_epipe *epp)
{
  dTHX;
#ifdef _WIN32
  fd_set rfd;
  int fd = s_epipe_fd (epp);

  FD_ZERO (&rfd);
  FD_SET (fd, &rfd);

  return PerlSock_select (fd + 1, &rfd, 0, 0, 0);
#else
  /* poll is preferable on posix systems */
  struct pollfd pfd;

  pfd.fd = s_epipe_fd (epp);
  pfd.events = POLLIN;

  return poll (&pfd, 1, 0);
#endif
}

#endif

Revision:	1.6
Committed:	Sat Jul 18 00:59:45 2009 UTC (14 years, 10 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.5:	+22 -23 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#ifndef SCHMORP_PERL_H_
2			#define SCHMORP_PERL_H_
3
4	root	1.2	/* WARNING
5			* This header file is a shared resource between many modules.
6			*/
7
8	root	1.4	#include <signal.h>
9	root	1.5	#include <errno.h>
10	root	1.4
11			#ifndef _WIN32
12			# include <poll.h>
13			#endif
14
15	root	1.1	/* useful stuff, used by schmorp mostly */
16
17	root	1.2	#include "patchlevel.h"
18
19	root	1.1	#define PERL_VERSION_ATLEAST(a,b,c) \
20			(PERL_REVISION > (a) \
21			\|\| (PERL_REVISION == (a) \
22			&& (PERL_VERSION > (b) \
23			\|\| (PERL_VERSION == (b) && PERL_SUBVERSION >= (c)))))
24
25			#if !PERL_VERSION_ATLEAST (5,6,0)
26			# ifndef PL_ppaddr
27			# define PL_ppaddr ppaddr
28			# endif
29			# ifndef call_sv
30			# define call_sv perl_call_sv
31			# endif
32			# ifndef get_sv
33			# define get_sv perl_get_sv
34			# endif
35			# ifndef get_cv
36			# define get_cv perl_get_cv
37			# endif
38			# ifndef IS_PADGV
39			# define IS_PADGV(v) 0
40			# endif
41			# ifndef IS_PADCONST
42			# define IS_PADCONST(v) 0
43			# endif
44			#endif
45
46			/* 5.11 */
47			#ifndef CxHASARGS
48			# define CxHASARGS(cx) (cx)->blk_sub.hasargs
49			#endif
50
51			/* 5.10.0 */
52			#ifndef SvREFCNT_inc_NN
53			# define SvREFCNT_inc_NN(sv) SvREFCNT_inc (sv)
54			#endif
55
56			/* 5.8.8 */
57			#ifndef GV_NOTQUAL
58			# define GV_NOTQUAL 0
59			#endif
60			#ifndef newSV
61			# define newSV(l) NEWSV(0,l)
62			#endif
63			#ifndef CvISXSUB_on
64			# define CvISXSUB_on(cv) (void)cv
65			#endif
66			#ifndef CvISXSUB
67			# define CvISXSUB(cv) (CvXSUB (cv) ? TRUE : FALSE)
68			#endif
69			#ifndef Newx
70			# define Newx(ptr,nitems,type) New (0,ptr,nitems,type)
71			#endif
72
73			/* 5.8.7 */
74			#ifndef SvRV_set
75			# define SvRV_set(s,v) SvRV(s) = (v)
76			#endif
77
78			static int
79			s_signum (SV *sig)
80			{
81			#ifndef SIG_SIZE
82			/* kudos to Slaven Rezic for the idea */
83			static char sig_size [] = { SIG_NUM };
84			# define SIG_SIZE (sizeof (sig_size) + 1)
85			#endif
86	root	1.2	dTHX;
87	root	1.1	int signum;
88
89			SvGETMAGIC (sig);
90
91			for (signum = 1; signum < SIG_SIZE; ++signum)
92			if (strEQ (SvPV_nolen (sig), PL_sig_name [signum]))
93			return signum;
94
95			signum = SvIV (sig);
96
97			if (signum > 0 && signum < SIG_SIZE)
98			return signum;
99
100			return -1;
101			}
102
103			static int
104			s_signum_croak (SV *sig)
105			{
106			int signum = s_signum (sig);
107
108			if (signum < 0)
109	root	1.2	{
110			dTHX;
111			croak ("%s: invalid signal name or number", SvPV_nolen (sig));
112			}
113	root	1.1
114			return signum;
115			}
116
117			static int
118			s_fileno (SV *fh, int wr)
119			{
120	root	1.2	dTHX;
121	root	1.1	SvGETMAGIC (fh);
122
123			if (SvROK (fh))
124			{
125			fh = SvRV (fh);
126			SvGETMAGIC (fh);
127			}
128
129			if (SvTYPE (fh) == SVt_PVGV)
130			return PerlIO_fileno (wr ? IoOFP (sv_2io (fh)) : IoIFP (sv_2io (fh)));
131
132			if (SvOK (fh) && (SvIV (fh) >= 0) && (SvIV (fh) < 0x7fffffffL))
133			return SvIV (fh);
134
135			return -1;
136			}
137
138			static int
139			s_fileno_croak (SV *fh, int wr)
140			{
141			int fd = s_fileno (fh, wr);
142
143			if (fd < 0)
144	root	1.2	{
145			dTHX;
146			croak ("%s: illegal fh argument, either not an OS file or read/write mode mismatch", SvPV_nolen (fh));
147			}
148	root	1.1
149			return fd;
150			}
151
152			static SV *
153			s_get_cv (SV *cb_sv)
154			{
155	root	1.2	dTHX;
156	root	1.1	HV *st;
157			GV *gvp;
158
159	root	1.2	return (SV *)sv_2cv (cb_sv, &st, &gvp, 0);
160	root	1.1	}
161
162			static SV *
163			s_get_cv_croak (SV *cb_sv)
164			{
165	root	1.2	SV *cv = s_get_cv (cb_sv);
166	root	1.1
167	root	1.2	if (!cv)
168			{
169			dTHX;
170			croak ("%s: callback must be a CODE reference or another callable object", SvPV_nolen (cb_sv));
171			}
172	root	1.1
173	root	1.2	return cv;
174	root	1.1	}
175
176			/*****************************************************************************/
177			/* gensub: simple closure generation utility */
178
179			#define S_GENSUB_ARG CvXSUBANY (cv).any_ptr
180
181			/* create a closure from XS, returns a code reference */
182			/* the arg can be accessed via GENSUB_ARG from the callback */
183			/* the callback must use dXSARGS/XSRETURN */
184			static SV *
185			s_gensub (pTHX_ void (xsub)(pTHX_ CV ), void *arg)
186			{
187			CV cv = (CV )newSV (0);
188
189			sv_upgrade ((SV *)cv, SVt_PVCV);
190
191			CvANON_on (cv);
192			CvISXSUB_on (cv);
193			CvXSUB (cv) = xsub;
194			S_GENSUB_ARG = arg;
195
196			return newRV_noinc ((SV *)cv);
197			}
198
199	root	1.4	/*****************************************************************************/
200			/* portable pipe/socketpair */
201	root	1.3
202			#ifdef USE_SOCKETS_AS_HANDLES
203	root	1.4	# define S_TO_HANDLE(x) ((HANDLE)win32_get_osfhandle (x))
204	root	1.3	#else
205	root	1.4	# define S_TO_HANDLE(x) ((HANDLE)x)
206	root	1.3	#endif
207
208			#ifdef _WIN32
209			/* taken almost verbatim from libev's ev_win32.c */
210			/* oh, the humanity! */
211			static int
212			s_pipe (int filedes [2])
213			{
214	root	1.6	dTHX;
215
216	root	1.3	struct sockaddr_in addr = { 0 };
217			int addr_size = sizeof (addr);
218			struct sockaddr_in adr2;
219			int adr2_size = sizeof (adr2);
220			SOCKET listener;
221			SOCKET sock [2] = { -1, -1 };
222
223			if ((listener = socket (AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
224			return -1;
225
226			addr.sin_family = AF_INET;
227			addr.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
228			addr.sin_port = 0;
229
230			if (bind (listener, (struct sockaddr *)&addr, addr_size))
231			goto fail;
232
233			if (getsockname (listener, (struct sockaddr *)&addr, &addr_size))
234			goto fail;
235
236			if (listen (listener, 1))
237			goto fail;
238
239			if ((sock [0] = socket (AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
240			goto fail;
241
242			if (connect (sock [0], (struct sockaddr *)&addr, addr_size))
243			goto fail;
244
245			if ((sock [1] = accept (listener, 0, 0)) < 0)
246			goto fail;
247
248			/* windows vista returns fantasy port numbers for getpeername.
249			* example for two interconnected tcp sockets:
250			*
251			* (Socket::unpack_sockaddr_in getsockname $sock0)[0] == 53364
252			* (Socket::unpack_sockaddr_in getpeername $sock0)[0] == 53363
253			* (Socket::unpack_sockaddr_in getsockname $sock1)[0] == 53363
254			* (Socket::unpack_sockaddr_in getpeername $sock1)[0] == 53365
255			*
256			* wow! tridirectional sockets!
257			*
258			* this way of checking ports seems to work:
259			*/
260			if (getpeername (sock [0], (struct sockaddr *)&addr, &addr_size))
261			goto fail;
262
263			if (getsockname (sock [1], (struct sockaddr *)&adr2, &adr2_size))
264			goto fail;
265
266			errno = WSAEINVAL;
267			if (addr_size != adr2_size
268			\|\| addr.sin_addr.s_addr != adr2.sin_addr.s_addr /* just to be sure, I mean, it's windows */
269			\|\| addr.sin_port != adr2.sin_port)
270			goto fail;
271
272			closesocket (listener);
273
274			#ifdef USE_SOCKETS_AS_HANDLES
275			/* when select isn't winsocket, we also expect socket, connect, accept etc.
276			* to work on fds */
277			filedes [0] = sock [0];
278			filedes [1] = sock [1];
279			#else
280			filedes [0] = _open_osfhandle (sock [0], 0);
281			filedes [1] = _open_osfhandle (sock [1], 0);
282			#endif
283
284			return 0;
285
286			fail:
287			closesocket (listener);
288
289			if (sock [0] != INVALID_SOCKET) closesocket (sock [0]);
290			if (sock [1] != INVALID_SOCKET) closesocket (sock [1]);
291
292			return -1;
293			}
294
295			#define s_socketpair(domain,type,protocol,filedes) s_pipe (filedes)
296
297	root	1.4	static int
298			s_fd_blocking (int fd, int blocking)
299			{
300			u_long nonblocking = !blocking;
301
302			return ioctlsocket ((SOCKET)S_TO_HANDLE (fd), FIONBIO, &nonblocking);
303			}
304
305			#define s_fd_prepare(fd) s_fd_blocking (fd, 0)
306
307	root	1.3	#else
308
309			#define s_socketpair(domain,type,protocol,filedes) socketpair (domain, type, protocol, filedes)
310			#define s_pipe(filedes) pipe (filedes)
311
312	root	1.4	static int
313			s_fd_blocking (int fd, int blocking)
314			{
315			return fcntl (fd, F_SETFL, blocking ? 0 : O_NONBLOCK);
316			}
317
318			static int
319			s_fd_prepare (int fd)
320			{
321			return s_fd_blocking (fd, 0)
322			\|\| fcntl (fd, F_SETFD, FD_CLOEXEC);
323			}
324
325			#endif
326
327			#if __linux && (__GLIBC__ > 2 \|\| (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 7))
328			/* our minimum requirement is glibc 2.7 which has the stub, but not the header */
329			# include <stdint.h>
330			# ifdef __cplusplus
331			extern "C" {
332			# endif
333			int eventfd (unsigned int initval, int flags);
334			# ifdef __cplusplus
335			}
336			# endif
337			#else
338			# define eventfd(initval,flags) -1
339			#endif
340
341			typedef struct {
342			int fd[2]; /* read, write fd, might be equal */
343			int len; /* write length (1 pipe/socket, 8 eventfd) */
344			} s_epipe;
345
346			static int
347			s_epipe_new (s_epipe *epp)
348			{
349			s_epipe ep;
350
351			ep.fd [0] = ep.fd [1] = eventfd (0, 0);
352
353			if (ep.fd [0] >= 0)
354			{
355			s_fd_prepare (ep.fd [0]);
356			ep.len = 8;
357			}
358			else
359			{
360			if (s_pipe (ep.fd))
361			return -1;
362
363			if (s_fd_prepare (ep.fd [0])
364			\|\| s_fd_prepare (ep.fd [1]))
365			{
366	root	1.6	dTHX;
367
368	root	1.4	close (ep.fd [0]);
369			close (ep.fd [1]);
370			return -1;
371			}
372
373			ep.len = 1;
374			}
375
376			*epp = ep;
377			return 0;
378			}
379
380			static void
381			s_epipe_destroy (s_epipe *epp)
382			{
383	root	1.6	dTHX;
384
385	root	1.4	close (epp->fd [0]);
386
387			if (epp->fd [1] != epp->fd [0])
388			close (epp->fd [1]);
389
390			epp->len = 0;
391			}
392
393			static void
394			s_epipe_signal (s_epipe *epp)
395			{
396			#ifdef _WIN32
397	root	1.6	/* perl overrides send with a function that crashes in other threads.
398			* unfortunately, it overrides it with an argument-less macro, so
399			* there is no way to force usage of the real send function.
400			* incompetent windows programmers - is this redundant?
401			*/
402			DWORD dummy;
403			WriteFile (S_TO_HANDLE (epp->fd [1]), (LPCVOID)&dummy, 1, &dummy, 0);
404	root	1.4	#else
405	root	1.6	static uint64_t counter = 1;
406			/* some modules accept fd's from outside, support eventfd here */
407			if (write (epp->fd [1], &counter, epp->len) < 0
408			&& errno == EINVAL
409			&& epp->len != 8)
410			write (epp->fd [1], &counter, (epp->len = 8));
411	root	1.4	#endif
412			}
413
414			static void
415			s_epipe_drain (s_epipe *epp)
416			{
417	root	1.6	dTHX;
418	root	1.4	char buf [9];
419
420			#ifdef _WIN32
421			recv (epp->fd [0], buf, sizeof (buf), 0);
422			#else
423			read (epp->fd [0], buf, sizeof (buf));
424	root	1.3	#endif
425	root	1.4	}
426
427			/* like new, but dups over old */
428			static int
429			s_epipe_renew (s_epipe *epp)
430			{
431	root	1.6	dTHX;
432	root	1.4	s_epipe epn;
433
434			if (epp->fd [1] != epp->fd [0])
435			close (epp->fd [1]);
436
437			if (s_epipe_new (&epn))
438			return -1;
439
440			if (epp->len)
441			{
442			if (dup2 (epn.fd [0], epp->fd [0]) < 0)
443			croak ("unable to dup over old event pipe"); /* should not croak */
444
445			if (epp->fd [1] != epp->fd [0])
446			close (epn.fd [0]);
447
448			epn.fd [0] = epp->fd [0];
449			}
450
451			*epp = epn;
452
453			return 0;
454			}
455
456			#define s_epipe_fd(epp) ((epp)->fd [0])
457
458			static int
459			s_epipe_wait (s_epipe *epp)
460			{
461	root	1.6	dTHX;
462	root	1.4	#ifdef _WIN32
463			fd_set rfd;
464			int fd = s_epipe_fd (epp);
465
466			FD_ZERO (&rfd);
467			FD_SET (fd, &rfd);
468
469			return PerlSock_select (fd + 1, &rfd, 0, 0, 0);
470			#else
471			/* poll is preferable on posix systems */
472			struct pollfd pfd;
473
474			pfd.fd = s_epipe_fd (epp);
475			pfd.events = POLLIN;
476
477			return poll (&pfd, 1, 0);
478			#endif
479			}
480
481	root	1.1	#endif
482