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
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) == 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->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);
}


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 int fork_started;

static void atfork_prepare (void)
{
  pthread_mutex_lock (&frklock);

  fork_started = started;

  for (;;) {
    while (nreqs)
      {
        poll_wait ();
        poll_cb ();
      }

    max_parallel (0);
  
    pthread_mutex_lock (&reqlock);

    if (!nreqs && !started)
      break;

    pthread_mutex_unlock (&reqlock);

    min_parallel (fork_started);
  }

  pthread_mutex_lock (&reslock);

  assert (!started);
  assert (!nreqs);
  assert (!reqs && !reqe);
  assert (!ress && !rese);
}

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

static void atfork_child (void)
{
  reqs = reqe = 0;

  atfork_parent ();
}

/*****************************************************************************/
/* 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:
{
        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");

        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:	1.23
Committed:	Tue Aug 16 23:33:34 2005 UTC (18 years, 9 months ago) by root
Branch:	MAIN
CVS Tags:	rel-1_2
Changes since 1.22:	+1 -1 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			static void
74			poll_wait ()
75			{
76	root	1.11	if (nreqs && !ress)
77			{
78			fd_set rfd;
79			FD_ZERO(&rfd);
80			FD_SET(respipe [0], &rfd);
81	root	1.3
82	root	1.11	select (respipe [0] + 1, &rfd, 0, 0, 0);
83			}
84	root	1.1	}
85
86			static int
87	root	1.5	poll_cb ()
88	root	1.1	{
89			dSP;
90			int count = 0;
91	root	1.11	aio_req req, prv;
92
93			pthread_mutex_lock (&reslock);
94
95	root	1.3	{
96	root	1.11	/* read any signals sent by the worker threads */
97	root	1.3	char buf [32];
98	root	1.22	while (read (respipe [0], buf, 32) == 32)
99	root	1.3	;
100			}
101	root	1.1
102	root	1.11	req = ress;
103			ress = rese = 0;
104	root	1.3
105	root	1.11	pthread_mutex_unlock (&reslock);
106	root	1.3
107	root	1.11	while (req)
108			{
109	root	1.1	nreqs--;
110
111			if (req->type == REQ_QUIT)
112			started--;
113			else
114			{
115			int errorno = errno;
116			errno = req->errorno;
117
118			if (req->type == REQ_READ)
119			SvCUR_set (req->data, req->dataoffset
120			+ req->result > 0 ? req->result : 0);
121
122			if (req->data)
123			SvREFCNT_dec (req->data);
124
125	root	1.13	if (req->fh)
126			SvREFCNT_dec (req->fh);
127
128	root	1.1	if (req->type == REQ_STAT \|\| req->type == REQ_LSTAT \|\| req->type == REQ_FSTAT)
129			{
130			PL_laststype = req->type == REQ_LSTAT ? OP_LSTAT : OP_STAT;
131			PL_laststatval = req->result;
132			PL_statcache = *(req->statdata);
133
134			Safefree (req->statdata);
135			}
136
137	root	1.13	ENTER;
138	root	1.1	PUSHMARK (SP);
139			XPUSHs (sv_2mortal (newSViv (req->result)));
140	root	1.2
141			if (req->type == REQ_OPEN)
142			{
143			/* convert fd to fh */
144			SV *fh;
145
146			PUTBACK;
147			call_pv ("IO::AIO::_fd2fh", G_SCALAR \| G_EVAL);
148			SPAGAIN;
149
150	root	1.13	fh = SvREFCNT_inc (POPs);
151	root	1.2
152			PUSHMARK (SP);
153	root	1.13	XPUSHs (sv_2mortal (fh));
154	root	1.2	}
155
156	root	1.8	if (SvOK (req->callback))
157			{
158			PUTBACK;
159			call_sv (req->callback, G_VOID \| G_EVAL);
160			SPAGAIN;
161			}
162	root	1.13
163			LEAVE;
164	root	1.1
165			if (req->callback)
166			SvREFCNT_dec (req->callback);
167
168			errno = errorno;
169			count++;
170			}
171
172	root	1.11	prv = req;
173			req = req->next;
174			Safefree (prv);
175
176			/* TODO: croak on errors? */
177	root	1.1	}
178
179			return count;
180			}
181
182	root	1.4	static void aio_proc(void arg);
183
184			static void
185			start_thread (void)
186			{
187			sigset_t fullsigset, oldsigset;
188			pthread_t tid;
189			pthread_attr_t attr;
190
191			pthread_attr_init (&attr);
192			pthread_attr_setstacksize (&attr, STACKSIZE);
193			pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
194
195			sigfillset (&fullsigset);
196			sigprocmask (SIG_SETMASK, &fullsigset, &oldsigset);
197
198			if (pthread_create (&tid, &attr, aio_proc, 0) == 0)
199			started++;
200
201			sigprocmask (SIG_SETMASK, &oldsigset, 0);
202			}
203
204			static void
205			send_req (aio_req req)
206			{
207			nreqs++;
208
209			pthread_mutex_lock (&reqlock);
210
211			req->next = 0;
212
213			if (reqe)
214			{
215			reqe->next = req;
216			reqe = req;
217			}
218			else
219			reqe = reqs = req;
220
221			pthread_cond_signal (&reqwait);
222			pthread_mutex_unlock (&reqlock);
223
224			while (nreqs > max_outstanding)
225			{
226			poll_wait ();
227			poll_cb ();
228			}
229			}
230
231			static void
232			end_thread (void)
233			{
234			aio_req req;
235			New (0, req, 1, aio_cb);
236			req->type = REQ_QUIT;
237
238			send_req (req);
239			}
240
241	root	1.22
242			static void min_parallel (int nthreads)
243			{
244			while (nthreads > started)
245			start_thread ();
246			}
247
248			static void max_parallel (int nthreads)
249			{
250			int cur = started;
251			while (cur > nthreads)
252			{
253			end_thread ();
254			cur--;
255			}
256
257			while (started > nthreads)
258			{
259			poll_wait ();
260			poll_cb ();
261			}
262			}
263
264			static int fork_started;
265
266			static void atfork_prepare (void)
267			{
268			pthread_mutex_lock (&frklock);
269
270			fork_started = started;
271
272			for (;;) {
273			while (nreqs)
274			{
275			poll_wait ();
276			poll_cb ();
277			}
278
279			max_parallel (0);
280
281			pthread_mutex_lock (&reqlock);
282
283			if (!nreqs && !started)
284			break;
285
286			pthread_mutex_unlock (&reqlock);
287
288			min_parallel (fork_started);
289			}
290
291			pthread_mutex_lock (&reslock);
292
293			assert (!started);
294			assert (!nreqs);
295			assert (!reqs && !reqe);
296			assert (!ress && !rese);
297			}
298
299			static void atfork_parent (void)
300			{
301			pthread_mutex_unlock (&reslock);
302			min_parallel (fork_started);
303			pthread_mutex_unlock (&reqlock);
304			pthread_mutex_unlock (&frklock);
305			}
306
307			static void atfork_child (void)
308			{
309			reqs = reqe = 0;
310
311			atfork_parent ();
312			}
313
314			/*****************************************************************************/
315	root	1.17	/* work around various missing functions */
316
317			#if !HAVE_PREADWRITE
318			# define pread aio_pread
319			# define pwrite aio_pwrite
320
321			/*
322			* make our pread/pwrite safe against themselves, but not against
323			* normal read/write by using a mutex. slows down execution a lot,
324			* but that's your problem, not mine.
325			*/
326			static pthread_mutex_t iolock = PTHREAD_MUTEX_INITIALIZER;
327
328			static ssize_t
329			pread (int fd, void *buf, size_t count, off_t offset)
330			{
331			ssize_t res;
332			off_t ooffset;
333
334			pthread_mutex_lock (&iolock);
335			ooffset = lseek (fd, 0, SEEK_CUR);
336			lseek (fd, offset, SEEK_SET);
337			res = read (fd, buf, count);
338			lseek (fd, ooffset, SEEK_SET);
339			pthread_mutex_unlock (&iolock);
340
341			return res;
342			}
343
344			static ssize_t
345			pwrite (int fd, void *buf, size_t count, off_t offset)
346			{
347			ssize_t res;
348			off_t ooffset;
349
350			pthread_mutex_lock (&iolock);
351			ooffset = lseek (fd, 0, SEEK_CUR);
352			lseek (fd, offset, SEEK_SET);
353			res = write (fd, buf, count);
354			lseek (fd, offset, SEEK_SET);
355			pthread_mutex_unlock (&iolock);
356
357			return res;
358			}
359			#endif
360
361			#if !HAVE_FDATASYNC
362			# define fdatasync fsync
363			#endif
364
365			#if !HAVE_READAHEAD
366			# define readahead aio_readahead
367
368			static char readahead_buf[4096];
369
370			static ssize_t
371			readahead (int fd, off_t offset, size_t count)
372			{
373			while (count > 0)
374			{
375			size_t len = count < sizeof (readahead_buf) ? count : sizeof (readahead_buf);
376
377			pread (fd, readahead_buf, len, offset);
378			offset += len;
379			count -= len;
380			}
381
382			errno = 0;
383			}
384			#endif
385
386	root	1.22	/*****************************************************************************/
387
388	root	1.1	static void *
389			aio_proc (void *thr_arg)
390			{
391			aio_req req;
392	root	1.3	int type;
393	root	1.1
394	root	1.3	do
395	root	1.1	{
396	root	1.3	pthread_mutex_lock (&reqlock);
397
398			for (;;)
399			{
400			req = reqs;
401
402			if (reqs)
403			{
404			reqs = reqs->next;
405			if (!reqs) reqe = 0;
406			}
407
408			if (req)
409			break;
410
411			pthread_cond_wait (&reqwait, &reqlock);
412			}
413
414			pthread_mutex_unlock (&reqlock);
415
416	root	1.1	errno = 0; /* strictly unnecessary */
417
418	root	1.3	type = req->type;
419
420			switch (type)
421	root	1.1	{
422	root	1.10	case REQ_READ: req->result = pread (req->fd, req->dataptr, req->length, req->offset); break;
423			case REQ_WRITE: req->result = pwrite (req->fd, req->dataptr, req->length, req->offset); break;
424	root	1.16
425	root	1.1	case REQ_READAHEAD: req->result = readahead (req->fd, req->offset, req->length); break;
426
427			case REQ_STAT: req->result = stat (req->dataptr, req->statdata); break;
428			case REQ_LSTAT: req->result = lstat (req->dataptr, req->statdata); break;
429			case REQ_FSTAT: req->result = fstat (req->fd , req->statdata); break;
430
431			case REQ_OPEN: req->result = open (req->dataptr, req->fd, req->mode); break;
432			case REQ_CLOSE: req->result = close (req->fd); break;
433			case REQ_UNLINK: req->result = unlink (req->dataptr); break;
434	root	1.22	case REQ_RMDIR: req->result = rmdir (req->dataptr); break;
435			case REQ_SYMLINK: req->result = symlink (req->data2ptr, req->dataptr); break;
436	root	1.1
437	root	1.17	case REQ_FDATASYNC: req->result = fdatasync (req->fd); break;
438	root	1.1	case REQ_FSYNC: req->result = fsync (req->fd); break;
439
440			case REQ_QUIT:
441	root	1.3	break;
442	root	1.1
443			default:
444			req->result = ENOSYS;
445			break;
446			}
447
448			req->errorno = errno;
449	root	1.3
450			pthread_mutex_lock (&reslock);
451
452			req->next = 0;
453
454			if (rese)
455			{
456			rese->next = req;
457			rese = req;
458			}
459			else
460			{
461			rese = ress = req;
462
463			/* write a dummy byte to the pipe so fh becomes ready */
464			write (respipe [1], &respipe, 1);
465			}
466
467			pthread_mutex_unlock (&reslock);
468	root	1.1	}
469	root	1.3	while (type != REQ_QUIT);
470	root	1.1
471			return 0;
472			}
473
474	root	1.22	#define dREQ \
475			aio_req req; \
476			\
477			if (SvOK (callback) && !SvROK (callback)) \
478			croak ("clalback must be undef or of reference type"); \
479			\
480			Newz (0, req, 1, aio_cb); \
481			if (!req) \
482			croak ("out of memory during aio_req allocation"); \
483			\
484			req->callback = SvREFCNT_inc (callback);
485
486	root	1.1	MODULE = IO::AIO PACKAGE = IO::AIO
487
488	root	1.8	PROTOTYPES: ENABLE
489
490	root	1.1	BOOT:
491			{
492	root	1.3	if (pipe (respipe))
493			croak ("unable to initialize result pipe");
494	root	1.1
495	root	1.3	if (fcntl (respipe [0], F_SETFL, O_NONBLOCK))
496	root	1.1	croak ("cannot set result pipe to nonblocking mode");
497
498	root	1.3	if (fcntl (respipe [1], F_SETFL, O_NONBLOCK))
499	root	1.1	croak ("cannot set result pipe to nonblocking mode");
500	root	1.22
501			pthread_atfork (atfork_prepare, atfork_parent, atfork_child);
502	root	1.1	}
503
504			void
505			min_parallel(nthreads)
506			int nthreads
507			PROTOTYPE: $
508
509			void
510			max_parallel(nthreads)
511			int nthreads
512			PROTOTYPE: $
513
514	root	1.4	int
515			max_outstanding(nreqs)
516			int nreqs
517			PROTOTYPE: $
518			CODE:
519			RETVAL = max_outstanding;
520			max_outstanding = nreqs;
521
522	root	1.1	void
523	root	1.8	aio_open(pathname,flags,mode,callback=&PL_sv_undef)
524	root	1.1	SV * pathname
525			int flags
526			int mode
527			SV * callback
528	root	1.8	PROTOTYPE: $$$;$
529	root	1.1	CODE:
530			{
531	root	1.22	dREQ;
532	root	1.1
533			req->type = REQ_OPEN;
534			req->data = newSVsv (pathname);
535	root	1.22	req->dataptr = SvPVbyte_nolen (req->data);
536	root	1.1	req->fd = flags;
537			req->mode = mode;
538
539			send_req (req);
540			}
541
542			void
543	root	1.8	aio_close(fh,callback=&PL_sv_undef)
544	root	1.13	SV * fh
545			SV * callback
546	root	1.8	PROTOTYPE: $;$
547	root	1.1	ALIAS:
548			aio_close = REQ_CLOSE
549			aio_fsync = REQ_FSYNC
550			aio_fdatasync = REQ_FDATASYNC
551			CODE:
552			{
553	root	1.22	dREQ;
554	root	1.1
555			req->type = ix;
556	root	1.13	req->fh = newSVsv (fh);
557			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
558	root	1.1
559			send_req (req);
560			}
561
562			void
563	root	1.8	aio_read(fh,offset,length,data,dataoffset,callback=&PL_sv_undef)
564	root	1.13	SV * fh
565			UV offset
566			IV length
567			SV * data
568			IV dataoffset
569			SV * callback
570			ALIAS:
571			aio_read = REQ_READ
572			aio_write = REQ_WRITE
573	root	1.8	PROTOTYPE: $$$$$;$
574	root	1.1	CODE:
575	root	1.13	{
576			aio_req req;
577			STRLEN svlen;
578	root	1.21	char *svptr = SvPVbyte (data, svlen);
579	root	1.13
580			SvUPGRADE (data, SVt_PV);
581			SvPOK_on (data);
582	root	1.1
583	root	1.13	if (dataoffset < 0)
584			dataoffset += svlen;
585
586			if (dataoffset < 0 \|\| dataoffset > svlen)
587			croak ("data offset outside of string");
588
589			if (ix == REQ_WRITE)
590			{
591			/* write: check length and adjust. */
592			if (length < 0 \|\| length + dataoffset > svlen)
593			length = svlen - dataoffset;
594			}
595			else
596			{
597			/* read: grow scalar as necessary */
598			svptr = SvGROW (data, length + dataoffset);
599			}
600
601			if (length < 0)
602			croak ("length must not be negative");
603
604	root	1.22	{
605			dREQ;
606	root	1.13
607	root	1.22	req->type = ix;
608			req->fh = newSVsv (fh);
609			req->fd = PerlIO_fileno (ix == REQ_READ ? IoIFP (sv_2io (fh))
610			: IoOFP (sv_2io (fh)));
611			req->offset = offset;
612			req->length = length;
613			req->data = SvREFCNT_inc (data);
614			req->dataptr = (char *)svptr + dataoffset;
615			req->callback = SvREFCNT_inc (callback);
616	root	1.13
617	root	1.22	send_req (req);
618			}
619	root	1.13	}
620	root	1.1
621			void
622	root	1.8	aio_readahead(fh,offset,length,callback=&PL_sv_undef)
623	root	1.13	SV * fh
624			UV offset
625			IV length
626			SV * callback
627	root	1.8	PROTOTYPE: $$$;$
628	root	1.1	CODE:
629			{
630	root	1.22	dREQ;
631	root	1.1
632			req->type = REQ_READAHEAD;
633	root	1.13	req->fh = newSVsv (fh);
634			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
635	root	1.1	req->offset = offset;
636			req->length = length;
637
638			send_req (req);
639			}
640
641			void
642	root	1.8	aio_stat(fh_or_path,callback=&PL_sv_undef)
643	root	1.1	SV * fh_or_path
644			SV * callback
645			ALIAS:
646	root	1.8	aio_stat = REQ_STAT
647			aio_lstat = REQ_LSTAT
648	root	1.1	CODE:
649			{
650	root	1.22	dREQ;
651	root	1.1
652			New (0, req->statdata, 1, Stat_t);
653			if (!req->statdata)
654	root	1.22	croak ("out of memory during aio_req->statdata allocation (sorry, i just leaked memory, too)");
655	root	1.1
656			if (SvPOK (fh_or_path))
657			{
658	root	1.8	req->type = ix;
659	root	1.1	req->data = newSVsv (fh_or_path);
660	root	1.22	req->dataptr = SvPVbyte_nolen (req->data);
661	root	1.1	}
662			else
663			{
664			req->type = REQ_FSTAT;
665	root	1.13	req->fh = newSVsv (fh_or_path);
666	root	1.1	req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
667			}
668
669			send_req (req);
670			}
671
672			void
673	root	1.8	aio_unlink(pathname,callback=&PL_sv_undef)
674	root	1.1	SV * pathname
675			SV * callback
676	root	1.22	ALIAS:
677			aio_unlink = REQ_UNLINK
678			aio_rmdir = REQ_RMDIR
679	root	1.1	CODE:
680			{
681	root	1.22	dREQ;
682	root	1.1
683	root	1.22	req->type = ix;
684			req->data = newSVsv (pathname);
685			req->dataptr = SvPVbyte_nolen (req->data);
686	root	1.1
687	root	1.22	send_req (req);
688			}
689
690			void
691			aio_symlink(oldpath,newpath,callback=&PL_sv_undef)
692			SV * oldpath
693			SV * newpath
694			SV * callback
695			CODE:
696			{
697			dREQ;
698	root	1.1
699	root	1.22	req->type = REQ_SYMLINK;
700			req->fh = newSVsv (oldpath);
701			req->data2ptr = SvPVbyte_nolen (req->fh);
702			req->data = newSVsv (newpath);
703			req->dataptr = SvPVbyte_nolen (req->data);
704	root	1.1
705			send_req (req);
706			}
707
708	root	1.6	void
709			flush()
710			PROTOTYPE:
711			CODE:
712			while (nreqs)
713			{
714			poll_wait ();
715			poll_cb ();
716			}
717
718	root	1.7	void
719			poll()
720			PROTOTYPE:
721			CODE:
722			if (nreqs)
723			{
724			poll_wait ();
725			poll_cb ();
726			}
727
728	root	1.1	int
729			poll_fileno()
730			PROTOTYPE:
731			CODE:
732	root	1.3	RETVAL = respipe [0];
733	root	1.1	OUTPUT:
734			RETVAL
735
736			int
737			poll_cb(...)
738			PROTOTYPE:
739			CODE:
740	root	1.5	RETVAL = poll_cb ();
741	root	1.1	OUTPUT:
742			RETVAL
743
744			void
745			poll_wait()
746			PROTOTYPE:
747			CODE:
748	root	1.3	if (nreqs)
749			poll_wait ();
750	root	1.1
751			int
752			nreqs()
753			PROTOTYPE:
754			CODE:
755			RETVAL = nreqs;
756			OUTPUT:
757			RETVAL
758