Guard/Guard.xs

#define PERL_NO_GET_CONTEXT

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

/* apparently < 5.8.8 */
#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:	1.11
Committed:	Sun Jul 19 04:59:54 2009 UTC (14 years, 10 months ago) by root
Branch:	MAIN
CVS Tags:	rel-1_021, rel-1_022
Changes since 1.10:	+1 -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	1.11	/* apparently < 5.8.8 */
8	root	1.10	#ifndef SvSTASH_set
9			# define SvSTASH_set(x,a) SvSTASH(x) = (a)
10			#endif
11
12			#ifndef PERL_MAGIC_ext
13			# define PERL_MAGIC_ext '~'
14			#endif
15
16	root	1.3	static HV *guard_stash;
17
18	root	1.1	static SV *
19			guard_get_cv (pTHX_ SV *cb_sv)
20			{
21			HV *st;
22			GV *gvp;
23			CV *cv = sv_2cv (cb_sv, &st, &gvp, 0);
24
25			if (!cv)
26			croak ("expected a CODE reference for guard");
27
28			return (SV *)cv;
29			}
30
31			static void
32			exec_guard_cb (pTHX_ SV *cb)
33			{
34			dSP;
35			SV *saveerr = SvOK (ERRSV) ? sv_mortalcopy (ERRSV) : 0;
36	root	1.4	SV *savedie = PL_diehook;
37
38			PL_diehook = 0;
39	root	1.1
40	root	1.2	PUSHSTACKi (PERLSI_DESTROY);
41	root	1.1
42			PUSHMARK (SP);
43			PUTBACK;
44			call_sv (cb, G_VOID \| G_DISCARD \| G_EVAL);
45
46			if (SvTRUE (ERRSV))
47			{
48	root	1.7	SPAGAIN;
49
50	root	1.1	PUSHMARK (SP);
51			PUTBACK;
52			call_sv (get_sv ("Guard::DIED", 1), G_VOID \| G_DISCARD \| G_EVAL \| G_KEEPERR);
53
54	root	1.4	sv_setpvn (ERRSV, "", 0);
55	root	1.1	}
56
57			if (saveerr)
58			sv_setsv (ERRSV, saveerr);
59
60	root	1.4	{
61			SV *oldhook = PL_diehook;
62			PL_diehook = savedie;
63			SvREFCNT_dec (oldhook);
64			}
65
66	root	1.1	POPSTACK;
67			}
68
69			static void
70			scope_guard_cb (pTHX_ void *cv)
71			{
72			exec_guard_cb (aTHX_ sv_2mortal ((SV *)cv));
73			}
74
75			static int
76			guard_free (pTHX_ SV cv, MAGIC mg)
77			{
78			exec_guard_cb (aTHX_ mg->mg_obj);
79	root	1.8
80			return 0;
81	root	1.1	}
82
83			static MGVTBL guard_vtbl = {
84			0, 0, 0, 0,
85			guard_free
86			};
87
88			MODULE = Guard PACKAGE = Guard
89
90	root	1.3	BOOT:
91			guard_stash = gv_stashpv ("Guard", 1);
92	root	1.9	CvNODEBUG_on (get_cv ("Guard::scope_guard", 0)); /* otherwise calling scope can be the debugger */
93	root	1.3
94			void
95	root	1.1	scope_guard (SV *block)
96			PROTOTYPE: &
97			CODE:
98			LEAVE; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */
99			SAVEDESTRUCTOR_X (scope_guard_cb, (void *)SvREFCNT_inc (guard_get_cv (aTHX_ block)));
100			ENTER; /* unfortunately, perl sandwiches XS calls into ENTER/LEAVE */
101
102			SV *
103			guard (SV *block)
104			PROTOTYPE: &
105			CODE:
106			{
107			SV *cv = guard_get_cv (aTHX_ block);
108			SV *guard = NEWSV (0, 0);
109			SvUPGRADE (guard, SVt_PVMG);
110			sv_magicext (guard, cv, PERL_MAGIC_ext, &guard_vtbl, 0, 0);
111			RETVAL = newRV_noinc (guard);
112	root	1.3	SvOBJECT_on (guard);
113			++PL_sv_objcount;
114			SvSTASH_set (guard, (HV)SvREFCNT_inc ((SV )guard_stash));
115	root	1.1	}
116			OUTPUT:
117			RETVAL
118
119			void
120			cancel (SV *guard)
121			PROTOTYPE: $
122			CODE:
123			{
124			MAGIC *mg;
125			if (!SvROK (guard)
126			\|\| !(mg = mg_find (SvRV (guard), PERL_MAGIC_ext))
127			\|\| mg->mg_virtual != &guard_vtbl)
128			croak ("Guard::cancel called on a non-guard object");
129
130			SvREFCNT_dec (mg->mg_obj);
131			mg->mg_obj = 0;
132			mg->mg_virtual = 0;
133			}