Async-Interrupt/Interrupt.xs

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

typedef volatile sig_atomic_t atomic_t;

static int *sig_pending, *psig_pend; /* make local copies because of missing THX */
static Sighandler_t old_sighandler;
static atomic_t async_pending;

#define PERL_VERSION_ATLEAST(a,b,c)                             \
  (PERL_REVISION > (a)                                          \
   || (PERL_REVISION == (a)                                     \
       && (PERL_VERSION > (b)                                   \
           || (PERL_VERSION == (b) && PERL_SUBVERSION >= (c)))))

#if defined(HAS_SIGACTION) && defined(SA_SIGINFO)
# define HAS_SA_SIGINFO 1
#endif

#if !PERL_VERSION_ATLEAST(5,10,0)
# undef HAS_SA_SIGINFO
#endif

static int
extract_fd (SV *fh, int wr)
{
  int fd = PerlIO_fileno (wr ? IoOFP (sv_2io (fh)) : IoIFP (sv_2io (fh)));

  if (fd < 0)
    croak ("illegal fh argument, either not an OS file or read/write mode mismatch");

  return fd;
}

static SV *
get_cb (SV *cb_sv)
{
  HV *st;
  GV *gvp;
  CV *cv;

  if (!SvOK (cb_sv))
    return 0;

  cv = sv_2cv (cb_sv, &st, &gvp, 0);

  if (!cv)
    croak ("Async::Interrupt callback must be undef or a CODE reference");

  return (SV *)cv;
}

static AV *asyncs;

struct async {
  SV *cb;
  void (*c_cb)(pTHX_ void *c_arg, int value);
  void *c_arg;
  SV *fh_r, *fh_w;
  int blocked;

  int fd_r, fd_w;
  atomic_t value;
  atomic_t pending;
};

/* the main workhorse to signal */
static void
async_signal (void *signal_arg, int value)
{
  struct async *async = (struct async *)signal_arg;
  int pending = async->pending;

  async->value   = value;
  async->pending = 1;
  async_pending  = 1;
  psig_pend [9]  = 1;
  *sig_pending   = 1;

  if (!pending && async->fd_w >= 0)
    write (async->fd_w, async, 1);
}

static void
handle_async (struct async *async)
{
  int old_errno = errno;
  int value = async->value;

  async->pending = 0;

  /* drain pipe */
  if (async->fd_r >= 0)
    {
      char dummy [4];

      while (read (async->fd_r, dummy, sizeof (dummy)) == sizeof (dummy))
        ;
    }

  if (async->c_cb)
    {
      dTHX;
      async->c_cb (aTHX_ async->c_arg, value);
    }

  if (async->cb)
    {
      dSP;

      SV *saveerr = SvOK (ERRSV) ? sv_mortalcopy (ERRSV) : 0;
      SV *savedie = PL_diehook;

      PL_diehook = 0;

      PUSHSTACKi (PERLSI_SIGNAL);

      PUSHMARK (SP);
      XPUSHs (sv_2mortal (newSViv (value)));
      PUTBACK;
      call_sv (async->cb, G_VOID | G_DISCARD | G_EVAL);

      if (SvTRUE (ERRSV))
        {
          SPAGAIN;

          PUSHMARK (SP);
          PUTBACK;
          call_sv (get_sv ("Async::Interrupt::DIED", 1), G_VOID | G_DISCARD | G_EVAL | G_KEEPERR);

          sv_setpvn (ERRSV, "", 0);
        }

      if (saveerr)
        sv_setsv (ERRSV, saveerr);

      {
        SV *oldhook = PL_diehook;
        PL_diehook = savedie;
        SvREFCNT_dec (oldhook);
      }

      POPSTACK;
    }

  errno = old_errno;
}

static void
handle_asyncs (void)
{
  int i;

  async_pending = 0;

  for (i = AvFILLp (asyncs); i >= 0; --i)
    {
      struct async *async = INT2PTR (struct async *, SvIVX (AvARRAY (asyncs)[i]));

      if (async->pending && !async->blocked)
        handle_async (async);
    }
}

#if HAS_SA_SIGINFO
static Signal_t async_sighandler (int signum, siginfo_t *si, void *sarg)
{
  if (signum == 9)
    handle_asyncs ();
  else
    old_sighandler (signum, si, sarg);
}
#else
static Signal_t async_sighandler (int signum)
{
  if (signum == 9)
    handle_asyncs ();
  else
    old_sighandler (signum);
}
#endif

static void
scope_block_cb (pTHX_ void *async_sv)
{
  struct async *async = INT2PTR (struct async *, SvIVX ((SV *)async_sv));

  --async->blocked;
  if (async->pending && !async->blocked)
    handle_async (async);

  SvREFCNT_dec (async_sv);
}

MODULE = Async::Interrupt               PACKAGE = Async::Interrupt

BOOT:
        old_sighandler = PL_sighandlerp;
        PL_sighandlerp = async_sighandler;
        sig_pending = &PL_sig_pending;
        psig_pend   = PL_psig_pend;
        asyncs      = newAV ();
        CvNODEBUG_on (get_cv ("Async::Interrupt::scope_block", 0)); /* otherwise calling scope can be the debugger */

PROTOTYPES: DISABLE

SV *
_alloc (SV *cb, void *c_cb, void *c_arg, SV *fh_r, SV *fh_w)
        CODE:
{
        SV *cv   = SvOK (cb) ? SvREFCNT_inc (get_cb (cb)) : 0;
        int fd_r = SvOK (fh_r) ? extract_fd (fh_r, 0) : -1;
        int fd_w = SvOK (fh_w) ? extract_fd (fh_w, 1) : -1;
        struct async *async;

        Newz (0, async, 1, struct async);

        async->fh_r   = fd_r >= 0 ? newSVsv (fh_r) : 0; async->fd_r = fd_r;
        async->fh_w   = fd_w >= 0 ? newSVsv (fh_w) : 0; async->fd_w = fd_w;
        async->cb     = cv;
        async->c_cb   = c_cb;
        async->c_arg  = c_arg;

        printf ("r,w %d,%d\n", fd_r, fd_w);//D

        RETVAL = newSViv (PTR2IV (async));
        av_push (asyncs, RETVAL);
}
        OUTPUT:
        RETVAL

void
signal_func (SV *self)
        PPCODE:
        EXTEND (SP, 2);
        PUSHs (sv_2mortal (newSViv (PTR2IV (async_signal))));
        PUSHs (sv_2mortal (newSViv (SvIVX (SvRV (self)))));

void
signal (SV *self, int value = 0)
        CODE:
        async_signal (INT2PTR (void *, SvIVX (SvRV (self))), value);

void
block (SV *self)
        CODE:
{
        struct async *async = INT2PTR (struct async *, SvIVX (SvRV (self)));
        ++async->blocked;
}

void
unblock (SV *self)
        CODE:
{
        struct async *async = INT2PTR (struct async *, SvIVX (SvRV (self)));
        --async->blocked;
        if (async->pending && !async->blocked)
          handle_async (async);
}

void
scope_block (SV *self)
        CODE:
{
        SV *async_sv = SvRV (self);
        struct async *async = INT2PTR (struct async *, SvIVX (async_sv));
        ++async->blocked;

        LEAVE; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */
        SAVEDESTRUCTOR_X (scope_block_cb, (void *)SvREFCNT_inc (async_sv));
        ENTER; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */
}

void
DESTROY (SV *self)
        CODE:
{
        int i;
        SV *async_sv = SvRV (self);
        struct async *async = INT2PTR (struct async *, SvIVX (async_sv));

        for (i = AvFILLp (asyncs); i >= 0; --i)
          if (AvARRAY (asyncs)[i] == async_sv)
            {
              if (i < AvFILLp (asyncs))
                AvARRAY (asyncs)[i] = AvARRAY (asyncs)[AvFILLp (asyncs)];

              assert (av_pop (asyncs) == async_sv);
              goto found;
            }

        if (!PL_dirty)
          warn ("Async::Interrupt::DESTROY could not find async object in list of asyncs, please report");

        found:
        SvREFCNT_dec (async->fh_r);
        SvREFCNT_dec (async->fh_w);
        SvREFCNT_dec (async->cb);

        Safefree (async);
}

Revision:	1.5
Committed:	Fri Jul 3 21:11:22 2009 UTC (14 years, 11 months ago) by root
Branch:	MAIN
CVS Tags:	rel-0_03
Changes since 1.4:	+16 -2 lines
Log Message:	0.03
#	User	Rev	Content
1	root	1.1	#include "EXTERN.h"
2			#include "perl.h"
3			#include "XSUB.h"
4
5			typedef volatile sig_atomic_t atomic_t;
6
7			static int sig_pending, psig_pend; /* make local copies because of missing THX */
8			static Sighandler_t old_sighandler;
9			static atomic_t async_pending;
10
11	root	1.5	#define PERL_VERSION_ATLEAST(a,b,c) \
12			(PERL_REVISION > (a) \
13			\|\| (PERL_REVISION == (a) \
14			&& (PERL_VERSION > (b) \
15			\|\| (PERL_VERSION == (b) && PERL_SUBVERSION >= (c)))))
16
17			#if defined(HAS_SIGACTION) && defined(SA_SIGINFO)
18			# define HAS_SA_SIGINFO 1
19			#endif
20
21			#if !PERL_VERSION_ATLEAST(5,10,0)
22			# undef HAS_SA_SIGINFO
23			#endif
24
25	root	1.1	static int
26			extract_fd (SV *fh, int wr)
27			{
28			int fd = PerlIO_fileno (wr ? IoOFP (sv_2io (fh)) : IoIFP (sv_2io (fh)));
29
30			if (fd < 0)
31			croak ("illegal fh argument, either not an OS file or read/write mode mismatch");
32
33			return fd;
34			}
35
36			static SV *
37			get_cb (SV *cb_sv)
38			{
39			HV *st;
40			GV *gvp;
41			CV *cv;
42
43			if (!SvOK (cb_sv))
44			return 0;
45
46			cv = sv_2cv (cb_sv, &st, &gvp, 0);
47
48			if (!cv)
49			croak ("Async::Interrupt callback must be undef or a CODE reference");
50
51			return (SV *)cv;
52			}
53
54			static AV *asyncs;
55
56			struct async {
57			SV *cb;
58	root	1.2	void (c_cb)(pTHX_ void c_arg, int value);
59			void *c_arg;
60			SV fh_r, fh_w;
61			int blocked;
62	root	1.1
63	root	1.2	int fd_r, fd_w;
64	root	1.1	atomic_t value;
65	root	1.2	atomic_t pending;
66	root	1.1	};
67
68			/* the main workhorse to signal */
69			static void
70			async_signal (void *signal_arg, int value)
71			{
72			struct async async = (struct async )signal_arg;
73	root	1.2	int pending = async->pending;
74	root	1.1
75	root	1.2	async->value = value;
76			async->pending = 1;
77			async_pending = 1;
78			psig_pend [9] = 1;
79			*sig_pending = 1;
80	root	1.1
81	root	1.2	if (!pending && async->fd_w >= 0)
82			write (async->fd_w, async, 1);
83			}
84
85			static void
86			handle_async (struct async *async)
87			{
88			int old_errno = errno;
89			int value = async->value;
90
91			async->pending = 0;
92
93			/* drain pipe */
94			if (async->fd_r >= 0)
95	root	1.1	{
96	root	1.2	char dummy [4];
97
98			while (read (async->fd_r, dummy, sizeof (dummy)) == sizeof (dummy))
99			;
100			}
101
102			if (async->c_cb)
103			{
104			dTHX;
105			async->c_cb (aTHX_ async->c_arg, value);
106			}
107
108			if (async->cb)
109			{
110			dSP;
111
112			SV *saveerr = SvOK (ERRSV) ? sv_mortalcopy (ERRSV) : 0;
113			SV *savedie = PL_diehook;
114
115			PL_diehook = 0;
116
117			PUSHSTACKi (PERLSI_SIGNAL);
118
119			PUSHMARK (SP);
120			XPUSHs (sv_2mortal (newSViv (value)));
121			PUTBACK;
122			call_sv (async->cb, G_VOID \| G_DISCARD \| G_EVAL);
123
124			if (SvTRUE (ERRSV))
125			{
126			SPAGAIN;
127
128			PUSHMARK (SP);
129			PUTBACK;
130			call_sv (get_sv ("Async::Interrupt::DIED", 1), G_VOID \| G_DISCARD \| G_EVAL \| G_KEEPERR);
131
132			sv_setpvn (ERRSV, "", 0);
133			}
134
135			if (saveerr)
136			sv_setsv (ERRSV, saveerr);
137	root	1.1
138	root	1.2	{
139			SV *oldhook = PL_diehook;
140			PL_diehook = savedie;
141			SvREFCNT_dec (oldhook);
142			}
143
144			POPSTACK;
145	root	1.1	}
146
147	root	1.2	errno = old_errno;
148	root	1.1	}
149
150			static void
151	root	1.2	handle_asyncs (void)
152	root	1.1	{
153	root	1.2	int i;
154
155	root	1.1	async_pending = 0;
156	root	1.2
157			for (i = AvFILLp (asyncs); i >= 0; --i)
158			{
159			struct async async = INT2PTR (struct async , SvIVX (AvARRAY (asyncs)[i]));
160
161			if (async->pending && !async->blocked)
162			handle_async (async);
163			}
164	root	1.1	}
165
166	root	1.5	#if HAS_SA_SIGINFO
167	root	1.1	static Signal_t async_sighandler (int signum, siginfo_t si, void sarg)
168			{
169			if (signum == 9)
170	root	1.2	handle_asyncs ();
171	root	1.1	else
172			old_sighandler (signum, si, sarg);
173			}
174			#else
175	root	1.3	static Signal_t async_sighandler (int signum)
176	root	1.1	{
177			if (signum == 9)
178	root	1.3	handle_asyncs ();
179	root	1.1	else
180			old_sighandler (signum);
181			}
182			#endif
183
184	root	1.4	static void
185			scope_block_cb (pTHX_ void *async_sv)
186			{
187			struct async async = INT2PTR (struct async , SvIVX ((SV *)async_sv));
188
189			--async->blocked;
190			if (async->pending && !async->blocked)
191			handle_async (async);
192
193			SvREFCNT_dec (async_sv);
194			}
195	root	1.1
196			MODULE = Async::Interrupt PACKAGE = Async::Interrupt
197
198			BOOT:
199			old_sighandler = PL_sighandlerp;
200			PL_sighandlerp = async_sighandler;
201			sig_pending = &PL_sig_pending;
202			psig_pend = PL_psig_pend;
203			asyncs = newAV ();
204	root	1.4	CvNODEBUG_on (get_cv ("Async::Interrupt::scope_block", 0)); /* otherwise calling scope can be the debugger */
205	root	1.1
206	root	1.3	PROTOTYPES: DISABLE
207
208	root	1.1	SV *
209	root	1.2	_alloc (SV cb, void c_cb, void c_arg, SV fh_r, SV *fh_w)
210	root	1.1	CODE:
211			{
212	root	1.5	SV *cv = SvOK (cb) ? SvREFCNT_inc (get_cb (cb)) : 0;
213	root	1.2	int fd_r = SvOK (fh_r) ? extract_fd (fh_r, 0) : -1;
214			int fd_w = SvOK (fh_w) ? extract_fd (fh_w, 1) : -1;
215			struct async *async;
216	root	1.1
217			Newz (0, async, 1, struct async);
218
219	root	1.2	async->fh_r = fd_r >= 0 ? newSVsv (fh_r) : 0; async->fd_r = fd_r;
220			async->fh_w = fd_w >= 0 ? newSVsv (fh_w) : 0; async->fd_w = fd_w;
221			async->cb = cv;
222	root	1.1	async->c_cb = c_cb;
223	root	1.2	async->c_arg = c_arg;
224
225			printf ("r,w %d,%d\n", fd_r, fd_w);//D
226	root	1.1
227			RETVAL = newSViv (PTR2IV (async));
228			av_push (asyncs, RETVAL);
229			}
230			OUTPUT:
231			RETVAL
232
233			void
234	root	1.2	signal_func (SV *self)
235	root	1.1	PPCODE:
236			EXTEND (SP, 2);
237			PUSHs (sv_2mortal (newSViv (PTR2IV (async_signal))));
238	root	1.2	PUSHs (sv_2mortal (newSViv (SvIVX (SvRV (self)))));
239	root	1.1
240			void
241			signal (SV *self, int value = 0)
242			CODE:
243	root	1.2	async_signal (INT2PTR (void *, SvIVX (SvRV (self))), value);
244
245			void
246			block (SV *self)
247			CODE:
248			{
249			struct async async = INT2PTR (struct async , SvIVX (SvRV (self)));
250			++async->blocked;
251			}
252
253			void
254			unblock (SV *self)
255			CODE:
256			{
257			struct async async = INT2PTR (struct async , SvIVX (SvRV (self)));
258			--async->blocked;
259			if (async->pending && !async->blocked)
260			handle_async (async);
261			}
262	root	1.1
263			void
264	root	1.4	scope_block (SV *self)
265			CODE:
266			{
267			SV *async_sv = SvRV (self);
268			struct async async = INT2PTR (struct async , SvIVX (async_sv));
269			++async->blocked;
270
271			LEAVE; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */
272			SAVEDESTRUCTOR_X (scope_block_cb, (void *)SvREFCNT_inc (async_sv));
273			ENTER; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */
274			}
275
276			void
277	root	1.1	DESTROY (SV *self)
278			CODE:
279			{
280			int i;
281			SV *async_sv = SvRV (self);
282	root	1.2	struct async async = INT2PTR (struct async , SvIVX (async_sv));
283	root	1.1
284	root	1.2	for (i = AvFILLp (asyncs); i >= 0; --i)
285	root	1.1	if (AvARRAY (asyncs)[i] == async_sv)
286			{
287			if (i < AvFILLp (asyncs))
288	root	1.3	AvARRAY (asyncs)[i] = AvARRAY (asyncs)[AvFILLp (asyncs)];
289	root	1.1
290			assert (av_pop (asyncs) == async_sv);
291			goto found;
292			}
293
294			if (!PL_dirty)
295	root	1.2	warn ("Async::Interrupt::DESTROY could not find async object in list of asyncs, please report");
296	root	1.1
297			found:
298	root	1.2	SvREFCNT_dec (async->fh_r);
299			SvREFCNT_dec (async->fh_w);
300	root	1.1	SvREFCNT_dec (async->cb);
301
302			Safefree (async);
303			}
304