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_mutex_t frklock = 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->type == REQ_STAT || req->type == REQ_LSTAT || req->type == REQ_FSTAT)
    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, prv;

  pthread_mutex_lock (&reslock);

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

  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->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);
            }

          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;

          do_croak = SvTRUE (ERRSV);
          
          errno = errorno;
          count++;
        }

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

      if (do_croak)
        croak (0);
    }

  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;
  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)
{
  pthread_mutex_lock (&frklock);
  pthread_mutex_lock (&reqlock);
  pthread_mutex_lock (&reslock);
}

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

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

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

  reqs = reqe = 0;

  while (ress)
    {
      free_req (ress);
      ress = ress->next;
    }

  ress = rese = 0;

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

  create_pipe ();

  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 = SvREFCNT_inc (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;
          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:
{
        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)
          croak ("out of memory during aio_req->statdata allocation (sorry, i just leaked memory, too)");

        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:	1.26
Committed:	Wed Aug 17 03:52:20 2005 UTC (18 years, 9 months ago) by root
Branch:	MAIN
Changes since 1.25:	+64 -56 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	root	1.22	static pthread_mutex_t frklock = PTHREAD_MUTEX_INITIALIZER;
68	root	1.3	static pthread_cond_t reqwait = PTHREAD_COND_INITIALIZER;
69
70			static volatile aio_req reqs, reqe; /* queue start, queue end */
71			static volatile aio_req ress, rese; /* queue start, queue end */
72	root	1.1
73	root	1.26	static void free_req (aio_req req)
74			{
75			if (req->data)
76			SvREFCNT_dec (req->data);
77
78			if (req->fh)
79			SvREFCNT_dec (req->fh);
80
81			if (req->type == REQ_STAT \|\| req->type == REQ_LSTAT \|\| req->type == REQ_FSTAT)
82			Safefree (req->statdata);
83
84			if (req->callback)
85			SvREFCNT_dec (req->callback);
86
87			Safefree (req);
88			}
89
90	root	1.1	static void
91			poll_wait ()
92			{
93	root	1.11	if (nreqs && !ress)
94			{
95			fd_set rfd;
96			FD_ZERO(&rfd);
97			FD_SET(respipe [0], &rfd);
98	root	1.3
99	root	1.11	select (respipe [0] + 1, &rfd, 0, 0, 0);
100			}
101	root	1.1	}
102
103			static int
104	root	1.5	poll_cb ()
105	root	1.1	{
106			dSP;
107			int count = 0;
108	root	1.24	int do_croak = 0;
109	root	1.11	aio_req req, prv;
110
111			pthread_mutex_lock (&reslock);
112
113	root	1.3	{
114	root	1.11	/* read any signals sent by the worker threads */
115	root	1.3	char buf [32];
116	root	1.22	while (read (respipe [0], buf, 32) == 32)
117	root	1.3	;
118			}
119	root	1.1
120	root	1.11	req = ress;
121			ress = rese = 0;
122	root	1.3
123	root	1.11	pthread_mutex_unlock (&reslock);
124	root	1.3
125	root	1.11	while (req)
126			{
127	root	1.1	nreqs--;
128
129			if (req->type == REQ_QUIT)
130			started--;
131			else
132			{
133			int errorno = errno;
134			errno = req->errorno;
135
136			if (req->type == REQ_READ)
137			SvCUR_set (req->data, req->dataoffset
138			+ req->result > 0 ? req->result : 0);
139
140			if (req->type == REQ_STAT \|\| req->type == REQ_LSTAT \|\| req->type == REQ_FSTAT)
141			{
142			PL_laststype = req->type == REQ_LSTAT ? OP_LSTAT : OP_STAT;
143			PL_laststatval = req->result;
144			PL_statcache = *(req->statdata);
145			}
146
147	root	1.13	ENTER;
148	root	1.1	PUSHMARK (SP);
149			XPUSHs (sv_2mortal (newSViv (req->result)));
150	root	1.2
151			if (req->type == REQ_OPEN)
152			{
153			/* convert fd to fh */
154			SV *fh;
155
156			PUTBACK;
157			call_pv ("IO::AIO::_fd2fh", G_SCALAR \| G_EVAL);
158			SPAGAIN;
159
160	root	1.13	fh = SvREFCNT_inc (POPs);
161	root	1.2
162			PUSHMARK (SP);
163	root	1.13	XPUSHs (sv_2mortal (fh));
164	root	1.2	}
165
166	root	1.8	if (SvOK (req->callback))
167			{
168			PUTBACK;
169			call_sv (req->callback, G_VOID \| G_EVAL);
170			SPAGAIN;
171			}
172	root	1.13
173	root	1.26	LEAVE;
174
175	root	1.24	do_croak = SvTRUE (ERRSV);
176	root	1.1
177			errno = errorno;
178			count++;
179			}
180
181	root	1.11	prv = req;
182			req = req->next;
183	root	1.26	free_req (prv);
184	root	1.11
185	root	1.24	if (do_croak)
186			croak (0);
187	root	1.1	}
188
189			return count;
190			}
191
192	root	1.4	static void aio_proc(void arg);
193
194			static void
195			start_thread (void)
196			{
197			sigset_t fullsigset, oldsigset;
198			pthread_t tid;
199			pthread_attr_t attr;
200
201			pthread_attr_init (&attr);
202			pthread_attr_setstacksize (&attr, STACKSIZE);
203			pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
204
205			sigfillset (&fullsigset);
206			sigprocmask (SIG_SETMASK, &fullsigset, &oldsigset);
207
208			if (pthread_create (&tid, &attr, aio_proc, 0) == 0)
209			started++;
210
211			sigprocmask (SIG_SETMASK, &oldsigset, 0);
212			}
213
214			static void
215			send_req (aio_req req)
216			{
217			nreqs++;
218
219			pthread_mutex_lock (&reqlock);
220
221			req->next = 0;
222
223			if (reqe)
224			{
225			reqe->next = req;
226			reqe = req;
227			}
228			else
229			reqe = reqs = req;
230
231			pthread_cond_signal (&reqwait);
232			pthread_mutex_unlock (&reqlock);
233
234			while (nreqs > max_outstanding)
235			{
236			poll_wait ();
237			poll_cb ();
238			}
239			}
240
241			static void
242			end_thread (void)
243			{
244			aio_req req;
245	root	1.26	Newz (0, req, 1, aio_cb);
246	root	1.4	req->type = REQ_QUIT;
247
248			send_req (req);
249			}
250
251	root	1.22
252			static void min_parallel (int nthreads)
253			{
254			while (nthreads > started)
255			start_thread ();
256			}
257
258			static void max_parallel (int nthreads)
259			{
260			int cur = started;
261			while (cur > nthreads)
262			{
263			end_thread ();
264			cur--;
265			}
266
267			while (started > nthreads)
268			{
269			poll_wait ();
270			poll_cb ();
271			}
272			}
273
274	root	1.26	static void create_pipe ()
275	root	1.22	{
276	root	1.26	if (pipe (respipe))
277			croak ("unable to initialize result pipe");
278	root	1.22
279	root	1.26	if (fcntl (respipe [0], F_SETFL, O_NONBLOCK))
280			croak ("cannot set result pipe to nonblocking mode");
281	root	1.22
282	root	1.26	if (fcntl (respipe [1], F_SETFL, O_NONBLOCK))
283			croak ("cannot set result pipe to nonblocking mode");
284			}
285	root	1.22
286	root	1.26	static void atfork_prepare (void)
287			{
288	root	1.25	pthread_mutex_lock (&frklock);
289	root	1.26	pthread_mutex_lock (&reqlock);
290	root	1.22	pthread_mutex_lock (&reslock);
291			}
292
293			static void atfork_parent (void)
294			{
295			pthread_mutex_unlock (&reslock);
296	root	1.26	pthread_mutex_unlock (&reqlock);
297	root	1.25	pthread_mutex_unlock (&frklock);
298	root	1.26	}
299
300			static void atfork_child (void)
301			{
302			int restart = started;
303			started = 0;
304
305			while (reqs)
306			{
307			free_req (reqs);
308			reqs = reqs->next;
309			}
310
311			reqs = reqe = 0;
312
313			while (ress)
314			{
315			free_req (ress);
316			ress = ress->next;
317			}
318
319			ress = rese = 0;
320
321			close (respipe [0]);
322			close (respipe [1]);
323
324			create_pipe ();
325
326			atfork_parent ();
327	root	1.25
328	root	1.26	min_parallel (restart);
329	root	1.22	}
330
331			/*****************************************************************************/
332	root	1.17	/* work around various missing functions */
333
334			#if !HAVE_PREADWRITE
335			# define pread aio_pread
336			# define pwrite aio_pwrite
337
338			/*
339			* make our pread/pwrite safe against themselves, but not against
340			* normal read/write by using a mutex. slows down execution a lot,
341			* but that's your problem, not mine.
342			*/
343			static pthread_mutex_t iolock = PTHREAD_MUTEX_INITIALIZER;
344
345			static ssize_t
346			pread (int fd, void *buf, size_t count, off_t offset)
347			{
348			ssize_t res;
349			off_t ooffset;
350
351			pthread_mutex_lock (&iolock);
352			ooffset = lseek (fd, 0, SEEK_CUR);
353			lseek (fd, offset, SEEK_SET);
354			res = read (fd, buf, count);
355			lseek (fd, ooffset, SEEK_SET);
356			pthread_mutex_unlock (&iolock);
357
358			return res;
359			}
360
361			static ssize_t
362			pwrite (int fd, void *buf, size_t count, off_t offset)
363			{
364			ssize_t res;
365			off_t ooffset;
366
367			pthread_mutex_lock (&iolock);
368			ooffset = lseek (fd, 0, SEEK_CUR);
369			lseek (fd, offset, SEEK_SET);
370			res = write (fd, buf, count);
371			lseek (fd, offset, SEEK_SET);
372			pthread_mutex_unlock (&iolock);
373
374			return res;
375			}
376			#endif
377
378			#if !HAVE_FDATASYNC
379			# define fdatasync fsync
380			#endif
381
382			#if !HAVE_READAHEAD
383			# define readahead aio_readahead
384
385			static char readahead_buf[4096];
386
387			static ssize_t
388			readahead (int fd, off_t offset, size_t count)
389			{
390			while (count > 0)
391			{
392			size_t len = count < sizeof (readahead_buf) ? count : sizeof (readahead_buf);
393
394			pread (fd, readahead_buf, len, offset);
395			offset += len;
396			count -= len;
397			}
398
399			errno = 0;
400			}
401			#endif
402
403	root	1.22	/*****************************************************************************/
404
405	root	1.1	static void *
406			aio_proc (void *thr_arg)
407			{
408			aio_req req;
409	root	1.3	int type;
410	root	1.1
411	root	1.3	do
412	root	1.1	{
413	root	1.3	pthread_mutex_lock (&reqlock);
414
415			for (;;)
416			{
417			req = reqs;
418
419			if (reqs)
420			{
421			reqs = reqs->next;
422			if (!reqs) reqe = 0;
423			}
424
425			if (req)
426			break;
427
428			pthread_cond_wait (&reqwait, &reqlock);
429			}
430
431			pthread_mutex_unlock (&reqlock);
432
433	root	1.1	errno = 0; /* strictly unnecessary */
434
435	root	1.3	type = req->type;
436
437			switch (type)
438	root	1.1	{
439	root	1.10	case REQ_READ: req->result = pread (req->fd, req->dataptr, req->length, req->offset); break;
440			case REQ_WRITE: req->result = pwrite (req->fd, req->dataptr, req->length, req->offset); break;
441	root	1.16
442	root	1.1	case REQ_READAHEAD: req->result = readahead (req->fd, req->offset, req->length); break;
443
444			case REQ_STAT: req->result = stat (req->dataptr, req->statdata); break;
445			case REQ_LSTAT: req->result = lstat (req->dataptr, req->statdata); break;
446			case REQ_FSTAT: req->result = fstat (req->fd , req->statdata); break;
447
448			case REQ_OPEN: req->result = open (req->dataptr, req->fd, req->mode); break;
449			case REQ_CLOSE: req->result = close (req->fd); break;
450			case REQ_UNLINK: req->result = unlink (req->dataptr); break;
451	root	1.22	case REQ_RMDIR: req->result = rmdir (req->dataptr); break;
452			case REQ_SYMLINK: req->result = symlink (req->data2ptr, req->dataptr); break;
453	root	1.1
454	root	1.17	case REQ_FDATASYNC: req->result = fdatasync (req->fd); break;
455	root	1.1	case REQ_FSYNC: req->result = fsync (req->fd); break;
456
457			case REQ_QUIT:
458	root	1.3	break;
459	root	1.1
460			default:
461			req->result = ENOSYS;
462			break;
463			}
464
465			req->errorno = errno;
466	root	1.3
467			pthread_mutex_lock (&reslock);
468
469			req->next = 0;
470
471			if (rese)
472			{
473			rese->next = req;
474			rese = req;
475			}
476			else
477			{
478			rese = ress = req;
479
480			/* write a dummy byte to the pipe so fh becomes ready */
481			write (respipe [1], &respipe, 1);
482			}
483
484			pthread_mutex_unlock (&reslock);
485	root	1.1	}
486	root	1.3	while (type != REQ_QUIT);
487	root	1.1
488			return 0;
489			}
490
491	root	1.22	#define dREQ \
492			aio_req req; \
493			\
494			if (SvOK (callback) && !SvROK (callback)) \
495			croak ("clalback must be undef or of reference type"); \
496			\
497			Newz (0, req, 1, aio_cb); \
498			if (!req) \
499			croak ("out of memory during aio_req allocation"); \
500			\
501			req->callback = SvREFCNT_inc (callback);
502
503	root	1.1	MODULE = IO::AIO PACKAGE = IO::AIO
504
505	root	1.8	PROTOTYPES: ENABLE
506
507	root	1.1	BOOT:
508			{
509	root	1.26	create_pipe ();
510	root	1.22	pthread_atfork (atfork_prepare, atfork_parent, atfork_child);
511	root	1.1	}
512
513			void
514			min_parallel(nthreads)
515			int nthreads
516			PROTOTYPE: $
517
518			void
519			max_parallel(nthreads)
520			int nthreads
521			PROTOTYPE: $
522
523	root	1.4	int
524			max_outstanding(nreqs)
525			int nreqs
526			PROTOTYPE: $
527			CODE:
528			RETVAL = max_outstanding;
529			max_outstanding = nreqs;
530
531	root	1.1	void
532	root	1.8	aio_open(pathname,flags,mode,callback=&PL_sv_undef)
533	root	1.1	SV * pathname
534			int flags
535			int mode
536			SV * callback
537	root	1.8	PROTOTYPE: $$$;$
538	root	1.1	CODE:
539			{
540	root	1.22	dREQ;
541	root	1.1
542			req->type = REQ_OPEN;
543			req->data = newSVsv (pathname);
544	root	1.22	req->dataptr = SvPVbyte_nolen (req->data);
545	root	1.1	req->fd = flags;
546			req->mode = mode;
547
548			send_req (req);
549			}
550
551			void
552	root	1.8	aio_close(fh,callback=&PL_sv_undef)
553	root	1.13	SV * fh
554			SV * callback
555	root	1.8	PROTOTYPE: $;$
556	root	1.1	ALIAS:
557			aio_close = REQ_CLOSE
558			aio_fsync = REQ_FSYNC
559			aio_fdatasync = REQ_FDATASYNC
560			CODE:
561			{
562	root	1.22	dREQ;
563	root	1.1
564			req->type = ix;
565	root	1.13	req->fh = newSVsv (fh);
566			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
567	root	1.1
568			send_req (req);
569			}
570
571			void
572	root	1.8	aio_read(fh,offset,length,data,dataoffset,callback=&PL_sv_undef)
573	root	1.13	SV * fh
574			UV offset
575			IV length
576			SV * data
577			IV dataoffset
578			SV * callback
579			ALIAS:
580			aio_read = REQ_READ
581			aio_write = REQ_WRITE
582	root	1.8	PROTOTYPE: $$$$$;$
583	root	1.1	CODE:
584	root	1.13	{
585			aio_req req;
586			STRLEN svlen;
587	root	1.21	char *svptr = SvPVbyte (data, svlen);
588	root	1.13
589			SvUPGRADE (data, SVt_PV);
590			SvPOK_on (data);
591	root	1.1
592	root	1.13	if (dataoffset < 0)
593			dataoffset += svlen;
594
595			if (dataoffset < 0 \|\| dataoffset > svlen)
596			croak ("data offset outside of string");
597
598			if (ix == REQ_WRITE)
599			{
600			/* write: check length and adjust. */
601			if (length < 0 \|\| length + dataoffset > svlen)
602			length = svlen - dataoffset;
603			}
604			else
605			{
606			/* read: grow scalar as necessary */
607			svptr = SvGROW (data, length + dataoffset);
608			}
609
610			if (length < 0)
611			croak ("length must not be negative");
612
613	root	1.22	{
614			dREQ;
615	root	1.13
616	root	1.22	req->type = ix;
617			req->fh = newSVsv (fh);
618			req->fd = PerlIO_fileno (ix == REQ_READ ? IoIFP (sv_2io (fh))
619			: IoOFP (sv_2io (fh)));
620			req->offset = offset;
621			req->length = length;
622			req->data = SvREFCNT_inc (data);
623			req->dataptr = (char *)svptr + dataoffset;
624			req->callback = SvREFCNT_inc (callback);
625	root	1.13
626	root	1.22	send_req (req);
627			}
628	root	1.13	}
629	root	1.1
630			void
631	root	1.8	aio_readahead(fh,offset,length,callback=&PL_sv_undef)
632	root	1.13	SV * fh
633			UV offset
634			IV length
635			SV * callback
636	root	1.8	PROTOTYPE: $$$;$
637	root	1.1	CODE:
638			{
639	root	1.22	dREQ;
640	root	1.1
641			req->type = REQ_READAHEAD;
642	root	1.13	req->fh = newSVsv (fh);
643			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
644	root	1.1	req->offset = offset;
645			req->length = length;
646
647			send_req (req);
648			}
649
650			void
651	root	1.8	aio_stat(fh_or_path,callback=&PL_sv_undef)
652	root	1.1	SV * fh_or_path
653			SV * callback
654			ALIAS:
655	root	1.8	aio_stat = REQ_STAT
656			aio_lstat = REQ_LSTAT
657	root	1.1	CODE:
658			{
659	root	1.22	dREQ;
660	root	1.1
661			New (0, req->statdata, 1, Stat_t);
662			if (!req->statdata)
663	root	1.22	croak ("out of memory during aio_req->statdata allocation (sorry, i just leaked memory, too)");
664	root	1.1
665			if (SvPOK (fh_or_path))
666			{
667	root	1.8	req->type = ix;
668	root	1.1	req->data = newSVsv (fh_or_path);
669	root	1.22	req->dataptr = SvPVbyte_nolen (req->data);
670	root	1.1	}
671			else
672			{
673			req->type = REQ_FSTAT;
674	root	1.13	req->fh = newSVsv (fh_or_path);
675	root	1.1	req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
676			}
677
678			send_req (req);
679			}
680
681			void
682	root	1.8	aio_unlink(pathname,callback=&PL_sv_undef)
683	root	1.1	SV * pathname
684			SV * callback
685	root	1.22	ALIAS:
686			aio_unlink = REQ_UNLINK
687			aio_rmdir = REQ_RMDIR
688	root	1.1	CODE:
689			{
690	root	1.22	dREQ;
691	root	1.1
692	root	1.22	req->type = ix;
693			req->data = newSVsv (pathname);
694			req->dataptr = SvPVbyte_nolen (req->data);
695	root	1.1
696	root	1.22	send_req (req);
697			}
698
699			void
700			aio_symlink(oldpath,newpath,callback=&PL_sv_undef)
701			SV * oldpath
702			SV * newpath
703			SV * callback
704			CODE:
705			{
706			dREQ;
707	root	1.1
708	root	1.22	req->type = REQ_SYMLINK;
709			req->fh = newSVsv (oldpath);
710			req->data2ptr = SvPVbyte_nolen (req->fh);
711			req->data = newSVsv (newpath);
712			req->dataptr = SvPVbyte_nolen (req->data);
713	root	1.1
714			send_req (req);
715			}
716
717	root	1.6	void
718			flush()
719			PROTOTYPE:
720			CODE:
721			while (nreqs)
722			{
723			poll_wait ();
724			poll_cb ();
725			}
726
727	root	1.7	void
728			poll()
729			PROTOTYPE:
730			CODE:
731			if (nreqs)
732			{
733			poll_wait ();
734			poll_cb ();
735			}
736
737	root	1.1	int
738			poll_fileno()
739			PROTOTYPE:
740			CODE:
741	root	1.3	RETVAL = respipe [0];
742	root	1.1	OUTPUT:
743			RETVAL
744
745			int
746			poll_cb(...)
747			PROTOTYPE:
748			CODE:
749	root	1.5	RETVAL = poll_cb ();
750	root	1.1	OUTPUT:
751			RETVAL
752
753			void
754			poll_wait()
755			PROTOTYPE:
756			CODE:
757	root	1.3	if (nreqs)
758			poll_wait ();
759	root	1.1
760			int
761			nreqs()
762			PROTOTYPE:
763			CODE:
764			RETVAL = nreqs;
765			OUTPUT:
766			RETVAL
767