IO-AIO/AIO.xs

#define PERL_NO_GET_CONTEXT

#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>
#include <endian.h>

#include <pthread.h>
#include <sys/syscall.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 ;) */

#if __i386 || __amd64
# define STACKSIZE ( 256 * sizeof (long))
#elif __ia64
# define STACKSIZE (8192 * sizeof (long))
#else
# define STACKSIZE ( 512 * sizeof (long))
#endif

enum {
  REQ_QUIT,
  REQ_OPEN, REQ_CLOSE,
  REQ_READ, REQ_WRITE, REQ_READAHEAD,
  REQ_STAT, REQ_LSTAT, REQ_FSTAT, REQ_UNLINK,
  REQ_FSYNC, REQ_FDATASYNC,
};

typedef struct aio_cb {
  struct aio_cb *next;

  int type;

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

  Stat_t *statdata;
} aio_cb;

typedef aio_cb *aio_req;

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

static aio_req qs, qe; /* queue start, queue end */

static void *aio_proc(void *arg);

static void
start_thread (void)
{
  sigset_t fullsigset, oldsigset;
  pthread_t tid;
  pthread_attr_t attr;

  pthread_attr_init (&attr);
  pthread_attr_setstacksize (&attr, STACKSIZE);
  pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);

  sigfillset (&fullsigset);
  sigprocmask (SIG_SETMASK, &fullsigset, &oldsigset);

  if (pthread_create (&tid, &attr, aio_proc, 0) == 0)
    started++;

  sigprocmask (SIG_SETMASK, &oldsigset, 0);
}

static void
send_reqs (void)
{
  /* this write is atomic */
  while (qs && write (reqpipe[1], &qs, sizeof qs) == sizeof qs)
   {
     qs = qs->next;
     if (!qs) qe = 0;
   }
}

static void
send_req (aio_req req)
{
  nreqs++;
  req->next = 0;

  if (qe)
    {
      qe->next = req;
      qe = req;
    }
  else
    qe = qs = req;

  send_reqs ();
}

static void
end_thread (void)
{
  aio_req req;
  New (0, req, 1, aio_cb);
  req->type = REQ_QUIT;

  send_req (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 void
poll_wait ()
{
  fd_set rfd;
  FD_ZERO(&rfd);
  FD_SET(respipe[0], &rfd);

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

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

  while (read (respipe[0], (void *)&req, sizeof (req)) == sizeof (req))
    {
      nreqs--;

      if (req->type == REQ_QUIT)
        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   = *(req->statdata);

              Safefree (req->statdata);
            }

          PUSHMARK (SP);
          XPUSHs (sv_2mortal (newSViv (req->result)));

          if (req->type == REQ_OPEN)
            {
              /* convert fd to fh */
              SV *fh;

              PUTBACK;
              call_pv ("IO::AIO::_fd2fh", G_SCALAR | G_EVAL);
              SPAGAIN;

              fh = POPs;

              PUSHMARK (SP);
              XPUSHs (fh);
            }

          PUTBACK;
          call_sv (req->callback, G_VOID | G_EVAL);
          SPAGAIN;
          
          if (req->callback)
            SvREFCNT_dec (req->callback);

          errno = errorno;
          count++;
        }

      Safefree (req);
    }

  if (qs)
    send_reqs ();

  return count;
}

static void *
aio_proc (void *thr_arg)
{
  aio_req req;

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

      switch (req->type)
        {
          case REQ_READ:      req->result = pread64   (req->fd, req->dataptr, req->length, req->offset); break;
          case REQ_WRITE:     req->result = pwrite64  (req->fd, req->dataptr, req->length, req->offset); break;
#if SYS_readahead
          case REQ_READAHEAD: req->result = readahead (req->fd, req->offset, req->length); break;
#else
          case REQ_READAHEAD: req->result = -1; errno = ENOSYS; break;
#endif

          case REQ_STAT:      req->result = stat      (req->dataptr, req->statdata); break;
          case REQ_LSTAT:     req->result = lstat     (req->dataptr, req->statdata); break;
          case REQ_FSTAT:     req->result = fstat     (req->fd     , req->statdata); break;

          case REQ_OPEN:      req->result = open      (req->dataptr, req->fd, req->mode); break;
          case REQ_CLOSE:     req->result = close     (req->fd); break;
          case REQ_UNLINK:    req->result = unlink    (req->dataptr); break;

          case REQ_FSYNC:     req->result = fsync     (req->fd); break;
          case REQ_FDATASYNC: req->result = fdatasync (req->fd); break;

          case REQ_QUIT:
            write (respipe[1], (void *)&req, sizeof (req));
            return 0;

          default:
            req->result = ENOSYS;
            break;
        }

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

  return 0;
}

MODULE = IO::AIO                PACKAGE = IO::AIO

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

        if (fcntl (reqpipe[1], F_SETFL, O_NONBLOCK))
          croak ("cannot set result pipe to nonblocking mode");

        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)
          {
            poll_wait ();
            poll_cb (aTHX);
          }
}

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: $$
        ALIAS:
           aio_close     = REQ_CLOSE
           aio_fsync     = REQ_FSYNC
           aio_fdatasync = REQ_FDATASYNC
        CODE:
{
        aio_req req;

        Newz (0, req, 1, aio_cb);

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

        req->type = ix;
        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_readahead(fh,offset,length,callback)
        InputStream     fh
        UV              offset
        IV              length
        SV *            callback
        PROTOTYPE: $$$$
        CODE:
{
        aio_req req;

        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 = REQ_READAHEAD;
        req->fd = PerlIO_fileno (fh);
        req->offset = offset;
        req->length = length;
        req->callback = SvREFCNT_inc (callback);

        send_req (req);
}

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, Stat_t);

        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);
}

void
aio_unlink(pathname,callback)
        SV * pathname
        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_UNLINK;
        req->data = newSVsv (pathname);
        req->dataptr = SvPV_nolen (req->data);
        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

void
poll_wait()
        PROTOTYPE:
        CODE:
        poll_wait ();

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

Revision:	1.2
Committed:	Sun Jul 10 18:16:49 2005 UTC (18 years, 10 months ago) by root
Branch:	MAIN
CVS Tags:	rel-0_1
Changes since 1.1:	+17 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#define PERL_NO_GET_CONTEXT
2
3			#include "EXTERN.h"
4			#include "perl.h"
5			#include "XSUB.h"
6
7			#include <sys/types.h>
8			#include <sys/stat.h>
9			#include <unistd.h>
10			#include <fcntl.h>
11			#include <signal.h>
12			#include <sched.h>
13			#include <endian.h>
14
15			#include <pthread.h>
16			#include <sys/syscall.h>
17
18			typedef void InputStream; / hack, but 5.6.1 is simply toooo old ;) */
19			typedef void OutputStream; / hack, but 5.6.1 is simply toooo old ;) */
20			typedef void InOutStream; / hack, but 5.6.1 is simply toooo old ;) */
21
22			#if __i386 \|\| __amd64
23			# define STACKSIZE ( 256 * sizeof (long))
24			#elif __ia64
25			# define STACKSIZE (8192 * sizeof (long))
26			#else
27			# define STACKSIZE ( 512 * sizeof (long))
28			#endif
29
30			enum {
31			REQ_QUIT,
32			REQ_OPEN, REQ_CLOSE,
33			REQ_READ, REQ_WRITE, REQ_READAHEAD,
34			REQ_STAT, REQ_LSTAT, REQ_FSTAT, REQ_UNLINK,
35			REQ_FSYNC, REQ_FDATASYNC,
36			};
37
38			typedef struct aio_cb {
39			struct aio_cb *next;
40
41			int type;
42
43			int fd;
44			off_t offset;
45			size_t length;
46			ssize_t result;
47			mode_t mode; /* open */
48			int errorno;
49			SV data, callback;
50			void *dataptr;
51			STRLEN dataoffset;
52
53			Stat_t *statdata;
54			} aio_cb;
55
56			typedef aio_cb *aio_req;
57
58			static int started;
59			static int nreqs;
60			static int reqpipe[2], respipe[2];
61
62			static aio_req qs, qe; /* queue start, queue end */
63
64			static void aio_proc(void arg);
65
66			static void
67			start_thread (void)
68			{
69			sigset_t fullsigset, oldsigset;
70			pthread_t tid;
71			pthread_attr_t attr;
72
73			pthread_attr_init (&attr);
74			pthread_attr_setstacksize (&attr, STACKSIZE);
75			pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
76
77			sigfillset (&fullsigset);
78			sigprocmask (SIG_SETMASK, &fullsigset, &oldsigset);
79
80			if (pthread_create (&tid, &attr, aio_proc, 0) == 0)
81			started++;
82
83			sigprocmask (SIG_SETMASK, &oldsigset, 0);
84			}
85
86			static void
87			send_reqs (void)
88			{
89			/* this write is atomic */
90			while (qs && write (reqpipe[1], &qs, sizeof qs) == sizeof qs)
91			{
92			qs = qs->next;
93			if (!qs) qe = 0;
94			}
95			}
96
97			static void
98			send_req (aio_req req)
99			{
100			nreqs++;
101			req->next = 0;
102
103			if (qe)
104			{
105			qe->next = req;
106			qe = req;
107			}
108			else
109			qe = qs = req;
110
111			send_reqs ();
112			}
113
114			static void
115			end_thread (void)
116			{
117			aio_req req;
118			New (0, req, 1, aio_cb);
119			req->type = REQ_QUIT;
120
121			send_req (req);
122			}
123
124			static void
125			read_write (pTHX_
126			int dowrite, int fd, off_t offset, size_t length,
127			SV data, STRLEN dataoffset, SV callback)
128			{
129			aio_req req;
130			STRLEN svlen;
131			char *svptr = SvPV (data, svlen);
132
133			SvUPGRADE (data, SVt_PV);
134			SvPOK_on (data);
135
136			if (dataoffset < 0)
137			dataoffset += svlen;
138
139			if (dataoffset < 0 \|\| dataoffset > svlen)
140			croak ("data offset outside of string");
141
142			if (dowrite)
143			{
144			/* write: check length and adjust. */
145			if (length < 0 \|\| length + dataoffset > svlen)
146			length = svlen - dataoffset;
147			}
148			else
149			{
150			/* read: grow scalar as necessary */
151			svptr = SvGROW (data, length + dataoffset);
152			}
153
154			if (length < 0)
155			croak ("length must not be negative");
156
157			Newz (0, req, 1, aio_cb);
158
159			if (!req)
160			croak ("out of memory during aio_req allocation");
161
162			req->type = dowrite ? REQ_WRITE : REQ_READ;
163			req->fd = fd;
164			req->offset = offset;
165			req->length = length;
166			req->data = SvREFCNT_inc (data);
167			req->dataptr = (char *)svptr + dataoffset;
168			req->callback = SvREFCNT_inc (callback);
169
170			send_req (req);
171			}
172
173			static void
174			poll_wait ()
175			{
176			fd_set rfd;
177			FD_ZERO(&rfd);
178			FD_SET(respipe[0], &rfd);
179
180			select (respipe[0] + 1, &rfd, 0, 0, 0);
181			}
182
183			static int
184			poll_cb (pTHX)
185			{
186			dSP;
187			int count = 0;
188			aio_req req;
189
190			while (read (respipe[0], (void *)&req, sizeof (req)) == sizeof (req))
191			{
192			nreqs--;
193
194			if (req->type == REQ_QUIT)
195			started--;
196			else
197			{
198			int errorno = errno;
199			errno = req->errorno;
200
201			if (req->type == REQ_READ)
202			SvCUR_set (req->data, req->dataoffset
203			+ req->result > 0 ? req->result : 0);
204
205			if (req->data)
206			SvREFCNT_dec (req->data);
207
208			if (req->type == REQ_STAT \|\| req->type == REQ_LSTAT \|\| req->type == REQ_FSTAT)
209			{
210			PL_laststype = req->type == REQ_LSTAT ? OP_LSTAT : OP_STAT;
211			PL_laststatval = req->result;
212			PL_statcache = *(req->statdata);
213
214			Safefree (req->statdata);
215			}
216
217			PUSHMARK (SP);
218			XPUSHs (sv_2mortal (newSViv (req->result)));
219	root	1.2
220			if (req->type == REQ_OPEN)
221			{
222			/* convert fd to fh */
223			SV *fh;
224
225			PUTBACK;
226			call_pv ("IO::AIO::_fd2fh", G_SCALAR \| G_EVAL);
227			SPAGAIN;
228
229			fh = POPs;
230
231			PUSHMARK (SP);
232			XPUSHs (fh);
233			}
234
235	root	1.1	PUTBACK;
236	root	1.2	call_sv (req->callback, G_VOID \| G_EVAL);
237	root	1.1	SPAGAIN;
238
239			if (req->callback)
240			SvREFCNT_dec (req->callback);
241
242			errno = errorno;
243			count++;
244			}
245
246			Safefree (req);
247			}
248
249			if (qs)
250			send_reqs ();
251
252			return count;
253			}
254
255			static void *
256			aio_proc (void *thr_arg)
257			{
258			aio_req req;
259
260			/* then loop */
261			while (read (reqpipe[0], (void *)&req, sizeof (req)) == sizeof (req))
262			{
263			errno = 0; /* strictly unnecessary */
264
265			switch (req->type)
266			{
267			case REQ_READ: req->result = pread64 (req->fd, req->dataptr, req->length, req->offset); break;
268			case REQ_WRITE: req->result = pwrite64 (req->fd, req->dataptr, req->length, req->offset); break;
269			#if SYS_readahead
270			case REQ_READAHEAD: req->result = readahead (req->fd, req->offset, req->length); break;
271			#else
272			case REQ_READAHEAD: req->result = -1; errno = ENOSYS; break;
273			#endif
274
275			case REQ_STAT: req->result = stat (req->dataptr, req->statdata); break;
276			case REQ_LSTAT: req->result = lstat (req->dataptr, req->statdata); break;
277			case REQ_FSTAT: req->result = fstat (req->fd , req->statdata); break;
278
279			case REQ_OPEN: req->result = open (req->dataptr, req->fd, req->mode); break;
280			case REQ_CLOSE: req->result = close (req->fd); break;
281			case REQ_UNLINK: req->result = unlink (req->dataptr); break;
282
283			case REQ_FSYNC: req->result = fsync (req->fd); break;
284			case REQ_FDATASYNC: req->result = fdatasync (req->fd); break;
285
286			case REQ_QUIT:
287			write (respipe[1], (void *)&req, sizeof (req));
288			return 0;
289
290			default:
291			req->result = ENOSYS;
292			break;
293			}
294
295			req->errorno = errno;
296			write (respipe[1], (void *)&req, sizeof (req));
297			}
298
299			return 0;
300			}
301
302			MODULE = IO::AIO PACKAGE = IO::AIO
303
304			BOOT:
305			{
306			if (pipe (reqpipe) \|\| pipe (respipe))
307			croak ("unable to initialize request or result pipe");
308
309			if (fcntl (reqpipe[1], F_SETFL, O_NONBLOCK))
310			croak ("cannot set result pipe to nonblocking mode");
311
312			if (fcntl (respipe[0], F_SETFL, O_NONBLOCK))
313			croak ("cannot set result pipe to nonblocking mode");
314			}
315
316			void
317			min_parallel(nthreads)
318			int nthreads
319			PROTOTYPE: $
320			CODE:
321			while (nthreads > started)
322			start_thread ();
323
324			void
325			max_parallel(nthreads)
326			int nthreads
327			PROTOTYPE: $
328			CODE:
329			{
330			int cur = started;
331			while (cur > nthreads)
332			{
333			end_thread ();
334			cur--;
335			}
336
337			while (started > nthreads)
338			{
339			poll_wait ();
340			poll_cb (aTHX);
341			}
342			}
343
344			void
345			aio_open(pathname,flags,mode,callback)
346			SV * pathname
347			int flags
348			int mode
349			SV * callback
350			PROTOTYPE: $$$$
351			CODE:
352			{
353			aio_req req;
354
355			Newz (0, req, 1, aio_cb);
356
357			if (!req)
358			croak ("out of memory during aio_req allocation");
359
360			req->type = REQ_OPEN;
361			req->data = newSVsv (pathname);
362			req->dataptr = SvPV_nolen (req->data);
363			req->fd = flags;
364			req->mode = mode;
365			req->callback = SvREFCNT_inc (callback);
366
367			send_req (req);
368			}
369
370			void
371			aio_close(fh,callback)
372			InputStream fh
373			SV * callback
374			PROTOTYPE: $$
375			ALIAS:
376			aio_close = REQ_CLOSE
377			aio_fsync = REQ_FSYNC
378			aio_fdatasync = REQ_FDATASYNC
379			CODE:
380			{
381			aio_req req;
382
383			Newz (0, req, 1, aio_cb);
384
385			if (!req)
386			croak ("out of memory during aio_req allocation");
387
388			req->type = ix;
389			req->fd = PerlIO_fileno (fh);
390			req->callback = SvREFCNT_inc (callback);
391
392			send_req (req);
393			}
394
395			void
396			aio_read(fh,offset,length,data,dataoffset,callback)
397			InputStream fh
398			UV offset
399			IV length
400			SV * data
401			IV dataoffset
402			SV * callback
403			PROTOTYPE: $$$$$$
404			CODE:
405			read_write (aTHX_ 0, PerlIO_fileno (fh), offset, length, data, dataoffset, callback);
406
407			void
408			aio_write(fh,offset,length,data,dataoffset,callback)
409			OutputStream fh
410			UV offset
411			IV length
412			SV * data
413			IV dataoffset
414			SV * callback
415			PROTOTYPE: $$$$$$
416			CODE:
417			read_write (aTHX_ 1, PerlIO_fileno (fh), offset, length, data, dataoffset, callback);
418
419			void
420			aio_readahead(fh,offset,length,callback)
421			InputStream fh
422			UV offset
423			IV length
424			SV * callback
425			PROTOTYPE: $$$$
426			CODE:
427			{
428			aio_req req;
429
430			if (length < 0)
431			croak ("length must not be negative");
432
433			Newz (0, req, 1, aio_cb);
434
435			if (!req)
436			croak ("out of memory during aio_req allocation");
437
438			req->type = REQ_READAHEAD;
439			req->fd = PerlIO_fileno (fh);
440			req->offset = offset;
441			req->length = length;
442			req->callback = SvREFCNT_inc (callback);
443
444			send_req (req);
445			}
446
447			void
448			aio_stat(fh_or_path,callback)
449			SV * fh_or_path
450			SV * callback
451			PROTOTYPE: $$
452			ALIAS:
453			aio_lstat = 1
454			CODE:
455			{
456			aio_req req;
457
458			Newz (0, req, 1, aio_cb);
459
460			if (!req)
461			croak ("out of memory during aio_req allocation");
462
463			New (0, req->statdata, 1, Stat_t);
464
465			if (!req->statdata)
466			croak ("out of memory during aio_req->statdata allocation");
467
468			if (SvPOK (fh_or_path))
469			{
470			req->type = ix ? REQ_LSTAT : REQ_STAT;
471			req->data = newSVsv (fh_or_path);
472			req->dataptr = SvPV_nolen (req->data);
473			}
474			else
475			{
476			req->type = REQ_FSTAT;
477			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
478			}
479
480			req->callback = SvREFCNT_inc (callback);
481
482			send_req (req);
483			}
484
485			void
486			aio_unlink(pathname,callback)
487			SV * pathname
488			SV * callback
489			PROTOTYPE: $$
490			CODE:
491			{
492			aio_req req;
493
494			Newz (0, req, 1, aio_cb);
495
496			if (!req)
497			croak ("out of memory during aio_req allocation");
498
499			req->type = REQ_UNLINK;
500			req->data = newSVsv (pathname);
501			req->dataptr = SvPV_nolen (req->data);
502			req->callback = SvREFCNT_inc (callback);
503
504			send_req (req);
505			}
506
507			int
508			poll_fileno()
509			PROTOTYPE:
510			CODE:
511			RETVAL = respipe[0];
512			OUTPUT:
513			RETVAL
514
515			int
516			poll_cb(...)
517			PROTOTYPE:
518			CODE:
519			RETVAL = poll_cb (aTHX);
520			OUTPUT:
521			RETVAL
522
523			void
524			poll_wait()
525			PROTOTYPE:
526			CODE:
527			poll_wait ();
528
529			int
530			nreqs()
531			PROTOTYPE:
532			CODE:
533			RETVAL = nreqs;
534			OUTPUT:
535			RETVAL
536