IO-AIO/AIO.xs

#define _REENTRANT 1
#include <errno.h>

#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_FSYNC, REQ_FDATASYNC,
  REQ_UNLINK, REQ_RMDIR,
  REQ_SYMLINK,
};

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, *data2ptr;
  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 free_req (aio_req req)
{
  if (req->data)
    SvREFCNT_dec (req->data);

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

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

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

  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)
            {
              rese = 0;

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

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

              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)
{
  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)
{
  while (nthreads > started)
    start_thread ();
}

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

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

  while (started > nthreads)
    {
      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");
}

static void atfork_prepare (void)
{
  for (;;) {

    for (;;)
      {
        poll_cb ();

        if (!nreqs)
          break;

        poll_wait ();
      }

    pthread_mutex_lock (&reqlock);

    if (!nreqs)
      break;

    pthread_mutex_unlock (&reqlock);
  }

  pthread_mutex_lock (&reslock);

  assert (!nreqs && !reqs && !ress);
}

static void atfork_parent (void)
{
  pthread_mutex_unlock (&reslock);
  pthread_mutex_unlock (&reqlock);
}

static void atfork_child (void)
{
  int restart = started;
  started = 0;

  atfork_parent ();

  min_parallel (restart);
}

/*****************************************************************************/
/* 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_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_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;
}

#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
        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 = 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;

          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
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:	1.27
Committed:	Wed Aug 17 04:47:02 2005 UTC (18 years, 9 months ago) by root
Branch:	MAIN
Changes since 1.26:	+70 -59 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.20	#define _REENTRANT 1
2	root	1.19	#include <errno.h>
3
4	root	1.15	#include "EXTERN.h"
5	root	1.1	#include "perl.h"
6			#include "XSUB.h"
7
8	root	1.16	#include "autoconf/config.h"
9
10	root	1.1	#include <sys/types.h>
11			#include <sys/stat.h>
12	root	1.10
13	root	1.1	#include <unistd.h>
14			#include <fcntl.h>
15			#include <signal.h>
16			#include <sched.h>
17
18			#include <pthread.h>
19
20			typedef void InputStream; / hack, but 5.6.1 is simply toooo old ;) */
21			typedef void OutputStream; / hack, but 5.6.1 is simply toooo old ;) */
22			typedef void InOutStream; / hack, but 5.6.1 is simply toooo old ;) */
23
24	root	1.4	#if __ia64
25			# define STACKSIZE 65536
26	root	1.1	#else
27	root	1.4	# define STACKSIZE 4096
28	root	1.1	#endif
29
30			enum {
31			REQ_QUIT,
32			REQ_OPEN, REQ_CLOSE,
33			REQ_READ, REQ_WRITE, REQ_READAHEAD,
34	root	1.22	REQ_STAT, REQ_LSTAT, REQ_FSTAT,
35	root	1.1	REQ_FSYNC, REQ_FDATASYNC,
36	root	1.23	REQ_UNLINK, REQ_RMDIR,
37	root	1.22	REQ_SYMLINK,
38	root	1.1	};
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	1.22	void dataptr, data2ptr;
53	root	1.1	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	root	1.26	static void free_req (aio_req req)
73			{
74			if (req->data)
75			SvREFCNT_dec (req->data);
76
77			if (req->fh)
78			SvREFCNT_dec (req->fh);
79
80	root	1.27	if (req->statdata)
81	root	1.26	Safefree (req->statdata);
82
83			if (req->callback)
84			SvREFCNT_dec (req->callback);
85
86			Safefree (req);
87			}
88
89	root	1.1	static void
90			poll_wait ()
91			{
92	root	1.11	if (nreqs && !ress)
93			{
94			fd_set rfd;
95			FD_ZERO(&rfd);
96			FD_SET(respipe [0], &rfd);
97	root	1.3
98	root	1.11	select (respipe [0] + 1, &rfd, 0, 0, 0);
99			}
100	root	1.1	}
101
102			static int
103	root	1.5	poll_cb ()
104	root	1.1	{
105			dSP;
106			int count = 0;
107	root	1.24	int do_croak = 0;
108	root	1.27	aio_req req;
109
110			for (;;)
111			{
112			pthread_mutex_lock (&reslock);
113			req = ress;
114
115			if (req)
116			{
117			ress = req->next;
118	root	1.11
119	root	1.27	if (!ress)
120			{
121			rese = 0;
122	root	1.11
123	root	1.27	/* read any signals sent by the worker threads */
124			char buf [32];
125			while (read (respipe [0], buf, 32) == 32)
126			;
127			}
128			}
129	root	1.1
130	root	1.27	pthread_mutex_unlock (&reslock);
131	root	1.3
132	root	1.27	if (!req)
133			break;
134	root	1.3
135	root	1.1	nreqs--;
136
137			if (req->type == REQ_QUIT)
138			started--;
139			else
140			{
141			int errorno = errno;
142			errno = req->errorno;
143
144			if (req->type == REQ_READ)
145	root	1.27	SvCUR_set (req->data, req->dataoffset + (req->result > 0 ? req->result : 0));
146	root	1.1
147	root	1.27	if (req->statdata)
148	root	1.1	{
149			PL_laststype = req->type == REQ_LSTAT ? OP_LSTAT : OP_STAT;
150			PL_laststatval = req->result;
151			PL_statcache = *(req->statdata);
152			}
153
154	root	1.13	ENTER;
155	root	1.1	PUSHMARK (SP);
156			XPUSHs (sv_2mortal (newSViv (req->result)));
157	root	1.2
158			if (req->type == REQ_OPEN)
159			{
160			/* convert fd to fh */
161			SV *fh;
162
163			PUTBACK;
164			call_pv ("IO::AIO::_fd2fh", G_SCALAR \| G_EVAL);
165			SPAGAIN;
166
167	root	1.13	fh = SvREFCNT_inc (POPs);
168	root	1.2
169			PUSHMARK (SP);
170	root	1.13	XPUSHs (sv_2mortal (fh));
171	root	1.2	}
172
173	root	1.8	if (SvOK (req->callback))
174			{
175			PUTBACK;
176			call_sv (req->callback, G_VOID \| G_EVAL);
177			SPAGAIN;
178	root	1.27
179			if (SvTRUE (ERRSV))
180			{
181			free_req (req);
182			croak (0);
183			}
184	root	1.8	}
185	root	1.13
186	root	1.26	LEAVE;
187
188	root	1.1	errno = errorno;
189			count++;
190			}
191
192	root	1.27	free_req (req);
193	root	1.1	}
194
195			return count;
196			}
197
198	root	1.4	static void aio_proc(void arg);
199
200			static void
201			start_thread (void)
202			{
203			sigset_t fullsigset, oldsigset;
204			pthread_t tid;
205			pthread_attr_t attr;
206
207			pthread_attr_init (&attr);
208			pthread_attr_setstacksize (&attr, STACKSIZE);
209			pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
210
211			sigfillset (&fullsigset);
212			sigprocmask (SIG_SETMASK, &fullsigset, &oldsigset);
213
214			if (pthread_create (&tid, &attr, aio_proc, 0) == 0)
215			started++;
216
217			sigprocmask (SIG_SETMASK, &oldsigset, 0);
218			}
219
220			static void
221			send_req (aio_req req)
222			{
223			nreqs++;
224
225			pthread_mutex_lock (&reqlock);
226
227			req->next = 0;
228
229			if (reqe)
230			{
231			reqe->next = req;
232			reqe = req;
233			}
234			else
235			reqe = reqs = req;
236
237			pthread_cond_signal (&reqwait);
238			pthread_mutex_unlock (&reqlock);
239
240	root	1.27	if (nreqs > max_outstanding)
241			for (;;)
242			{
243			poll_cb ();
244
245			if (nreqs <= max_outstanding)
246			break;
247
248			poll_wait ();
249			}
250	root	1.4	}
251
252			static void
253			end_thread (void)
254			{
255			aio_req req;
256	root	1.26	Newz (0, req, 1, aio_cb);
257	root	1.4	req->type = REQ_QUIT;
258
259			send_req (req);
260			}
261
262	root	1.22	static void min_parallel (int nthreads)
263			{
264			while (nthreads > started)
265			start_thread ();
266			}
267
268			static void max_parallel (int nthreads)
269			{
270			int cur = started;
271	root	1.27
272	root	1.22	while (cur > nthreads)
273			{
274			end_thread ();
275			cur--;
276			}
277
278			while (started > nthreads)
279			{
280			poll_wait ();
281			poll_cb ();
282			}
283			}
284
285	root	1.26	static void create_pipe ()
286	root	1.22	{
287	root	1.26	if (pipe (respipe))
288			croak ("unable to initialize result pipe");
289	root	1.22
290	root	1.26	if (fcntl (respipe [0], F_SETFL, O_NONBLOCK))
291			croak ("cannot set result pipe to nonblocking mode");
292	root	1.22
293	root	1.26	if (fcntl (respipe [1], F_SETFL, O_NONBLOCK))
294			croak ("cannot set result pipe to nonblocking mode");
295			}
296	root	1.22
297	root	1.26	static void atfork_prepare (void)
298			{
299	root	1.27	for (;;) {
300
301			for (;;)
302			{
303			poll_cb ();
304
305			if (!nreqs)
306			break;
307
308			poll_wait ();
309			}
310
311			pthread_mutex_lock (&reqlock);
312
313			if (!nreqs)
314			break;
315
316			pthread_mutex_unlock (&reqlock);
317			}
318
319	root	1.22	pthread_mutex_lock (&reslock);
320	root	1.27
321			assert (!nreqs && !reqs && !ress);
322	root	1.22	}
323
324			static void atfork_parent (void)
325			{
326			pthread_mutex_unlock (&reslock);
327	root	1.26	pthread_mutex_unlock (&reqlock);
328			}
329
330			static void atfork_child (void)
331			{
332			int restart = started;
333			started = 0;
334
335			atfork_parent ();
336	root	1.25
337	root	1.26	min_parallel (restart);
338	root	1.22	}
339
340			/*****************************************************************************/
341	root	1.17	/* work around various missing functions */
342
343			#if !HAVE_PREADWRITE
344			# define pread aio_pread
345			# define pwrite aio_pwrite
346
347			/*
348			* make our pread/pwrite safe against themselves, but not against
349			* normal read/write by using a mutex. slows down execution a lot,
350			* but that's your problem, not mine.
351			*/
352			static pthread_mutex_t iolock = PTHREAD_MUTEX_INITIALIZER;
353
354			static ssize_t
355			pread (int fd, void *buf, size_t count, off_t offset)
356			{
357			ssize_t res;
358			off_t ooffset;
359
360			pthread_mutex_lock (&iolock);
361			ooffset = lseek (fd, 0, SEEK_CUR);
362			lseek (fd, offset, SEEK_SET);
363			res = read (fd, buf, count);
364			lseek (fd, ooffset, SEEK_SET);
365			pthread_mutex_unlock (&iolock);
366
367			return res;
368			}
369
370			static ssize_t
371			pwrite (int fd, void *buf, size_t count, off_t offset)
372			{
373			ssize_t res;
374			off_t ooffset;
375
376			pthread_mutex_lock (&iolock);
377			ooffset = lseek (fd, 0, SEEK_CUR);
378			lseek (fd, offset, SEEK_SET);
379			res = write (fd, buf, count);
380			lseek (fd, offset, SEEK_SET);
381			pthread_mutex_unlock (&iolock);
382
383			return res;
384			}
385			#endif
386
387			#if !HAVE_FDATASYNC
388			# define fdatasync fsync
389			#endif
390
391			#if !HAVE_READAHEAD
392			# define readahead aio_readahead
393
394			static char readahead_buf[4096];
395
396			static ssize_t
397			readahead (int fd, off_t offset, size_t count)
398			{
399			while (count > 0)
400			{
401			size_t len = count < sizeof (readahead_buf) ? count : sizeof (readahead_buf);
402
403			pread (fd, readahead_buf, len, offset);
404			offset += len;
405			count -= len;
406			}
407
408			errno = 0;
409			}
410			#endif
411
412	root	1.22	/*****************************************************************************/
413
414	root	1.1	static void *
415			aio_proc (void *thr_arg)
416			{
417			aio_req req;
418	root	1.3	int type;
419	root	1.1
420	root	1.3	do
421	root	1.1	{
422	root	1.3	pthread_mutex_lock (&reqlock);
423
424			for (;;)
425			{
426			req = reqs;
427
428			if (reqs)
429			{
430			reqs = reqs->next;
431			if (!reqs) reqe = 0;
432			}
433
434			if (req)
435			break;
436
437			pthread_cond_wait (&reqwait, &reqlock);
438			}
439
440			pthread_mutex_unlock (&reqlock);
441
442	root	1.1	errno = 0; /* strictly unnecessary */
443
444	root	1.3	type = req->type;
445
446			switch (type)
447	root	1.1	{
448	root	1.10	case REQ_READ: req->result = pread (req->fd, req->dataptr, req->length, req->offset); break;
449			case REQ_WRITE: req->result = pwrite (req->fd, req->dataptr, req->length, req->offset); break;
450	root	1.16
451	root	1.1	case REQ_READAHEAD: req->result = readahead (req->fd, req->offset, req->length); break;
452
453			case REQ_STAT: req->result = stat (req->dataptr, req->statdata); break;
454			case REQ_LSTAT: req->result = lstat (req->dataptr, req->statdata); break;
455			case REQ_FSTAT: req->result = fstat (req->fd , req->statdata); break;
456
457			case REQ_OPEN: req->result = open (req->dataptr, req->fd, req->mode); break;
458			case REQ_CLOSE: req->result = close (req->fd); break;
459			case REQ_UNLINK: req->result = unlink (req->dataptr); break;
460	root	1.22	case REQ_RMDIR: req->result = rmdir (req->dataptr); break;
461			case REQ_SYMLINK: req->result = symlink (req->data2ptr, req->dataptr); break;
462	root	1.1
463	root	1.17	case REQ_FDATASYNC: req->result = fdatasync (req->fd); break;
464	root	1.1	case REQ_FSYNC: req->result = fsync (req->fd); break;
465
466			case REQ_QUIT:
467	root	1.3	break;
468	root	1.1
469			default:
470			req->result = ENOSYS;
471			break;
472			}
473
474			req->errorno = errno;
475	root	1.3
476			pthread_mutex_lock (&reslock);
477
478			req->next = 0;
479
480			if (rese)
481			{
482			rese->next = req;
483			rese = req;
484			}
485			else
486			{
487			rese = ress = req;
488
489			/* write a dummy byte to the pipe so fh becomes ready */
490			write (respipe [1], &respipe, 1);
491			}
492
493			pthread_mutex_unlock (&reslock);
494	root	1.1	}
495	root	1.3	while (type != REQ_QUIT);
496	root	1.1
497			return 0;
498			}
499
500	root	1.22	#define dREQ \
501			aio_req req; \
502			\
503			if (SvOK (callback) && !SvROK (callback)) \
504			croak ("clalback must be undef or of reference type"); \
505			\
506			Newz (0, req, 1, aio_cb); \
507			if (!req) \
508			croak ("out of memory during aio_req allocation"); \
509			\
510	root	1.27	req->callback = newSVsv (callback);
511	root	1.22
512	root	1.1	MODULE = IO::AIO PACKAGE = IO::AIO
513
514	root	1.8	PROTOTYPES: ENABLE
515
516	root	1.1	BOOT:
517			{
518	root	1.26	create_pipe ();
519	root	1.22	pthread_atfork (atfork_prepare, atfork_parent, atfork_child);
520	root	1.1	}
521
522			void
523			min_parallel(nthreads)
524			int nthreads
525			PROTOTYPE: $
526
527			void
528			max_parallel(nthreads)
529			int nthreads
530			PROTOTYPE: $
531
532	root	1.4	int
533			max_outstanding(nreqs)
534			int nreqs
535			PROTOTYPE: $
536			CODE:
537			RETVAL = max_outstanding;
538			max_outstanding = nreqs;
539
540	root	1.1	void
541	root	1.8	aio_open(pathname,flags,mode,callback=&PL_sv_undef)
542	root	1.1	SV * pathname
543			int flags
544			int mode
545			SV * callback
546	root	1.8	PROTOTYPE: $$$;$
547	root	1.1	CODE:
548			{
549	root	1.22	dREQ;
550	root	1.1
551			req->type = REQ_OPEN;
552			req->data = newSVsv (pathname);
553	root	1.22	req->dataptr = SvPVbyte_nolen (req->data);
554	root	1.1	req->fd = flags;
555			req->mode = mode;
556
557			send_req (req);
558			}
559
560			void
561	root	1.8	aio_close(fh,callback=&PL_sv_undef)
562	root	1.13	SV * fh
563			SV * callback
564	root	1.8	PROTOTYPE: $;$
565	root	1.1	ALIAS:
566			aio_close = REQ_CLOSE
567			aio_fsync = REQ_FSYNC
568			aio_fdatasync = REQ_FDATASYNC
569			CODE:
570			{
571	root	1.22	dREQ;
572	root	1.1
573			req->type = ix;
574	root	1.13	req->fh = newSVsv (fh);
575			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
576	root	1.1
577			send_req (req);
578			}
579
580			void
581	root	1.8	aio_read(fh,offset,length,data,dataoffset,callback=&PL_sv_undef)
582	root	1.13	SV * fh
583			UV offset
584			IV length
585			SV * data
586			IV dataoffset
587			SV * callback
588			ALIAS:
589			aio_read = REQ_READ
590			aio_write = REQ_WRITE
591	root	1.8	PROTOTYPE: $$$$$;$
592	root	1.1	CODE:
593	root	1.13	{
594			aio_req req;
595			STRLEN svlen;
596	root	1.21	char *svptr = SvPVbyte (data, svlen);
597	root	1.13
598			SvUPGRADE (data, SVt_PV);
599			SvPOK_on (data);
600	root	1.1
601	root	1.13	if (dataoffset < 0)
602			dataoffset += svlen;
603
604			if (dataoffset < 0 \|\| dataoffset > svlen)
605			croak ("data offset outside of string");
606
607			if (ix == REQ_WRITE)
608			{
609			/* write: check length and adjust. */
610			if (length < 0 \|\| length + dataoffset > svlen)
611			length = svlen - dataoffset;
612			}
613			else
614			{
615			/* read: grow scalar as necessary */
616			svptr = SvGROW (data, length + dataoffset);
617			}
618
619			if (length < 0)
620			croak ("length must not be negative");
621
622	root	1.22	{
623			dREQ;
624	root	1.13
625	root	1.22	req->type = ix;
626			req->fh = newSVsv (fh);
627			req->fd = PerlIO_fileno (ix == REQ_READ ? IoIFP (sv_2io (fh))
628			: IoOFP (sv_2io (fh)));
629			req->offset = offset;
630			req->length = length;
631			req->data = SvREFCNT_inc (data);
632			req->dataptr = (char *)svptr + dataoffset;
633	root	1.13
634	root	1.22	send_req (req);
635			}
636	root	1.13	}
637	root	1.1
638			void
639	root	1.8	aio_readahead(fh,offset,length,callback=&PL_sv_undef)
640	root	1.13	SV * fh
641			UV offset
642			IV length
643			SV * callback
644	root	1.8	PROTOTYPE: $$$;$
645	root	1.1	CODE:
646			{
647	root	1.22	dREQ;
648	root	1.1
649			req->type = REQ_READAHEAD;
650	root	1.13	req->fh = newSVsv (fh);
651			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
652	root	1.1	req->offset = offset;
653			req->length = length;
654
655			send_req (req);
656			}
657
658			void
659	root	1.8	aio_stat(fh_or_path,callback=&PL_sv_undef)
660	root	1.1	SV * fh_or_path
661			SV * callback
662			ALIAS:
663	root	1.8	aio_stat = REQ_STAT
664			aio_lstat = REQ_LSTAT
665	root	1.1	CODE:
666			{
667	root	1.22	dREQ;
668	root	1.1
669			New (0, req->statdata, 1, Stat_t);
670			if (!req->statdata)
671	root	1.27	{
672			free_req (req);
673			croak ("out of memory during aio_req->statdata allocation");
674			}
675	root	1.1
676			if (SvPOK (fh_or_path))
677			{
678	root	1.8	req->type = ix;
679	root	1.1	req->data = newSVsv (fh_or_path);
680	root	1.22	req->dataptr = SvPVbyte_nolen (req->data);
681	root	1.1	}
682			else
683			{
684			req->type = REQ_FSTAT;
685	root	1.13	req->fh = newSVsv (fh_or_path);
686	root	1.1	req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
687			}
688
689			send_req (req);
690			}
691
692			void
693	root	1.8	aio_unlink(pathname,callback=&PL_sv_undef)
694	root	1.1	SV * pathname
695			SV * callback
696	root	1.22	ALIAS:
697			aio_unlink = REQ_UNLINK
698			aio_rmdir = REQ_RMDIR
699	root	1.1	CODE:
700			{
701	root	1.22	dREQ;
702	root	1.1
703	root	1.22	req->type = ix;
704			req->data = newSVsv (pathname);
705			req->dataptr = SvPVbyte_nolen (req->data);
706	root	1.1
707	root	1.22	send_req (req);
708			}
709
710			void
711			aio_symlink(oldpath,newpath,callback=&PL_sv_undef)
712			SV * oldpath
713			SV * newpath
714			SV * callback
715			CODE:
716			{
717			dREQ;
718	root	1.1
719	root	1.22	req->type = REQ_SYMLINK;
720			req->fh = newSVsv (oldpath);
721			req->data2ptr = SvPVbyte_nolen (req->fh);
722			req->data = newSVsv (newpath);
723			req->dataptr = SvPVbyte_nolen (req->data);
724	root	1.1
725			send_req (req);
726			}
727
728	root	1.6	void
729			flush()
730			PROTOTYPE:
731			CODE:
732			while (nreqs)
733			{
734			poll_wait ();
735			poll_cb ();
736			}
737
738	root	1.7	void
739			poll()
740			PROTOTYPE:
741			CODE:
742			if (nreqs)
743			{
744			poll_wait ();
745			poll_cb ();
746			}
747
748	root	1.1	int
749			poll_fileno()
750			PROTOTYPE:
751			CODE:
752	root	1.3	RETVAL = respipe [0];
753	root	1.1	OUTPUT:
754			RETVAL
755
756			int
757			poll_cb(...)
758			PROTOTYPE:
759			CODE:
760	root	1.5	RETVAL = poll_cb ();
761	root	1.1	OUTPUT:
762			RETVAL
763
764			void
765			poll_wait()
766			PROTOTYPE:
767			CODE:
768	root	1.3	if (nreqs)
769			poll_wait ();
770	root	1.1
771			int
772			nreqs()
773			PROTOTYPE:
774			CODE:
775			RETVAL = nreqs;
776			OUTPUT:
777			RETVAL
778