################################################################################

##

##  Version 3.x, Copyright (C) 2004-2013, Marcus Holland-Moritz.

##  Version 2.x, Copyright (C) 2001, Paul Marquess.

##  Version 1.x, Copyright (C) 1999, Kenneth Albanowski.

##

##  This program is free software; you can redistribute it and/or

##  modify it under the same terms as Perl itself.

##

################################################################################

=provides

START_MY_CXT

dMY_CXT_SV

dMY_CXT

MY_CXT_INIT

MY_CXT_CLONE

MY_CXT

pMY_CXT

pMY_CXT_

_pMY_CXT

aMY_CXT

aMY_CXT_

_aMY_CXT

=implementation

/*

 * Boilerplate macros for initializing and accessing interpreter-local

 * data from C.  All statics in extensions should be reworked to use

 * this, if you want to make the extension thread-safe.  See ext/re/re.xs

 * for an example of the use of these macros.

 *

 * Code that uses these macros is responsible for the following:

 * 1. #define MY_CXT_KEY to a unique string, e.g. "DynaLoader_guts"

 * 2. Declare a typedef named my_cxt_t that is a structure that contains

 *    all the data that needs to be interpreter-local.

 * 3. Use the START_MY_CXT macro after the declaration of my_cxt_t.

 * 4. Use the MY_CXT_INIT macro such that it is called exactly once

 *    (typically put in the BOOT: section).

 * 5. Use the members of the my_cxt_t structure everywhere as

 *    MY_CXT.member.

 * 6. Use the dMY_CXT macro (a declaration) in all the functions that

 *    access MY_CXT.

 */

#if defined(MULTIPLICITY) || defined(PERL_OBJECT) || \

    defined(PERL_CAPI)    || defined(PERL_IMPLICIT_CONTEXT)

#ifndef START_MY_CXT

/* This must appear in all extensions that define a my_cxt_t structure,

 * right after the definition (i.e. at file scope).  The non-threads

 * case below uses it to declare the data as static. */

#define START_MY_CXT

#if { VERSION < 5.004_68 }

/* Fetches the SV that keeps the per-interpreter data. */

#define dMY_CXT_SV \

        SV *my_cxt_sv = get_sv(MY_CXT_KEY, FALSE)

#else /* >= perl5.004_68 */

#define dMY_CXT_SV \

        SV *my_cxt_sv = *hv_fetch(PL_modglobal, MY_CXT_KEY,             \

                                  sizeof(MY_CXT_KEY)-1, TRUE)

#endif /* < perl5.004_68 */

/* This declaration should be used within all functions that use the

 * interpreter-local data. */

#define dMY_CXT \

        dMY_CXT_SV;                                                     \

        my_cxt_t *my_cxtp = INT2PTR(my_cxt_t*,SvUV(my_cxt_sv))

/* Creates and zeroes the per-interpreter data.

 * (We allocate my_cxtp in a Perl SV so that it will be released when

 * the interpreter goes away.) */

#define MY_CXT_INIT \

        dMY_CXT_SV;                                                     \

        /* newSV() allocates one more than needed */                    \

        my_cxt_t *my_cxtp = (my_cxt_t*)SvPVX(newSV(sizeof(my_cxt_t)-1));\

        Zero(my_cxtp, 1, my_cxt_t);                                     \

        sv_setuv(my_cxt_sv, PTR2UV(my_cxtp))

/* This macro must be used to access members of the my_cxt_t structure.

 * e.g. MYCXT.some_data */

#define MY_CXT          (*my_cxtp)

/* Judicious use of these macros can reduce the number of times dMY_CXT

 * is used.  Use is similar to pTHX, aTHX etc. */

#define pMY_CXT         my_cxt_t *my_cxtp

#define pMY_CXT_        pMY_CXT,

#define _pMY_CXT        ,pMY_CXT

#define aMY_CXT         my_cxtp

#define aMY_CXT_        aMY_CXT,

#define _aMY_CXT        ,aMY_CXT

#endif /* START_MY_CXT */

#ifndef MY_CXT_CLONE

/* Clones the per-interpreter data. */

#define MY_CXT_CLONE \

        dMY_CXT_SV;                                                     \

        my_cxt_t *my_cxtp = (my_cxt_t*)SvPVX(newSV(sizeof(my_cxt_t)-1));\

        Copy(INT2PTR(my_cxt_t*, SvUV(my_cxt_sv)), my_cxtp, 1, my_cxt_t);\

        sv_setuv(my_cxt_sv, PTR2UV(my_cxtp))

#endif

#else /* single interpreter */

#ifndef START_MY_CXT

#define START_MY_CXT    static my_cxt_t my_cxt;

#define dMY_CXT_SV      dNOOP

#define dMY_CXT         dNOOP

#define MY_CXT_INIT     NOOP

#define MY_CXT          my_cxt

#define pMY_CXT         void

#define pMY_CXT_

#define _pMY_CXT

#define aMY_CXT

#define aMY_CXT_

#define _aMY_CXT

#endif /* START_MY_CXT */

#ifndef MY_CXT_CLONE

#define MY_CXT_CLONE    NOOP

#endif

#endif

=xsmisc

#define MY_CXT_KEY "Devel::PPPort::_guts" XS_VERSION

typedef struct {

  /* Put Global Data in here */

  int dummy;

} my_cxt_t;

START_MY_CXT

=xsboot

{

  MY_CXT_INIT;

  /* If any of the fields in the my_cxt_t struct need

   * to be initialised, do it here.

   */

  MY_CXT.dummy = 42;

}

=xsubs

int

MY_CXT_1()

        CODE:

                dMY_CXT;

                RETVAL = MY_CXT.dummy == 42;

                ++MY_CXT.dummy;

        OUTPUT:

                RETVAL

int

MY_CXT_2()

        CODE:

                dMY_CXT;

                RETVAL = MY_CXT.dummy == 43;

        OUTPUT:

                RETVAL

int

MY_CXT_CLONE()

        CODE:

                MY_CXT_CLONE;

                RETVAL = 42;

        OUTPUT:

                RETVAL

=tests plan => 3

ok(&Devel::PPPort::MY_CXT_1());

ok(&Devel::PPPort::MY_CXT_2());

ok(&Devel::PPPort::MY_CXT_CLONE());