Linux-AIO/AIO.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <sched.h>

typedef void *InputStream; /* hack, but 5.6.1 is simply toooo old ;) */
typedef void *OutputStream; /* hack, but 5.6.1 is simply toooo old ;) */
typedef void *InOutStream; /* hack, but 5.6.1 is simply toooo old ;) */

#ifndef __NR_pread64
# define __NR_pread64 __NR_pread
#endif
#ifndef __NR_pwrite64
# define __NR_pwrite64 __NR_pwrite
#endif

#define STACKSIZE 1024 /* yeah */

enum { REQ_QUIT, REQ_OPEN, REQ_CLOSE, REQ_READ, REQ_WRITE, REQ_STAT, REQ_LSTAT, REQ_FSTAT};

typedef struct {
  char stack[STACKSIZE];
} aio_thread;

typedef struct {
  int type;
  aio_thread *thread;

  int fd;
  off_t offset;
  size_t length;
  ssize_t result;
  mode_t mode; /* open */
  int errorno;
  SV *data, *callback;
  void *dataptr;
  STRLEN dataoffset;

  struct stat64 *statdata;
} aio_cb;

typedef aio_cb *aio_req;

static int started;
static int nreqs;
static int reqpipe[2], respipe[2];

static int aio_proc(void *arg);

static void
start_thread(void)
{
  aio_thread *thr;

  New (0, thr, 1, aio_thread);

  if (clone (aio_proc,
             &(thr->stack[STACKSIZE]),
             CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND,
             thr) >= 0)
    started++;
  else
    Safefree (thr);
}

static void
end_thread(void)
{
  aio_req req;
  New (0, req, 1, aio_cb);
  req->type = REQ_QUIT;
  write (reqpipe[1], &req, sizeof (aio_req));
}

static void
send_req (aio_req req)
{
  nreqs++;
  write (reqpipe[1], &req, sizeof (aio_req));
}

static void
read_write (pTHX_ int dowrite, int fd, off_t offset, size_t length,
            SV *data, STRLEN dataoffset, SV*callback)
{
  aio_req req;
  STRLEN svlen;
  char *svptr = SvPV (data, svlen);

  SvUPGRADE (data, SVt_PV);
  SvPOK_on (data);

  if (dataoffset < 0)
    dataoffset += svlen;

  if (dataoffset < 0 || dataoffset > svlen)
    croak ("data offset outside of string");

  if (dowrite)
    {
      /* write: check length and adjust. */
      if (length < 0 || length + dataoffset > svlen)
        length = svlen - dataoffset;
    }
  else
    {
      /* read: grow scalar as necessary */
      svptr = SvGROW (data, length + dataoffset);
    }

  if (length < 0)
    croak ("length must not be negative");

  Newz (0, req, 1, aio_cb);

  if (!req)
    croak ("out of memory during aio_req allocation");

  req->type = dowrite ? REQ_WRITE : REQ_READ;
  req->fd = fd;
  req->offset = offset;
  req->length = length;
  req->data = SvREFCNT_inc (data);
  req->dataptr = (char *)svptr + dataoffset;
  req->callback = SvREFCNT_inc (callback);

  send_req (req);
}

static int
poll_cb (pTHX)
{
  dSP;
  int count = 0;
  aio_req req;

  while (read (respipe[0], (void *)&req, sizeof (req)) == sizeof (req))
    {
      if (req->type == REQ_QUIT)
        {
          Safefree (req->thread);
          started--;
        }
      else
        {
          int errorno = errno;
          errno = req->errorno;

          if (req->type == REQ_READ)
            SvCUR_set (req->data, req->dataoffset
                                  + req->result > 0 ? req->result : 0);

          if (req->data)
            SvREFCNT_dec (req->data);

          if (req->type == REQ_STAT || req->type == REQ_LSTAT || req->type == REQ_FSTAT)
            {
              PL_laststype            = req->type == REQ_LSTAT ? OP_LSTAT : OP_STAT;
              PL_laststatval          = req->result;
              PL_statcache.st_dev     = req->statdata->st_dev;
              PL_statcache.st_ino     = req->statdata->st_ino;
              PL_statcache.st_mode    = req->statdata->st_mode;
              PL_statcache.st_nlink   = req->statdata->st_nlink;
              PL_statcache.st_uid     = req->statdata->st_uid;
              PL_statcache.st_gid     = req->statdata->st_gid;
              PL_statcache.st_rdev    = req->statdata->st_rdev;
              PL_statcache.st_size    = req->statdata->st_size;
              PL_statcache.st_atime   = req->statdata->st_atime;
              PL_statcache.st_mtime   = req->statdata->st_mtime;
              PL_statcache.st_ctime   = req->statdata->st_ctime;
              PL_statcache.st_blksize = req->statdata->st_blksize;
              PL_statcache.st_blocks  = req->statdata->st_blocks;

              Safefree (req->statdata);
            }

          PUSHMARK (SP);
          XPUSHs (sv_2mortal (newSViv (req->result)));
          PUTBACK;
          call_sv (req->callback, G_VOID);
          SPAGAIN;
          
          if (req->callback)
            SvREFCNT_dec (req->callback);

          errno = errorno;
          nreqs--;
          count++;
        }

      Safefree (req);
    }

  return count;
}

static sigset_t fullsigset;

#undef errno
#include <asm/unistd.h>

static int
aio_proc(void *thr_arg)
{
  aio_thread *thr = thr_arg;
  aio_req req;
  int errno;

  /* this is very much x86 and kernel-specific :(:(:( */
  /* we rely on gcc's ability to create closures. */
  _syscall3(int,read,int,fd,char *,buf,size_t,count)
  _syscall3(int,write,int,fd,char *,buf,size_t,count)

  _syscall3(int,open,char *,pathname,int,flags,mode_t,mode)
  _syscall1(int,close,int,fd)

  _syscall5(int,pread64,int,fd,char *,buf,size_t,count,unsigned int,offset_lo,unsigned int,offset_hi)
  _syscall5(int,pwrite64,int,fd,char *,buf,size_t,count,unsigned int,offset_lo,unsigned int,offset_hi)

  _syscall2(int,stat64, const char *, filename, struct stat64 *, buf)
  _syscall2(int,lstat64, const char *, filename, struct stat64 *, buf)
  _syscall2(int,fstat64, int, fd, struct stat64 *, buf)

  sigprocmask (SIG_SETMASK, &fullsigset, 0);

  /* then loop */
  while (read (reqpipe[0], (void *)&req, sizeof (req)) == sizeof (req))
    {
      req->thread = thr;
      errno = 0; /* strictly unnecessary */

      if (req->type == REQ_READ)
        req->result = pread64 (req->fd, req->dataptr, req->length, req->offset & 0xffffffff, req->offset >> 32);
      else if (req->type == REQ_WRITE)
        req->result = pwrite64(req->fd, req->dataptr, req->length, req->offset & 0xffffffff, req->offset >> 32);
      else if (req->type == REQ_OPEN)
        req->result = open    (req->dataptr, req->fd, req->mode);
      else if (req->type == REQ_CLOSE)
        req->result = close    (req->fd);
      else if (req->type == REQ_STAT)
        req->result = stat64   (req->dataptr, req->statdata);
      else if (req->type == REQ_LSTAT)
        req->result = lstat64  (req->dataptr, req->statdata);
      else if (req->type == REQ_FSTAT)
        req->result = fstat64  (req->fd, req->statdata);
      else
        {
          write (respipe[1], (void *)&req, sizeof (req));
          break;
        }

      req->errorno = errno;
      write (respipe[1], (void *)&req, sizeof (req));
    }

  return 0;
}

MODULE = Linux::AIO                PACKAGE = Linux::AIO

BOOT:
{
        sigfillset (&fullsigset);
        sigdelset (&fullsigset, SIGTERM);
        sigdelset (&fullsigset, SIGQUIT);
        sigdelset (&fullsigset, SIGABRT);
        sigdelset (&fullsigset, SIGINT);

        if (pipe (reqpipe) || pipe (respipe))
          croak ("unable to initialize request or result pipe");

        if (fcntl (respipe[0], F_SETFL, O_NONBLOCK))
          croak ("cannot set result pipe to nonblocking mode");
}

void
min_parallel(nthreads)
        int     nthreads
        PROTOTYPE: $
        CODE:
        while (nthreads > started)
          start_thread ();

void
max_parallel(nthreads)
        int     nthreads
        PROTOTYPE: $
        CODE:
        int cur = started;
        while (cur > nthreads)
          {          
            end_thread ();
            cur--;
          }

        while (started > nthreads)
          {
            fd_set rfd;
            FD_ZERO(&rfd);
            FD_SET(respipe[0], &rfd);

            select (respipe[0] + 1, &rfd, 0, 0, 0);
            poll_cb ();
          }

void
aio_open(pathname,flags,mode,callback)
        SV *    pathname
        int     flags
        int     mode
        SV *    callback
        PROTOTYPE: $$$$
        CODE:
        aio_req req;

        Newz (0, req, 1, aio_cb);

        if (!req)
          croak ("out of memory during aio_req allocation");

        req->type = REQ_OPEN;
        req->data = newSVsv (pathname);
        req->dataptr = SvPV_nolen (req->data);
        req->fd = flags;
        req->mode = mode;
        req->callback = SvREFCNT_inc (callback);

        send_req (req);

void
aio_close(fh,callback)
        InputStream     fh
        SV *            callback
        PROTOTYPE: $$
        CODE:
        aio_req req;

        Newz (0, req, 1, aio_cb);

        if (!req)
          croak ("out of memory during aio_req allocation");

        req->type = REQ_CLOSE;
        req->fd = PerlIO_fileno (fh);
        req->callback = SvREFCNT_inc (callback);

        send_req (req);

void
aio_read(fh,offset,length,data,dataoffset,callback)
        InputStream     fh
        UV              offset
        IV              length
        SV *            data
        IV              dataoffset
        SV *            callback
        PROTOTYPE: $$$$$$
        CODE:
        read_write (aTHX_ 0, PerlIO_fileno (fh), offset, length, data, dataoffset, callback);

void
aio_write(fh,offset,length,data,dataoffset,callback)
        OutputStream    fh
        UV              offset
        IV              length
        SV *            data
        IV              dataoffset
        SV *            callback
        PROTOTYPE: $$$$$$
        CODE:
        read_write (aTHX_ 1, PerlIO_fileno (fh), offset, length, data, dataoffset, callback);

void
aio_stat(fh_or_path,callback)
        SV *            fh_or_path
        SV *            callback
        PROTOTYPE: $$
        ALIAS:
           aio_lstat = 1
        CODE:
        aio_req req;

        Newz (0, req, 1, aio_cb);

        if (!req)
          croak ("out of memory during aio_req allocation");

        New (0, req->statdata, 1, struct stat64);

        if (!req->statdata)
          croak ("out of memory during aio_req->statdata allocation");

        if (SvPOK (fh_or_path))
          {
            req->type = ix ? REQ_LSTAT : REQ_STAT;
            req->data = newSVsv (fh_or_path);
            req->dataptr = SvPV_nolen (req->data);
          }
        else
          {
            req->type = REQ_FSTAT;
            req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
          }

        req->callback = SvREFCNT_inc (callback);

        send_req (req);

int
poll_fileno()
        PROTOTYPE:
        CODE:
        RETVAL = respipe[0];
        OUTPUT:
        RETVAL

int
poll_cb(...)
        PROTOTYPE:
        CODE:
        RETVAL = poll_cb (aTHX);
        OUTPUT:
        RETVAL

int
nreqs()
        PROTOTYPE:
        CODE:
        RETVAL = nreqs;
        OUTPUT:
        RETVAL

Revision:	1.16
Committed:	Wed May 5 10:13:30 2004 UTC (20 years ago) by root
Branch:	MAIN
Changes since 1.15:	+16 -9 lines
Log Message:	* empty log message *
#	Content
1	#include "EXTERN.h"
2	#include "perl.h"
3	#include "XSUB.h"
4
5	#include <sys/types.h>
6	#include <sys/stat.h>
7	#include <unistd.h>
8	#include <fcntl.h>
9	#include <signal.h>
10	#include <sched.h>
11
12	typedef void InputStream; / hack, but 5.6.1 is simply toooo old ;) */
13	typedef void OutputStream; / hack, but 5.6.1 is simply toooo old ;) */
14	typedef void InOutStream; / hack, but 5.6.1 is simply toooo old ;) */
15
16	#ifndef __NR_pread64
17	# define __NR_pread64 __NR_pread
18	#endif
19	#ifndef __NR_pwrite64
20	# define __NR_pwrite64 __NR_pwrite
21	#endif
22
23	#define STACKSIZE 1024 /* yeah */
24
25	enum { REQ_QUIT, REQ_OPEN, REQ_CLOSE, REQ_READ, REQ_WRITE, REQ_STAT, REQ_LSTAT, REQ_FSTAT};
26
27	typedef struct {
28	char stack[STACKSIZE];
29	} aio_thread;
30
31	typedef struct {
32	int type;
33	aio_thread *thread;
34
35	int fd;
36	off_t offset;
37	size_t length;
38	ssize_t result;
39	mode_t mode; /* open */
40	int errorno;
41	SV data, callback;
42	void *dataptr;
43	STRLEN dataoffset;
44
45	struct stat64 *statdata;
46	} aio_cb;
47
48	typedef aio_cb *aio_req;
49
50	static int started;
51	static int nreqs;
52	static int reqpipe[2], respipe[2];
53
54	static int aio_proc(void *arg);
55
56	static void
57	start_thread(void)
58	{
59	aio_thread *thr;
60
61	New (0, thr, 1, aio_thread);
62
63	if (clone (aio_proc,
64	&(thr->stack[STACKSIZE]),
65	CLONE_VM\|CLONE_FS\|CLONE_FILES\|CLONE_SIGHAND,
66	thr) >= 0)
67	started++;
68	else
69	Safefree (thr);
70	}
71
72	static void
73	end_thread(void)
74	{
75	aio_req req;
76	New (0, req, 1, aio_cb);
77	req->type = REQ_QUIT;
78	write (reqpipe[1], &req, sizeof (aio_req));
79	}
80
81	static void
82	send_req (aio_req req)
83	{
84	nreqs++;
85	write (reqpipe[1], &req, sizeof (aio_req));
86	}
87
88	static void
89	read_write (pTHX_ int dowrite, int fd, off_t offset, size_t length,
90	SV data, STRLEN dataoffset, SVcallback)
91	{
92	aio_req req;
93	STRLEN svlen;
94	char *svptr = SvPV (data, svlen);
95
96	SvUPGRADE (data, SVt_PV);
97	SvPOK_on (data);
98
99	if (dataoffset < 0)
100	dataoffset += svlen;
101
102	if (dataoffset < 0 \|\| dataoffset > svlen)
103	croak ("data offset outside of string");
104
105	if (dowrite)
106	{
107	/* write: check length and adjust. */
108	if (length < 0 \|\| length + dataoffset > svlen)
109	length = svlen - dataoffset;
110	}
111	else
112	{
113	/* read: grow scalar as necessary */
114	svptr = SvGROW (data, length + dataoffset);
115	}
116
117	if (length < 0)
118	croak ("length must not be negative");
119
120	Newz (0, req, 1, aio_cb);
121
122	if (!req)
123	croak ("out of memory during aio_req allocation");
124
125	req->type = dowrite ? REQ_WRITE : REQ_READ;
126	req->fd = fd;
127	req->offset = offset;
128	req->length = length;
129	req->data = SvREFCNT_inc (data);
130	req->dataptr = (char *)svptr + dataoffset;
131	req->callback = SvREFCNT_inc (callback);
132
133	send_req (req);
134	}
135
136	static int
137	poll_cb (pTHX)
138	{
139	dSP;
140	int count = 0;
141	aio_req req;
142
143	while (read (respipe[0], (void *)&req, sizeof (req)) == sizeof (req))
144	{
145	if (req->type == REQ_QUIT)
146	{
147	Safefree (req->thread);
148	started--;
149	}
150	else
151	{
152	int errorno = errno;
153	errno = req->errorno;
154
155	if (req->type == REQ_READ)
156	SvCUR_set (req->data, req->dataoffset
157	+ req->result > 0 ? req->result : 0);
158
159	if (req->data)
160	SvREFCNT_dec (req->data);
161
162	if (req->type == REQ_STAT \|\| req->type == REQ_LSTAT \|\| req->type == REQ_FSTAT)
163	{
164	PL_laststype = req->type == REQ_LSTAT ? OP_LSTAT : OP_STAT;
165	PL_laststatval = req->result;
166	PL_statcache.st_dev = req->statdata->st_dev;
167	PL_statcache.st_ino = req->statdata->st_ino;
168	PL_statcache.st_mode = req->statdata->st_mode;
169	PL_statcache.st_nlink = req->statdata->st_nlink;
170	PL_statcache.st_uid = req->statdata->st_uid;
171	PL_statcache.st_gid = req->statdata->st_gid;
172	PL_statcache.st_rdev = req->statdata->st_rdev;
173	PL_statcache.st_size = req->statdata->st_size;
174	PL_statcache.st_atime = req->statdata->st_atime;
175	PL_statcache.st_mtime = req->statdata->st_mtime;
176	PL_statcache.st_ctime = req->statdata->st_ctime;
177	PL_statcache.st_blksize = req->statdata->st_blksize;
178	PL_statcache.st_blocks = req->statdata->st_blocks;
179
180	Safefree (req->statdata);
181	}
182
183	PUSHMARK (SP);
184	XPUSHs (sv_2mortal (newSViv (req->result)));
185	PUTBACK;
186	call_sv (req->callback, G_VOID);
187	SPAGAIN;
188
189	if (req->callback)
190	SvREFCNT_dec (req->callback);
191
192	errno = errorno;
193	nreqs--;
194	count++;
195	}
196
197	Safefree (req);
198	}
199
200	return count;
201	}
202
203	static sigset_t fullsigset;
204
205	#undef errno
206	#include <asm/unistd.h>
207
208	static int
209	aio_proc(void *thr_arg)
210	{
211	aio_thread *thr = thr_arg;
212	aio_req req;
213	int errno;
214
215	/* this is very much x86 and kernel-specific :(:(:( */
216	/* we rely on gcc's ability to create closures. */
217	_syscall3(int,read,int,fd,char *,buf,size_t,count)
218	_syscall3(int,write,int,fd,char *,buf,size_t,count)
219
220	_syscall3(int,open,char *,pathname,int,flags,mode_t,mode)
221	_syscall1(int,close,int,fd)
222
223	_syscall5(int,pread64,int,fd,char *,buf,size_t,count,unsigned int,offset_lo,unsigned int,offset_hi)
224	_syscall5(int,pwrite64,int,fd,char *,buf,size_t,count,unsigned int,offset_lo,unsigned int,offset_hi)
225
226	_syscall2(int,stat64, const char , filename, struct stat64 , buf)
227	_syscall2(int,lstat64, const char , filename, struct stat64 , buf)
228	_syscall2(int,fstat64, int, fd, struct stat64 *, buf)
229
230	sigprocmask (SIG_SETMASK, &fullsigset, 0);
231
232	/* then loop */
233	while (read (reqpipe[0], (void *)&req, sizeof (req)) == sizeof (req))
234	{
235	req->thread = thr;
236	errno = 0; /* strictly unnecessary */
237
238	if (req->type == REQ_READ)
239	req->result = pread64 (req->fd, req->dataptr, req->length, req->offset & 0xffffffff, req->offset >> 32);
240	else if (req->type == REQ_WRITE)
241	req->result = pwrite64(req->fd, req->dataptr, req->length, req->offset & 0xffffffff, req->offset >> 32);
242	else if (req->type == REQ_OPEN)
243	req->result = open (req->dataptr, req->fd, req->mode);
244	else if (req->type == REQ_CLOSE)
245	req->result = close (req->fd);
246	else if (req->type == REQ_STAT)
247	req->result = stat64 (req->dataptr, req->statdata);
248	else if (req->type == REQ_LSTAT)
249	req->result = lstat64 (req->dataptr, req->statdata);
250	else if (req->type == REQ_FSTAT)
251	req->result = fstat64 (req->fd, req->statdata);
252	else
253	{
254	write (respipe[1], (void *)&req, sizeof (req));
255	break;
256	}
257
258	req->errorno = errno;
259	write (respipe[1], (void *)&req, sizeof (req));
260	}
261
262	return 0;
263	}
264
265	MODULE = Linux::AIO PACKAGE = Linux::AIO
266
267	BOOT:
268	{
269	sigfillset (&fullsigset);
270	sigdelset (&fullsigset, SIGTERM);
271	sigdelset (&fullsigset, SIGQUIT);
272	sigdelset (&fullsigset, SIGABRT);
273	sigdelset (&fullsigset, SIGINT);
274
275	if (pipe (reqpipe) \|\| pipe (respipe))
276	croak ("unable to initialize request or result pipe");
277
278	if (fcntl (respipe[0], F_SETFL, O_NONBLOCK))
279	croak ("cannot set result pipe to nonblocking mode");
280	}
281
282	void
283	min_parallel(nthreads)
284	int nthreads
285	PROTOTYPE: $
286	CODE:
287	while (nthreads > started)
288	start_thread ();
289
290	void
291	max_parallel(nthreads)
292	int nthreads
293	PROTOTYPE: $
294	CODE:
295	int cur = started;
296	while (cur > nthreads)
297	{
298	end_thread ();
299	cur--;
300	}
301
302	while (started > nthreads)
303	{
304	fd_set rfd;
305	FD_ZERO(&rfd);
306	FD_SET(respipe[0], &rfd);
307
308	select (respipe[0] + 1, &rfd, 0, 0, 0);
309	poll_cb ();
310	}
311
312	void
313	aio_open(pathname,flags,mode,callback)
314	SV * pathname
315	int flags
316	int mode
317	SV * callback
318	PROTOTYPE: $$$$
319	CODE:
320	aio_req req;
321
322	Newz (0, req, 1, aio_cb);
323
324	if (!req)
325	croak ("out of memory during aio_req allocation");
326
327	req->type = REQ_OPEN;
328	req->data = newSVsv (pathname);
329	req->dataptr = SvPV_nolen (req->data);
330	req->fd = flags;
331	req->mode = mode;
332	req->callback = SvREFCNT_inc (callback);
333
334	send_req (req);
335
336	void
337	aio_close(fh,callback)
338	InputStream fh
339	SV * callback
340	PROTOTYPE: $$
341	CODE:
342	aio_req req;
343
344	Newz (0, req, 1, aio_cb);
345
346	if (!req)
347	croak ("out of memory during aio_req allocation");
348
349	req->type = REQ_CLOSE;
350	req->fd = PerlIO_fileno (fh);
351	req->callback = SvREFCNT_inc (callback);
352
353	send_req (req);
354
355	void
356	aio_read(fh,offset,length,data,dataoffset,callback)
357	InputStream fh
358	UV offset
359	IV length
360	SV * data
361	IV dataoffset
362	SV * callback
363	PROTOTYPE: $$$$$$
364	CODE:
365	read_write (aTHX_ 0, PerlIO_fileno (fh), offset, length, data, dataoffset, callback);
366
367	void
368	aio_write(fh,offset,length,data,dataoffset,callback)
369	OutputStream fh
370	UV offset
371	IV length
372	SV * data
373	IV dataoffset
374	SV * callback
375	PROTOTYPE: $$$$$$
376	CODE:
377	read_write (aTHX_ 1, PerlIO_fileno (fh), offset, length, data, dataoffset, callback);
378
379	void
380	aio_stat(fh_or_path,callback)
381	SV * fh_or_path
382	SV * callback
383	PROTOTYPE: $$
384	ALIAS:
385	aio_lstat = 1
386	CODE:
387	aio_req req;
388
389	Newz (0, req, 1, aio_cb);
390
391	if (!req)
392	croak ("out of memory during aio_req allocation");
393
394	New (0, req->statdata, 1, struct stat64);
395
396	if (!req->statdata)
397	croak ("out of memory during aio_req->statdata allocation");
398
399	if (SvPOK (fh_or_path))
400	{
401	req->type = ix ? REQ_LSTAT : REQ_STAT;
402	req->data = newSVsv (fh_or_path);
403	req->dataptr = SvPV_nolen (req->data);
404	}
405	else
406	{
407	req->type = REQ_FSTAT;
408	req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
409	}
410
411	req->callback = SvREFCNT_inc (callback);
412
413	send_req (req);
414
415	int
416	poll_fileno()
417	PROTOTYPE:
418	CODE:
419	RETVAL = respipe[0];
420	OUTPUT:
421	RETVAL
422
423	int
424	poll_cb(...)
425	PROTOTYPE:
426	CODE:
427	RETVAL = poll_cb (aTHX);
428	OUTPUT:
429	RETVAL
430
431	int
432	nreqs()
433	PROTOTYPE:
434	CODE:
435	RETVAL = nreqs;
436	OUTPUT:
437	RETVAL
438