Re^2: Perl calls C calls Perl CallBack: How Perl callback use the same interpreter/context as Perl caller?

Hi,

Appreciate your response!

In general the flow of my current code is divided to 5 stages(as seen bellow):
1. Create an interpreter (my_perl)
2. Push parameters to the Perl stack (XPUSHs)
3. Call Perl function (call_pv)
4. POP return value (POPi)
5. Destruct the interpreter

Code wise, stages 2 and 4 depends on the existance of 'my_perl' interpreter pointer (XPUSHs and POPi macros are using it).

How can I get a pointer to the interpreter of the Perl function that called the C code? Should I use other macros?

Thanks a lot for your help :)

Itamar

    HV* my_hash;
    AV* my_arr;
    int retVal = 0;
    char* my_argv[] = { "", cb->cbFunc.perlCbFunc.fileName };

    // PERL interpreter creation
    my_perl = perl_alloc();
    perl_construct( my_perl );

    // PERL interpreter initiation
    perl_parse( my_perl,        // The interpreter
                NULL,           // XSINIT value - Should be NULL if no
+ external modules are being used
                2,              // Number of entries in 'my_argv'
                my_argv,        // PERL 'command line'.
                (char **)NULL); // ENV, not relevant for our usage

    // Run the PERL interpreter
    perl_run(my_perl);

    // Call a PERL function
    dSP;                                                        /* Ini
+tialize stack pointer         */
    ENTER;                                                      /* Eve
+rything created after here    */
    SAVETMPS;                                                   /* ...
+is a temporary variable.      */
    PUSHMARK(SP);                                               /* Rem
+ember the stack pointer       */

    XPUSHs(sv_2mortal(newSViv((unsigned int)cbCtx)));           /* Pus
+h callback context onto stack */
    
    my_hash = newHV();
    my_arr  = newAV();

    hv_store( my_hash, "aaaaaa", 6, newSViv(1), 0 );
    hv_store( my_hash, "bbb", 3, newSViv(2), 0 );
    hv_store( my_hash, "cccccccccc", 10, newSViv(3), 0 );
    hv_store( my_hash, "ddddddddd", 9, newSViv(4), 0 );
    hv_store( my_hash, "eeeeeee", 7, newSViv(5), 0 );
    hv_store( my_hash, "ffff", 4, newSViv(6), 0 );
    hv_store( my_hash, "gggggg", 6, newSViv(7), 0 );
    hv_store( my_hash, "hhhhhhh", 7, newSViv(8), 0 );

    for ( int i = 0; i < 50; i++ )
    {
        av_push( my_arr, newSViv((unsigned int)arr[i]) );
    }

    // Store reference to parameters on the HASH
    hv_store( my_hash, "arr", 6, newRV((SV*)my_arr), 0 );

    XPUSHs( sv_2mortal(newRV((SV*)my_hash)) );

    PUTBACK;                                                    /* Mak
+e local stack pointer global  */
    call_pv( funcName, G_SCALAR );                              /* Cal
+l the function                */
    retVal = POPi;                                              /* POP
+ the return of the PERL function */
    SPAGAIN;                                                    /* Ref
+resh stack pointer            */
    PUTBACK;
    FREETMPS;                                                   /* fre
+e that return value           */
    LEAVE;                                                      /* ...
+and the XPUSHed "mortal" args */

    // Destruct PERL interpreter
    perl_destruct(my_perl);
    perl_free(my_perl);
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Comment on Re^2: Perl calls C calls Perl CallBack: How Perl callback use the same interpreter/context as Perl caller? Download Code

Replies are listed 'Best First'.
Re^3: Perl calls C calls Perl CallBack: How Perl callback use the same interpreter/context as Perl caller? by Corion (Patriarch) on Jul 08, 2014 at 10:47 UTC
I think that basically you will have to make `my_perl` a global variable so that it is available everywhere. You could also pass the information through Perl as an integer (SvIV), but that makes for a horribly brittle design.	[reply] [d/l]
Re^4: Perl calls C calls Perl CallBack: How Perl callback use the same interpreter/context as Perl caller? by itamarat (Acolyte) on Jul 08, 2014 at 10:56 UTC
Hi, Is there a Perl syntax for getting interpreter pointer? Making my_perl global will require a new compilation of the Perl LIB (perl514.lib). Thanks, Itamar	[reply]
Re^5: Perl calls C calls Perl CallBack: How Perl callback use the same interpreter/context as Perl caller? by salva (Canon) on Jul 08, 2014 at 11:21 UTC
Is there a Perl syntax for getting interpreter pointer? You can pass it around from XS to C using the `pTHX` and `aTHX` (and `pTHX_` and `pTHX_`) macros. Another option is to retrieve the current Perl interpreter calling `Perl_get_context()`. It is more or less explained on perlguts. Also, search CPAN for code containing `call_sv` and see how others have done it!	[reply] [d/l] [select]
Re^6: Perl calls C calls Perl CallBack: How Perl callback use the same interpreter/context as Perl caller? by itamarat (Acolyte) on Jul 08, 2014 at 12:55 UTC
Re^7: Perl calls C calls Perl CallBack: How Perl callback use the same interpreter/context as Perl caller? by salva (Canon) on Jul 08, 2014 at 13:17 UTC
Some notes below your chosen depth have not been shown here
Re^5: Perl calls C calls Perl CallBack: How Perl callback use the same interpreter/context as Perl caller? by Corion (Patriarch) on Jul 08, 2014 at 11:39 UTC
I thought that `my_perl` was a variable in your C code, but I now realize that your C code gets called from Perl. I don't find a convenient way in perlguts, perlapi or perlcall, but maybe you don't even need special things like passing the Perl interpreter around as the current Perl interpreter already is a global variable.	[reply] [d/l]