1 files changed, 91 insertions, 0 deletions
diff --git a/lib/OpenSLX/ScopedResource.pm b/lib/OpenSLX/ScopedResource.pm
new file mode 100644
index 00000000..c905b50a
--- /dev/null
+++ b/lib/OpenSLX/ScopedResource.pm
@@ -0,0 +1,91 @@
+# Copyright (c) 2008 - OpenSLX GmbH
+#
+# This program is free software distributed under the GPL version 2.
+# See http://openslx.org/COPYING
+#
+# If you have any feedback please consult http://openslx.org/feedback and
+# send your suggestions, praise, or complaints to feedback@openslx.org
+#
+# General information about OpenSLX can be found at http://openslx.org/
+# -----------------------------------------------------------------------------
+# ScopedResource.pm
+#    - a helper class that releases resources if the object leaves scope
+# -----------------------------------------------------------------------------
+package OpenSLX::ScopedResource;
+
+use strict;
+use warnings;
+
+our $VERSION = 1.01;        # API-version . implementation-version
+
+# make sure that we catch any signals in order to properly released scoped
+# resources
+use sigtrap qw( die normal-signals error-signals );
+
+use OpenSLX::Basics;
+
+sub new
+{
+    my $class = shift;
+    my $params = shift;
+    
+    checkParams($params, {
+        name    => '!',
+        acquire => '!',
+        release => '!',
+    });
+
+    my $self = {
+        name    => $params->{name},
+        owner   => 0,
+        acquire => $params->{acquire},
+        release => $params->{release},
+    };
+    
+    bless $self, $class;
+    
+    $self->acquire();
+    
+    return $self;
+}
+
+sub acquire
+{
+    my $self = shift;
+
+    # acquire the resource and set ourselves as owner
+    if ($self->{acquire}->()) {
+        vlog(1, "process $$ acquired resource $self->{name}");
+        $self->{owner} = $$;
+    }
+}
+
+sub release
+{
+    my $self = shift;
+
+    # only release the resource if invoked by the owning process
+    vlog(3, "process $$ tries to release resource $self->{name}");
+    return if $self->{owner} != $$;
+    
+    # release the resource and unset owner
+    if ($self->{release}->()) {
+        vlog(1, "process $$ released resource $self->{name}");
+        $self->{owner} = 0;
+    }
+}
+
+sub DESTROY
+{
+    my $self = shift;
+    
+    $self->release();
+    
+    # remove references to functions, in order to release any closures
+    $self->{acquire} = undef;
+    $self->{release} = undef;
+    
+    return;
+}
+
+1;