>From 7c294d251454a0b53b4ec7f6b790f7eb80bf3047 Mon Sep 17 00:00:00 2001 From: Richard Jones Date: Thu, 10 Jun 2010 15:25:43 +0100 Subject: [PATCH] perl: Add explicit close() method (RHBZ#602592). This add an optional explicit $g->close method which may be used to force the handle to be closed immediately. Note the provisos about this method in the manual page entry. Callers should *not* normally use this method. The implementation of the handle also changes. Before, the handle was a blessed reference to an integer (the integer being the pointer to the C guestfs_h handle). Now we change this to a hashref containing currently the following field: _g => pointer to C guestfs_h handle (as an integer) If this field is not present, it means that the handle has been explicitly closed. This avoids double-freeing the handle. The user may add their own fields to this hash in order to store per-handle data. However any fields whose names begin with an underscore are reserved for use by the Perl bindings. This commit also adds a regression test. This commit also changes the existing warning when you call a method without a Sys::Guestfs handle as the first parameter, into an error. This is because such cases are always errors. --- perl/t/800-explicit-close.t | 51 +++++++++++++++++++++++++++++++++++++++++++ perl/typemap | 20 +++++++++++----- src/generator.ml | 38 +++++++++++++++++++++++++++++++- 3 files changed, 102 insertions(+), 7 deletions(-) create mode 100644 perl/t/800-explicit-close.t diff --git a/perl/t/800-explicit-close.t b/perl/t/800-explicit-close.t new file mode 100644 index 0000000..8185168 --- /dev/null +++ b/perl/t/800-explicit-close.t @@ -0,0 +1,51 @@ +# libguestfs Perl bindings -*- perl -*- +# Copyright (C) 2010 Red Hat Inc. +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program; if not, write to the Free Software +# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +# Test implicit vs explicit closes of the handle (RHBZ#602592). + +use strict; +use warnings; +use Test::More tests => 10; + +use Sys::Guestfs; + +my $g; + +$g = Sys::Guestfs->new (); +ok($g); +$g->close (); # explicit close +ok($g); +undef $g; # implicit close - should be no error/warning +ok(1); + +# Expect an error if we call a method on a closed handle. +$g = Sys::Guestfs->new (); +ok($g); +$g->close (); +ok($g); +eval { $g->set_memsize (512); }; +ok($g); +ok($@ && $@ =~ /closed handle/); +undef $g; +ok(1); + +# Try calling a method without a blessed reference. This should +# give a different error. +eval { Sys::Guestfs::set_memsize (undef, 512); }; +ok ($@ && $@ =~ /not.*blessed/); +eval { Sys::Guestfs::set_memsize (42, 512); }; +ok ($@ && $@ =~ /not.*blessed/); diff --git a/perl/typemap b/perl/typemap index 752ca0d..32cd0d1 100644 --- a/perl/typemap +++ b/perl/typemap @@ -6,13 +6,21 @@ int64_t T_IV INPUT O_OBJECT_guestfs_h - if (sv_isobject ($arg) && SvTYPE (SvRV ($arg)) == SVt_PVMG) - $var = ($type) SvIV ((SV *) SvRV ($arg)); - else { - warn (\"${Package}::$func_name(): $var is not a blessed SV reference\"); - XSRETURN_UNDEF; + if (sv_isobject ($arg) && sv_derived_from ($arg, \"Sys::Guestfs\") && + SvTYPE ($arg) == SVt_RV && + SvTYPE (SvRV ($arg)) == SVt_PVHV) { + HV *hv = (HV *) SvRV ($arg); + SV **svp = hv_fetch (hv, \"_g\", 2, 0); + if (svp == NULL) + croak (\"${Package}::$func_name(): called on a closed handle\"); + $var = ($type) SvIV (*svp); + } else { + croak (\"${Package}::$func_name(): $var is not a blessed HV reference\"); } OUTPUT O_OBJECT_guestfs_h - sv_setref_pv ($arg, "Sys::Guestfs", (void *) $var); + SvREFCNT_dec ($arg); /* get rid of mortal created by wrapper code */ + HV *hv = newHV (); + (void) hv_store (hv, \"_g\", 2, newSViv (PTR2IV ($var)), 0); + $arg = sv_bless (newRV ((SV*) hv), gv_stashpv(\"Sys::Guestfs\", 1)); diff --git a/src/generator.ml b/src/generator.ml index cf28978..beacd99 100755 --- a/src/generator.ml +++ b/src/generator.ml @@ -8821,10 +8821,30 @@ _create () RETVAL void -DESTROY (g) +DESTROY (sv) + SV *sv; + PPCODE: + /* For the 'g' argument above we do the conversion explicitly and + * don't rely on the typemap, because if the handle has been + * explicitly closed we don't want the typemap conversion to + * display an error. + */ + HV *hv = (HV *) SvRV (sv); + SV **svp = hv_fetch (hv, \"_g\", 2, 0); + if (svp != NULL) { + guestfs_h *g = (guestfs_h *) SvIV (*svp); + assert (g != NULL); + guestfs_close (g); + } + +void +close (g) guestfs_h *g; PPCODE: guestfs_close (g); + /* Avoid double-free in DESTROY method. */ + HV *hv = (HV *) SvRV (ST(0)); + (void) hv_delete (hv, \"_g\", 2, G_DISCARD); "; @@ -9184,6 +9204,22 @@ sub new { return $self; } +=item $h->close (); + +Explicitly close the guestfs handle. + +B You should not usually call this function. The handle will +be closed implicitly when its reference count goes to zero (eg. +when it goes out of scope or the program ends). This call is +only required in some exceptional cases, such as where the program +may contain cached references to the handle 'somewhere' and you +really have to have the close happen right away. After calling +C the program must not call any method (including C) +on the handle (but the implicit call to C that happens +when the final reference is cleaned up is OK). + +=cut + " max_proc_nr; (* Actions. We only need to print documentation for these as -- 1.6.6.1