Guard/Guard.xs

#define PERL_NO_GET_CONTEXT

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

#ifndef SvSTASH_set
# define SvSTASH_set(x,a) SvSTASH(x) = (a)
#endif

#ifndef PERL_MAGIC_ext
# define PERL_MAGIC_ext '~'
#endif

static HV *guard_stash;

static SV *
guard_get_cv (pTHX_ SV *cb_sv)
{
  HV *st;
  GV *gvp;
  CV *cv = sv_2cv (cb_sv, &st, &gvp, 0);

  if (!cv)
    croak ("expected a CODE reference for guard");

  return (SV *)cv;
}

static void
exec_guard_cb (pTHX_ SV *cb)
{
  dSP;
  SV *saveerr = SvOK (ERRSV) ? sv_mortalcopy (ERRSV) : 0;
  SV *savedie = PL_diehook;

  PL_diehook = 0;

  PUSHSTACKi (PERLSI_DESTROY);

  PUSHMARK (SP);
  PUTBACK;
  call_sv (cb, G_VOID | G_DISCARD | G_EVAL);

  if (SvTRUE (ERRSV))
    {
      SPAGAIN;

      PUSHMARK (SP);
      PUTBACK;
      call_sv (get_sv ("Guard::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;
}

static void
scope_guard_cb (pTHX_ void *cv)
{
  exec_guard_cb (aTHX_ sv_2mortal ((SV *)cv));
}

static int
guard_free (pTHX_ SV *cv, MAGIC *mg)
{
  exec_guard_cb (aTHX_ mg->mg_obj);

  return 0;
}

static MGVTBL guard_vtbl = {
  0, 0, 0, 0,
  guard_free
};

MODULE = Guard          PACKAGE = Guard

BOOT:
        guard_stash = gv_stashpv ("Guard", 1);
        CvNODEBUG_on (get_cv ("Guard::scope_guard", 0)); /* otherwise calling scope can be the debugger */

void
scope_guard (SV *block)
        PROTOTYPE: &
        CODE:
        LEAVE; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */
        SAVEDESTRUCTOR_X (scope_guard_cb, (void *)SvREFCNT_inc (guard_get_cv (aTHX_ block)));
        ENTER; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */

SV *
guard (SV *block)
        PROTOTYPE: &
        CODE:
{
        SV *cv = guard_get_cv (aTHX_ block);
        SV *guard = NEWSV (0, 0);
        SvUPGRADE (guard, SVt_PVMG);
        sv_magicext (guard, cv, PERL_MAGIC_ext, &guard_vtbl, 0, 0);
        RETVAL = newRV_noinc (guard);
        SvOBJECT_on (guard);
        ++PL_sv_objcount;
        SvSTASH_set (guard, (HV*)SvREFCNT_inc ((SV *)guard_stash));
}
        OUTPUT:
        RETVAL

void
cancel (SV *guard)
        PROTOTYPE: $
        CODE:
{
        MAGIC *mg;
        if (!SvROK (guard)
            || !(mg = mg_find (SvRV (guard), PERL_MAGIC_ext))
            || mg->mg_virtual != &guard_vtbl)
          croak ("Guard::cancel called on a non-guard object");

        SvREFCNT_dec (mg->mg_obj);
        mg->mg_obj     = 0;
        mg->mg_virtual = 0;
}
Revision:	1.10
Committed:	Sun Jul 19 04:43:47 2009 UTC (14 years, 10 months ago) by root
Branch:	MAIN
Changes since 1.9:	+8 -0 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#define PERL_NO_GET_CONTEXT
2
3			#include "EXTERN.h"
4			#include "perl.h"
5			#include "XSUB.h"
6
7	root	1.10	#ifndef SvSTASH_set
8			# define SvSTASH_set(x,a) SvSTASH(x) = (a)
9			#endif
10
11			#ifndef PERL_MAGIC_ext
12			# define PERL_MAGIC_ext '~'
13			#endif
14
15	root	1.3	static HV *guard_stash;
16
17	root	1.1	static SV *
18			guard_get_cv (pTHX_ SV *cb_sv)
19			{
20			HV *st;
21			GV *gvp;
22			CV *cv = sv_2cv (cb_sv, &st, &gvp, 0);
23
24			if (!cv)
25			croak ("expected a CODE reference for guard");
26
27			return (SV *)cv;
28			}
29
30			static void
31			exec_guard_cb (pTHX_ SV *cb)
32			{
33			dSP;
34			SV *saveerr = SvOK (ERRSV) ? sv_mortalcopy (ERRSV) : 0;
35	root	1.4	SV *savedie = PL_diehook;
36
37			PL_diehook = 0;
38	root	1.1
39	root	1.2	PUSHSTACKi (PERLSI_DESTROY);
40	root	1.1
41			PUSHMARK (SP);
42			PUTBACK;
43			call_sv (cb, G_VOID \| G_DISCARD \| G_EVAL);
44
45			if (SvTRUE (ERRSV))
46			{
47	root	1.7	SPAGAIN;
48
49	root	1.1	PUSHMARK (SP);
50			PUTBACK;
51			call_sv (get_sv ("Guard::DIED", 1), G_VOID \| G_DISCARD \| G_EVAL \| G_KEEPERR);
52
53	root	1.4	sv_setpvn (ERRSV, "", 0);
54	root	1.1	}
55
56			if (saveerr)
57			sv_setsv (ERRSV, saveerr);
58
59	root	1.4	{
60			SV *oldhook = PL_diehook;
61			PL_diehook = savedie;
62			SvREFCNT_dec (oldhook);
63			}
64
65	root	1.1	POPSTACK;
66			}
67
68			static void
69			scope_guard_cb (pTHX_ void *cv)
70			{
71			exec_guard_cb (aTHX_ sv_2mortal ((SV *)cv));
72			}
73
74			static int
75			guard_free (pTHX_ SV cv, MAGIC mg)
76			{
77			exec_guard_cb (aTHX_ mg->mg_obj);
78	root	1.8
79			return 0;
80	root	1.1	}
81
82			static MGVTBL guard_vtbl = {
83			0, 0, 0, 0,
84			guard_free
85			};
86
87			MODULE = Guard PACKAGE = Guard
88
89	root	1.3	BOOT:
90			guard_stash = gv_stashpv ("Guard", 1);
91	root	1.9	CvNODEBUG_on (get_cv ("Guard::scope_guard", 0)); /* otherwise calling scope can be the debugger */
92	root	1.3
93			void
94	root	1.1	scope_guard (SV *block)
95			PROTOTYPE: &
96			CODE:
97			LEAVE; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */
98			SAVEDESTRUCTOR_X (scope_guard_cb, (void *)SvREFCNT_inc (guard_get_cv (aTHX_ block)));
99			ENTER; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */
100
101			SV *
102			guard (SV *block)
103			PROTOTYPE: &
104			CODE:
105			{
106			SV *cv = guard_get_cv (aTHX_ block);
107			SV *guard = NEWSV (0, 0);
108			SvUPGRADE (guard, SVt_PVMG);
109			sv_magicext (guard, cv, PERL_MAGIC_ext, &guard_vtbl, 0, 0);
110			RETVAL = newRV_noinc (guard);
111	root	1.3	SvOBJECT_on (guard);
112			++PL_sv_objcount;
113			SvSTASH_set (guard, (HV)SvREFCNT_inc ((SV )guard_stash));
114	root	1.1	}
115			OUTPUT:
116			RETVAL
117
118			void
119			cancel (SV *guard)
120			PROTOTYPE: $
121			CODE:
122			{
123			MAGIC *mg;
124			if (!SvROK (guard)
125			\|\| !(mg = mg_find (SvRV (guard), PERL_MAGIC_ext))
126			\|\| mg->mg_virtual != &guard_vtbl)
127			croak ("Guard::cancel called on a non-guard object");
128
129			SvREFCNT_dec (mg->mg_obj);
130			mg->mg_obj = 0;
131			mg->mg_virtual = 0;
132			}