diff --git a/doc/src/sgml/plperl.sgml b/doc/src/sgml/plperl.sgml
index 6fee031..0054f5a 100644
*** a/doc/src/sgml/plperl.sgml
--- b/doc/src/sgml/plperl.sgml
*************** CREATE TRIGGER test_valid_id_trig
*** 1030,1036 ****
    </para>
   </sect1>
  
!  <sect1 id="plperl-missing">
    <title>Limitations and Missing Features</title>
  
    <para>
--- 1030,1100 ----
    </para>
   </sect1>
  
!  <sect1 id="plperl-under-the-hood">
!   <title>PL/Perl Under the Hood</title>
! 
!  <sect2 id="plperl-config">
!   <title>Configuration</title>
! 
!   <para>
!   This section lists configuration parameters that affect <application>PL/Perl</>.
!   To set any of these parameters before <application>PL/Perl</> has been loaded,
!   it is necessary to have added <quote><literal>plperl</></> to the
!   <xref linkend="guc-custom-variable-classes"> list in
!   <filename>postgresql.conf</filename>.
!   </para>
! 
!   <variablelist>
! 
!      <varlistentry id="guc-plperl-on-perl-init" xreflabel="plperl.on_perl_init">
!       <term><varname>plperl.on_perl_init</varname> (<type>string</type>)</term>
!       <indexterm>
!        <primary><varname>plperl.on_perl_init</> configuration parameter</primary>
!       </indexterm>
!       <listitem>
!        <para>
!        Specifies perl code to be executed when a perl interpreter is first initialized.
!        The SPI functions are not available when this code is executed.
!        If the code fails with an error it will abort the initialization of the interpreter
!        and propagate out to the calling query, causing the current transaction
!        or subtransaction to be aborted.
!        </para>
!        <para>
! 	   The perl code is limited to a single string. Longer code can be placed
! 	   into a module and loaded by the <literal>on_perl_init</> string.
! 	   Examples:
! <programlisting>
! plplerl.on_perl_init = '$ENV{NYTPROF}="start=no"; require Devel::NYTProf::PgPLPerl'
! plplerl.on_perl_init = 'use lib "/my/app"; use MyApp::PgInit;'
! </programlisting>
!        </para>
!        <para>
!        Initialization will happen in the postmaster if the plperl library is included
!        in <literal>shared_preload_libraries</> (see <xref linkend="shared_preload_libraries">),
!        in which case extra consideration should be given to the risk of destabilizing the postmaster.
!        </para>
!        <para>
!        This parameter can only be set in the postgresql.conf file or on the server command line.
!        </para>
!       </listitem>
!      </varlistentry>
! 
!      <varlistentry id="guc-plperl-use-strict" xreflabel="plperl.use_strict">
!       <term><varname>plperl.use_strict</varname> (<type>boolean</type>)</term>
!       <indexterm>
!        <primary><varname>plperl.use_strict</> configuration parameter</primary>
!       </indexterm>
!       <listitem>
!        <para>
!        When set true subsequent compilations of PL/Perl functions have the <literal>strict</> pragma enabled.
!        This parameter does not affect functions already compiled in the current session.
!        </para>
!       </listitem>
!      </varlistentry>
! 
!   </variablelist>
! 
!  <sect2 id="plperl-missing">
    <title>Limitations and Missing Features</title>
  
    <para>
diff --git a/src/pl/plperl/plc_perlboot.pl b/src/pl/plperl/plc_perlboot.pl
index 769721d..5f6ae91 100644
*** a/src/pl/plperl/plc_perlboot.pl
--- b/src/pl/plperl/plc_perlboot.pl
***************
*** 1,5 ****
  PostgreSQL::InServer::Util::bootstrap();
- PostgreSQL::InServer::SPI::bootstrap();
  
  use strict;
  use warnings;
--- 1,4 ----
diff --git a/src/pl/plperl/plperl.c b/src/pl/plperl/plperl.c
index 9277072..8315d5a 100644
*** a/src/pl/plperl/plperl.c
--- b/src/pl/plperl/plperl.c
*************** static HTAB *plperl_proc_hash = NULL;
*** 138,143 ****
--- 138,145 ----
  static HTAB *plperl_query_hash = NULL;
  
  static bool plperl_use_strict = false;
+ static char *plperl_on_perl_init = NULL;
+ static bool plperl_ending = false;
  
  /* this is saved and restored by plperl_call_handler */
  static plperl_call_data *current_call_data = NULL;
*************** Datum		plperl_validator(PG_FUNCTION_ARGS
*** 151,156 ****
--- 153,160 ----
  void		_PG_init(void);
  
  static PerlInterpreter *plperl_init_interp(void);
+ static void plperl_destroy_interp(PerlInterpreter **);
+ static void plperl_fini(void);
  
  static Datum plperl_func_handler(PG_FUNCTION_ARGS);
  static Datum plperl_trigger_handler(PG_FUNCTION_ARGS);
*************** _PG_init(void)
*** 237,242 ****
--- 241,254 ----
  							 PGC_USERSET, 0,
  							 NULL, NULL);
  
+ 	DefineCustomStringVariable("plperl.on_perl_init",
+ 							gettext_noop("Perl code to execute when the perl interpreter is initialized."),
+ 							NULL,
+ 							&plperl_on_perl_init,
+ 							NULL,
+ 							PGC_SIGHUP, 0,
+ 							NULL, NULL);
+ 
  	EmitWarningsOnPlaceholders("plperl");
  
  	MemSet(&hash_ctl, 0, sizeof(hash_ctl));
*************** _PG_init(void)
*** 261,266 ****
--- 273,293 ----
  	inited = true;
  }
  
+ 
+ /*
+  * Cleanup perl interpreters, including running END blocks.
+  * Does not fully undo the actions of _PG_init() nor make it callable again.
+  */
+ static void
+ plperl_fini(void)
+ {
+ 	plperl_ending = true;
+ 	plperl_destroy_interp(&plperl_trusted_interp);
+ 	plperl_destroy_interp(&plperl_untrusted_interp);
+ 	plperl_destroy_interp(&plperl_held_interp);
+ }
+ 
+ 
  #define SAFE_MODULE \
  	"require Safe; $Safe::VERSION"
  
*************** _PG_init(void)
*** 277,282 ****
--- 304,311 ----
  static void
  select_perl_context(bool trusted)
  {
+ 	EXTERN_C void boot_PostgreSQL__InServer__SPI(pTHX_ CV *cv);
+ 
  	/*
  	 * handle simple cases
  	 */
*************** select_perl_context(bool trusted)
*** 288,293 ****
--- 317,326 ----
  	 */
  	if (interp_state == INTERP_HELD)
  	{
+ 		/* first actual use of a perl interpreter */
+ 
+ 		atexit(plperl_fini);
+ 
  		if (trusted)
  		{
  			plperl_trusted_interp = plperl_held_interp;
*************** select_perl_context(bool trusted)
*** 325,330 ****
--- 358,379 ----
  		plperl_safe_init();
  		PL_ppaddr[OP_REQUIRE] = pp_require_safe;
  	}
+ 
+ 	/*
+ 	 * enable access to the database
+ 	 */
+ 	newXS("PostgreSQL::InServer::SPI::bootstrap",
+ 		boot_PostgreSQL__InServer__SPI, __FILE__);
+ 
+ 	eval_pv("PostgreSQL::InServer::SPI::bootstrap()", FALSE);
+ 	if (SvTRUE(ERRSV))
+ 	{
+ 		ereport(ERROR,
+ 			(errcode(ERRCODE_INTERNAL_ERROR),
+ 			errmsg("%s", strip_trailing_ws(SvPV_nolen(ERRSV))),
+ 			errdetail("While executing PostgreSQL::InServer::SPI::bootstrap")));
+ 	}
+ 
  }
  
  /*
*************** plperl_init_interp(void)
*** 361,371 ****
  	PerlInterpreter *plperl;
  	static int perl_sys_init_done;
  
! 	static char *embedding[3] = {
  		"", "-e", PLC_PERLBOOT
  	};
  	int			nargs = 3;
  
  #ifdef WIN32
  
  	/*
--- 410,426 ----
  	PerlInterpreter *plperl;
  	static int perl_sys_init_done;
  
! 	static char *embedding[3+2] = {
  		"", "-e", PLC_PERLBOOT
  	};
  	int			nargs = 3;
  
+ 	if (plperl_on_perl_init)
+ 	{
+ 		embedding[nargs++] = "-e";
+ 		embedding[nargs++] = plperl_on_perl_init;
+ 	}
+ 
  #ifdef WIN32
  
  	/*
*************** plperl_init_interp(void)
*** 437,442 ****
--- 492,500 ----
  	PERL_SET_CONTEXT(plperl);
  	perl_construct(plperl);
  
+ 	/* run END blocks in perl_destruct instead of perl_run */
+ 	PL_exit_flags |= PERL_EXIT_DESTRUCT_END;
+ 
  	/*
  	 * Record the original function for the 'require' opcode.
  	 * Ensure it's used for new interpreters.
*************** plperl_init_interp(void)
*** 446,454 ****
  	else
  		PL_ppaddr[OP_REQUIRE] = pp_require_orig;
  
! 	perl_parse(plperl, plperl_init_shared_libs,
! 			   nargs, embedding, NULL);
! 	perl_run(plperl);
  
  #ifdef WIN32
  
--- 504,521 ----
  	else
  		PL_ppaddr[OP_REQUIRE] = pp_require_orig;
  
! 	if (perl_parse(plperl, plperl_init_shared_libs,
! 			   nargs, embedding, NULL) != 0)
! 		ereport(ERROR,
! 			(errcode(ERRCODE_INTERNAL_ERROR),
! 				errmsg("while parsing perl initialization"),
! 				errdetail("%s", strip_trailing_ws(SvPV_nolen(ERRSV))) ));
! 
! 	if (perl_run(plperl) != 0)
! 		ereport(ERROR,
! 			(errcode(ERRCODE_INTERNAL_ERROR),
! 				errmsg("while running perl initialization"),
! 				errdetail("%s", strip_trailing_ws(SvPV_nolen(ERRSV))) ));
  
  #ifdef WIN32
  
*************** pp_require_safe(pTHX)
*** 524,529 ****
--- 591,608 ----
  
  
  static void
+ plperl_destroy_interp(PerlInterpreter **interp)
+ {
+ 	if (interp && *interp)
+ 	{
+ 		perl_destruct(*interp);
+ 		perl_free(*interp);
+ 		*interp = NULL;
+ 	}
+ }
+ 
+ 
+ static void
  plperl_safe_init(void)
  {
  	SV		   *safe_version_sv;
*************** plperl_safe_init(void)
*** 544,551 ****
  		{
  			ereport(ERROR,
  				(errcode(ERRCODE_INTERNAL_ERROR),
! 				 errmsg("%s", strip_trailing_ws(SvPV_nolen(ERRSV))),
! 				 errdetail("While executing PLC_SAFE_BAD")));
  		}
  
  	}
--- 623,630 ----
  		{
  			ereport(ERROR,
  				(errcode(ERRCODE_INTERNAL_ERROR),
! 				 errmsg("while executing PLC_SAFE_BAD"),
! 				 errdetail("%s", strip_trailing_ws(SvPV_nolen(ERRSV))) ));
  		}
  
  	}
*************** plperl_safe_init(void)
*** 556,563 ****
  		{
  			ereport(ERROR,
  				(errcode(ERRCODE_INTERNAL_ERROR),
! 				 errmsg("%s", strip_trailing_ws(SvPV_nolen(ERRSV))),
! 				 errdetail("While executing PLC_SAFE_OK")));
  		}
  
  		if (GetDatabaseEncoding() == PG_UTF8)
--- 635,642 ----
  		{
  			ereport(ERROR,
  				(errcode(ERRCODE_INTERNAL_ERROR),
! 				 errmsg("while executing PLC_SAFE_OK"),
! 				 errdetail("%s", strip_trailing_ws(SvPV_nolen(ERRSV))) ));
  		}
  
  		if (GetDatabaseEncoding() == PG_UTF8)
*************** plperl_create_sub(plperl_proc_desc *prod
*** 1150,1167 ****
   *
   **********************************************************************/
  
- EXTERN_C void boot_DynaLoader(pTHX_ CV *cv);
- EXTERN_C void boot_PostgreSQL__InServer__SPI(pTHX_ CV *cv);
- EXTERN_C void boot_PostgreSQL__InServer__Util(pTHX_ CV *cv);
- 
  static void
  plperl_init_shared_libs(pTHX)
  {
  	char	   *file = __FILE__;
  
  	newXS("DynaLoader::boot_DynaLoader", boot_DynaLoader, file);
- 	newXS("PostgreSQL::InServer::SPI::bootstrap",
- 		  boot_PostgreSQL__InServer__SPI, file);
  	newXS("PostgreSQL::InServer::Util::bootstrap",
  		boot_PostgreSQL__InServer__Util, file);
  }
--- 1229,1242 ----
   *
   **********************************************************************/
  
  static void
  plperl_init_shared_libs(pTHX)
  {
  	char	   *file = __FILE__;
+ 	EXTERN_C void boot_DynaLoader(pTHX_ CV *cv);
+ 	EXTERN_C void boot_PostgreSQL__InServer__Util(pTHX_ CV *cv);
  
  	newXS("DynaLoader::boot_DynaLoader", boot_DynaLoader, file);
  	newXS("PostgreSQL::InServer::Util::bootstrap",
  		boot_PostgreSQL__InServer__Util, file);
  }
*************** plperl_hash_from_tuple(HeapTuple tuple, 
*** 1897,1902 ****
--- 1972,1987 ----
  }
  
  
+ static void
+ check_spi_usage_allowed()
+ {
+ 	if (plperl_ending) {
+ 		/* simple croak as we don't want to involve PostgreSQL code */
+ 		croak("SPI functions can not be used in END blocks");
+ 	}
+ }
+ 
+ 
  HV *
  plperl_spi_exec(char *query, int limit)
  {
*************** plperl_spi_exec(char *query, int limit)
*** 1909,1914 ****
--- 1994,2001 ----
  	MemoryContext oldcontext = CurrentMemoryContext;
  	ResourceOwner oldowner = CurrentResourceOwner;
  
+ 	check_spi_usage_allowed();
+ 
  	BeginInternalSubTransaction(NULL);
  	/* Want to run inside function's memory context */
  	MemoryContextSwitchTo(oldcontext);
*************** plperl_spi_execute_fetch_result(SPITuple
*** 1972,1977 ****
--- 2059,2066 ----
  {
  	HV		   *result;
  
+ 	check_spi_usage_allowed();
+ 
  	result = newHV();
  
  	hv_store_string(result, "status",
*************** plperl_spi_query(char *query)
*** 2145,2150 ****
--- 2234,2241 ----
  	MemoryContext oldcontext = CurrentMemoryContext;
  	ResourceOwner oldowner = CurrentResourceOwner;
  
+ 	check_spi_usage_allowed();
+ 
  	BeginInternalSubTransaction(NULL);
  	/* Want to run inside function's memory context */
  	MemoryContextSwitchTo(oldcontext);
*************** plperl_spi_fetchrow(char *cursor)
*** 2223,2228 ****
--- 2314,2321 ----
  	MemoryContext oldcontext = CurrentMemoryContext;
  	ResourceOwner oldowner = CurrentResourceOwner;
  
+ 	check_spi_usage_allowed();
+ 
  	BeginInternalSubTransaction(NULL);
  	/* Want to run inside function's memory context */
  	MemoryContextSwitchTo(oldcontext);
*************** plperl_spi_fetchrow(char *cursor)
*** 2297,2303 ****
  void
  plperl_spi_cursor_close(char *cursor)
  {
! 	Portal		p = SPI_cursor_find(cursor);
  
  	if (p)
  		SPI_cursor_close(p);
--- 2390,2400 ----
  void
  plperl_spi_cursor_close(char *cursor)
  {
! 	Portal		p;
! 
! 	check_spi_usage_allowed();
! 
! 	p = SPI_cursor_find(cursor);
  
  	if (p)
  		SPI_cursor_close(p);
*************** plperl_spi_prepare(char *query, int argc
*** 2315,2320 ****
--- 2412,2419 ----
  	MemoryContext oldcontext = CurrentMemoryContext;
  	ResourceOwner oldowner = CurrentResourceOwner;
  
+ 	check_spi_usage_allowed();
+ 
  	BeginInternalSubTransaction(NULL);
  	MemoryContextSwitchTo(oldcontext);
  
*************** plperl_spi_exec_prepared(char *query, HV
*** 2450,2455 ****
--- 2549,2556 ----
  	MemoryContext oldcontext = CurrentMemoryContext;
  	ResourceOwner oldowner = CurrentResourceOwner;
  
+ 	check_spi_usage_allowed();
+ 
  	BeginInternalSubTransaction(NULL);
  	/* Want to run inside function's memory context */
  	MemoryContextSwitchTo(oldcontext);
*************** plperl_spi_query_prepared(char *query, i
*** 2592,2597 ****
--- 2693,2700 ----
  	MemoryContext oldcontext = CurrentMemoryContext;
  	ResourceOwner oldowner = CurrentResourceOwner;
  
+ 	check_spi_usage_allowed();
+ 
  	BeginInternalSubTransaction(NULL);
  	/* Want to run inside function's memory context */
  	MemoryContextSwitchTo(oldcontext);
*************** plperl_spi_freeplan(char *query)
*** 2715,2720 ****
--- 2818,2825 ----
  	plperl_query_desc *qdesc;
  	plperl_query_entry *hash_entry;
  
+ 	check_spi_usage_allowed();
+ 
  	hash_entry = hash_search(plperl_query_hash, query,
  							 HASH_FIND, NULL);
  	if (hash_entry == NULL)
diff --git a/src/pl/plperl/sql/plperl_end.sql b/src/pl/plperl/sql/plperl_end.sql
index ...d4f1444 .
*** a/src/pl/plperl/sql/plperl_end.sql
--- b/src/pl/plperl/sql/plperl_end.sql
***************
*** 0 ****
--- 1,18 ----
+ -- test END block handling
+ 
+ -- Not included in the normal testing
+ -- because it's beyond the scope of the test harness.
+ -- Available here for manual developer testing.
+ 
+ DO $do$
+ 	open my $fh, ">/tmp/plperl_end.$$.log";
+ 	$SIG{__WARN__} = sub { printf $fh "Warn: @_" };
+ 	$SIG{__DIE__}  = sub { printf $fh "Die: @_"; die @_ };
+ 	END {
+ 		warn "end\n";
+ 		eval {
+ 			spi_exec_query("select 1");
+ 		};
+ 		warn "spi_exec_query: $@";
+ 	}
+ $do$ language plperlu;
diff --git a/src/pl/plperl/sql/plperl_plperlu.sql b/src/pl/plperl/sql/plperl_plperlu.sql
index fc2bb7b..15b5aa2 100644
*** a/src/pl/plperl/sql/plperl_plperlu.sql
--- b/src/pl/plperl/sql/plperl_plperlu.sql
*************** $$ LANGUAGE plperlu; -- compile plperlu 
*** 16,19 ****
  SELECT * FROM bar(); -- throws exception normally (running plperl)
  SELECT * FROM foo(); -- used to cause backend crash (after switching to plperlu)
  
- 
--- 16,18 ----