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

              rese = 0;
            }
        }

      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->data2ptr && (req->type == REQ_READ || req->type == REQ_WRITE))
            SvREADONLY_off (req->data);

          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)
{
  while (started < wanted && nreqs >= started)
    start_thread ();

  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)
{
  if (wanted < nthreads)
    wanted = nthreads;
}

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

  if (wanted > nthreads)
    wanted = nthreads;

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

  while (started > wanted)
    {
      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 (&reqlock);
  pthread_mutex_lock (&reslock);
}

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

static void atfork_child (void)
{
  aio_req prv;

  started = 0;

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

  reqs = reqe = 0;
      
  while (ress)
    {
      prv = ress;
      ress = prv->next;
      free_req (prv);
    }
      
  ress = rese = 0;

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

  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 = 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;

          if (!SvREADONLY (data))
            {
              SvREADONLY_on (data);
              req->data2ptr = (void *)data;
            }

          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:	1.30
Committed:	Thu Aug 18 16:32:10 2005 UTC (18 years, 9 months ago) by root
Branch:	MAIN
Changes since 1.29:	+15 -12 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	root	1.30	static int started, wanted;
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			/* read any signals sent by the worker threads */
122			char buf [32];
123			while (read (respipe [0], buf, 32) == 32)
124			;
125	root	1.30
126			rese = 0;
127	root	1.27	}
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	1.28	if (req->data2ptr && (req->type == REQ_READ \|\| req->type == REQ_WRITE))
148			SvREADONLY_off (req->data);
149
150	root	1.27	if (req->statdata)
151	root	1.1	{
152			PL_laststype = req->type == REQ_LSTAT ? OP_LSTAT : OP_STAT;
153			PL_laststatval = req->result;
154			PL_statcache = *(req->statdata);
155			}
156
157	root	1.13	ENTER;
158	root	1.1	PUSHMARK (SP);
159			XPUSHs (sv_2mortal (newSViv (req->result)));
160	root	1.2
161			if (req->type == REQ_OPEN)
162			{
163			/* convert fd to fh */
164			SV *fh;
165
166			PUTBACK;
167			call_pv ("IO::AIO::_fd2fh", G_SCALAR \| G_EVAL);
168			SPAGAIN;
169
170	root	1.13	fh = SvREFCNT_inc (POPs);
171	root	1.2
172			PUSHMARK (SP);
173	root	1.13	XPUSHs (sv_2mortal (fh));
174	root	1.2	}
175
176	root	1.8	if (SvOK (req->callback))
177			{
178			PUTBACK;
179			call_sv (req->callback, G_VOID \| G_EVAL);
180			SPAGAIN;
181	root	1.27
182			if (SvTRUE (ERRSV))
183			{
184			free_req (req);
185			croak (0);
186			}
187	root	1.8	}
188	root	1.13
189	root	1.26	LEAVE;
190
191	root	1.1	errno = errorno;
192			count++;
193			}
194
195	root	1.27	free_req (req);
196	root	1.1	}
197
198			return count;
199			}
200
201	root	1.4	static void aio_proc(void arg);
202
203			static void
204			start_thread (void)
205			{
206			sigset_t fullsigset, oldsigset;
207			pthread_t tid;
208			pthread_attr_t attr;
209
210			pthread_attr_init (&attr);
211			pthread_attr_setstacksize (&attr, STACKSIZE);
212	root	1.30	// pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
213	root	1.4
214			sigfillset (&fullsigset);
215			sigprocmask (SIG_SETMASK, &fullsigset, &oldsigset);
216
217			if (pthread_create (&tid, &attr, aio_proc, 0) == 0)
218			started++;
219
220			sigprocmask (SIG_SETMASK, &oldsigset, 0);
221			}
222
223			static void
224			send_req (aio_req req)
225			{
226	root	1.30	while (started < wanted && nreqs >= started)
227			start_thread ();
228
229	root	1.4	nreqs++;
230
231			pthread_mutex_lock (&reqlock);
232
233			req->next = 0;
234
235			if (reqe)
236			{
237			reqe->next = req;
238			reqe = req;
239			}
240			else
241			reqe = reqs = req;
242
243			pthread_cond_signal (&reqwait);
244			pthread_mutex_unlock (&reqlock);
245
246	root	1.27	if (nreqs > max_outstanding)
247			for (;;)
248			{
249			poll_cb ();
250
251			if (nreqs <= max_outstanding)
252			break;
253
254			poll_wait ();
255			}
256	root	1.4	}
257
258			static void
259			end_thread (void)
260			{
261			aio_req req;
262	root	1.26	Newz (0, req, 1, aio_cb);
263	root	1.4	req->type = REQ_QUIT;
264
265			send_req (req);
266			}
267
268	root	1.22	static void min_parallel (int nthreads)
269			{
270	root	1.30	if (wanted < nthreads)
271			wanted = nthreads;
272	root	1.22	}
273
274			static void max_parallel (int nthreads)
275			{
276			int cur = started;
277	root	1.27
278	root	1.30	if (wanted > nthreads)
279			wanted = nthreads;
280
281			while (cur > wanted)
282			{
283	root	1.22	end_thread ();
284			cur--;
285			}
286
287	root	1.30	while (started > wanted)
288	root	1.22	{
289			poll_wait ();
290			poll_cb ();
291			}
292			}
293
294	root	1.26	static void create_pipe ()
295	root	1.22	{
296	root	1.26	if (pipe (respipe))
297			croak ("unable to initialize result pipe");
298	root	1.22
299	root	1.26	if (fcntl (respipe [0], F_SETFL, O_NONBLOCK))
300			croak ("cannot set result pipe to nonblocking mode");
301	root	1.22
302	root	1.26	if (fcntl (respipe [1], F_SETFL, O_NONBLOCK))
303			croak ("cannot set result pipe to nonblocking mode");
304			}
305	root	1.22
306	root	1.26	static void atfork_prepare (void)
307			{
308	root	1.28	pthread_mutex_lock (&reqlock);
309	root	1.22	pthread_mutex_lock (&reslock);
310			}
311
312			static void atfork_parent (void)
313			{
314			pthread_mutex_unlock (&reslock);
315	root	1.26	pthread_mutex_unlock (&reqlock);
316			}
317
318			static void atfork_child (void)
319			{
320	root	1.28	aio_req prv;
321
322	root	1.26	started = 0;
323
324	root	1.28	while (reqs)
325			{
326			prv = reqs;
327			reqs = prv->next;
328			free_req (prv);
329			}
330
331			reqs = reqe = 0;
332
333			while (ress)
334			{
335			prv = ress;
336			ress = prv->next;
337			free_req (prv);
338			}
339
340			ress = rese = 0;
341
342	root	1.29	close (respipe [0]);
343			close (respipe [1]);
344			create_pipe ();
345
346	root	1.26	atfork_parent ();
347	root	1.22	}
348
349			/*****************************************************************************/
350	root	1.17	/* work around various missing functions */
351
352			#if !HAVE_PREADWRITE
353			# define pread aio_pread
354			# define pwrite aio_pwrite
355
356			/*
357			* make our pread/pwrite safe against themselves, but not against
358			* normal read/write by using a mutex. slows down execution a lot,
359			* but that's your problem, not mine.
360			*/
361			static pthread_mutex_t iolock = PTHREAD_MUTEX_INITIALIZER;
362
363			static ssize_t
364			pread (int fd, void *buf, size_t count, off_t offset)
365			{
366			ssize_t res;
367			off_t ooffset;
368
369			pthread_mutex_lock (&iolock);
370			ooffset = lseek (fd, 0, SEEK_CUR);
371			lseek (fd, offset, SEEK_SET);
372			res = read (fd, buf, count);
373			lseek (fd, ooffset, SEEK_SET);
374			pthread_mutex_unlock (&iolock);
375
376			return res;
377			}
378
379			static ssize_t
380			pwrite (int fd, void *buf, size_t count, off_t offset)
381			{
382			ssize_t res;
383			off_t ooffset;
384
385			pthread_mutex_lock (&iolock);
386			ooffset = lseek (fd, 0, SEEK_CUR);
387			lseek (fd, offset, SEEK_SET);
388			res = write (fd, buf, count);
389			lseek (fd, offset, SEEK_SET);
390			pthread_mutex_unlock (&iolock);
391
392			return res;
393			}
394			#endif
395
396			#if !HAVE_FDATASYNC
397			# define fdatasync fsync
398			#endif
399
400			#if !HAVE_READAHEAD
401			# define readahead aio_readahead
402
403			static char readahead_buf[4096];
404
405			static ssize_t
406			readahead (int fd, off_t offset, size_t count)
407			{
408			while (count > 0)
409			{
410			size_t len = count < sizeof (readahead_buf) ? count : sizeof (readahead_buf);
411
412			pread (fd, readahead_buf, len, offset);
413			offset += len;
414			count -= len;
415			}
416
417			errno = 0;
418			}
419			#endif
420
421	root	1.22	/*****************************************************************************/
422
423	root	1.1	static void *
424			aio_proc (void *thr_arg)
425			{
426			aio_req req;
427	root	1.3	int type;
428	root	1.1
429	root	1.3	do
430	root	1.1	{
431	root	1.3	pthread_mutex_lock (&reqlock);
432
433			for (;;)
434			{
435			req = reqs;
436
437			if (reqs)
438			{
439			reqs = reqs->next;
440			if (!reqs) reqe = 0;
441			}
442
443			if (req)
444			break;
445
446			pthread_cond_wait (&reqwait, &reqlock);
447			}
448
449			pthread_mutex_unlock (&reqlock);
450
451	root	1.1	errno = 0; /* strictly unnecessary */
452
453	root	1.3	type = req->type;
454
455			switch (type)
456	root	1.1	{
457	root	1.10	case REQ_READ: req->result = pread (req->fd, req->dataptr, req->length, req->offset); break;
458			case REQ_WRITE: req->result = pwrite (req->fd, req->dataptr, req->length, req->offset); break;
459	root	1.16
460	root	1.1	case REQ_READAHEAD: req->result = readahead (req->fd, req->offset, req->length); break;
461
462			case REQ_STAT: req->result = stat (req->dataptr, req->statdata); break;
463			case REQ_LSTAT: req->result = lstat (req->dataptr, req->statdata); break;
464			case REQ_FSTAT: req->result = fstat (req->fd , req->statdata); break;
465
466			case REQ_OPEN: req->result = open (req->dataptr, req->fd, req->mode); break;
467			case REQ_CLOSE: req->result = close (req->fd); break;
468			case REQ_UNLINK: req->result = unlink (req->dataptr); break;
469	root	1.22	case REQ_RMDIR: req->result = rmdir (req->dataptr); break;
470			case REQ_SYMLINK: req->result = symlink (req->data2ptr, req->dataptr); break;
471	root	1.1
472	root	1.17	case REQ_FDATASYNC: req->result = fdatasync (req->fd); break;
473	root	1.1	case REQ_FSYNC: req->result = fsync (req->fd); break;
474
475			case REQ_QUIT:
476	root	1.3	break;
477	root	1.1
478			default:
479			req->result = ENOSYS;
480			break;
481			}
482
483			req->errorno = errno;
484	root	1.3
485			pthread_mutex_lock (&reslock);
486
487			req->next = 0;
488
489			if (rese)
490			{
491			rese->next = req;
492			rese = req;
493			}
494			else
495			{
496			rese = ress = req;
497
498			/* write a dummy byte to the pipe so fh becomes ready */
499			write (respipe [1], &respipe, 1);
500			}
501
502			pthread_mutex_unlock (&reslock);
503	root	1.1	}
504	root	1.3	while (type != REQ_QUIT);
505	root	1.1
506			return 0;
507			}
508
509	root	1.22	#define dREQ \
510			aio_req req; \
511			\
512			if (SvOK (callback) && !SvROK (callback)) \
513			croak ("clalback must be undef or of reference type"); \
514			\
515			Newz (0, req, 1, aio_cb); \
516			if (!req) \
517			croak ("out of memory during aio_req allocation"); \
518			\
519	root	1.27	req->callback = newSVsv (callback);
520	root	1.22
521	root	1.1	MODULE = IO::AIO PACKAGE = IO::AIO
522
523	root	1.8	PROTOTYPES: ENABLE
524
525	root	1.1	BOOT:
526			{
527	root	1.26	create_pipe ();
528	root	1.22	pthread_atfork (atfork_prepare, atfork_parent, atfork_child);
529	root	1.1	}
530
531			void
532			min_parallel(nthreads)
533			int nthreads
534			PROTOTYPE: $
535
536			void
537			max_parallel(nthreads)
538			int nthreads
539			PROTOTYPE: $
540
541	root	1.4	int
542			max_outstanding(nreqs)
543			int nreqs
544			PROTOTYPE: $
545			CODE:
546			RETVAL = max_outstanding;
547			max_outstanding = nreqs;
548
549	root	1.1	void
550	root	1.8	aio_open(pathname,flags,mode,callback=&PL_sv_undef)
551	root	1.1	SV * pathname
552			int flags
553			int mode
554			SV * callback
555	root	1.8	PROTOTYPE: $$$;$
556	root	1.1	CODE:
557			{
558	root	1.22	dREQ;
559	root	1.1
560			req->type = REQ_OPEN;
561			req->data = newSVsv (pathname);
562	root	1.22	req->dataptr = SvPVbyte_nolen (req->data);
563	root	1.1	req->fd = flags;
564			req->mode = mode;
565
566			send_req (req);
567			}
568
569			void
570	root	1.8	aio_close(fh,callback=&PL_sv_undef)
571	root	1.13	SV * fh
572			SV * callback
573	root	1.8	PROTOTYPE: $;$
574	root	1.1	ALIAS:
575			aio_close = REQ_CLOSE
576			aio_fsync = REQ_FSYNC
577			aio_fdatasync = REQ_FDATASYNC
578			CODE:
579			{
580	root	1.22	dREQ;
581	root	1.1
582			req->type = ix;
583	root	1.13	req->fh = newSVsv (fh);
584			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
585	root	1.1
586			send_req (req);
587			}
588
589			void
590	root	1.8	aio_read(fh,offset,length,data,dataoffset,callback=&PL_sv_undef)
591	root	1.13	SV * fh
592			UV offset
593			IV length
594			SV * data
595			IV dataoffset
596			SV * callback
597			ALIAS:
598			aio_read = REQ_READ
599			aio_write = REQ_WRITE
600	root	1.8	PROTOTYPE: $$$$$;$
601	root	1.1	CODE:
602	root	1.13	{
603			aio_req req;
604			STRLEN svlen;
605	root	1.21	char *svptr = SvPVbyte (data, svlen);
606	root	1.13
607			SvUPGRADE (data, SVt_PV);
608			SvPOK_on (data);
609	root	1.1
610	root	1.13	if (dataoffset < 0)
611			dataoffset += svlen;
612
613			if (dataoffset < 0 \|\| dataoffset > svlen)
614			croak ("data offset outside of string");
615
616			if (ix == REQ_WRITE)
617			{
618			/* write: check length and adjust. */
619			if (length < 0 \|\| length + dataoffset > svlen)
620			length = svlen - dataoffset;
621			}
622			else
623			{
624			/* read: grow scalar as necessary */
625			svptr = SvGROW (data, length + dataoffset);
626			}
627
628			if (length < 0)
629			croak ("length must not be negative");
630
631	root	1.22	{
632			dREQ;
633	root	1.13
634	root	1.22	req->type = ix;
635			req->fh = newSVsv (fh);
636			req->fd = PerlIO_fileno (ix == REQ_READ ? IoIFP (sv_2io (fh))
637			: IoOFP (sv_2io (fh)));
638			req->offset = offset;
639			req->length = length;
640			req->data = SvREFCNT_inc (data);
641			req->dataptr = (char *)svptr + dataoffset;
642	root	1.13
643	root	1.28	if (!SvREADONLY (data))
644			{
645			SvREADONLY_on (data);
646			req->data2ptr = (void *)data;
647			}
648
649	root	1.22	send_req (req);
650			}
651	root	1.13	}
652	root	1.1
653			void
654	root	1.8	aio_readahead(fh,offset,length,callback=&PL_sv_undef)
655	root	1.13	SV * fh
656			UV offset
657			IV length
658			SV * callback
659	root	1.8	PROTOTYPE: $$$;$
660	root	1.1	CODE:
661			{
662	root	1.22	dREQ;
663	root	1.1
664			req->type = REQ_READAHEAD;
665	root	1.13	req->fh = newSVsv (fh);
666			req->fd = PerlIO_fileno (IoIFP (sv_2io (fh)));
667	root	1.1	req->offset = offset;
668			req->length = length;
669
670			send_req (req);
671			}
672
673			void
674	root	1.8	aio_stat(fh_or_path,callback=&PL_sv_undef)
675	root	1.1	SV * fh_or_path
676			SV * callback
677			ALIAS:
678	root	1.8	aio_stat = REQ_STAT
679			aio_lstat = REQ_LSTAT
680	root	1.1	CODE:
681			{
682	root	1.22	dREQ;
683	root	1.1
684			New (0, req->statdata, 1, Stat_t);
685			if (!req->statdata)
686	root	1.27	{
687			free_req (req);
688			croak ("out of memory during aio_req->statdata allocation");
689			}
690	root	1.1
691			if (SvPOK (fh_or_path))
692			{
693	root	1.8	req->type = ix;
694	root	1.1	req->data = newSVsv (fh_or_path);
695	root	1.22	req->dataptr = SvPVbyte_nolen (req->data);
696	root	1.1	}
697			else
698			{
699			req->type = REQ_FSTAT;
700	root	1.13	req->fh = newSVsv (fh_or_path);
701	root	1.1	req->fd = PerlIO_fileno (IoIFP (sv_2io (fh_or_path)));
702			}
703
704			send_req (req);
705			}
706
707			void
708	root	1.8	aio_unlink(pathname,callback=&PL_sv_undef)
709	root	1.1	SV * pathname
710			SV * callback
711	root	1.22	ALIAS:
712			aio_unlink = REQ_UNLINK
713			aio_rmdir = REQ_RMDIR
714	root	1.1	CODE:
715			{
716	root	1.22	dREQ;
717	root	1.1
718	root	1.22	req->type = ix;
719			req->data = newSVsv (pathname);
720			req->dataptr = SvPVbyte_nolen (req->data);
721	root	1.1
722	root	1.22	send_req (req);
723			}
724
725			void
726			aio_symlink(oldpath,newpath,callback=&PL_sv_undef)
727			SV * oldpath
728			SV * newpath
729			SV * callback
730			CODE:
731			{
732			dREQ;
733	root	1.1
734	root	1.22	req->type = REQ_SYMLINK;
735			req->fh = newSVsv (oldpath);
736			req->data2ptr = SvPVbyte_nolen (req->fh);
737			req->data = newSVsv (newpath);
738			req->dataptr = SvPVbyte_nolen (req->data);
739	root	1.1
740			send_req (req);
741			}
742
743	root	1.6	void
744			flush()
745			PROTOTYPE:
746			CODE:
747			while (nreqs)
748			{
749			poll_wait ();
750			poll_cb ();
751			}
752
753	root	1.7	void
754			poll()
755			PROTOTYPE:
756			CODE:
757			if (nreqs)
758			{
759			poll_wait ();
760			poll_cb ();
761			}
762
763	root	1.1	int
764			poll_fileno()
765			PROTOTYPE:
766			CODE:
767	root	1.3	RETVAL = respipe [0];
768	root	1.1	OUTPUT:
769			RETVAL
770
771			int
772			poll_cb(...)
773			PROTOTYPE:
774			CODE:
775	root	1.5	RETVAL = poll_cb ();
776	root	1.1	OUTPUT:
777			RETVAL
778
779			void
780			poll_wait()
781			PROTOTYPE:
782			CODE:
783	root	1.3	if (nreqs)
784			poll_wait ();
785	root	1.1
786			int
787			nreqs()
788			PROTOTYPE:
789			CODE:
790			RETVAL = nreqs;
791			OUTPUT:
792			RETVAL
793