Linux-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>

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 aio_cb {
  struct aio_cb *next;

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

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
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;
  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 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);
    }

  if (qs)
    send_reqs ();

  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 */

      switch (req->type)
        {
          case REQ_READ:  req->result = pread64 (req->fd, req->dataptr, req->length, req->offset & 0xffffffff, req->offset >> 32); break;
          case REQ_WRITE: req->result = pwrite64(req->fd, req->dataptr, req->length, req->offset & 0xffffffff, req->offset >> 32); 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_STAT:  req->result = stat64  (req->dataptr, req->statdata); break;
          case REQ_LSTAT: req->result = lstat64 (req->dataptr, req->statdata); break;
          case REQ_FSTAT: req->result = fstat64 (req->fd, req->statdata); break;

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

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

            select (respipe[0] + 1, &rfd, 0, 0, 0);
            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: $$
        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:	1.19
Committed:	Fri May 7 00:57:29 2004 UTC (20 years ago) by root
Branch:	MAIN
Changes since 1.18:	+0 -3 lines
Log Message:	* empty log message *
#	Content
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
14	typedef void InputStream; / hack, but 5.6.1 is simply toooo old ;) */
15	typedef void OutputStream; / hack, but 5.6.1 is simply toooo old ;) */
16	typedef void InOutStream; / hack, but 5.6.1 is simply toooo old ;) */
17
18	#ifndef __NR_pread64
19	# define __NR_pread64 __NR_pread
20	#endif
21	#ifndef __NR_pwrite64
22	# define __NR_pwrite64 __NR_pwrite
23	#endif
24
25	#define STACKSIZE 1024 /* yeah */
26
27	enum { REQ_QUIT, REQ_OPEN, REQ_CLOSE, REQ_READ, REQ_WRITE, REQ_STAT, REQ_LSTAT, REQ_FSTAT};
28
29	typedef struct {
30	char stack[STACKSIZE];
31	} aio_thread;
32
33	typedef struct aio_cb {
34	struct aio_cb *next;
35
36	int type;
37	aio_thread *thread;
38
39	int fd;
40	off_t offset;
41	size_t length;
42	ssize_t result;
43	mode_t mode; /* open */
44	int errorno;
45	SV data, callback;
46	void *dataptr;
47	STRLEN dataoffset;
48
49	struct stat64 *statdata;
50	} aio_cb;
51
52	typedef aio_cb *aio_req;
53
54	static int started;
55	static int nreqs;
56	static int reqpipe[2], respipe[2];
57
58	static aio_req qs, qe; /* queue start, queue end */
59
60	static int aio_proc(void *arg);
61
62	static void
63	start_thread (void)
64	{
65	aio_thread *thr;
66
67	New (0, thr, 1, aio_thread);
68
69	if (clone (aio_proc,
70	&(thr->stack[STACKSIZE]),
71	CLONE_VM\|CLONE_FS\|CLONE_FILES\|CLONE_SIGHAND,
72	thr) >= 0)
73	started++;
74	else
75	Safefree (thr);
76	}
77
78	static void
79	send_reqs (void)
80	{
81	/* this write is atomic */
82	while (qs && write (reqpipe[1], &qs, sizeof qs) == sizeof qs)
83	{
84	qs = qs->next;
85	if (!qs) qe = 0;
86	}
87	}
88
89	static void
90	send_req (aio_req req)
91	{
92	nreqs++;
93	req->next = 0;
94
95	if (qe)
96	qe->next = req;
97	else
98	qe = qs = req;
99
100	send_reqs ();
101	}
102
103	static void
104	end_thread (void)
105	{
106	aio_req req;
107	New (0, req, 1, aio_cb);
108	req->type = REQ_QUIT;
109
110	send_req (req);
111	}
112
113	static void
114	read_write (pTHX_
115	int dowrite, int fd, off_t offset, size_t length,
116	SV data, STRLEN dataoffset, SV callback)
117	{
118	aio_req req;
119	STRLEN svlen;
120	char *svptr = SvPV (data, svlen);
121
122	SvUPGRADE (data, SVt_PV);
123	SvPOK_on (data);
124
125	if (dataoffset < 0)
126	dataoffset += svlen;
127
128	if (dataoffset < 0 \|\| dataoffset > svlen)
129	croak ("data offset outside of string");
130
131	if (dowrite)
132	{
133	/* write: check length and adjust. */
134	if (length < 0 \|\| length + dataoffset > svlen)
135	length = svlen - dataoffset;
136	}
137	else
138	{
139	/* read: grow scalar as necessary */
140	svptr = SvGROW (data, length + dataoffset);
141	}
142
143	if (length < 0)
144	croak ("length must not be negative");
145
146	Newz (0, req, 1, aio_cb);
147
148	if (!req)
149	croak ("out of memory during aio_req allocation");
150
151	req->type = dowrite ? REQ_WRITE : REQ_READ;
152	req->fd = fd;
153	req->offset = offset;
154	req->length = length;
155	req->data = SvREFCNT_inc (data);
156	req->dataptr = (char *)svptr + dataoffset;
157	req->callback = SvREFCNT_inc (callback);
158
159	send_req (req);
160	}
161
162	static int
163	poll_cb (pTHX)
164	{
165	dSP;
166	int count = 0;
167	aio_req req;
168
169	while (read (respipe[0], (void *)&req, sizeof (req)) == sizeof (req))
170	{
171	if (req->type == REQ_QUIT)
172	{
173	Safefree (req->thread);
174	started--;
175	}
176	else
177	{
178	int errorno = errno;
179	errno = req->errorno;
180
181	if (req->type == REQ_READ)
182	SvCUR_set (req->data, req->dataoffset
183	+ req->result > 0 ? req->result : 0);
184
185	if (req->data)
186	SvREFCNT_dec (req->data);
187
188	if (req->type == REQ_STAT \|\| req->type == REQ_LSTAT \|\| req->type == REQ_FSTAT)
189	{
190	PL_laststype = req->type == REQ_LSTAT ? OP_LSTAT : OP_STAT;
191	PL_laststatval = req->result;
192	PL_statcache.st_dev = req->statdata->st_dev;
193	PL_statcache.st_ino = req->statdata->st_ino;
194	PL_statcache.st_mode = req->statdata->st_mode;
195	PL_statcache.st_nlink = req->statdata->st_nlink;
196	PL_statcache.st_uid = req->statdata->st_uid;
197	PL_statcache.st_gid = req->statdata->st_gid;
198	PL_statcache.st_rdev = req->statdata->st_rdev;
199	PL_statcache.st_size = req->statdata->st_size;
200	PL_statcache.st_atime = req->statdata->st_atime;
201	PL_statcache.st_mtime = req->statdata->st_mtime;
202	PL_statcache.st_ctime = req->statdata->st_ctime;
203	PL_statcache.st_blksize = req->statdata->st_blksize;
204	PL_statcache.st_blocks = req->statdata->st_blocks;
205
206	Safefree (req->statdata);
207	}
208
209	PUSHMARK (SP);
210	XPUSHs (sv_2mortal (newSViv (req->result)));
211	PUTBACK;
212	call_sv (req->callback, G_VOID);
213	SPAGAIN;
214
215	if (req->callback)
216	SvREFCNT_dec (req->callback);
217
218	errno = errorno;
219	nreqs--;
220	count++;
221	}
222
223	Safefree (req);
224	}
225
226	if (qs)
227	send_reqs ();
228
229	return count;
230	}
231
232	static sigset_t fullsigset;
233
234	#undef errno
235	#include <asm/unistd.h>
236
237	static int
238	aio_proc (void *thr_arg)
239	{
240	aio_thread *thr = thr_arg;
241	aio_req req;
242	int errno;
243
244	/* this is very much x86 and kernel-specific :(:(:( */
245	/* we rely on gcc's ability to create closures. */
246	_syscall3(int,read,int,fd,char *,buf,size_t,count)
247	_syscall3(int,write,int,fd,char *,buf,size_t,count)
248
249	_syscall3(int,open,char *,pathname,int,flags,mode_t,mode)
250	_syscall1(int,close,int,fd)
251
252	_syscall5(int,pread64,int,fd,char *,buf,size_t,count,unsigned int,offset_lo,unsigned int,offset_hi)
253	_syscall5(int,pwrite64,int,fd,char *,buf,size_t,count,unsigned int,offset_lo,unsigned int,offset_hi)
254
255	_syscall2(int,stat64, const char , filename, struct stat64 , buf)
256	_syscall2(int,lstat64, const char , filename, struct stat64 , buf)
257	_syscall2(int,fstat64, int, fd, struct stat64 *, buf)
258
259	sigprocmask (SIG_SETMASK, &fullsigset, 0);
260
261	/* then loop */
262	while (read (reqpipe[0], (void *)&req, sizeof (req)) == sizeof (req))
263	{
264	req->thread = thr;
265	errno = 0; /* strictly unnecessary */
266
267	switch (req->type)
268	{
269	case REQ_READ: req->result = pread64 (req->fd, req->dataptr, req->length, req->offset & 0xffffffff, req->offset >> 32); break;
270	case REQ_WRITE: req->result = pwrite64(req->fd, req->dataptr, req->length, req->offset & 0xffffffff, req->offset >> 32); break;
271	case REQ_OPEN: req->result = open (req->dataptr, req->fd, req->mode); break;
272	case REQ_CLOSE: req->result = close (req->fd); break;
273	case REQ_STAT: req->result = stat64 (req->dataptr, req->statdata); break;
274	case REQ_LSTAT: req->result = lstat64 (req->dataptr, req->statdata); break;
275	case REQ_FSTAT: req->result = fstat64 (req->fd, req->statdata); break;
276
277	case REQ_QUIT:
278	default:
279	write (respipe[1], (void *)&req, sizeof (req));
280	return 0;
281	}
282
283	req->errorno = errno;
284	write (respipe[1], (void *)&req, sizeof (req));
285	}
286
287	return 0;
288	}
289
290	MODULE = Linux::AIO PACKAGE = Linux::AIO
291
292	BOOT:
293	{
294	sigfillset (&fullsigset);
295	sigdelset (&fullsigset, SIGTERM);
296	sigdelset (&fullsigset, SIGQUIT);
297	sigdelset (&fullsigset, SIGABRT);
298	sigdelset (&fullsigset, SIGINT);
299
300	if (pipe (reqpipe) \|\| pipe (respipe))
301	croak ("unable to initialize request or result pipe");
302
303	if (fcntl (reqpipe[1], F_SETFL, O_NONBLOCK))
304	croak ("cannot set result pipe to nonblocking mode");
305
306	if (fcntl (respipe[0], F_SETFL, O_NONBLOCK))
307	croak ("cannot set result pipe to nonblocking mode");
308	}
309
310	void
311	min_parallel(nthreads)
312	int nthreads
313	PROTOTYPE: $
314	CODE:
315	while (nthreads > started)
316	start_thread ();
317
318	void
319	max_parallel(nthreads)
320	int nthreads
321	PROTOTYPE: $
322	CODE:
323	int cur = started;
324	while (cur > nthreads)
325	{
326	end_thread ();
327	cur--;
328	}
329
330	while (started > nthreads)
331	{
332	fd_set rfd;
333	FD_ZERO(&rfd);
334	FD_SET(respipe[0], &rfd);
335
336	select (respipe[0] + 1, &rfd, 0, 0, 0);
337	poll_cb (aTHX);
338	}
339
340	void
341	aio_open(pathname,flags,mode,callback)
342	SV * pathname
343	int flags
344	int mode
345	SV * callback
346	PROTOTYPE: $$$$
347	CODE:
348	aio_req req;
349
350	Newz (0, req, 1, aio_cb);
351
352	if (!req)
353	croak ("out of memory during aio_req allocation");
354
355	req->type = REQ_OPEN;
356	req->data = newSVsv (pathname);
357	req->dataptr = SvPV_nolen (req->data);
358	req->fd = flags;
359	req->mode = mode;
360	req->callback = SvREFCNT_inc (callback);
361
362	send_req (req);
363
364	void
365	aio_close(fh,callback)
366	InputStream fh
367	SV * callback
368	PROTOTYPE: $$
369	CODE:
370	aio_req req;
371
372	Newz (0, req, 1, aio_cb);
373
374	if (!req)
375	croak ("out of memory during aio_req allocation");
376
377	req->type = REQ_CLOSE;
378	req->fd = PerlIO_fileno (fh);
379	req->callback = SvREFCNT_inc (callback);
380
381	send_req (req);
382
383	void
384	aio_read(fh,offset,length,data,dataoffset,callback)
385	InputStream fh
386	UV offset
387	IV length
388	SV * data
389	IV dataoffset
390	SV * callback
391	PROTOTYPE: $$$$$$
392	CODE:
393	read_write (aTHX_ 0, PerlIO_fileno (fh), offset, length, data, dataoffset, callback);
394
395	void
396	aio_write(fh,offset,length,data,dataoffset,callback)
397	OutputStream fh
398	UV offset
399	IV length
400	SV * data
401	IV dataoffset
402	SV * callback
403	PROTOTYPE: $$$$$$
404	CODE:
405	read_write (aTHX_ 1, PerlIO_fileno (fh), offset, length, data, dataoffset, callback);
406
407	void
408	aio_stat(fh_or_path,callback)
409	SV * fh_or_path
410	SV * callback
411	PROTOTYPE: $$
412	ALIAS:
413	aio_lstat = 1
414	CODE:
415	aio_req req;
416
417	Newz (0, req, 1, aio_cb);
418
419	if (!req)
420	croak ("out of memory during aio_req allocation");
421
422	New (0, req->statdata, 1, struct stat64);
423
424	if (!req->statdata)
425	croak ("out of memory during aio_req->statdata allocation");
426
427	if (SvPOK (fh_or_path))
428	{
429	req->type = ix ? REQ_LSTAT : REQ_STAT;
430	req->data = newSVsv (fh_or_path);
431	req->dataptr = SvPV_nolen (req->data);
432	}
433	else
434	{
435	req->type = REQ_FSTAT;
436	req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
437	}
438
439	req->callback = SvREFCNT_inc (callback);
440
441	send_req (req);
442
443	int
444	poll_fileno()
445	PROTOTYPE:
446	CODE:
447	RETVAL = respipe[0];
448	OUTPUT:
449	RETVAL
450
451	int
452	poll_cb(...)
453	PROTOTYPE:
454	CODE:
455	RETVAL = poll_cb (aTHX);
456	OUTPUT:
457	RETVAL
458
459	int
460	nreqs()
461	PROTOTYPE:
462	CODE:
463	RETVAL = nreqs;
464	OUTPUT:
465	RETVAL
466