IO-AIO/AIO.xs

#define _REENTRANT 1
#include <errno.h>

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

#include "autoconf/config.h"

#include <pthread.h>

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

#if HAVE_SENDFILE
# if __linux
#  include <sys/sendfile.h>
# elif __freebsd
#  include <sys/socket.h>
#  include <sys/uio.h>
# elif __hpux
#  include <sys/socket.h>
# elif __solaris /* not yet */
#  include <sys/sendfile.h>
# else
#  error sendfile support requested but not available
# endif
#endif

#if __ia64
# define STACKSIZE 65536
#else
# define STACKSIZE  8192
#endif

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

typedef struct aio_cb {
  struct aio_cb *volatile next;

  int type;

  /* should receive a cleanup, with unions */
  int fd, fd2;
  off_t offset;
  size_t length;
  ssize_t result;
  mode_t mode; /* open */
  int errorno;
  SV *data, *callback;
  SV *fh, *fh2;
  void *dataptr, *data2ptr;
  STRLEN dataoffset;

  Stat_t *statdata;
} aio_cb;

typedef aio_cb *aio_req;

static int started, wanted;
static volatile int nreqs;
static int max_outstanding = 1<<30;
static int respipe [2];

static pthread_mutex_t reslock = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t reqlock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t  reqwait = PTHREAD_COND_INITIALIZER;

static volatile aio_req reqs, reqe; /* queue start, queue end */
static volatile aio_req ress, rese; /* queue start, queue end */

static void free_req (aio_req req)
{
  if (req->data)
    SvREFCNT_dec (req->data);

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

  if (req->fh2)
    SvREFCNT_dec (req->fh2);

  if (req->statdata)
    Safefree (req->statdata);

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

  if (req->type == REQ_READDIR && req->result >= 0)
    free (req->data2ptr);

  Safefree (req);
}

static void
poll_wait ()
{
  if (nreqs && !ress)
    {
      fd_set rfd;
      FD_ZERO(&rfd);
      FD_SET(respipe [0], &rfd);

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

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

  for (;;)
    {
      pthread_mutex_lock (&reslock);
      req = ress;

      if (req)
        {
          ress = req->next;

          if (!ress)
            {
              /* read any signals sent by the worker threads */
              char buf [32];
              while (read (respipe [0], buf, 32) == 32)
                ;

              rese = 0;
            }
        }

      pthread_mutex_unlock (&reslock);

      if (!req)
        break;

      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->data2ptr && (req->type == REQ_READ || req->type == REQ_WRITE))
            SvREADONLY_off (req->data);

          if (req->statdata)
            {
              PL_laststype   = req->type == REQ_LSTAT ? OP_LSTAT : OP_STAT;
              PL_laststatval = req->result;
              PL_statcache   = *(req->statdata);
            }

          ENTER;
          PUSHMARK (SP);

          if (req->type == REQ_READDIR)
            {
              SV *rv = &PL_sv_undef;

              if (req->result >= 0)
                {
                  char *buf = req->data2ptr;
                  AV *av = newAV ();

                  while (req->result)
                    {
                      SV *sv = newSVpv (buf, 0);

                      av_push (av, sv);
                      buf += SvCUR (sv) + 1;
                      req->result--;
                    }

                  rv = sv_2mortal (newRV_noinc ((SV *)av));
                }

              XPUSHs (rv);
            }
          else
            {
              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 = SvREFCNT_inc (POPs);

                  PUSHMARK (SP);
                  XPUSHs (sv_2mortal (fh));
                }
            }

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

              if (SvTRUE (ERRSV))
                {
                  free_req (req);
                  croak (0);
                }
            }

          LEAVE;

          errno = errorno;
          count++;
        }

      free_req (req);
    }

  return count;
}

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_req (aio_req req)
{
  while (started < wanted && nreqs >= started)
    start_thread ();

  nreqs++;

  pthread_mutex_lock (&reqlock);

  req->next = 0;

  if (reqe)
    {
      reqe->next = req;
      reqe = req;
    }
  else
    reqe = reqs = req;

  pthread_cond_signal (&reqwait);
  pthread_mutex_unlock (&reqlock);

  if (nreqs > max_outstanding)
    for (;;)
      {
        poll_cb ();

        if (nreqs <= max_outstanding)
          break;

        poll_wait ();
      }
}

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

  send_req (req);
}

static void min_parallel (int nthreads)
{
  if (wanted < nthreads)
    wanted = nthreads;
}

static void max_parallel (int nthreads)
{
  int cur = started;

  if (wanted > nthreads)
    wanted = nthreads;

  while (cur > wanted)
    {
      end_thread ();
      cur--;
    }

  while (started > wanted)
    {
      poll_wait ();
      poll_cb ();
    }
}

static void create_pipe ()
{
  if (pipe (respipe))
    croak ("unable to initialize result pipe");

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

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

/*****************************************************************************/
/* work around various missing functions */

#if !HAVE_PREADWRITE
# define pread  aio_pread
# define pwrite aio_pwrite

/*
 * make our pread/pwrite safe against themselves, but not against
 * normal read/write by using a mutex. slows down execution a lot,
 * but that's your problem, not mine.
 */
static pthread_mutex_t preadwritelock = PTHREAD_MUTEX_INITIALIZER;

static ssize_t
pread (int fd, void *buf, size_t count, off_t offset)
{
  ssize_t res;
  off_t ooffset;

  pthread_mutex_lock (&preadwritelock);
  ooffset = lseek (fd, 0, SEEK_CUR);
  lseek (fd, offset, SEEK_SET);
  res = read (fd, buf, count);
  lseek (fd, ooffset, SEEK_SET);
  pthread_mutex_unlock (&preadwritelock);

  return res;
}

static ssize_t
pwrite (int fd, void *buf, size_t count, off_t offset)
{
  ssize_t res;
  off_t ooffset;

  pthread_mutex_lock (&preadwritelock);
  ooffset = lseek (fd, 0, SEEK_CUR);
  lseek (fd, offset, SEEK_SET);
  res = write (fd, buf, count);
  lseek (fd, offset, SEEK_SET);
  pthread_mutex_unlock (&preadwritelock);

  return res;
}
#endif

#if !HAVE_FDATASYNC
# define fdatasync fsync
#endif

#if !HAVE_READAHEAD
# define readahead aio_readahead

static ssize_t
readahead (int fd, off_t offset, size_t count)
{
  char readahead_buf[4096];

  while (count > 0)
    {
      size_t len = count < sizeof (readahead_buf) ? count : sizeof (readahead_buf);

      pread (fd, readahead_buf, len, offset);
      offset += len;
      count  -= len;
    }

  errno = 0;
}
#endif

#if !HAVE_READDIR_R
# define readdir_r aio_readdir_r

static pthread_mutex_t readdirlock = PTHREAD_MUTEX_INITIALIZER;
  
static int
readdir_r (DIR *dirp, struct dirent *ent, struct dirent **res)
{
  struct dirent *e;
  int errorno;

  pthread_mutex_lock (&readdirlock);

  e = readdir (dirp);
  errorno = errno;

  if (e)
    {
      *res = ent;
      strcpy (ent->d_name, e->d_name);
    }
  else
    *res = 0;

  pthread_mutex_unlock (&readdirlock);

  errno = errorno;
  return e ? 0 : -1;
}
#endif

/* sendfile always needs emulation */
static ssize_t
sendfile_ (int ofd, int ifd, off_t offset, size_t count)
{
  ssize_t res;

  if (!count)
    return 0;

#if HAVE_SENDFILE
# if __linux
  res = sendfile (ofd, ifd, &offset, count);

# elif __freebsd
  /*
   * Of course, the freebsd sendfile is a dire hack with no thoughts
   * wasted on making it similar to other I/O functions.
   */
  {
    off_t sbytes;
    res = sendfile (ifd, ofd, offset, count, 0, &sbytes, 0);

    if (res < 0 && sbytes)
      /* maybe only on EAGAIN only: as usual, the manpage leaves you guessing */
      res = sbytes;
  }

# elif __hpux
  res = sendfile (ofd, ifd, offset, count, 0, 0);

# elif __solaris
  {
    struct sendfilevec vec;
    size_t sbytes;

    vec.sfv_fd   = ifd;
    vec.sfv_flag = 0;
    vec.sfv_off  = offset;
    vec.sfv_len  = count;

    res = sendfilev (ofd, &vec, 1, &sbytes);

    if (res < 0 && sbytes)
      res = sbytes;
  }

# else
  res = -1;
  errno = ENOSYS;
# endif
#endif

  if (res <  0
      && (errno == ENOSYS || errno == EINVAL || errno == ENOTSOCK
#if __solaris
          || errno == EAFNOSUPPORT || errno == EPROTOTYPE
#endif
         )
      )
    {
      /* emulate sendfile. this is a major pain in the ass */
      char buf[4096];
      res = 0;

      for (;;)
        {
          ssize_t cnt;
          
          cnt = pread (ifd, buf, 4096, offset);

          if (cnt <= 0)
            {
              if (cnt && !res) res = -1;
              break;
            }

          cnt = write (ofd, buf, cnt);

          if (cnt <= 0)
            {
              if (cnt && !res) res = -1;
              break;
            }

          offset += cnt;
          res    += cnt;
        }
    }

  return res;
}

/* read a full directory */
static int
scandir_ (const char *path, void **namesp)
{
  DIR *dirp = opendir (path);
  union
  {    
    struct dirent d;
    char b [offsetof (struct dirent, d_name) + NAME_MAX + 1];
  } u;
  struct dirent *entp;
  char *name, *names;
  int memlen = 4096;
  int memofs = 0;
  int res = 0;
  int errorno;

  if (!dirp)
    return -1;

  names = malloc (memlen);

  for (;;)
    {
      errno = 0, readdir_r (dirp, &u.d, &entp);

      if (!entp)
        break;

      name = entp->d_name;

      if (name [0] != '.' || (name [1] && (name [1] != '.' || name [2])))
        {
          int len = strlen (name) + 1;

          res++;

          while (memofs + len > memlen)
            {
              memlen *= 2;
              names = realloc (names, memlen);
              if (!names)
                break;
            }

          memcpy (names + memofs, name, len);
          memofs += len;
        }
    }

  errorno = errno;
  closedir (dirp);

  if (errorno)
    {
      free (names);
      errno = errorno;
      res = -1;
    }

  *namesp = (void *)names;
  return res;
}

/*****************************************************************************/

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

  do
    {
      pthread_mutex_lock (&reqlock);

      for (;;)
        {
          req = reqs;

          if (reqs)
            {
              reqs = reqs->next;
              if (!reqs) reqe = 0;
            }

          if (req)
            break;

          pthread_cond_wait (&reqwait, &reqlock);
        }

      pthread_mutex_unlock (&reqlock);
     
      errno = 0; /* strictly unnecessary */

      type = req->type;

      switch (type)
        {
          case REQ_READ:      req->result = pread     (req->fd, req->dataptr, req->length, req->offset); break;
          case REQ_WRITE:     req->result = pwrite    (req->fd, req->dataptr, req->length, req->offset); break;

          case REQ_READAHEAD: req->result = readahead (req->fd, req->offset, req->length); break;
          case REQ_SENDFILE:  req->result = sendfile_ (req->fd, req->fd2, req->offset, req->length); break;

          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_RMDIR:     req->result = rmdir     (req->dataptr); break;
          case REQ_SYMLINK:   req->result = symlink   (req->data2ptr, req->dataptr); break;

          case REQ_FDATASYNC: req->result = fdatasync (req->fd); break;
          case REQ_FSYNC:     req->result = fsync     (req->fd); break;
          case REQ_READDIR:   req->result = scandir_  (req->dataptr, &req->data2ptr); break;

          case REQ_QUIT:
            break;

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

      req->errorno = errno;

      pthread_mutex_lock (&reslock);

      req->next = 0;

      if (rese)
        {
          rese->next = req;
          rese = req;
        }
      else
        {
          rese = ress = req;

          /* write a dummy byte to the pipe so fh becomes ready */
          write (respipe [1], &respipe, 1);
        }

      pthread_mutex_unlock (&reslock);
    }
  while (type != REQ_QUIT);

  return 0;
}

/*****************************************************************************/

static void atfork_prepare (void)
{
  pthread_mutex_lock (&reqlock);
  pthread_mutex_lock (&reslock);
#if !HAVE_PREADWRITE
  pthread_mutex_lock (&preadwritelock);
#endif
#if !HAVE_READDIR_R
  pthread_mutex_lock (&readdirlock);
#endif
}

static void atfork_parent (void)
{
#if !HAVE_READDIR_R
  pthread_mutex_unlock (&readdirlock);
#endif
#if !HAVE_PREADWRITE
  pthread_mutex_unlock (&preadwritelock);
#endif
  pthread_mutex_unlock (&reslock);
  pthread_mutex_unlock (&reqlock);
}

static void atfork_child (void)
{
  aio_req prv;

  started = 0;

  while (reqs)
    {
      prv = reqs;
      reqs = prv->next;
      free_req (prv);
    }

  reqs = reqe = 0;
      
  while (ress)
    {
      prv = ress;
      ress = prv->next;
      free_req (prv);
    }
      
  ress = rese = 0;

  close (respipe [0]);
  close (respipe [1]);
  create_pipe ();

  atfork_parent ();
}

#define dREQ                                                    \
  aio_req req;                                                  \
                                                                \
  if (SvOK (callback) && !SvROK (callback))                     \
    croak ("clalback must be undef or of reference type");      \
                                                                \
  Newz (0, req, 1, aio_cb);                                     \
  if (!req)                                                     \
    croak ("out of memory during aio_req allocation");          \
                                                                \
  req->callback = newSVsv (callback);
        
MODULE = IO::AIO                PACKAGE = IO::AIO

PROTOTYPES: ENABLE

BOOT:
{
        create_pipe ();
        pthread_atfork (atfork_prepare, atfork_parent, atfork_child);
}

void
min_parallel(nthreads)
        int     nthreads
        PROTOTYPE: $

void
max_parallel(nthreads)
        int     nthreads
        PROTOTYPE: $

int
max_outstanding(nreqs)
        int nreqs
        PROTOTYPE: $
        CODE:
        RETVAL = max_outstanding;
        max_outstanding = nreqs;

void
aio_open(pathname,flags,mode,callback=&PL_sv_undef)
        SV *    pathname
        int     flags
        int     mode
        SV *    callback
        PROTOTYPE: $$$;$
        CODE:
{
        dREQ;

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

        send_req (req);
}

void
aio_close(fh,callback=&PL_sv_undef)
        SV *    fh
        SV *    callback
        PROTOTYPE: $;$
        ALIAS:
           aio_close     = REQ_CLOSE
           aio_fsync     = REQ_FSYNC
           aio_fdatasync = REQ_FDATASYNC
        CODE:
{
        dREQ;

        req->type = ix;
        req->fh = newSVsv (fh);
        req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));

        send_req (req);
}

void
aio_read(fh,offset,length,data,dataoffset,callback=&PL_sv_undef)
        SV *    fh
        UV      offset
        UV      length
        SV *    data
        UV      dataoffset
        SV *    callback
        ALIAS:
           aio_read  = REQ_READ
           aio_write = REQ_WRITE
        PROTOTYPE: $$$$$;$
        CODE:
{
        aio_req req;
        STRLEN svlen;
        char *svptr = SvPVbyte (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 (ix == REQ_WRITE)
          {
            /* 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");

        {
          dREQ;

          req->type = ix;
          req->fh = newSVsv (fh);
          req->fd = PerlIO_fileno (ix == REQ_READ ? IoIFP (sv_2io (fh))
                                                  : IoOFP (sv_2io (fh)));
          req->offset = offset;
          req->length = length;
          req->data = SvREFCNT_inc (data);
          req->dataptr = (char *)svptr + dataoffset;

          if (!SvREADONLY (data))
            {
              SvREADONLY_on (data);
              req->data2ptr = (void *)data;
            }

          send_req (req);
        }
}

void
aio_sendfile(out_fh,in_fh,in_offset,length,callback=&PL_sv_undef)
        SV *    out_fh
        SV *    in_fh
        UV      in_offset
        UV      length
        SV *    callback
        PROTOTYPE: $$$$;$
        CODE:
{
        dREQ;

        req->type = REQ_SENDFILE;
        req->fh = newSVsv (out_fh);
        req->fd = PerlIO_fileno (IoIFP (sv_2io (out_fh)));
        req->fh2 = newSVsv (in_fh);
        req->fd2 = PerlIO_fileno (IoIFP (sv_2io (in_fh)));
        req->offset = in_offset;
        req->length = length;

        send_req (req);
}

void
aio_readahead(fh,offset,length,callback=&PL_sv_undef)
        SV *    fh
        UV      offset
        IV      length
        SV *    callback
        PROTOTYPE: $$$;$
        CODE:
{
        dREQ;

        req->type = REQ_READAHEAD;
        req->fh = newSVsv (fh);
        req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
        req->offset = offset;
        req->length = length;

        send_req (req);
}

void
aio_stat(fh_or_path,callback=&PL_sv_undef)
        SV *            fh_or_path
        SV *            callback
        ALIAS:
           aio_stat  = REQ_STAT
           aio_lstat = REQ_LSTAT
        CODE:
{
        dREQ;

        New (0, req->statdata, 1, Stat_t);
        if (!req->statdata)
          {
            free_req (req);
            croak ("out of memory during aio_req->statdata allocation");
          }

        if (SvPOK (fh_or_path))
          {
            req->type = ix;
            req->data = newSVsv (fh_or_path);
            req->dataptr = SvPVbyte_nolen (req->data);
          }
        else
          {
            req->type = REQ_FSTAT;
            req->fh = newSVsv (fh_or_path);
            req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
          }

        send_req (req);
}

void
aio_unlink(pathname,callback=&PL_sv_undef)
        SV * pathname
        SV * callback
        ALIAS:
           aio_unlink = REQ_UNLINK
           aio_rmdir  = REQ_RMDIR
        CODE:
{
        dREQ;
        
        req->type = ix;
        req->data = newSVsv (pathname);
        req->dataptr = SvPVbyte_nolen (req->data);
        
        send_req (req);
}

void
aio_symlink(oldpath,newpath,callback=&PL_sv_undef)
        SV * oldpath
        SV * newpath
        SV * callback
        CODE:
{
        dREQ;
        
        req->type = REQ_SYMLINK;
        req->fh = newSVsv (oldpath);
        req->data2ptr = SvPVbyte_nolen (req->fh);
        req->data = newSVsv (newpath);
        req->dataptr = SvPVbyte_nolen (req->data);
        
        send_req (req);
}

void
aio_readdir(pathname,callback=&PL_sv_undef)
        SV * pathname
        SV * callback
        CODE:
{
        dREQ;
        
        req->type = REQ_READDIR;
        req->data = newSVsv (pathname);
        req->dataptr = SvPVbyte_nolen (req->data);
        
        send_req (req);
}

void
flush()
        PROTOTYPE:
        CODE:
        while (nreqs)
          {
            poll_wait ();
            poll_cb ();
          }

void
poll()
        PROTOTYPE:
        CODE:
        if (nreqs)
          {
            poll_wait ();
            poll_cb ();
          }

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

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

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

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

Revision:	1.37
Committed:	Tue Aug 23 12:37:19 2005 UTC (18 years, 8 months ago) by root
Branch:	MAIN
Changes since 1.36:	+288 -136 lines
Log Message:	* empty log message *
#	Content
1	#define _REENTRANT 1
2	#include <errno.h>
3
4	#include "EXTERN.h"
5	#include "perl.h"
6	#include "XSUB.h"
7
8	#include "autoconf/config.h"
9
10	#include <pthread.h>
11
12	#include <stddef.h>
13	#include <sys/types.h>
14	#include <sys/stat.h>
15	#include <limits.h>
16	#include <unistd.h>
17	#include <fcntl.h>
18	#include <signal.h>
19	#include <sched.h>
20
21	#if HAVE_SENDFILE
22	# if __linux
23	# include <sys/sendfile.h>
24	# elif __freebsd
25	# include <sys/socket.h>
26	# include <sys/uio.h>
27	# elif __hpux
28	# include <sys/socket.h>
29	# elif __solaris /* not yet */
30	# include <sys/sendfile.h>
31	# else
32	# error sendfile support requested but not available
33	# endif
34	#endif
35
36	#if __ia64
37	# define STACKSIZE 65536
38	#else
39	# define STACKSIZE 8192
40	#endif
41
42	enum {
43	REQ_QUIT,
44	REQ_OPEN, REQ_CLOSE,
45	REQ_READ, REQ_WRITE, REQ_READAHEAD,
46	REQ_SENDFILE,
47	REQ_STAT, REQ_LSTAT, REQ_FSTAT,
48	REQ_FSYNC, REQ_FDATASYNC,
49	REQ_UNLINK, REQ_RMDIR,
50	REQ_READDIR,
51	REQ_SYMLINK,
52	};
53
54	typedef struct aio_cb {
55	struct aio_cb *volatile next;
56
57	int type;
58
59	/* should receive a cleanup, with unions */
60	int fd, fd2;
61	off_t offset;
62	size_t length;
63	ssize_t result;
64	mode_t mode; /* open */
65	int errorno;
66	SV data, callback;
67	SV fh, fh2;
68	void dataptr, data2ptr;
69	STRLEN dataoffset;
70
71	Stat_t *statdata;
72	} aio_cb;
73
74	typedef aio_cb *aio_req;
75
76	static int started, wanted;
77	static volatile int nreqs;
78	static int max_outstanding = 1<<30;
79	static int respipe [2];
80
81	static pthread_mutex_t reslock = PTHREAD_MUTEX_INITIALIZER;
82	static pthread_mutex_t reqlock = PTHREAD_MUTEX_INITIALIZER;
83	static pthread_cond_t reqwait = PTHREAD_COND_INITIALIZER;
84
85	static volatile aio_req reqs, reqe; /* queue start, queue end */
86	static volatile aio_req ress, rese; /* queue start, queue end */
87
88	static void free_req (aio_req req)
89	{
90	if (req->data)
91	SvREFCNT_dec (req->data);
92
93	if (req->fh)
94	SvREFCNT_dec (req->fh);
95
96	if (req->fh2)
97	SvREFCNT_dec (req->fh2);
98
99	if (req->statdata)
100	Safefree (req->statdata);
101
102	if (req->callback)
103	SvREFCNT_dec (req->callback);
104
105	if (req->type == REQ_READDIR && req->result >= 0)
106	free (req->data2ptr);
107
108	Safefree (req);
109	}
110
111	static void
112	poll_wait ()
113	{
114	if (nreqs && !ress)
115	{
116	fd_set rfd;
117	FD_ZERO(&rfd);
118	FD_SET(respipe [0], &rfd);
119
120	select (respipe [0] + 1, &rfd, 0, 0, 0);
121	}
122	}
123
124	static int
125	poll_cb ()
126	{
127	dSP;
128	int count = 0;
129	int do_croak = 0;
130	aio_req req;
131
132	for (;;)
133	{
134	pthread_mutex_lock (&reslock);
135	req = ress;
136
137	if (req)
138	{
139	ress = req->next;
140
141	if (!ress)
142	{
143	/* read any signals sent by the worker threads */
144	char buf [32];
145	while (read (respipe [0], buf, 32) == 32)
146	;
147
148	rese = 0;
149	}
150	}
151
152	pthread_mutex_unlock (&reslock);
153
154	if (!req)
155	break;
156
157	nreqs--;
158
159	if (req->type == REQ_QUIT)
160	started--;
161	else
162	{
163	int errorno = errno;
164	errno = req->errorno;
165
166	if (req->type == REQ_READ)
167	SvCUR_set (req->data, req->dataoffset + (req->result > 0 ? req->result : 0));
168
169	if (req->data2ptr && (req->type == REQ_READ \|\| req->type == REQ_WRITE))
170	SvREADONLY_off (req->data);
171
172	if (req->statdata)
173	{
174	PL_laststype = req->type == REQ_LSTAT ? OP_LSTAT : OP_STAT;
175	PL_laststatval = req->result;
176	PL_statcache = *(req->statdata);
177	}
178
179	ENTER;
180	PUSHMARK (SP);
181
182	if (req->type == REQ_READDIR)
183	{
184	SV *rv = &PL_sv_undef;
185
186	if (req->result >= 0)
187	{
188	char *buf = req->data2ptr;
189	AV *av = newAV ();
190
191	while (req->result)
192	{
193	SV *sv = newSVpv (buf, 0);
194
195	av_push (av, sv);
196	buf += SvCUR (sv) + 1;
197	req->result--;
198	}
199
200	rv = sv_2mortal (newRV_noinc ((SV *)av));
201	}
202
203	XPUSHs (rv);
204	}
205	else
206	{
207	XPUSHs (sv_2mortal (newSViv (req->result)));
208
209	if (req->type == REQ_OPEN)
210	{
211	/* convert fd to fh */
212	SV *fh;
213
214	PUTBACK;
215	call_pv ("IO::AIO::_fd2fh", G_SCALAR \| G_EVAL);
216	SPAGAIN;
217
218	fh = SvREFCNT_inc (POPs);
219
220	PUSHMARK (SP);
221	XPUSHs (sv_2mortal (fh));
222	}
223	}
224
225	if (SvOK (req->callback))
226	{
227	PUTBACK;
228	call_sv (req->callback, G_VOID \| G_EVAL);
229	SPAGAIN;
230
231	if (SvTRUE (ERRSV))
232	{
233	free_req (req);
234	croak (0);
235	}
236	}
237
238	LEAVE;
239
240	errno = errorno;
241	count++;
242	}
243
244	free_req (req);
245	}
246
247	return count;
248	}
249
250	static void aio_proc(void arg);
251
252	static void
253	start_thread (void)
254	{
255	sigset_t fullsigset, oldsigset;
256	pthread_t tid;
257	pthread_attr_t attr;
258
259	pthread_attr_init (&attr);
260	pthread_attr_setstacksize (&attr, STACKSIZE);
261	pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
262
263	sigfillset (&fullsigset);
264	sigprocmask (SIG_SETMASK, &fullsigset, &oldsigset);
265
266	if (pthread_create (&tid, &attr, aio_proc, 0) == 0)
267	started++;
268
269	sigprocmask (SIG_SETMASK, &oldsigset, 0);
270	}
271
272	static void
273	send_req (aio_req req)
274	{
275	while (started < wanted && nreqs >= started)
276	start_thread ();
277
278	nreqs++;
279
280	pthread_mutex_lock (&reqlock);
281
282	req->next = 0;
283
284	if (reqe)
285	{
286	reqe->next = req;
287	reqe = req;
288	}
289	else
290	reqe = reqs = req;
291
292	pthread_cond_signal (&reqwait);
293	pthread_mutex_unlock (&reqlock);
294
295	if (nreqs > max_outstanding)
296	for (;;)
297	{
298	poll_cb ();
299
300	if (nreqs <= max_outstanding)
301	break;
302
303	poll_wait ();
304	}
305	}
306
307	static void
308	end_thread (void)
309	{
310	aio_req req;
311	Newz (0, req, 1, aio_cb);
312	req->type = REQ_QUIT;
313
314	send_req (req);
315	}
316
317	static void min_parallel (int nthreads)
318	{
319	if (wanted < nthreads)
320	wanted = nthreads;
321	}
322
323	static void max_parallel (int nthreads)
324	{
325	int cur = started;
326
327	if (wanted > nthreads)
328	wanted = nthreads;
329
330	while (cur > wanted)
331	{
332	end_thread ();
333	cur--;
334	}
335
336	while (started > wanted)
337	{
338	poll_wait ();
339	poll_cb ();
340	}
341	}
342
343	static void create_pipe ()
344	{
345	if (pipe (respipe))
346	croak ("unable to initialize result pipe");
347
348	if (fcntl (respipe [0], F_SETFL, O_NONBLOCK))
349	croak ("cannot set result pipe to nonblocking mode");
350
351	if (fcntl (respipe [1], F_SETFL, O_NONBLOCK))
352	croak ("cannot set result pipe to nonblocking mode");
353	}
354
355	/*****************************************************************************/
356	/* work around various missing functions */
357
358	#if !HAVE_PREADWRITE
359	# define pread aio_pread
360	# define pwrite aio_pwrite
361
362	/*
363	* make our pread/pwrite safe against themselves, but not against
364	* normal read/write by using a mutex. slows down execution a lot,
365	* but that's your problem, not mine.
366	*/
367	static pthread_mutex_t preadwritelock = PTHREAD_MUTEX_INITIALIZER;
368
369	static ssize_t
370	pread (int fd, void *buf, size_t count, off_t offset)
371	{
372	ssize_t res;
373	off_t ooffset;
374
375	pthread_mutex_lock (&preadwritelock);
376	ooffset = lseek (fd, 0, SEEK_CUR);
377	lseek (fd, offset, SEEK_SET);
378	res = read (fd, buf, count);
379	lseek (fd, ooffset, SEEK_SET);
380	pthread_mutex_unlock (&preadwritelock);
381
382	return res;
383	}
384
385	static ssize_t
386	pwrite (int fd, void *buf, size_t count, off_t offset)
387	{
388	ssize_t res;
389	off_t ooffset;
390
391	pthread_mutex_lock (&preadwritelock);
392	ooffset = lseek (fd, 0, SEEK_CUR);
393	lseek (fd, offset, SEEK_SET);
394	res = write (fd, buf, count);
395	lseek (fd, offset, SEEK_SET);
396	pthread_mutex_unlock (&preadwritelock);
397
398	return res;
399	}
400	#endif
401
402	#if !HAVE_FDATASYNC
403	# define fdatasync fsync
404	#endif
405
406	#if !HAVE_READAHEAD
407	# define readahead aio_readahead
408
409	static ssize_t
410	readahead (int fd, off_t offset, size_t count)
411	{
412	char readahead_buf[4096];
413
414	while (count > 0)
415	{
416	size_t len = count < sizeof (readahead_buf) ? count : sizeof (readahead_buf);
417
418	pread (fd, readahead_buf, len, offset);
419	offset += len;
420	count -= len;
421	}
422
423	errno = 0;
424	}
425	#endif
426
427	#if !HAVE_READDIR_R
428	# define readdir_r aio_readdir_r
429
430	static pthread_mutex_t readdirlock = PTHREAD_MUTEX_INITIALIZER;
431
432	static int
433	readdir_r (DIR dirp, struct dirent ent, struct dirent **res)
434	{
435	struct dirent *e;
436	int errorno;
437
438	pthread_mutex_lock (&readdirlock);
439
440	e = readdir (dirp);
441	errorno = errno;
442
443	if (e)
444	{
445	*res = ent;
446	strcpy (ent->d_name, e->d_name);
447	}
448	else
449	*res = 0;
450
451	pthread_mutex_unlock (&readdirlock);
452
453	errno = errorno;
454	return e ? 0 : -1;
455	}
456	#endif
457
458	/* sendfile always needs emulation */
459	static ssize_t
460	sendfile_ (int ofd, int ifd, off_t offset, size_t count)
461	{
462	ssize_t res;
463
464	if (!count)
465	return 0;
466
467	#if HAVE_SENDFILE
468	# if __linux
469	res = sendfile (ofd, ifd, &offset, count);
470
471	# elif __freebsd
472	/*
473	* Of course, the freebsd sendfile is a dire hack with no thoughts
474	* wasted on making it similar to other I/O functions.
475	*/
476	{
477	off_t sbytes;
478	res = sendfile (ifd, ofd, offset, count, 0, &sbytes, 0);
479
480	if (res < 0 && sbytes)
481	/* maybe only on EAGAIN only: as usual, the manpage leaves you guessing */
482	res = sbytes;
483	}
484
485	# elif __hpux
486	res = sendfile (ofd, ifd, offset, count, 0, 0);
487
488	# elif __solaris
489	{
490	struct sendfilevec vec;
491	size_t sbytes;
492
493	vec.sfv_fd = ifd;
494	vec.sfv_flag = 0;
495	vec.sfv_off = offset;
496	vec.sfv_len = count;
497
498	res = sendfilev (ofd, &vec, 1, &sbytes);
499
500	if (res < 0 && sbytes)
501	res = sbytes;
502	}
503
504	# else
505	res = -1;
506	errno = ENOSYS;
507	# endif
508	#endif
509
510	if (res < 0
511	&& (errno == ENOSYS \|\| errno == EINVAL \|\| errno == ENOTSOCK
512	#if __solaris
513	\|\| errno == EAFNOSUPPORT \|\| errno == EPROTOTYPE
514	#endif
515	)
516	)
517	{
518	/* emulate sendfile. this is a major pain in the ass */
519	char buf[4096];
520	res = 0;
521
522	for (;;)
523	{
524	ssize_t cnt;
525
526	cnt = pread (ifd, buf, 4096, offset);
527
528	if (cnt <= 0)
529	{
530	if (cnt && !res) res = -1;
531	break;
532	}
533
534	cnt = write (ofd, buf, cnt);
535
536	if (cnt <= 0)
537	{
538	if (cnt && !res) res = -1;
539	break;
540	}
541
542	offset += cnt;
543	res += cnt;
544	}
545	}
546
547	return res;
548	}
549
550	/* read a full directory */
551	static int
552	scandir_ (const char path, void *namesp)
553	{
554	DIR *dirp = opendir (path);
555	union
556	{
557	struct dirent d;
558	char b [offsetof (struct dirent, d_name) + NAME_MAX + 1];
559	} u;
560	struct dirent *entp;
561	char name, names;
562	int memlen = 4096;
563	int memofs = 0;
564	int res = 0;
565	int errorno;
566
567	if (!dirp)
568	return -1;
569
570	names = malloc (memlen);
571
572	for (;;)
573	{
574	errno = 0, readdir_r (dirp, &u.d, &entp);
575
576	if (!entp)
577	break;
578
579	name = entp->d_name;
580
581	if (name [0] != '.' \|\| (name [1] && (name [1] != '.' \|\| name [2])))
582	{
583	int len = strlen (name) + 1;
584
585	res++;
586
587	while (memofs + len > memlen)
588	{
589	memlen *= 2;
590	names = realloc (names, memlen);
591	if (!names)
592	break;
593	}
594
595	memcpy (names + memofs, name, len);
596	memofs += len;
597	}
598	}
599
600	errorno = errno;
601	closedir (dirp);
602
603	if (errorno)
604	{
605	free (names);
606	errno = errorno;
607	res = -1;
608	}
609
610	namesp = (void )names;
611	return res;
612	}
613
614	/*****************************************************************************/
615
616	static void *
617	aio_proc (void *thr_arg)
618	{
619	aio_req req;
620	int type;
621
622	do
623	{
624	pthread_mutex_lock (&reqlock);
625
626	for (;;)
627	{
628	req = reqs;
629
630	if (reqs)
631	{
632	reqs = reqs->next;
633	if (!reqs) reqe = 0;
634	}
635
636	if (req)
637	break;
638
639	pthread_cond_wait (&reqwait, &reqlock);
640	}
641
642	pthread_mutex_unlock (&reqlock);
643
644	errno = 0; /* strictly unnecessary */
645
646	type = req->type;
647
648	switch (type)
649	{
650	case REQ_READ: req->result = pread (req->fd, req->dataptr, req->length, req->offset); break;
651	case REQ_WRITE: req->result = pwrite (req->fd, req->dataptr, req->length, req->offset); break;
652
653	case REQ_READAHEAD: req->result = readahead (req->fd, req->offset, req->length); break;
654	case REQ_SENDFILE: req->result = sendfile_ (req->fd, req->fd2, req->offset, req->length); break;
655
656	case REQ_STAT: req->result = stat (req->dataptr, req->statdata); break;
657	case REQ_LSTAT: req->result = lstat (req->dataptr, req->statdata); break;
658	case REQ_FSTAT: req->result = fstat (req->fd , req->statdata); break;
659
660	case REQ_OPEN: req->result = open (req->dataptr, req->fd, req->mode); break;
661	case REQ_CLOSE: req->result = close (req->fd); break;
662	case REQ_UNLINK: req->result = unlink (req->dataptr); break;
663	case REQ_RMDIR: req->result = rmdir (req->dataptr); break;
664	case REQ_SYMLINK: req->result = symlink (req->data2ptr, req->dataptr); break;
665
666	case REQ_FDATASYNC: req->result = fdatasync (req->fd); break;
667	case REQ_FSYNC: req->result = fsync (req->fd); break;
668	case REQ_READDIR: req->result = scandir_ (req->dataptr, &req->data2ptr); break;
669
670	case REQ_QUIT:
671	break;
672
673	default:
674	req->result = ENOSYS;
675	break;
676	}
677
678	req->errorno = errno;
679
680	pthread_mutex_lock (&reslock);
681
682	req->next = 0;
683
684	if (rese)
685	{
686	rese->next = req;
687	rese = req;
688	}
689	else
690	{
691	rese = ress = req;
692
693	/* write a dummy byte to the pipe so fh becomes ready */
694	write (respipe [1], &respipe, 1);
695	}
696
697	pthread_mutex_unlock (&reslock);
698	}
699	while (type != REQ_QUIT);
700
701	return 0;
702	}
703
704	/*****************************************************************************/
705
706	static void atfork_prepare (void)
707	{
708	pthread_mutex_lock (&reqlock);
709	pthread_mutex_lock (&reslock);
710	#if !HAVE_PREADWRITE
711	pthread_mutex_lock (&preadwritelock);
712	#endif
713	#if !HAVE_READDIR_R
714	pthread_mutex_lock (&readdirlock);
715	#endif
716	}
717
718	static void atfork_parent (void)
719	{
720	#if !HAVE_READDIR_R
721	pthread_mutex_unlock (&readdirlock);
722	#endif
723	#if !HAVE_PREADWRITE
724	pthread_mutex_unlock (&preadwritelock);
725	#endif
726	pthread_mutex_unlock (&reslock);
727	pthread_mutex_unlock (&reqlock);
728	}
729
730	static void atfork_child (void)
731	{
732	aio_req prv;
733
734	started = 0;
735
736	while (reqs)
737	{
738	prv = reqs;
739	reqs = prv->next;
740	free_req (prv);
741	}
742
743	reqs = reqe = 0;
744
745	while (ress)
746	{
747	prv = ress;
748	ress = prv->next;
749	free_req (prv);
750	}
751
752	ress = rese = 0;
753
754	close (respipe [0]);
755	close (respipe [1]);
756	create_pipe ();
757
758	atfork_parent ();
759	}
760
761	#define dREQ \
762	aio_req req; \
763	\
764	if (SvOK (callback) && !SvROK (callback)) \
765	croak ("clalback must be undef or of reference type"); \
766	\
767	Newz (0, req, 1, aio_cb); \
768	if (!req) \
769	croak ("out of memory during aio_req allocation"); \
770	\
771	req->callback = newSVsv (callback);
772
773	MODULE = IO::AIO PACKAGE = IO::AIO
774
775	PROTOTYPES: ENABLE
776
777	BOOT:
778	{
779	create_pipe ();
780	pthread_atfork (atfork_prepare, atfork_parent, atfork_child);
781	}
782
783	void
784	min_parallel(nthreads)
785	int nthreads
786	PROTOTYPE: $
787
788	void
789	max_parallel(nthreads)
790	int nthreads
791	PROTOTYPE: $
792
793	int
794	max_outstanding(nreqs)
795	int nreqs
796	PROTOTYPE: $
797	CODE:
798	RETVAL = max_outstanding;
799	max_outstanding = nreqs;
800
801	void
802	aio_open(pathname,flags,mode,callback=&PL_sv_undef)
803	SV * pathname
804	int flags
805	int mode
806	SV * callback
807	PROTOTYPE: $$$;$
808	CODE:
809	{
810	dREQ;
811
812	req->type = REQ_OPEN;
813	req->data = newSVsv (pathname);
814	req->dataptr = SvPVbyte_nolen (req->data);
815	req->fd = flags;
816	req->mode = mode;
817
818	send_req (req);
819	}
820
821	void
822	aio_close(fh,callback=&PL_sv_undef)
823	SV * fh
824	SV * callback
825	PROTOTYPE: $;$
826	ALIAS:
827	aio_close = REQ_CLOSE
828	aio_fsync = REQ_FSYNC
829	aio_fdatasync = REQ_FDATASYNC
830	CODE:
831	{
832	dREQ;
833
834	req->type = ix;
835	req->fh = newSVsv (fh);
836	req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
837
838	send_req (req);
839	}
840
841	void
842	aio_read(fh,offset,length,data,dataoffset,callback=&PL_sv_undef)
843	SV * fh
844	UV offset
845	UV length
846	SV * data
847	UV dataoffset
848	SV * callback
849	ALIAS:
850	aio_read = REQ_READ
851	aio_write = REQ_WRITE
852	PROTOTYPE: $$$$$;$
853	CODE:
854	{
855	aio_req req;
856	STRLEN svlen;
857	char *svptr = SvPVbyte (data, svlen);
858
859	SvUPGRADE (data, SVt_PV);
860	SvPOK_on (data);
861
862	if (dataoffset < 0)
863	dataoffset += svlen;
864
865	if (dataoffset < 0 \|\| dataoffset > svlen)
866	croak ("data offset outside of string");
867
868	if (ix == REQ_WRITE)
869	{
870	/* write: check length and adjust. */
871	if (length < 0 \|\| length + dataoffset > svlen)
872	length = svlen - dataoffset;
873	}
874	else
875	{
876	/* read: grow scalar as necessary */
877	svptr = SvGROW (data, length + dataoffset);
878	}
879
880	if (length < 0)
881	croak ("length must not be negative");
882
883	{
884	dREQ;
885
886	req->type = ix;
887	req->fh = newSVsv (fh);
888	req->fd = PerlIO_fileno (ix == REQ_READ ? IoIFP (sv_2io (fh))
889	: IoOFP (sv_2io (fh)));
890	req->offset = offset;
891	req->length = length;
892	req->data = SvREFCNT_inc (data);
893	req->dataptr = (char *)svptr + dataoffset;
894
895	if (!SvREADONLY (data))
896	{
897	SvREADONLY_on (data);
898	req->data2ptr = (void *)data;
899	}
900
901	send_req (req);
902	}
903	}
904
905	void
906	aio_sendfile(out_fh,in_fh,in_offset,length,callback=&PL_sv_undef)
907	SV * out_fh
908	SV * in_fh
909	UV in_offset
910	UV length
911	SV * callback
912	PROTOTYPE: $$$$;$
913	CODE:
914	{
915	dREQ;
916
917	req->type = REQ_SENDFILE;
918	req->fh = newSVsv (out_fh);
919	req->fd = PerlIO_fileno (IoIFP (sv_2io (out_fh)));
920	req->fh2 = newSVsv (in_fh);
921	req->fd2 = PerlIO_fileno (IoIFP (sv_2io (in_fh)));
922	req->offset = in_offset;
923	req->length = length;
924
925	send_req (req);
926	}
927
928	void
929	aio_readahead(fh,offset,length,callback=&PL_sv_undef)
930	SV * fh
931	UV offset
932	IV length
933	SV * callback
934	PROTOTYPE: $$$;$
935	CODE:
936	{
937	dREQ;
938
939	req->type = REQ_READAHEAD;
940	req->fh = newSVsv (fh);
941	req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
942	req->offset = offset;
943	req->length = length;
944
945	send_req (req);
946	}
947
948	void
949	aio_stat(fh_or_path,callback=&PL_sv_undef)
950	SV * fh_or_path
951	SV * callback
952	ALIAS:
953	aio_stat = REQ_STAT
954	aio_lstat = REQ_LSTAT
955	CODE:
956	{
957	dREQ;
958
959	New (0, req->statdata, 1, Stat_t);
960	if (!req->statdata)
961	{
962	free_req (req);
963	croak ("out of memory during aio_req->statdata allocation");
964	}
965
966	if (SvPOK (fh_or_path))
967	{
968	req->type = ix;
969	req->data = newSVsv (fh_or_path);
970	req->dataptr = SvPVbyte_nolen (req->data);
971	}
972	else
973	{
974	req->type = REQ_FSTAT;
975	req->fh = newSVsv (fh_or_path);
976	req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
977	}
978
979	send_req (req);
980	}
981
982	void
983	aio_unlink(pathname,callback=&PL_sv_undef)
984	SV * pathname
985	SV * callback
986	ALIAS:
987	aio_unlink = REQ_UNLINK
988	aio_rmdir = REQ_RMDIR
989	CODE:
990	{
991	dREQ;
992
993	req->type = ix;
994	req->data = newSVsv (pathname);
995	req->dataptr = SvPVbyte_nolen (req->data);
996
997	send_req (req);
998	}
999
1000	void
1001	aio_symlink(oldpath,newpath,callback=&PL_sv_undef)
1002	SV * oldpath
1003	SV * newpath
1004	SV * callback
1005	CODE:
1006	{
1007	dREQ;
1008
1009	req->type = REQ_SYMLINK;
1010	req->fh = newSVsv (oldpath);
1011	req->data2ptr = SvPVbyte_nolen (req->fh);
1012	req->data = newSVsv (newpath);
1013	req->dataptr = SvPVbyte_nolen (req->data);
1014
1015	send_req (req);
1016	}
1017
1018	void
1019	aio_readdir(pathname,callback=&PL_sv_undef)
1020	SV * pathname
1021	SV * callback
1022	CODE:
1023	{
1024	dREQ;
1025
1026	req->type = REQ_READDIR;
1027	req->data = newSVsv (pathname);
1028	req->dataptr = SvPVbyte_nolen (req->data);
1029
1030	send_req (req);
1031	}
1032
1033	void
1034	flush()
1035	PROTOTYPE:
1036	CODE:
1037	while (nreqs)
1038	{
1039	poll_wait ();
1040	poll_cb ();
1041	}
1042
1043	void
1044	poll()
1045	PROTOTYPE:
1046	CODE:
1047	if (nreqs)
1048	{
1049	poll_wait ();
1050	poll_cb ();
1051	}
1052
1053	int
1054	poll_fileno()
1055	PROTOTYPE:
1056	CODE:
1057	RETVAL = respipe [0];
1058	OUTPUT:
1059	RETVAL
1060
1061	int
1062	poll_cb(...)
1063	PROTOTYPE:
1064	CODE:
1065	RETVAL = poll_cb ();
1066	OUTPUT:
1067	RETVAL
1068
1069	void
1070	poll_wait()
1071	PROTOTYPE:
1072	CODE:
1073	if (nreqs)
1074	poll_wait ();
1075
1076	int
1077	nreqs()
1078	PROTOTYPE:
1079	CODE:
1080	RETVAL = nreqs;
1081	OUTPUT:
1082	RETVAL
1083