Linux-AIO/AIO.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <sched.h>

#define STACKSIZE 4096 /* yeah */

#define REQ_QUIT  0
#define REQ_READ  1
#define REQ_WRITE 2

typedef struct {
  char stack[STACKSIZE];
} aio_thread;

typedef struct {
  int type;
  aio_thread *thread;

/* read/write */
  int fd;
  off_t offset;
  size_t length;
  ssize_t result;
  int errorno;

  SV *data, *callback;
  void *dataptr;
  STRLEN dataoffset;
} aio_cb;

typedef aio_cb *aio_req;

static int started;
static int nreqs;
static int reqpipe[2], respipe[2];

static int aio_proc(void *arg);

static void
start_thread(void)
{
  aio_thread *thr;

  New (0, thr, 1, aio_thread);

  if (clone (aio_proc,
             &(thr->stack[STACKSIZE]),
             CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND,
             thr) >= 0)
    started++;
  else
    Safefree (thr);
}

static void
end_thread(void)
{
  aio_req req;
  New (0, req, 1, aio_cb);
  req->type = REQ_QUIT;
  write (reqpipe[1], &req, sizeof (aio_req));
}

static void
read_write (pTHX_ int dowrite, int fd, off_t offset, size_t length,
            SV *data, STRLEN dataoffset, SV*callback)
{
  aio_req req;
  STRLEN svlen;
  char *svptr = SvPV (data, svlen);

  if (dataoffset < 0)
    dataoffset += svlen;

  if (dataoffset < 0 || dataoffset > svlen)
    croak ("data offset outside of string");

  if (dowrite)
    {
      /* 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");

  New (0, req, 1, aio_cb);

  if (!req)
    croak ("out of memory during aio_req allocation");

  req->type = dowrite ? REQ_WRITE : REQ_READ;
  req->fd = fd;
  req->offset = offset;
  req->length = length;
  req->data = SvREFCNT_inc (data);
  req->dataptr = (char *)svptr + dataoffset;
  req->callback = SvREFCNT_inc (callback);

  nreqs++;
  write (reqpipe[1], &req, sizeof (aio_req));
}

static int
poll_cb (pTHX)
{
  dSP;
  int count = 0;
  aio_req req;

  while (read (respipe[0], (void *)&req, sizeof (req)) == sizeof (req))
    {
      if (req->type == REQ_QUIT)
        {
          Safefree (req->thread);
          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);

          PUSHMARK (SP);
          XPUSHs (sv_2mortal (newSViv (req->result)));
          PUTBACK;
          call_sv (req->callback, G_VOID);
          SPAGAIN;
          
          SvREFCNT_dec (req->data);
          SvREFCNT_dec (req->callback);

          errno = errorno;
          nreqs--;
          count++;
        }

      Safefree (req);
    }

  return count;
}

#undef errno
#include <asm/unistd.h>

static int
aio_proc(void *thr_arg)
{
  aio_thread *thr = thr_arg;
  int sig;
  int errno;
  aio_req req;

  /* we rely on gcc's ability to create closures. */
  _syscall3(int,lseek,int,fd,off_t,offset,int,whence);
  _syscall3(int,read,int,fd,char *,buf,off_t,count);
  _syscall3(int,write,int,fd,char *,buf,off_t,count);

  /* first get rid of any signals */
  for (sig = 1; sig < _NSIG; sig++)
    signal (sig, SIG_DFL);

  signal (SIGPIPE, SIG_IGN);
 
  /* then loop */
  while (read (reqpipe[0], (void *)&req, sizeof (req)) == sizeof (req))
    {
      req->thread = thr;

      if (req->type == REQ_READ || req->type == REQ_WRITE)
        {
          errno = 0;

          if (lseek (req->fd, req->offset, SEEK_SET) == req->offset)
            {
              if (req->type == REQ_READ)
                req->result = read (req->fd, req->dataptr, req->length);
              else
                req->result = write(req->fd, req->dataptr, req->length);
            }

          req->errorno = errno;
        }
      else
        {
          write (respipe[1], (void *)&req, sizeof (req));
          break;
        }

      write (respipe[1], (void *)&req, sizeof (req));
    }

  return 0;
}

MODULE = Linux::AIO                PACKAGE = Linux::AIO

BOOT:
{
        if (pipe (reqpipe) || pipe (respipe))
          croak ("unable to initialize request or result pipe");

        if (fcntl (respipe[0], F_SETFL, O_NONBLOCK))
          croak ("cannot set result pipe to nonblocking mode");
}

void
min_parallel(nthreads)
        int     nthreads
        PROTOTYPE: $
        CODE:
        while (nthreads > started)
          start_thread ();

void
max_parallel(nthreads)
        int     nthreads
        PROTOTYPE: $
        CODE:
        int cur = started;
        while (cur > nthreads)
          {          
            end_thread ();
            cur--;
          }

        poll_cb ();
        while (started > nthreads)
          {
            sched_yield ();
            poll_cb ();
          }

void
aio_read(fh,offset,length,data,dataoffset,callback)
        PerlIO *        fh
        UV              offset
        STRLEN          length
        SV *            data
        STRLEN          dataoffset
        SV *            callback
        PROTOTYPE: $$$$$$
        ALIAS:
          aio_write = 1
        CODE:
        SvUPGRADE (data, SVt_PV);
        SvPOK_on (data);
        read_write (aTHX_ ix, PerlIO_fileno (fh), offset, length, data, dataoffset, callback);

int
poll_fileno()
        PROTOTYPE:
        CODE:
        RETVAL = respipe[0];
        OUTPUT:
        RETVAL

int
poll_cb(...)
        PROTOTYPE:
        CODE:
        RETVAL = poll_cb (aTHX);
        OUTPUT:
        RETVAL

int
nreqs()
        PROTOTYPE:
        CODE:
        RETVAL = nreqs;
        OUTPUT:
        RETVAL

Revision:	1.7
Committed:	Wed Aug 15 03:24:08 2001 UTC (22 years, 9 months ago) by root
Branch:	MAIN
Changes since 1.6:	+1 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#include "EXTERN.h"
2			#include "perl.h"
3			#include "XSUB.h"
4
5			#include <sys/types.h>
6			#include <unistd.h>
7	root	1.5	#include <fcntl.h>
8	root	1.1	#include <sched.h>
9
10	root	1.7	#define STACKSIZE 4096 /* yeah */
11	root	1.1
12	root	1.2	#define REQ_QUIT 0
13	root	1.1	#define REQ_READ 1
14			#define REQ_WRITE 2
15
16			typedef struct {
17			char stack[STACKSIZE];
18			} aio_thread;
19
20			typedef struct {
21			int type;
22			aio_thread *thread;
23
24			/* read/write */
25			int fd;
26			off_t offset;
27			size_t length;
28	root	1.2	ssize_t result;
29	root	1.1	int errorno;
30
31	root	1.5	SV data, callback;
32	root	1.1	void *dataptr;
33	root	1.2	STRLEN dataoffset;
34	root	1.1	} aio_cb;
35
36			typedef aio_cb *aio_req;
37
38			static int started;
39	root	1.5	static int nreqs;
40	root	1.1	static int reqpipe[2], respipe[2];
41
42	root	1.2	static int aio_proc(void *arg);
43
44	root	1.1	static void
45			start_thread(void)
46			{
47	root	1.2	aio_thread *thr;
48
49			New (0, thr, 1, aio_thread);
50
51			if (clone (aio_proc,
52			&(thr->stack[STACKSIZE]),
53			CLONE_VM\|CLONE_FS\|CLONE_FILES\|CLONE_SIGHAND,
54			thr) >= 0)
55			started++;
56			else
57			Safefree (thr);
58	root	1.1	}
59
60			static void
61			end_thread(void)
62			{
63	root	1.5	aio_req req;
64			New (0, req, 1, aio_cb);
65			req->type = REQ_QUIT;
66	root	1.1	write (reqpipe[1], &req, sizeof (aio_req));
67	root	1.2	}
68
69			static void
70	root	1.5	read_write (pTHX_ int dowrite, int fd, off_t offset, size_t length,
71			SV data, STRLEN dataoffset, SVcallback)
72	root	1.2	{
73	root	1.5	aio_req req;
74			STRLEN svlen;
75			char *svptr = SvPV (data, svlen);
76
77			if (dataoffset < 0)
78			dataoffset += svlen;
79
80			if (dataoffset < 0 \|\| dataoffset > svlen)
81			croak ("data offset outside of string");
82
83			if (dowrite)
84			{
85			/* write: check length and adjust. */
86			if (length < 0 \|\| length + dataoffset > svlen)
87			length = svlen - dataoffset;
88			}
89			else
90			{
91			/* read: grow scalar as necessary */
92			svptr = SvGROW (data, length + dataoffset);
93			}
94
95			if (length < 0)
96			croak ("length must not be negative");
97
98			New (0, req, 1, aio_cb);
99
100			if (!req)
101			croak ("out of memory during aio_req allocation");
102
103			req->type = dowrite ? REQ_WRITE : REQ_READ;
104			req->fd = fd;
105			req->offset = offset;
106			req->length = length;
107			req->data = SvREFCNT_inc (data);
108	root	1.6	req->dataptr = (char *)svptr + dataoffset;
109	root	1.5	req->callback = SvREFCNT_inc (callback);
110
111			nreqs++;
112			write (reqpipe[1], &req, sizeof (aio_req));
113			}
114
115			static int
116			poll_cb (pTHX)
117			{
118			dSP;
119			int count = 0;
120			aio_req req;
121
122			while (read (respipe[0], (void *)&req, sizeof (req)) == sizeof (req))
123			{
124			if (req->type == REQ_QUIT)
125			{
126			Safefree (req->thread);
127			started--;
128			}
129			else
130			{
131			int errorno = errno;
132			errno = req->errorno;
133
134			if (req->type == REQ_READ)
135	root	1.6	SvCUR_set (req->data, req->dataoffset
136			+ req->result > 0 ? req->result : 0);
137	root	1.5
138			PUSHMARK (SP);
139			XPUSHs (sv_2mortal (newSViv (req->result)));
140			PUTBACK;
141			call_sv (req->callback, G_VOID);
142			SPAGAIN;
143
144			SvREFCNT_dec (req->data);
145			SvREFCNT_dec (req->callback);
146
147			errno = errorno;
148			nreqs--;
149			count++;
150			}
151
152			Safefree (req);
153			}
154
155			return count;
156	root	1.2	}
157
158			#undef errno
159			#include <asm/unistd.h>
160
161			static int
162			aio_proc(void *thr_arg)
163			{
164			aio_thread *thr = thr_arg;
165			int sig;
166			int errno;
167			aio_req req;
168
169			/* we rely on gcc's ability to create closures. */
170			_syscall3(int,lseek,int,fd,off_t,offset,int,whence);
171			_syscall3(int,read,int,fd,char *,buf,off_t,count);
172			_syscall3(int,write,int,fd,char *,buf,off_t,count);
173
174			/* first get rid of any signals */
175			for (sig = 1; sig < _NSIG; sig++)
176	root	1.5	signal (sig, SIG_DFL);
177	root	1.4
178	root	1.5	signal (SIGPIPE, SIG_IGN);
179	root	1.2
180			/* then loop */
181			while (read (reqpipe[0], (void *)&req, sizeof (req)) == sizeof (req))
182			{
183			req->thread = thr;
184
185			if (req->type == REQ_READ \|\| req->type == REQ_WRITE)
186			{
187			errno = 0;
188
189			if (lseek (req->fd, req->offset, SEEK_SET) == req->offset)
190			{
191			if (req->type == REQ_READ)
192			req->result = read (req->fd, req->dataptr, req->length);
193			else
194			req->result = write(req->fd, req->dataptr, req->length);
195			}
196
197			req->errorno = errno;
198			}
199			else
200			{
201			write (respipe[1], (void *)&req, sizeof (req));
202			break;
203			}
204
205			write (respipe[1], (void *)&req, sizeof (req));
206			}
207
208			return 0;
209	root	1.1	}
210
211			MODULE = Linux::AIO PACKAGE = Linux::AIO
212
213			BOOT:
214			{
215			if (pipe (reqpipe) \|\| pipe (respipe))
216			croak ("unable to initialize request or result pipe");
217	root	1.5
218			if (fcntl (respipe[0], F_SETFL, O_NONBLOCK))
219			croak ("cannot set result pipe to nonblocking mode");
220	root	1.1	}
221
222			void
223			min_parallel(nthreads)
224			int nthreads
225	root	1.5	PROTOTYPE: $
226	root	1.1	CODE:
227			while (nthreads > started)
228			start_thread ();
229
230			void
231			max_parallel(nthreads)
232			int nthreads
233	root	1.5	PROTOTYPE: $
234	root	1.1	CODE:
235	root	1.5	int cur = started;
236			while (cur > nthreads)
237			{
238			end_thread ();
239			cur--;
240			}
241
242			poll_cb ();
243	root	1.1	while (started > nthreads)
244	root	1.5	{
245			sched_yield ();
246			poll_cb ();
247			}
248	root	1.1
249			void
250	root	1.5	aio_read(fh,offset,length,data,dataoffset,callback)
251			PerlIO * fh
252	root	1.6	UV offset
253			STRLEN length
254	root	1.5	SV * data
255			STRLEN dataoffset
256			SV * callback
257			PROTOTYPE: $$$$$$
258	root	1.3	ALIAS:
259	root	1.5	aio_write = 1
260	root	1.1	CODE:
261	root	1.6	SvUPGRADE (data, SVt_PV);
262			SvPOK_on (data);
263	root	1.5	read_write (aTHX_ ix, PerlIO_fileno (fh), offset, length, data, dataoffset, callback);
264
265			int
266			poll_fileno()
267			PROTOTYPE:
268			CODE:
269			RETVAL = respipe[0];
270			OUTPUT:
271			RETVAL
272
273			int
274	root	1.6	poll_cb(...)
275	root	1.5	PROTOTYPE:
276			CODE:
277			RETVAL = poll_cb (aTHX);
278			OUTPUT:
279			RETVAL
280
281			int
282			nreqs()
283			PROTOTYPE:
284			CODE:
285			RETVAL = nreqs;
286			OUTPUT:
287			RETVAL
288