Thread: replicable problem with PL/Perl

replicable problem with PL/Perl

From
Rajesh Kumar Mallah
Date:

Hi this strage phenomenon is happening with my PL/Perl
if one  pl/perl function raises an ERROR even other pl/perl
functions stop working and keep rasing the previous error

Regds
Mallah.

tradein_clients=# UPDATE companies set xml = utils.print_file('/usr/local/perlapache/htdocs/templates/hp/data/company_'
||company_id || '.xml');
 
UPDATE 713
tradein_clients=#
tradein_clients=# UPDATE companies set xml = utils.print_file('/usr/local/perlapache/htdocs/templates/hp/data/company_'
||company_id || '.xml');
 
UPDATE 713
tradein_clients=# SELECT company_id, utils.pgxml_xpath_pl('/Company@CompanyId' , xml) from companies where xml is not
nulland company_id=619;
 
INFO:  pgxml_xpath_pl called

ERROR:  There was an error:
mismatched tag at line 45, column 867, byte 2849 at /opt/perl/lib/site_perl/5.8.0/i686-linux/XML/Parser.pm line 185

tradein_clients=# UPDATE companies set xml = utils.print_file('/usr/local/perlapache/htdocs/templates/hp/data/company_'
||company_id || '.xml');
 
ERROR:  plperl: error from function:
mismatched tag at line 45, column 867, byte 2849 at /opt/perl/lib/site_perl/5.8.0/i686-linux/XML/Parser.pm line 185

This query was working previously and utils.print_file is independent of utils.pgxml_xpath_pl


tradein_clients=#


-- 
Rajesh Kumar Mallah,
Project Manager (Development)
Infocom Network Limited, New Delhi
phone: +91(11)6152172 (221) (L) ,9811255597 (M)

Visit http://www.trade-india.com ,
India's Leading B2B eMarketplace.



Re: replicable problem with PL/Perl

From
Tom Lane
Date:
Rajesh Kumar Mallah <mallah@trade-india.com> writes:
> if one  pl/perl function raises an ERROR even other pl/perl
> functions stop working and keep rasing the previous error

This was reported before:
http://archives.postgresql.org/pgsql-hackers/2002-10/msg00170.php

I'm not convinced that John's proposed fix is correct though
(see followup discussion).  Someone should bring up the issue
with some Perl gurus and see whether clearing $@ is really an
appropriate thing to do.
        regards, tom lane



Re: replicable problem with PL/Perl

From
Rajesh Kumar Mallah
Date:

Thanks Tom,

and sorry for the repost :)

regds
mallah.

On Saturday 19 Apr 2003 10:04 pm, Tom Lane wrote:
> Rajesh Kumar Mallah <mallah@trade-india.com> writes:
> > if one  pl/perl function raises an ERROR even other pl/perl
> > functions stop working and keep rasing the previous error
>
> This was reported before:
> http://archives.postgresql.org/pgsql-hackers/2002-10/msg00170.php
>
> I'm not convinced that John's proposed fix is correct though
> (see followup discussion).  Someone should bring up the issue
> with some Perl gurus and see whether clearing $@ is really an
> appropriate thing to do.
>
>             regards, tom lane

-- 
Rajesh Kumar Mallah,
Project Manager (Development)
Infocom Network Limited, New Delhi
phone: +91(11)6152172 (221) (L) ,9811255597 (M)

Visit http://www.trade-india.com ,
India's Leading B2B eMarketplace.



Re: replicable problem with PL/Perl

From
Tom Lane
Date:
Rajesh Kumar Mallah <mallah@trade-india.com> writes:
> if one  pl/perl function raises an ERROR even other pl/perl
> functions stop working and keep rasing the previous error

> [ similar report last fall from John Worsley ]

I have applied the attached patch to fix these problems.  (It's against
7.3 or current, but should be adaptable to 7.2 if you need to.)  The
key point is to get rid of G_KEEPERR in the perl_call_sv function;
but it turns out that the setjmp/longjmp logic is broken too.  Since the
latter wasn't doing anything particularly useful, I just diked it out.
        regards, tom lane

*** src/pl/plperl/plperl.c.orig    Sat Sep 21 14:39:26 2002
--- src/pl/plperl/plperl.c    Sun Apr 20 17:15:34 2003
***************
*** 92,99 ****  * Global data  **********************************************************************/ static int
plperl_firstcall= 1;
 
- static int    plperl_call_level = 0;
- static int    plperl_restart_in_progress = 0; static PerlInterpreter *plperl_interp = NULL; static HV
*plperl_proc_hash= NULL; 
 
--- 92,97 ----
***************
*** 143,148 ****
--- 141,155 ----     if (!plperl_firstcall)         return; 
+     /************************************************************
+      * Free the proc hash table
+      ************************************************************/
+     if (plperl_proc_hash != NULL)
+     {
+         hv_undef(plperl_proc_hash);
+         SvREFCNT_dec((SV *) plperl_proc_hash);
+         plperl_proc_hash = NULL;
+     }      /************************************************************      * Destroy the existing Perl
interpreter
***************
*** 155,170 ****     }      /************************************************************
-      * Free the proc hash table
-      ************************************************************/
-     if (plperl_proc_hash != NULL)
-     {
-         hv_undef(plperl_proc_hash);
-         SvREFCNT_dec((SV *) plperl_proc_hash);
-         plperl_proc_hash = NULL;
-     }
- 
-     /************************************************************      * Now recreate a new Perl interpreter
************************************************************/    plperl_init_interp();
 
--- 162,167 ----
***************
*** 202,209 ****     perl_parse(plperl_interp, plperl_init_shared_libs, 3, embedding, NULL);
perl_run(plperl_interp);
 
- 
-      /************************************************************      * Initialize the proc and query hash tables
  ************************************************************/
 
--- 199,204 ----
***************
*** 212,218 **** }  
-  /**********************************************************************  * plperl_call_handler        - This is the
onlyvisible function  *                  of the PL interpreter. The PostgreSQL
 
--- 207,212 ----
***************
*** 229,235 ****     Datum        retval;      /************************************************************
!      * Initialize interpreters on first call      ************************************************************/
if(plperl_firstcall)         plperl_init_all();
 
--- 223,229 ----     Datum        retval;      /************************************************************
!      * Initialize interpreter on first call      ************************************************************/     if
(plperl_firstcall)        plperl_init_all();
 
***************
*** 239,248 ****      ************************************************************/     if (SPI_connect() !=
SPI_OK_CONNECT)        elog(ERROR, "plperl: cannot connect to SPI manager");
 
-     /************************************************************
-      * Keep track about the nesting of Perl-SPI-Perl-... calls
-      ************************************************************/
-     plperl_call_level++;      /************************************************************      * Determine if
calledas function or trigger and
 
--- 233,238 ----
***************
*** 261,268 ****     else         retval = plperl_func_handler(fcinfo); 
-     plperl_call_level--;
-      return retval; } 
--- 251,256 ----
***************
*** 272,284 ****  *        create the anonymous subroutine whose text is in the SV.  *        Returns the SV containing
theRV to the closure.  **********************************************************************/
 
! static
! SV * plperl_create_sub(char *s, bool trusted) {     dSP;
! 
!     SV           *subref = NULL;     int            count;      ENTER;
--- 260,270 ----  *        create the anonymous subroutine whose text is in the SV.  *        Returns the SV containing
theRV to the closure.  **********************************************************************/
 
! static SV * plperl_create_sub(char *s, bool trusted) {     dSP;
!     SV           *subref;     int            count;      ENTER;
***************
*** 286,295 ****
--- 272,294 ----     PUSHMARK(SP);     XPUSHs(sv_2mortal(newSVpv(s, 0)));     PUTBACK;
+     /*
+      * G_KEEPERR seems to be needed here, else we don't recognize compile
+      * errors properly.  Perhaps it's because there's another level of eval
+      * inside mksafefunc?
+      */     count = perl_call_pv((trusted ? "mksafefunc" : "mkunsafefunc"),                          G_SCALAR |
G_EVAL| G_KEEPERR);     SPAGAIN; 
 
+     if (count != 1)
+     {
+         PUTBACK;
+         FREETMPS;
+         LEAVE;
+         elog(ERROR, "plperl: didn't get a return item from mksafefunc");
+     }
+      if (SvTRUE(ERRSV))     {         POPs;
***************
*** 299,307 ****         elog(ERROR, "creation of function failed: %s", SvPV(ERRSV, PL_na));     } 
-     if (count != 1)
-         elog(ERROR, "creation of function failed - no return from mksafefunc");
-      /*      * need to make a deep copy of the return. it comes off the stack as a      * temporary.
--- 298,303 ----
***************
*** 324,329 ****
--- 320,326 ----     PUTBACK;     FREETMPS;     LEAVE;
+      return subref; } 
***************
*** 352,372 ****  * plperl_call_perl_func()        - calls a perl function through the RV  *            stored in the
prodescstructure. massages the input parms properly
**********************************************************************/
! static
! SV * plperl_call_perl_func(plperl_proc_desc * desc, FunctionCallInfo fcinfo) {     dSP;
-      SV           *retval;     int            i;     int            count; 
-      ENTER;     SAVETMPS; 
!     PUSHMARK(sp);     for (i = 0; i < desc->nargs; i++)     {         if (desc->arg_is_rel[i])
--- 349,366 ----  * plperl_call_perl_func()        - calls a perl function through the RV  *            stored in the
prodescstructure. massages the input parms properly
**********************************************************************/
! static SV * plperl_call_perl_func(plperl_proc_desc * desc, FunctionCallInfo fcinfo) {     dSP;     SV
*retval;    int            i;     int            count;      ENTER;     SAVETMPS; 
 
!     PUSHMARK(SP);     for (i = 0; i < desc->nargs; i++)     {         if (desc->arg_is_rel[i])
***************
*** 401,407 ****         }     }     PUTBACK;
!     count = perl_call_sv(desc->reference, G_SCALAR | G_EVAL | G_KEEPERR);      SPAGAIN; 
--- 395,403 ----         }     }     PUTBACK;
! 
!     /* Do NOT use G_KEEPERR here */
!     count = perl_call_sv(desc->reference, G_SCALAR | G_EVAL);      SPAGAIN; 
***************
*** 424,439 ****      retval = newSVsv(POPs); 
-      PUTBACK;     FREETMPS;     LEAVE;      return retval;
- 
-  }  /**********************************************************************  * plperl_func_handler()        - Handler
forregular function calls  **********************************************************************/
 
--- 420,433 ----      retval = newSVsv(POPs);      PUTBACK;     FREETMPS;     LEAVE;      return retval; } 
+  /**********************************************************************  * plperl_func_handler()        - Handler
forregular function calls  **********************************************************************/
 
***************
*** 443,465 ****     plperl_proc_desc *prodesc;     SV           *perlret;     Datum        retval;
-     sigjmp_buf    save_restart;      /* Find or compile the function */     prodesc =
compile_plperl_function(fcinfo->flinfo->fn_oid,false); 
 
-     /* Set up error handling */
-     memcpy(&save_restart, &Warn_restart, sizeof(save_restart));
- 
-     if (sigsetjmp(Warn_restart, 1) != 0)
-     {
-         memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
-         plperl_restart_in_progress = 1;
-         if (--plperl_call_level == 0)
-             plperl_restart_in_progress = 0;
-         siglongjmp(Warn_restart, 1);
-     }
-      /************************************************************      * Call the Perl function
************************************************************/
--- 437,446 ----
***************
*** 490,503 ****      SvREFCNT_dec(perlret); 
-     memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
-     if (plperl_restart_in_progress)
-     {
-         if (--plperl_call_level == 0)
-             plperl_restart_in_progress = 0;
-         siglongjmp(Warn_restart, 1);
-     }
-      return retval; } 
--- 471,476 ----