Async-Interrupt/Interrupt.xs

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

#include "schmorp.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

/*****************************************************************************/

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

  s_epipe ep;
  int fd_wlen;
  atomic_t fd_enable;
  atomic_t pending;
  volatile IV *valuep;
} async_t;

static AV *asyncs;
static async_t *sig_async [SIG_SIZE];

#define SvASYNC_nrv(sv) INT2PTR (async_t *, SvIVX (sv))
#define SvASYNC(rv)     SvASYNC_nrv (SvRV (rv))

/* the main workhorse to signal */
static void
async_signal (void *signal_arg, int value)
{
  static char pipedata [8];

  async_t *async = (async_t *)signal_arg;
  int pending = async->pending;

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

  {
    int fd_enable = async->fd_enable;

    if (!pending && fd_enable && async->ep.fd [1] >= 0)
      s_epipe_signal (&async->ep);
  }
}

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

  *async->valuep = 0;
  async->pending = 0;

  /* drain pipe */
  if (async->fd_enable && async->ep.fd [0] >= 0)
    s_epipe_drain (&async->ep);

  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)
    {
      async_t *async = SvASYNC_nrv (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
async_sigsend (int signum)
{
  async_signal (sig_async [signum], 0);
}

#define block(async) ++(async)->blocked

static void
unblock (async_t *async)
{
  --async->blocked;
  if (async->pending && !async->blocked)
    handle_async (async);
}

static void
scope_block_cb (pTHX_ void *async_sv)
{
  async_t *async = SvASYNC_nrv ((SV *)async_sv);
  unblock (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

void
_alloc (SV *cb, void *c_cb, void *c_arg, SV *fh_r, SV *fh_w, SV *signl, SV *pvalue)
        PPCODE:
{
        SV *cv   = SvOK (cb) ? SvREFCNT_inc (s_get_cv_croak (cb)) : 0;
        async_t *async;

        Newz (0, async, 1, async_t);

        XPUSHs (sv_2mortal (newSViv (PTR2IV (async))));
        /* TODO: need to bless right now to ensure deallocation */
        av_push (asyncs, TOPs);

        SvGETMAGIC (fh_r); SvGETMAGIC (fh_w);
        if (SvOK (fh_r) || SvOK (fh_w))
          {
            int fd_r = s_fileno_croak (fh_r, 0);
            int fd_w = s_fileno_croak (fh_w, 1);

            async->fh_r      = newSVsv (fh_r);
            async->fh_w      = newSVsv (fh_w);
            async->ep.fd [0] = fd_r;
            async->ep.fd [1] = fd_w;
            async->ep.len    = 1;
            async->fd_enable = 1;
          }

        async->value     = SvROK (pvalue)
                           ? SvREFCNT_inc_NN (SvRV (pvalue))
                           : NEWSV (0, 0);

        sv_setiv (async->value, 0);
        SvIOK_only (async->value); /* just to be sure */
        SvREADONLY_on (async->value);

        async->valuep    = &(SvIVX (async->value));

        async->cb        = cv;
        async->c_cb      = c_cb;
        async->c_arg     = c_arg;
        async->signum    = SvOK (signl) ? s_signum_croak (signl) : 0;

        if (async->signum)
          {
            if (async->signum < 0)
              croak ("Async::Interrupt::new got passed illegal signal name or number: %s", SvPV_nolen (signl));

            sig_async [async->signum] = async;
#if _WIN32
            signal (async->signum, async_sigsend);
#else
            {
              struct sigaction sa = { };
              sa.sa_handler = async_sigsend;
              sigfillset (&sa.sa_mask);
              sigaction (async->signum, &sa, 0);
            }
#endif
          }
}

void
signal_func (async_t *async)
        PPCODE:
        EXTEND (SP, 2);
        PUSHs (sv_2mortal (newSViv (PTR2IV (async_signal))));
        PUSHs (sv_2mortal (newSViv (PTR2IV (async))));

IV
c_var (async_t *async)
        CODE:
        RETVAL = PTR2IV (async->valuep);
        OUTPUT:
        RETVAL

void
signal (async_t *async, int value = 1)
        CODE:
        async_signal (async, value);

void
block (async_t *async)
        CODE:
        block (async);

void
unblock (async_t *async)
        CODE:
        unblock (async);

void
scope_block (SV *self)
        CODE:
{
        SV *async_sv = SvRV (self);
        async_t *async = SvASYNC_nrv (async_sv);
        block (async);

        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
pipe_enable (async_t *async)
        ALIAS:
        pipe_enable = 1
        pipe_disable = 0
        CODE:
        async->fd_enable = ix;

int
pipe_fileno (async_t *async)
        CODE:
        if (!async->ep.len)
          {
            int res;

            /*block (async);*//*TODO*/
            res = s_epipe_new (&async->ep);
            async->fd_enable = 1;
            /*unblock (async);*//*TODO*/

            if (res < 0)
              croak ("Async::Interrupt: unable to initialize event pipe");
          }

        RETVAL = async->ep.fd [0];
        OUTPUT:
        RETVAL


void
post_fork (async_t *async)
        CODE:
        if (async->ep.len)
          {
            int res;

            /*block (async);*//*TODO*/
            res = s_epipe_renew (&async->ep);
            /*unblock (async);*//*TODO*/

            if (res < 0)
              croak ("Async::Interrupt: unable to initialize event pipe after fork");
          }

void
DESTROY (SV *self)
        CODE:
{
        int i;
        SV *async_sv = SvRV (self);
        async_t *async = SvASYNC_nrv (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:

        if (async->signum)
          {
#if _WIN32
            signal (async->signum, SIG_DFL);
#else
            {
              struct sigaction sa = { };
              sa.sa_handler = SIG_DFL;
              sigaction (async->signum, &sa, 0);
            }
#endif
          }

        if (!async->fh_r && async->ep.len)
          s_epipe_destroy (&async->ep);

        SvREFCNT_dec (async->fh_r);
        SvREFCNT_dec (async->fh_w);
        SvREFCNT_dec (async->cb);
        SvREFCNT_dec (async->value);

        Safefree (async);
}

Revision:	1.9
Committed:	Fri Jul 17 01:51:32 2009 UTC (14 years, 11 months ago) by root
Branch:	MAIN
CVS Tags:	rel-0_5
Changes since 1.8:	+84 -25 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	root	1.8	#include "schmorp.h"
6
7	root	1.1	typedef volatile sig_atomic_t atomic_t;
8
9			static int sig_pending, psig_pend; /* make local copies because of missing THX */
10			static Sighandler_t old_sighandler;
11			static atomic_t async_pending;
12
13	root	1.5	#define PERL_VERSION_ATLEAST(a,b,c) \
14			(PERL_REVISION > (a) \
15			\|\| (PERL_REVISION == (a) \
16			&& (PERL_VERSION > (b) \
17			\|\| (PERL_VERSION == (b) && PERL_SUBVERSION >= (c)))))
18
19			#if defined(HAS_SIGACTION) && defined(SA_SIGINFO)
20			# define HAS_SA_SIGINFO 1
21			#endif
22
23			#if !PERL_VERSION_ATLEAST(5,10,0)
24			# undef HAS_SA_SIGINFO
25			#endif
26
27	root	1.6	/*****************************************************************************/
28	root	1.1
29	root	1.6	typedef struct {
30	root	1.1	SV *cb;
31	root	1.2	void (c_cb)(pTHX_ void c_arg, int value);
32			void *c_arg;
33			SV fh_r, fh_w;
34	root	1.9	SV *value;
35	root	1.6	int signum;
36	root	1.7	volatile int blocked;
37	root	1.1
38	root	1.9	s_epipe ep;
39	root	1.6	int fd_wlen;
40			atomic_t fd_enable;
41	root	1.2	atomic_t pending;
42	root	1.9	volatile IV *valuep;
43	root	1.6	} async_t;
44
45			static AV *asyncs;
46			static async_t *sig_async [SIG_SIZE];
47
48			#define SvASYNC_nrv(sv) INT2PTR (async_t *, SvIVX (sv))
49			#define SvASYNC(rv) SvASYNC_nrv (SvRV (rv))
50	root	1.1
51			/* the main workhorse to signal */
52			static void
53			async_signal (void *signal_arg, int value)
54			{
55	root	1.6	static char pipedata [8];
56
57			async_t async = (async_t )signal_arg;
58	root	1.2	int pending = async->pending;
59	root	1.1
60	root	1.9	*async->valuep = value ? value : 1;
61	root	1.2	async->pending = 1;
62			async_pending = 1;
63			psig_pend [9] = 1;
64			*sig_pending = 1;
65	root	1.1
66	root	1.7	{
67			int fd_enable = async->fd_enable;
68
69	root	1.9	if (!pending && fd_enable && async->ep.fd [1] >= 0)
70			s_epipe_signal (&async->ep);
71	root	1.7	}
72	root	1.2	}
73
74			static void
75	root	1.6	handle_async (async_t *async)
76	root	1.2	{
77			int old_errno = errno;
78	root	1.9	int value = *async->valuep;
79	root	1.2
80	root	1.9	*async->valuep = 0;
81	root	1.2	async->pending = 0;
82
83			/* drain pipe */
84	root	1.9	if (async->fd_enable && async->ep.fd [0] >= 0)
85			s_epipe_drain (&async->ep);
86	root	1.2
87			if (async->c_cb)
88			{
89			dTHX;
90			async->c_cb (aTHX_ async->c_arg, value);
91			}
92
93			if (async->cb)
94			{
95			dSP;
96
97			SV *saveerr = SvOK (ERRSV) ? sv_mortalcopy (ERRSV) : 0;
98			SV *savedie = PL_diehook;
99
100			PL_diehook = 0;
101
102			PUSHSTACKi (PERLSI_SIGNAL);
103
104			PUSHMARK (SP);
105			XPUSHs (sv_2mortal (newSViv (value)));
106			PUTBACK;
107			call_sv (async->cb, G_VOID \| G_DISCARD \| G_EVAL);
108
109			if (SvTRUE (ERRSV))
110			{
111			SPAGAIN;
112
113			PUSHMARK (SP);
114			PUTBACK;
115			call_sv (get_sv ("Async::Interrupt::DIED", 1), G_VOID \| G_DISCARD \| G_EVAL \| G_KEEPERR);
116
117			sv_setpvn (ERRSV, "", 0);
118			}
119
120			if (saveerr)
121			sv_setsv (ERRSV, saveerr);
122	root	1.1
123	root	1.2	{
124			SV *oldhook = PL_diehook;
125			PL_diehook = savedie;
126			SvREFCNT_dec (oldhook);
127			}
128
129			POPSTACK;
130	root	1.1	}
131
132	root	1.2	errno = old_errno;
133	root	1.1	}
134
135			static void
136	root	1.2	handle_asyncs (void)
137	root	1.1	{
138	root	1.2	int i;
139
140	root	1.1	async_pending = 0;
141	root	1.2
142			for (i = AvFILLp (asyncs); i >= 0; --i)
143			{
144	root	1.6	async_t *async = SvASYNC_nrv (AvARRAY (asyncs)[i]);
145	root	1.2
146			if (async->pending && !async->blocked)
147			handle_async (async);
148			}
149	root	1.1	}
150
151	root	1.5	#if HAS_SA_SIGINFO
152	root	1.1	static Signal_t async_sighandler (int signum, siginfo_t si, void sarg)
153			{
154			if (signum == 9)
155	root	1.2	handle_asyncs ();
156	root	1.1	else
157			old_sighandler (signum, si, sarg);
158			}
159			#else
160	root	1.3	static Signal_t async_sighandler (int signum)
161	root	1.1	{
162			if (signum == 9)
163	root	1.3	handle_asyncs ();
164	root	1.1	else
165			old_sighandler (signum);
166			}
167			#endif
168
169	root	1.4	static void
170	root	1.6	async_sigsend (int signum)
171			{
172			async_signal (sig_async [signum], 0);
173			}
174
175	root	1.7	#define block(async) ++(async)->blocked
176
177	root	1.6	static void
178	root	1.7	unblock (async_t *async)
179	root	1.4	{
180			--async->blocked;
181			if (async->pending && !async->blocked)
182			handle_async (async);
183	root	1.7	}
184	root	1.4
185	root	1.7	static void
186			scope_block_cb (pTHX_ void *async_sv)
187			{
188			async_t async = SvASYNC_nrv ((SV )async_sv);
189			unblock (async);
190	root	1.4	SvREFCNT_dec (async_sv);
191			}
192	root	1.1
193			MODULE = Async::Interrupt PACKAGE = Async::Interrupt
194
195			BOOT:
196			old_sighandler = PL_sighandlerp;
197			PL_sighandlerp = async_sighandler;
198			sig_pending = &PL_sig_pending;
199			psig_pend = PL_psig_pend;
200			asyncs = newAV ();
201	root	1.4	CvNODEBUG_on (get_cv ("Async::Interrupt::scope_block", 0)); /* otherwise calling scope can be the debugger */
202	root	1.1
203	root	1.3	PROTOTYPES: DISABLE
204
205	root	1.6	void
206	root	1.9	_alloc (SV cb, void c_cb, void c_arg, SV fh_r, SV fh_w, SV signl, SV *pvalue)
207	root	1.6	PPCODE:
208	root	1.1	{
209	root	1.8	SV *cv = SvOK (cb) ? SvREFCNT_inc (s_get_cv_croak (cb)) : 0;
210	root	1.6	async_t *async;
211	root	1.1
212	root	1.6	Newz (0, async, 1, async_t);
213	root	1.1
214	root	1.6	XPUSHs (sv_2mortal (newSViv (PTR2IV (async))));
215	root	1.9	/* TODO: need to bless right now to ensure deallocation */
216	root	1.6	av_push (asyncs, TOPs);
217	root	1.2
218	root	1.9	SvGETMAGIC (fh_r); SvGETMAGIC (fh_w);
219			if (SvOK (fh_r) \|\| SvOK (fh_w))
220			{
221			int fd_r = s_fileno_croak (fh_r, 0);
222			int fd_w = s_fileno_croak (fh_w, 1);
223
224			async->fh_r = newSVsv (fh_r);
225			async->fh_w = newSVsv (fh_w);
226			async->ep.fd [0] = fd_r;
227			async->ep.fd [1] = fd_w;
228			async->ep.len = 1;
229			async->fd_enable = 1;
230			}
231
232			async->value = SvROK (pvalue)
233			? SvREFCNT_inc_NN (SvRV (pvalue))
234			: NEWSV (0, 0);
235
236			sv_setiv (async->value, 0);
237			SvIOK_only (async->value); /* just to be sure */
238			SvREADONLY_on (async->value);
239
240			async->valuep = &(SvIVX (async->value));
241
242	root	1.6	async->cb = cv;
243			async->c_cb = c_cb;
244			async->c_arg = c_arg;
245	root	1.8	async->signum = SvOK (signl) ? s_signum_croak (signl) : 0;
246	root	1.6
247			if (async->signum)
248			{
249			if (async->signum < 0)
250			croak ("Async::Interrupt::new got passed illegal signal name or number: %s", SvPV_nolen (signl));
251
252			sig_async [async->signum] = async;
253			#if _WIN32
254			signal (async->signum, async_sigsend);
255			#else
256			{
257			struct sigaction sa = { };
258			sa.sa_handler = async_sigsend;
259			sigfillset (&sa.sa_mask);
260			sigaction (async->signum, &sa, 0);
261			}
262			#endif
263			}
264	root	1.1	}
265
266			void
267	root	1.6	signal_func (async_t *async)
268	root	1.1	PPCODE:
269			EXTEND (SP, 2);
270			PUSHs (sv_2mortal (newSViv (PTR2IV (async_signal))));
271	root	1.6	PUSHs (sv_2mortal (newSViv (PTR2IV (async))));
272	root	1.1
273	root	1.9	IV
274			c_var (async_t *async)
275			CODE:
276			RETVAL = PTR2IV (async->valuep);
277			OUTPUT:
278			RETVAL
279
280	root	1.1	void
281	root	1.9	signal (async_t *async, int value = 1)
282	root	1.1	CODE:
283	root	1.6	async_signal (async, value);
284	root	1.2
285			void
286	root	1.6	block (async_t *async)
287	root	1.2	CODE:
288	root	1.7	block (async);
289	root	1.2
290			void
291	root	1.6	unblock (async_t *async)
292	root	1.2	CODE:
293	root	1.7	unblock (async);
294	root	1.1
295			void
296	root	1.4	scope_block (SV *self)
297			CODE:
298			{
299			SV *async_sv = SvRV (self);
300	root	1.6	async_t *async = SvASYNC_nrv (async_sv);
301	root	1.7	block (async);
302	root	1.4
303			LEAVE; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */
304			SAVEDESTRUCTOR_X (scope_block_cb, (void *)SvREFCNT_inc (async_sv));
305			ENTER; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */
306			}
307
308			void
309	root	1.6	pipe_enable (async_t *async)
310			ALIAS:
311			pipe_enable = 1
312			pipe_disable = 0
313			CODE:
314			async->fd_enable = ix;
315
316	root	1.9	int
317			pipe_fileno (async_t *async)
318			CODE:
319			if (!async->ep.len)
320			{
321			int res;
322
323			/block (async);//TODO/
324			res = s_epipe_new (&async->ep);
325			async->fd_enable = 1;
326			/unblock (async);//TODO/
327
328			if (res < 0)
329			croak ("Async::Interrupt: unable to initialize event pipe");
330			}
331
332			RETVAL = async->ep.fd [0];
333			OUTPUT:
334			RETVAL
335
336
337			void
338			post_fork (async_t *async)
339			CODE:
340			if (async->ep.len)
341			{
342			int res;
343
344			/block (async);//TODO/
345			res = s_epipe_renew (&async->ep);
346			/unblock (async);//TODO/
347
348			if (res < 0)
349			croak ("Async::Interrupt: unable to initialize event pipe after fork");
350			}
351
352	root	1.6	void
353	root	1.1	DESTROY (SV *self)
354			CODE:
355			{
356			int i;
357			SV *async_sv = SvRV (self);
358	root	1.6	async_t *async = SvASYNC_nrv (async_sv);
359	root	1.1
360	root	1.2	for (i = AvFILLp (asyncs); i >= 0; --i)
361	root	1.1	if (AvARRAY (asyncs)[i] == async_sv)
362			{
363			if (i < AvFILLp (asyncs))
364	root	1.3	AvARRAY (asyncs)[i] = AvARRAY (asyncs)[AvFILLp (asyncs)];
365	root	1.1
366			assert (av_pop (asyncs) == async_sv);
367			goto found;
368			}
369
370			if (!PL_dirty)
371	root	1.2	warn ("Async::Interrupt::DESTROY could not find async object in list of asyncs, please report");
372	root	1.1
373			found:
374	root	1.6
375			if (async->signum)
376			{
377			#if _WIN32
378			signal (async->signum, SIG_DFL);
379			#else
380			{
381			struct sigaction sa = { };
382			sa.sa_handler = SIG_DFL;
383			sigaction (async->signum, &sa, 0);
384			}
385			#endif
386			}
387
388	root	1.9	if (!async->fh_r && async->ep.len)
389			s_epipe_destroy (&async->ep);
390
391	root	1.2	SvREFCNT_dec (async->fh_r);
392			SvREFCNT_dec (async->fh_w);
393	root	1.1	SvREFCNT_dec (async->cb);
394	root	1.9	SvREFCNT_dec (async->value);
395	root	1.1
396			Safefree (async);
397			}
398