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>

#ifndef _REENTRANT
# define _REENTRANT 1
#endif
#include <errno.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:	1.18
Committed:	Sun Jul 31 19:00:31 2005 UTC (18 years, 9 months ago) by root
Branch:	MAIN
Changes since 1.17:	+5 -0 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	root	1.18	#ifndef _REENTRANT
16			# define _REENTRANT 1
17			#endif
18			#include <errno.h>
19
20	root	1.1	#include <pthread.h>
21
22			typedef void InputStream; / hack, but 5.6.1 is simply toooo old ;) */
23			typedef void OutputStream; / hack, but 5.6.1 is simply toooo old ;) */
24			typedef void InOutStream; / hack, but 5.6.1 is simply toooo old ;) */
25
26	root	1.4	#if __ia64
27			# define STACKSIZE 65536
28	root	1.1	#else
29	root	1.4	# define STACKSIZE 4096
30	root	1.1	#endif
31
32			enum {
33			REQ_QUIT,
34			REQ_OPEN, REQ_CLOSE,
35			REQ_READ, REQ_WRITE, REQ_READAHEAD,
36			REQ_STAT, REQ_LSTAT, REQ_FSTAT, REQ_UNLINK,
37			REQ_FSYNC, REQ_FDATASYNC,
38			};
39
40			typedef struct aio_cb {
41	root	1.3	struct aio_cb *volatile next;
42	root	1.1
43			int type;
44
45			int fd;
46			off_t offset;
47			size_t length;
48			ssize_t result;
49			mode_t mode; /* open */
50			int errorno;
51	root	1.13	SV data, callback, *fh;
52	root	1.1	void *dataptr;
53			STRLEN dataoffset;
54
55			Stat_t *statdata;
56			} aio_cb;
57
58			typedef aio_cb *aio_req;
59
60			static int started;
61	root	1.11	static volatile int nreqs;
62	root	1.4	static int max_outstanding = 1<<30;
63	root	1.3	static int respipe [2];
64	root	1.1
65	root	1.3	static pthread_mutex_t reslock = PTHREAD_MUTEX_INITIALIZER;
66			static pthread_mutex_t reqlock = PTHREAD_MUTEX_INITIALIZER;
67			static pthread_cond_t reqwait = PTHREAD_COND_INITIALIZER;
68
69			static volatile aio_req reqs, reqe; /* queue start, queue end */
70			static volatile aio_req ress, rese; /* queue start, queue end */
71	root	1.1
72			static void
73			poll_wait ()
74			{
75	root	1.11	if (nreqs && !ress)
76			{
77			fd_set rfd;
78			FD_ZERO(&rfd);
79			FD_SET(respipe [0], &rfd);
80	root	1.3
81	root	1.11	select (respipe [0] + 1, &rfd, 0, 0, 0);
82			}
83	root	1.1	}
84
85			static int
86	root	1.5	poll_cb ()
87	root	1.1	{
88			dSP;
89			int count = 0;
90	root	1.11	aio_req req, prv;
91
92			pthread_mutex_lock (&reslock);
93
94	root	1.3	{
95	root	1.11	/* read any signals sent by the worker threads */
96	root	1.3	char buf [32];
97			while (read (respipe [0], buf, 32) > 0)
98			;
99			}
100	root	1.1
101	root	1.11	req = ress;
102			ress = rese = 0;
103	root	1.3
104	root	1.11	pthread_mutex_unlock (&reslock);
105	root	1.3
106	root	1.11	while (req)
107			{
108	root	1.1	nreqs--;
109
110			if (req->type == REQ_QUIT)
111			started--;
112			else
113			{
114			int errorno = errno;
115			errno = req->errorno;
116
117			if (req->type == REQ_READ)
118			SvCUR_set (req->data, req->dataoffset
119			+ req->result > 0 ? req->result : 0);
120
121			if (req->data)
122			SvREFCNT_dec (req->data);
123
124	root	1.13	if (req->fh)
125			SvREFCNT_dec (req->fh);
126
127	root	1.1	if (req->type == REQ_STAT \|\| req->type == REQ_LSTAT \|\| req->type == REQ_FSTAT)
128			{
129			PL_laststype = req->type == REQ_LSTAT ? OP_LSTAT : OP_STAT;
130			PL_laststatval = req->result;
131			PL_statcache = *(req->statdata);
132
133			Safefree (req->statdata);
134			}
135
136	root	1.13	ENTER;
137	root	1.1	PUSHMARK (SP);
138			XPUSHs (sv_2mortal (newSViv (req->result)));
139	root	1.2
140			if (req->type == REQ_OPEN)
141			{
142			/* convert fd to fh */
143			SV *fh;
144
145			PUTBACK;
146			call_pv ("IO::AIO::_fd2fh", G_SCALAR \| G_EVAL);
147			SPAGAIN;
148
149	root	1.13	fh = SvREFCNT_inc (POPs);
150	root	1.2
151			PUSHMARK (SP);
152	root	1.13	XPUSHs (sv_2mortal (fh));
153	root	1.2	}
154
155	root	1.8	if (SvOK (req->callback))
156			{
157			PUTBACK;
158			call_sv (req->callback, G_VOID \| G_EVAL);
159			SPAGAIN;
160			}
161	root	1.13
162			LEAVE;
163	root	1.1
164			if (req->callback)
165			SvREFCNT_dec (req->callback);
166
167			errno = errorno;
168			count++;
169			}
170
171	root	1.11	prv = req;
172			req = req->next;
173			Safefree (prv);
174
175			/* TODO: croak on errors? */
176	root	1.1	}
177
178			return count;
179			}
180
181	root	1.4	static void aio_proc(void arg);
182
183			static void
184			start_thread (void)
185			{
186			sigset_t fullsigset, oldsigset;
187			pthread_t tid;
188			pthread_attr_t attr;
189
190			pthread_attr_init (&attr);
191			pthread_attr_setstacksize (&attr, STACKSIZE);
192			pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
193
194			sigfillset (&fullsigset);
195			sigprocmask (SIG_SETMASK, &fullsigset, &oldsigset);
196
197			if (pthread_create (&tid, &attr, aio_proc, 0) == 0)
198			started++;
199
200			sigprocmask (SIG_SETMASK, &oldsigset, 0);
201			}
202
203			static void
204			send_req (aio_req req)
205			{
206			nreqs++;
207
208			pthread_mutex_lock (&reqlock);
209
210			req->next = 0;
211
212			if (reqe)
213			{
214			reqe->next = req;
215			reqe = req;
216			}
217			else
218			reqe = reqs = req;
219
220			pthread_cond_signal (&reqwait);
221			pthread_mutex_unlock (&reqlock);
222
223			while (nreqs > max_outstanding)
224			{
225			poll_wait ();
226			poll_cb ();
227			}
228			}
229
230			static void
231			end_thread (void)
232			{
233			aio_req req;
234			New (0, req, 1, aio_cb);
235			req->type = REQ_QUIT;
236
237			send_req (req);
238			}
239
240	root	1.17	/* work around various missing functions */
241
242			#if !HAVE_PREADWRITE
243			# define pread aio_pread
244			# define pwrite aio_pwrite
245
246			/*
247			* make our pread/pwrite safe against themselves, but not against
248			* normal read/write by using a mutex. slows down execution a lot,
249			* but that's your problem, not mine.
250			*/
251			static pthread_mutex_t iolock = PTHREAD_MUTEX_INITIALIZER;
252
253			static ssize_t
254			pread (int fd, void *buf, size_t count, off_t offset)
255			{
256			ssize_t res;
257			off_t ooffset;
258
259			pthread_mutex_lock (&iolock);
260			ooffset = lseek (fd, 0, SEEK_CUR);
261			lseek (fd, offset, SEEK_SET);
262			res = read (fd, buf, count);
263			lseek (fd, ooffset, SEEK_SET);
264			pthread_mutex_unlock (&iolock);
265
266			return res;
267			}
268
269			static ssize_t
270			pwrite (int fd, void *buf, size_t count, off_t offset)
271			{
272			ssize_t res;
273			off_t ooffset;
274
275			pthread_mutex_lock (&iolock);
276			ooffset = lseek (fd, 0, SEEK_CUR);
277			lseek (fd, offset, SEEK_SET);
278			res = write (fd, buf, count);
279			lseek (fd, offset, SEEK_SET);
280			pthread_mutex_unlock (&iolock);
281
282			return res;
283			}
284			#endif
285
286			#if !HAVE_FDATASYNC
287			# define fdatasync fsync
288			#endif
289
290			#if !HAVE_READAHEAD
291			# define readahead aio_readahead
292
293			static char readahead_buf[4096];
294
295			static ssize_t
296			readahead (int fd, off_t offset, size_t count)
297			{
298			while (count > 0)
299			{
300			size_t len = count < sizeof (readahead_buf) ? count : sizeof (readahead_buf);
301
302			pread (fd, readahead_buf, len, offset);
303			offset += len;
304			count -= len;
305			}
306
307			errno = 0;
308			}
309			#endif
310
311	root	1.1	static void *
312			aio_proc (void *thr_arg)
313			{
314			aio_req req;
315	root	1.3	int type;
316	root	1.1
317	root	1.3	do
318	root	1.1	{
319	root	1.3	pthread_mutex_lock (&reqlock);
320
321			for (;;)
322			{
323			req = reqs;
324
325			if (reqs)
326			{
327			reqs = reqs->next;
328			if (!reqs) reqe = 0;
329			}
330
331			if (req)
332			break;
333
334			pthread_cond_wait (&reqwait, &reqlock);
335			}
336
337			pthread_mutex_unlock (&reqlock);
338
339	root	1.1	errno = 0; /* strictly unnecessary */
340
341	root	1.3	type = req->type;
342
343			switch (type)
344	root	1.1	{
345	root	1.10	case REQ_READ: req->result = pread (req->fd, req->dataptr, req->length, req->offset); break;
346			case REQ_WRITE: req->result = pwrite (req->fd, req->dataptr, req->length, req->offset); break;
347	root	1.16
348	root	1.1	case REQ_READAHEAD: req->result = readahead (req->fd, req->offset, req->length); break;
349
350			case REQ_STAT: req->result = stat (req->dataptr, req->statdata); break;
351			case REQ_LSTAT: req->result = lstat (req->dataptr, req->statdata); break;
352			case REQ_FSTAT: req->result = fstat (req->fd , req->statdata); break;
353
354			case REQ_OPEN: req->result = open (req->dataptr, req->fd, req->mode); break;
355			case REQ_CLOSE: req->result = close (req->fd); break;
356			case REQ_UNLINK: req->result = unlink (req->dataptr); break;
357
358	root	1.17	case REQ_FDATASYNC: req->result = fdatasync (req->fd); break;
359	root	1.1	case REQ_FSYNC: req->result = fsync (req->fd); break;
360
361			case REQ_QUIT:
362	root	1.3	break;
363	root	1.1
364			default:
365			req->result = ENOSYS;
366			break;
367			}
368
369			req->errorno = errno;
370	root	1.3
371			pthread_mutex_lock (&reslock);
372
373			req->next = 0;
374
375			if (rese)
376			{
377			rese->next = req;
378			rese = req;
379			}
380			else
381			{
382			rese = ress = req;
383
384			/* write a dummy byte to the pipe so fh becomes ready */
385			write (respipe [1], &respipe, 1);
386			}
387
388			pthread_mutex_unlock (&reslock);
389	root	1.1	}
390	root	1.3	while (type != REQ_QUIT);
391	root	1.1
392			return 0;
393			}
394
395			MODULE = IO::AIO PACKAGE = IO::AIO
396
397	root	1.8	PROTOTYPES: ENABLE
398
399	root	1.1	BOOT:
400			{
401	root	1.3	if (pipe (respipe))
402			croak ("unable to initialize result pipe");
403	root	1.1
404	root	1.3	if (fcntl (respipe [0], F_SETFL, O_NONBLOCK))
405	root	1.1	croak ("cannot set result pipe to nonblocking mode");
406
407	root	1.3	if (fcntl (respipe [1], F_SETFL, O_NONBLOCK))
408	root	1.1	croak ("cannot set result pipe to nonblocking mode");
409			}
410
411			void
412			min_parallel(nthreads)
413			int nthreads
414			PROTOTYPE: $
415			CODE:
416			while (nthreads > started)
417			start_thread ();
418
419			void
420			max_parallel(nthreads)
421			int nthreads
422			PROTOTYPE: $
423			CODE:
424			{
425			int cur = started;
426			while (cur > nthreads)
427			{
428			end_thread ();
429			cur--;
430			}
431
432			while (started > nthreads)
433			{
434			poll_wait ();
435	root	1.5	poll_cb ();
436	root	1.1	}
437			}
438
439	root	1.4	int
440			max_outstanding(nreqs)
441			int nreqs
442			PROTOTYPE: $
443			CODE:
444			RETVAL = max_outstanding;
445			max_outstanding = nreqs;
446
447	root	1.1	void
448	root	1.8	aio_open(pathname,flags,mode,callback=&PL_sv_undef)
449	root	1.1	SV * pathname
450			int flags
451			int mode
452			SV * callback
453	root	1.8	PROTOTYPE: $$$;$
454	root	1.1	CODE:
455			{
456			aio_req req;
457
458			Newz (0, req, 1, aio_cb);
459
460			if (!req)
461			croak ("out of memory during aio_req allocation");
462
463			req->type = REQ_OPEN;
464			req->data = newSVsv (pathname);
465			req->dataptr = SvPV_nolen (req->data);
466			req->fd = flags;
467			req->mode = mode;
468			req->callback = SvREFCNT_inc (callback);
469
470			send_req (req);
471			}
472
473			void
474	root	1.8	aio_close(fh,callback=&PL_sv_undef)
475	root	1.13	SV * fh
476			SV * callback
477	root	1.8	PROTOTYPE: $;$
478	root	1.1	ALIAS:
479			aio_close = REQ_CLOSE
480			aio_fsync = REQ_FSYNC
481			aio_fdatasync = REQ_FDATASYNC
482			CODE:
483			{
484			aio_req req;
485
486			Newz (0, req, 1, aio_cb);
487
488			if (!req)
489			croak ("out of memory during aio_req allocation");
490
491			req->type = ix;
492	root	1.13	req->fh = newSVsv (fh);
493			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
494	root	1.1	req->callback = SvREFCNT_inc (callback);
495
496			send_req (req);
497			}
498
499			void
500	root	1.8	aio_read(fh,offset,length,data,dataoffset,callback=&PL_sv_undef)
501	root	1.13	SV * fh
502			UV offset
503			IV length
504			SV * data
505			IV dataoffset
506			SV * callback
507			ALIAS:
508			aio_read = REQ_READ
509			aio_write = REQ_WRITE
510	root	1.8	PROTOTYPE: $$$$$;$
511	root	1.1	CODE:
512	root	1.13	{
513			aio_req req;
514			STRLEN svlen;
515			char *svptr = SvPV (data, svlen);
516
517			SvUPGRADE (data, SVt_PV);
518			SvPOK_on (data);
519	root	1.1
520	root	1.13	if (dataoffset < 0)
521			dataoffset += svlen;
522
523			if (dataoffset < 0 \|\| dataoffset > svlen)
524			croak ("data offset outside of string");
525
526			if (ix == REQ_WRITE)
527			{
528			/* write: check length and adjust. */
529			if (length < 0 \|\| length + dataoffset > svlen)
530			length = svlen - dataoffset;
531			}
532			else
533			{
534			/* read: grow scalar as necessary */
535			svptr = SvGROW (data, length + dataoffset);
536			}
537
538			if (length < 0)
539			croak ("length must not be negative");
540
541			Newz (0, req, 1, aio_cb);
542
543			if (!req)
544			croak ("out of memory during aio_req allocation");
545
546			req->type = ix;
547			req->fh = newSVsv (fh);
548			req->fd = PerlIO_fileno (ix == REQ_READ ? IoIFP (sv_2io (fh))
549			: IoOFP (sv_2io (fh)));
550			req->offset = offset;
551			req->length = length;
552			req->data = SvREFCNT_inc (data);
553			req->dataptr = (char *)svptr + dataoffset;
554			req->callback = SvREFCNT_inc (callback);
555
556			send_req (req);
557			}
558	root	1.1
559			void
560	root	1.8	aio_readahead(fh,offset,length,callback=&PL_sv_undef)
561	root	1.13	SV * fh
562			UV offset
563			IV length
564			SV * callback
565	root	1.8	PROTOTYPE: $$$;$
566	root	1.1	CODE:
567			{
568			aio_req req;
569
570			if (length < 0)
571			croak ("length must not be negative");
572
573			Newz (0, req, 1, aio_cb);
574
575			if (!req)
576			croak ("out of memory during aio_req allocation");
577
578			req->type = REQ_READAHEAD;
579	root	1.13	req->fh = newSVsv (fh);
580			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
581	root	1.1	req->offset = offset;
582			req->length = length;
583			req->callback = SvREFCNT_inc (callback);
584
585			send_req (req);
586			}
587
588			void
589	root	1.8	aio_stat(fh_or_path,callback=&PL_sv_undef)
590	root	1.1	SV * fh_or_path
591			SV * callback
592			ALIAS:
593	root	1.8	aio_stat = REQ_STAT
594			aio_lstat = REQ_LSTAT
595	root	1.1	CODE:
596			{
597			aio_req req;
598
599			Newz (0, req, 1, aio_cb);
600
601			if (!req)
602			croak ("out of memory during aio_req allocation");
603
604			New (0, req->statdata, 1, Stat_t);
605
606			if (!req->statdata)
607			croak ("out of memory during aio_req->statdata allocation");
608
609			if (SvPOK (fh_or_path))
610			{
611	root	1.8	req->type = ix;
612	root	1.1	req->data = newSVsv (fh_or_path);
613			req->dataptr = SvPV_nolen (req->data);
614			}
615			else
616			{
617			req->type = REQ_FSTAT;
618	root	1.13	req->fh = newSVsv (fh_or_path);
619	root	1.1	req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
620			}
621
622			req->callback = SvREFCNT_inc (callback);
623
624			send_req (req);
625			}
626
627			void
628	root	1.8	aio_unlink(pathname,callback=&PL_sv_undef)
629	root	1.1	SV * pathname
630			SV * callback
631			CODE:
632			{
633			aio_req req;
634
635			Newz (0, req, 1, aio_cb);
636
637			if (!req)
638			croak ("out of memory during aio_req allocation");
639
640			req->type = REQ_UNLINK;
641			req->data = newSVsv (pathname);
642			req->dataptr = SvPV_nolen (req->data);
643			req->callback = SvREFCNT_inc (callback);
644
645			send_req (req);
646			}
647
648	root	1.6	void
649			flush()
650			PROTOTYPE:
651			CODE:
652			while (nreqs)
653			{
654			poll_wait ();
655			poll_cb ();
656			}
657
658	root	1.7	void
659			poll()
660			PROTOTYPE:
661			CODE:
662			if (nreqs)
663			{
664			poll_wait ();
665			poll_cb ();
666			}
667
668	root	1.1	int
669			poll_fileno()
670			PROTOTYPE:
671			CODE:
672	root	1.3	RETVAL = respipe [0];
673	root	1.1	OUTPUT:
674			RETVAL
675
676			int
677			poll_cb(...)
678			PROTOTYPE:
679			CODE:
680	root	1.5	RETVAL = poll_cb ();
681	root	1.1	OUTPUT:
682			RETVAL
683
684			void
685			poll_wait()
686			PROTOTYPE:
687			CODE:
688	root	1.3	if (nreqs)
689			poll_wait ();
690	root	1.1
691			int
692			nreqs()
693			PROTOTYPE:
694			CODE:
695			RETVAL = nreqs;
696			OUTPUT:
697			RETVAL
698