IO-AIO/AIO.xs

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

#include "autoconf/config.h"

#include <sys/types.h>
#include <sys/stat.h>

#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <sched.h>

#include <pthread.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 __ia64
# define STACKSIZE 65536
#else
# define STACKSIZE  4096
#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 *volatile next;

  int type;

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

  Stat_t *statdata;
} aio_cb;

typedef aio_cb *aio_req;

static int started;
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
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;
  aio_req req, prv;

  pthread_mutex_lock (&reslock);

  {
    /* read any signals sent by the worker threads */
    char buf [32];
    while (read (respipe [0], buf, 32) > 0)
      ;
  }

  req = ress;
  ress = rese = 0;

  pthread_mutex_unlock (&reslock);

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

          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);
            }

          ENTER;
          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 = SvREFCNT_inc (POPs);

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

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

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

          errno = errorno;
          count++;
        }

      prv = req;
      req = req->next;
      Safefree (prv);

      /* TODO: croak on errors? */
    }

  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)
{
  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);

  while (nreqs > max_outstanding)
    {
      poll_wait ();
      poll_cb ();
    }
}

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

  send_req (req);
}

/* 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 iolock = 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 (&iolock);
  ooffset = lseek (fd, 0, SEEK_CUR);
  lseek (fd, offset, SEEK_SET);
  res = read (fd, buf, count);
  lseek (fd, ooffset, SEEK_SET);
  pthread_mutex_unlock (&iolock);

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

  return res;
}
#endif

#if !HAVE_FDATASYNC
# define fdatasync fsync
#endif

#if !HAVE_READAHEAD
# define readahead aio_readahead

static char readahead_buf[4096];

static ssize_t
readahead (int fd, off_t offset, size_t count)
{
  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

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_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_FDATASYNC: req->result = fdatasync (req->fd); break;
          case REQ_FSYNC:     req->result = fsync     (req->fd); 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;
}

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

PROTOTYPES: ENABLE

BOOT:
{
        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");
}

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 ();
          }
}

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:
{
        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=&PL_sv_undef)
        SV *    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->fh = newSVsv (fh);
        req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
        req->callback = SvREFCNT_inc (callback);

        send_req (req);
}

void
aio_read(fh,offset,length,data,dataoffset,callback=&PL_sv_undef)
        SV *    fh
        UV      offset
        IV      length
        SV *    data
        IV      dataoffset
        SV *    callback
        ALIAS:
           aio_read  = REQ_READ
           aio_write = REQ_WRITE
        PROTOTYPE: $$$$$;$
        CODE:
{
        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 (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");

        Newz (0, req, 1, aio_cb);

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

        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;
        req->callback = SvREFCNT_inc (callback);

        send_req (req);
}

void
aio_readahead(fh,offset,length,callback=&PL_sv_undef)
        SV *    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->fh = newSVsv (fh);
        req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
        req->offset = offset;
        req->length = length;
        req->callback = SvREFCNT_inc (callback);

        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:
{
        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->data = newSVsv (fh_or_path);
            req->dataptr = SvPV_nolen (req->data);
          }
        else
          {
            req->type = REQ_FSTAT;
            req->fh = newSVsv (fh_or_path);
            req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
          }

        req->callback = SvREFCNT_inc (callback);

        send_req (req);
}

void
aio_unlink(pathname,callback=&PL_sv_undef)
        SV * pathname
        SV * callback
        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);
}

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:	1.17
Committed:	Sun Jul 31 18:45:48 2005 UTC (18 years, 9 months ago) by root
Branch:	MAIN
Changes since 1.16:	+72 -13 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.15	#include "EXTERN.h"
2	root	1.1	#include "perl.h"
3			#include "XSUB.h"
4
5	root	1.16	#include "autoconf/config.h"
6
7	root	1.1	#include <sys/types.h>
8			#include <sys/stat.h>
9	root	1.10
10	root	1.1	#include <unistd.h>
11			#include <fcntl.h>
12			#include <signal.h>
13			#include <sched.h>
14
15			#include <pthread.h>
16
17			typedef void InputStream; / hack, but 5.6.1 is simply toooo old ;) */
18			typedef void OutputStream; / hack, but 5.6.1 is simply toooo old ;) */
19			typedef void InOutStream; / hack, but 5.6.1 is simply toooo old ;) */
20
21	root	1.4	#if __ia64
22			# define STACKSIZE 65536
23	root	1.1	#else
24	root	1.4	# define STACKSIZE 4096
25	root	1.1	#endif
26
27			enum {
28			REQ_QUIT,
29			REQ_OPEN, REQ_CLOSE,
30			REQ_READ, REQ_WRITE, REQ_READAHEAD,
31			REQ_STAT, REQ_LSTAT, REQ_FSTAT, REQ_UNLINK,
32			REQ_FSYNC, REQ_FDATASYNC,
33			};
34
35			typedef struct aio_cb {
36	root	1.3	struct aio_cb *volatile next;
37	root	1.1
38			int type;
39
40			int fd;
41			off_t offset;
42			size_t length;
43			ssize_t result;
44			mode_t mode; /* open */
45			int errorno;
46	root	1.13	SV data, callback, *fh;
47	root	1.1	void *dataptr;
48			STRLEN dataoffset;
49
50			Stat_t *statdata;
51			} aio_cb;
52
53			typedef aio_cb *aio_req;
54
55			static int started;
56	root	1.11	static volatile int nreqs;
57	root	1.4	static int max_outstanding = 1<<30;
58	root	1.3	static int respipe [2];
59	root	1.1
60	root	1.3	static pthread_mutex_t reslock = PTHREAD_MUTEX_INITIALIZER;
61			static pthread_mutex_t reqlock = PTHREAD_MUTEX_INITIALIZER;
62			static pthread_cond_t reqwait = PTHREAD_COND_INITIALIZER;
63
64			static volatile aio_req reqs, reqe; /* queue start, queue end */
65			static volatile aio_req ress, rese; /* queue start, queue end */
66	root	1.1
67			static void
68			poll_wait ()
69			{
70	root	1.11	if (nreqs && !ress)
71			{
72			fd_set rfd;
73			FD_ZERO(&rfd);
74			FD_SET(respipe [0], &rfd);
75	root	1.3
76	root	1.11	select (respipe [0] + 1, &rfd, 0, 0, 0);
77			}
78	root	1.1	}
79
80			static int
81	root	1.5	poll_cb ()
82	root	1.1	{
83			dSP;
84			int count = 0;
85	root	1.11	aio_req req, prv;
86
87			pthread_mutex_lock (&reslock);
88
89	root	1.3	{
90	root	1.11	/* read any signals sent by the worker threads */
91	root	1.3	char buf [32];
92			while (read (respipe [0], buf, 32) > 0)
93			;
94			}
95	root	1.1
96	root	1.11	req = ress;
97			ress = rese = 0;
98	root	1.3
99	root	1.11	pthread_mutex_unlock (&reslock);
100	root	1.3
101	root	1.11	while (req)
102			{
103	root	1.1	nreqs--;
104
105			if (req->type == REQ_QUIT)
106			started--;
107			else
108			{
109			int errorno = errno;
110			errno = req->errorno;
111
112			if (req->type == REQ_READ)
113			SvCUR_set (req->data, req->dataoffset
114			+ req->result > 0 ? req->result : 0);
115
116			if (req->data)
117			SvREFCNT_dec (req->data);
118
119	root	1.13	if (req->fh)
120			SvREFCNT_dec (req->fh);
121
122	root	1.1	if (req->type == REQ_STAT \|\| req->type == REQ_LSTAT \|\| req->type == REQ_FSTAT)
123			{
124			PL_laststype = req->type == REQ_LSTAT ? OP_LSTAT : OP_STAT;
125			PL_laststatval = req->result;
126			PL_statcache = *(req->statdata);
127
128			Safefree (req->statdata);
129			}
130
131	root	1.13	ENTER;
132	root	1.1	PUSHMARK (SP);
133			XPUSHs (sv_2mortal (newSViv (req->result)));
134	root	1.2
135			if (req->type == REQ_OPEN)
136			{
137			/* convert fd to fh */
138			SV *fh;
139
140			PUTBACK;
141			call_pv ("IO::AIO::_fd2fh", G_SCALAR \| G_EVAL);
142			SPAGAIN;
143
144	root	1.13	fh = SvREFCNT_inc (POPs);
145	root	1.2
146			PUSHMARK (SP);
147	root	1.13	XPUSHs (sv_2mortal (fh));
148	root	1.2	}
149
150	root	1.8	if (SvOK (req->callback))
151			{
152			PUTBACK;
153			call_sv (req->callback, G_VOID \| G_EVAL);
154			SPAGAIN;
155			}
156	root	1.13
157			LEAVE;
158	root	1.1
159			if (req->callback)
160			SvREFCNT_dec (req->callback);
161
162			errno = errorno;
163			count++;
164			}
165
166	root	1.11	prv = req;
167			req = req->next;
168			Safefree (prv);
169
170			/* TODO: croak on errors? */
171	root	1.1	}
172
173			return count;
174			}
175
176	root	1.4	static void aio_proc(void arg);
177
178			static void
179			start_thread (void)
180			{
181			sigset_t fullsigset, oldsigset;
182			pthread_t tid;
183			pthread_attr_t attr;
184
185			pthread_attr_init (&attr);
186			pthread_attr_setstacksize (&attr, STACKSIZE);
187			pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
188
189			sigfillset (&fullsigset);
190			sigprocmask (SIG_SETMASK, &fullsigset, &oldsigset);
191
192			if (pthread_create (&tid, &attr, aio_proc, 0) == 0)
193			started++;
194
195			sigprocmask (SIG_SETMASK, &oldsigset, 0);
196			}
197
198			static void
199			send_req (aio_req req)
200			{
201			nreqs++;
202
203			pthread_mutex_lock (&reqlock);
204
205			req->next = 0;
206
207			if (reqe)
208			{
209			reqe->next = req;
210			reqe = req;
211			}
212			else
213			reqe = reqs = req;
214
215			pthread_cond_signal (&reqwait);
216			pthread_mutex_unlock (&reqlock);
217
218			while (nreqs > max_outstanding)
219			{
220			poll_wait ();
221			poll_cb ();
222			}
223			}
224
225			static void
226			end_thread (void)
227			{
228			aio_req req;
229			New (0, req, 1, aio_cb);
230			req->type = REQ_QUIT;
231
232			send_req (req);
233			}
234
235	root	1.17	/* work around various missing functions */
236
237			#if !HAVE_PREADWRITE
238			# define pread aio_pread
239			# define pwrite aio_pwrite
240
241			/*
242			* make our pread/pwrite safe against themselves, but not against
243			* normal read/write by using a mutex. slows down execution a lot,
244			* but that's your problem, not mine.
245			*/
246			static pthread_mutex_t iolock = PTHREAD_MUTEX_INITIALIZER;
247
248			static ssize_t
249			pread (int fd, void *buf, size_t count, off_t offset)
250			{
251			ssize_t res;
252			off_t ooffset;
253
254			pthread_mutex_lock (&iolock);
255			ooffset = lseek (fd, 0, SEEK_CUR);
256			lseek (fd, offset, SEEK_SET);
257			res = read (fd, buf, count);
258			lseek (fd, ooffset, SEEK_SET);
259			pthread_mutex_unlock (&iolock);
260
261			return res;
262			}
263
264			static ssize_t
265			pwrite (int fd, void *buf, size_t count, off_t offset)
266			{
267			ssize_t res;
268			off_t ooffset;
269
270			pthread_mutex_lock (&iolock);
271			ooffset = lseek (fd, 0, SEEK_CUR);
272			lseek (fd, offset, SEEK_SET);
273			res = write (fd, buf, count);
274			lseek (fd, offset, SEEK_SET);
275			pthread_mutex_unlock (&iolock);
276
277			return res;
278			}
279			#endif
280
281			#if !HAVE_FDATASYNC
282			# define fdatasync fsync
283			#endif
284
285			#if !HAVE_READAHEAD
286			# define readahead aio_readahead
287
288			static char readahead_buf[4096];
289
290			static ssize_t
291			readahead (int fd, off_t offset, size_t count)
292			{
293			while (count > 0)
294			{
295			size_t len = count < sizeof (readahead_buf) ? count : sizeof (readahead_buf);
296
297			pread (fd, readahead_buf, len, offset);
298			offset += len;
299			count -= len;
300			}
301
302			errno = 0;
303			}
304			#endif
305
306	root	1.1	static void *
307			aio_proc (void *thr_arg)
308			{
309			aio_req req;
310	root	1.3	int type;
311	root	1.1
312	root	1.3	do
313	root	1.1	{
314	root	1.3	pthread_mutex_lock (&reqlock);
315
316			for (;;)
317			{
318			req = reqs;
319
320			if (reqs)
321			{
322			reqs = reqs->next;
323			if (!reqs) reqe = 0;
324			}
325
326			if (req)
327			break;
328
329			pthread_cond_wait (&reqwait, &reqlock);
330			}
331
332			pthread_mutex_unlock (&reqlock);
333
334	root	1.1	errno = 0; /* strictly unnecessary */
335
336	root	1.3	type = req->type;
337
338			switch (type)
339	root	1.1	{
340	root	1.10	case REQ_READ: req->result = pread (req->fd, req->dataptr, req->length, req->offset); break;
341			case REQ_WRITE: req->result = pwrite (req->fd, req->dataptr, req->length, req->offset); break;
342	root	1.16
343	root	1.1	case REQ_READAHEAD: req->result = readahead (req->fd, req->offset, req->length); break;
344
345			case REQ_STAT: req->result = stat (req->dataptr, req->statdata); break;
346			case REQ_LSTAT: req->result = lstat (req->dataptr, req->statdata); break;
347			case REQ_FSTAT: req->result = fstat (req->fd , req->statdata); break;
348
349			case REQ_OPEN: req->result = open (req->dataptr, req->fd, req->mode); break;
350			case REQ_CLOSE: req->result = close (req->fd); break;
351			case REQ_UNLINK: req->result = unlink (req->dataptr); break;
352
353	root	1.17	case REQ_FDATASYNC: req->result = fdatasync (req->fd); break;
354	root	1.1	case REQ_FSYNC: req->result = fsync (req->fd); break;
355
356			case REQ_QUIT:
357	root	1.3	break;
358	root	1.1
359			default:
360			req->result = ENOSYS;
361			break;
362			}
363
364			req->errorno = errno;
365	root	1.3
366			pthread_mutex_lock (&reslock);
367
368			req->next = 0;
369
370			if (rese)
371			{
372			rese->next = req;
373			rese = req;
374			}
375			else
376			{
377			rese = ress = req;
378
379			/* write a dummy byte to the pipe so fh becomes ready */
380			write (respipe [1], &respipe, 1);
381			}
382
383			pthread_mutex_unlock (&reslock);
384	root	1.1	}
385	root	1.3	while (type != REQ_QUIT);
386	root	1.1
387			return 0;
388			}
389
390			MODULE = IO::AIO PACKAGE = IO::AIO
391
392	root	1.8	PROTOTYPES: ENABLE
393
394	root	1.1	BOOT:
395			{
396	root	1.3	if (pipe (respipe))
397			croak ("unable to initialize result pipe");
398	root	1.1
399	root	1.3	if (fcntl (respipe [0], F_SETFL, O_NONBLOCK))
400	root	1.1	croak ("cannot set result pipe to nonblocking mode");
401
402	root	1.3	if (fcntl (respipe [1], F_SETFL, O_NONBLOCK))
403	root	1.1	croak ("cannot set result pipe to nonblocking mode");
404			}
405
406			void
407			min_parallel(nthreads)
408			int nthreads
409			PROTOTYPE: $
410			CODE:
411			while (nthreads > started)
412			start_thread ();
413
414			void
415			max_parallel(nthreads)
416			int nthreads
417			PROTOTYPE: $
418			CODE:
419			{
420			int cur = started;
421			while (cur > nthreads)
422			{
423			end_thread ();
424			cur--;
425			}
426
427			while (started > nthreads)
428			{
429			poll_wait ();
430	root	1.5	poll_cb ();
431	root	1.1	}
432			}
433
434	root	1.4	int
435			max_outstanding(nreqs)
436			int nreqs
437			PROTOTYPE: $
438			CODE:
439			RETVAL = max_outstanding;
440			max_outstanding = nreqs;
441
442	root	1.1	void
443	root	1.8	aio_open(pathname,flags,mode,callback=&PL_sv_undef)
444	root	1.1	SV * pathname
445			int flags
446			int mode
447			SV * callback
448	root	1.8	PROTOTYPE: $$$;$
449	root	1.1	CODE:
450			{
451			aio_req req;
452
453			Newz (0, req, 1, aio_cb);
454
455			if (!req)
456			croak ("out of memory during aio_req allocation");
457
458			req->type = REQ_OPEN;
459			req->data = newSVsv (pathname);
460			req->dataptr = SvPV_nolen (req->data);
461			req->fd = flags;
462			req->mode = mode;
463			req->callback = SvREFCNT_inc (callback);
464
465			send_req (req);
466			}
467
468			void
469	root	1.8	aio_close(fh,callback=&PL_sv_undef)
470	root	1.13	SV * fh
471			SV * callback
472	root	1.8	PROTOTYPE: $;$
473	root	1.1	ALIAS:
474			aio_close = REQ_CLOSE
475			aio_fsync = REQ_FSYNC
476			aio_fdatasync = REQ_FDATASYNC
477			CODE:
478			{
479			aio_req req;
480
481			Newz (0, req, 1, aio_cb);
482
483			if (!req)
484			croak ("out of memory during aio_req allocation");
485
486			req->type = ix;
487	root	1.13	req->fh = newSVsv (fh);
488			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
489	root	1.1	req->callback = SvREFCNT_inc (callback);
490
491			send_req (req);
492			}
493
494			void
495	root	1.8	aio_read(fh,offset,length,data,dataoffset,callback=&PL_sv_undef)
496	root	1.13	SV * fh
497			UV offset
498			IV length
499			SV * data
500			IV dataoffset
501			SV * callback
502			ALIAS:
503			aio_read = REQ_READ
504			aio_write = REQ_WRITE
505	root	1.8	PROTOTYPE: $$$$$;$
506	root	1.1	CODE:
507	root	1.13	{
508			aio_req req;
509			STRLEN svlen;
510			char *svptr = SvPV (data, svlen);
511
512			SvUPGRADE (data, SVt_PV);
513			SvPOK_on (data);
514	root	1.1
515	root	1.13	if (dataoffset < 0)
516			dataoffset += svlen;
517
518			if (dataoffset < 0 \|\| dataoffset > svlen)
519			croak ("data offset outside of string");
520
521			if (ix == REQ_WRITE)
522			{
523			/* write: check length and adjust. */
524			if (length < 0 \|\| length + dataoffset > svlen)
525			length = svlen - dataoffset;
526			}
527			else
528			{
529			/* read: grow scalar as necessary */
530			svptr = SvGROW (data, length + dataoffset);
531			}
532
533			if (length < 0)
534			croak ("length must not be negative");
535
536			Newz (0, req, 1, aio_cb);
537
538			if (!req)
539			croak ("out of memory during aio_req allocation");
540
541			req->type = ix;
542			req->fh = newSVsv (fh);
543			req->fd = PerlIO_fileno (ix == REQ_READ ? IoIFP (sv_2io (fh))
544			: IoOFP (sv_2io (fh)));
545			req->offset = offset;
546			req->length = length;
547			req->data = SvREFCNT_inc (data);
548			req->dataptr = (char *)svptr + dataoffset;
549			req->callback = SvREFCNT_inc (callback);
550
551			send_req (req);
552			}
553	root	1.1
554			void
555	root	1.8	aio_readahead(fh,offset,length,callback=&PL_sv_undef)
556	root	1.13	SV * fh
557			UV offset
558			IV length
559			SV * callback
560	root	1.8	PROTOTYPE: $$$;$
561	root	1.1	CODE:
562			{
563			aio_req req;
564
565			if (length < 0)
566			croak ("length must not be negative");
567
568			Newz (0, req, 1, aio_cb);
569
570			if (!req)
571			croak ("out of memory during aio_req allocation");
572
573			req->type = REQ_READAHEAD;
574	root	1.13	req->fh = newSVsv (fh);
575			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
576	root	1.1	req->offset = offset;
577			req->length = length;
578			req->callback = SvREFCNT_inc (callback);
579
580			send_req (req);
581			}
582
583			void
584	root	1.8	aio_stat(fh_or_path,callback=&PL_sv_undef)
585	root	1.1	SV * fh_or_path
586			SV * callback
587			ALIAS:
588	root	1.8	aio_stat = REQ_STAT
589			aio_lstat = REQ_LSTAT
590	root	1.1	CODE:
591			{
592			aio_req req;
593
594			Newz (0, req, 1, aio_cb);
595
596			if (!req)
597			croak ("out of memory during aio_req allocation");
598
599			New (0, req->statdata, 1, Stat_t);
600
601			if (!req->statdata)
602			croak ("out of memory during aio_req->statdata allocation");
603
604			if (SvPOK (fh_or_path))
605			{
606	root	1.8	req->type = ix;
607	root	1.1	req->data = newSVsv (fh_or_path);
608			req->dataptr = SvPV_nolen (req->data);
609			}
610			else
611			{
612			req->type = REQ_FSTAT;
613	root	1.13	req->fh = newSVsv (fh_or_path);
614	root	1.1	req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
615			}
616
617			req->callback = SvREFCNT_inc (callback);
618
619			send_req (req);
620			}
621
622			void
623	root	1.8	aio_unlink(pathname,callback=&PL_sv_undef)
624	root	1.1	SV * pathname
625			SV * callback
626			CODE:
627			{
628			aio_req req;
629
630			Newz (0, req, 1, aio_cb);
631
632			if (!req)
633			croak ("out of memory during aio_req allocation");
634
635			req->type = REQ_UNLINK;
636			req->data = newSVsv (pathname);
637			req->dataptr = SvPV_nolen (req->data);
638			req->callback = SvREFCNT_inc (callback);
639
640			send_req (req);
641			}
642
643	root	1.6	void
644			flush()
645			PROTOTYPE:
646			CODE:
647			while (nreqs)
648			{
649			poll_wait ();
650			poll_cb ();
651			}
652
653	root	1.7	void
654			poll()
655			PROTOTYPE:
656			CODE:
657			if (nreqs)
658			{
659			poll_wait ();
660			poll_cb ();
661			}
662
663	root	1.1	int
664			poll_fileno()
665			PROTOTYPE:
666			CODE:
667	root	1.3	RETVAL = respipe [0];
668	root	1.1	OUTPUT:
669			RETVAL
670
671			int
672			poll_cb(...)
673			PROTOTYPE:
674			CODE:
675	root	1.5	RETVAL = poll_cb ();
676	root	1.1	OUTPUT:
677			RETVAL
678
679			void
680			poll_wait()
681			PROTOTYPE:
682			CODE:
683	root	1.3	if (nreqs)
684			poll_wait ();
685	root	1.1
686			int
687			nreqs()
688			PROTOTYPE:
689			CODE:
690			RETVAL = nreqs;
691			OUTPUT:
692			RETVAL
693