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])
{
  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) */
  volatile sig_atomic_t sent;
} 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]))
        {
           close (ep.fd [0]);
           close (ep.fd [1]);
           return -1;
        }

      ep.len = 1;
    }

  ep.sent = 0;
  *epp = ep;
  return 0;
}

static void
s_epipe_destroy (s_epipe *epp)
{
  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)
{
  if (epp->sent)
    return;

  epp->sent = 1;
  {
#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)
{
  char buf [9];

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

  epp->sent = 0;
}

/* like new, but dups over old */
static int
s_epipe_renew (s_epipe *epp)
{
  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)
{
#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:	1.5
Committed:	Fri Jul 17 14:49:33 2009 UTC (14 years, 10 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-3_7
Changes since 1.4:	+6 -1 lines
Log Message:	3.7
#	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			struct sockaddr_in addr = { 0 };
215			int addr_size = sizeof (addr);
216			struct sockaddr_in adr2;
217			int adr2_size = sizeof (adr2);
218			SOCKET listener;
219			SOCKET sock [2] = { -1, -1 };
220
221			if ((listener = socket (AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
222			return -1;
223
224			addr.sin_family = AF_INET;
225			addr.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
226			addr.sin_port = 0;
227
228			if (bind (listener, (struct sockaddr *)&addr, addr_size))
229			goto fail;
230
231			if (getsockname (listener, (struct sockaddr *)&addr, &addr_size))
232			goto fail;
233
234			if (listen (listener, 1))
235			goto fail;
236
237			if ((sock [0] = socket (AF_INET, SOCK_STREAM, 0)) == INVALID_SOCKET)
238			goto fail;
239
240			if (connect (sock [0], (struct sockaddr *)&addr, addr_size))
241			goto fail;
242
243			if ((sock [1] = accept (listener, 0, 0)) < 0)
244			goto fail;
245
246			/* windows vista returns fantasy port numbers for getpeername.
247			* example for two interconnected tcp sockets:
248			*
249			* (Socket::unpack_sockaddr_in getsockname $sock0)[0] == 53364
250			* (Socket::unpack_sockaddr_in getpeername $sock0)[0] == 53363
251			* (Socket::unpack_sockaddr_in getsockname $sock1)[0] == 53363
252			* (Socket::unpack_sockaddr_in getpeername $sock1)[0] == 53365
253			*
254			* wow! tridirectional sockets!
255			*
256			* this way of checking ports seems to work:
257			*/
258			if (getpeername (sock [0], (struct sockaddr *)&addr, &addr_size))
259			goto fail;
260
261			if (getsockname (sock [1], (struct sockaddr *)&adr2, &adr2_size))
262			goto fail;
263
264			errno = WSAEINVAL;
265			if (addr_size != adr2_size
266			\|\| addr.sin_addr.s_addr != adr2.sin_addr.s_addr /* just to be sure, I mean, it's windows */
267			\|\| addr.sin_port != adr2.sin_port)
268			goto fail;
269
270			closesocket (listener);
271
272			#ifdef USE_SOCKETS_AS_HANDLES
273			/* when select isn't winsocket, we also expect socket, connect, accept etc.
274			* to work on fds */
275			filedes [0] = sock [0];
276			filedes [1] = sock [1];
277			#else
278			filedes [0] = _open_osfhandle (sock [0], 0);
279			filedes [1] = _open_osfhandle (sock [1], 0);
280			#endif
281
282			return 0;
283
284			fail:
285			closesocket (listener);
286
287			if (sock [0] != INVALID_SOCKET) closesocket (sock [0]);
288			if (sock [1] != INVALID_SOCKET) closesocket (sock [1]);
289
290			return -1;
291			}
292
293			#define s_socketpair(domain,type,protocol,filedes) s_pipe (filedes)
294
295	root	1.4	static int
296			s_fd_blocking (int fd, int blocking)
297			{
298			u_long nonblocking = !blocking;
299
300			return ioctlsocket ((SOCKET)S_TO_HANDLE (fd), FIONBIO, &nonblocking);
301			}
302
303			#define s_fd_prepare(fd) s_fd_blocking (fd, 0)
304
305	root	1.3	#else
306
307			#define s_socketpair(domain,type,protocol,filedes) socketpair (domain, type, protocol, filedes)
308			#define s_pipe(filedes) pipe (filedes)
309
310	root	1.4	static int
311			s_fd_blocking (int fd, int blocking)
312			{
313			return fcntl (fd, F_SETFL, blocking ? 0 : O_NONBLOCK);
314			}
315
316			static int
317			s_fd_prepare (int fd)
318			{
319			return s_fd_blocking (fd, 0)
320			\|\| fcntl (fd, F_SETFD, FD_CLOEXEC);
321			}
322
323			#endif
324
325			#if __linux && (__GLIBC__ > 2 \|\| (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 7))
326			/* our minimum requirement is glibc 2.7 which has the stub, but not the header */
327			# include <stdint.h>
328			# ifdef __cplusplus
329			extern "C" {
330			# endif
331			int eventfd (unsigned int initval, int flags);
332			# ifdef __cplusplus
333			}
334			# endif
335			#else
336			# define eventfd(initval,flags) -1
337			#endif
338
339			typedef struct {
340			int fd[2]; /* read, write fd, might be equal */
341			int len; /* write length (1 pipe/socket, 8 eventfd) */
342			volatile sig_atomic_t sent;
343			} s_epipe;
344
345			static int
346			s_epipe_new (s_epipe *epp)
347			{
348			s_epipe ep;
349
350			ep.fd [0] = ep.fd [1] = eventfd (0, 0);
351
352			if (ep.fd [0] >= 0)
353			{
354			s_fd_prepare (ep.fd [0]);
355			ep.len = 8;
356			}
357			else
358			{
359			if (s_pipe (ep.fd))
360			return -1;
361
362			if (s_fd_prepare (ep.fd [0])
363			\|\| s_fd_prepare (ep.fd [1]))
364			{
365			close (ep.fd [0]);
366			close (ep.fd [1]);
367			return -1;
368			}
369
370			ep.len = 1;
371			}
372
373			ep.sent = 0;
374			*epp = ep;
375			return 0;
376			}
377
378			static void
379			s_epipe_destroy (s_epipe *epp)
380			{
381			close (epp->fd [0]);
382
383			if (epp->fd [1] != epp->fd [0])
384			close (epp->fd [1]);
385
386			epp->len = 0;
387			}
388
389			static void
390			s_epipe_signal (s_epipe *epp)
391			{
392			if (epp->sent)
393			return;
394
395			epp->sent = 1;
396			{
397			#ifdef _WIN32
398			/* perl overrides send with a function that crashes in other threads.
399			* unfortunately, it overrides it with an argument-less macro, so
400			* there is no way to force usage of the real send function.
401			* incompetent windows programmers - is this redundant?
402			*/
403			DWORD dummy;
404			WriteFile (S_TO_HANDLE (epp->fd [1]), (LPCVOID)&dummy, 1, &dummy, 0);
405			#else
406			static uint64_t counter = 1;
407	root	1.5	/* some modules accept fd's from outside, support eventfd here */
408			if (write (epp->fd [1], &counter, epp->len) < 0
409			&& errno == EINVAL
410			&& epp->len != 8)
411			write (epp->fd [1], &counter, (epp->len = 8));
412	root	1.4	#endif
413			}
414			}
415
416			static void
417			s_epipe_drain (s_epipe *epp)
418			{
419			char buf [9];
420
421			#ifdef _WIN32
422			recv (epp->fd [0], buf, sizeof (buf), 0);
423			#else
424			read (epp->fd [0], buf, sizeof (buf));
425	root	1.3	#endif
426
427	root	1.4	epp->sent = 0;
428			}
429
430			/* like new, but dups over old */
431			static int
432			s_epipe_renew (s_epipe *epp)
433			{
434			s_epipe epn;
435
436			if (epp->fd [1] != epp->fd [0])
437			close (epp->fd [1]);
438
439			if (s_epipe_new (&epn))
440			return -1;
441
442			if (epp->len)
443			{
444			if (dup2 (epn.fd [0], epp->fd [0]) < 0)
445			croak ("unable to dup over old event pipe"); /* should not croak */
446
447			if (epp->fd [1] != epp->fd [0])
448			close (epn.fd [0]);
449
450			epn.fd [0] = epp->fd [0];
451			}
452
453			*epp = epn;
454
455			return 0;
456			}
457
458			#define s_epipe_fd(epp) ((epp)->fd [0])
459
460			static int
461			s_epipe_wait (s_epipe *epp)
462			{
463			#ifdef _WIN32
464			fd_set rfd;
465			int fd = s_epipe_fd (epp);
466
467			FD_ZERO (&rfd);
468			FD_SET (fd, &rfd);
469
470			return PerlSock_select (fd + 1, &rfd, 0, 0, 0);
471			#else
472			/* poll is preferable on posix systems */
473			struct pollfd pfd;
474
475			pfd.fd = s_epipe_fd (epp);
476			pfd.events = POLLIN;
477
478			return poll (&pfd, 1, 0);
479			#endif
480			}
481
482	root	1.1	#endif
483