--- /dev/null
+package Lock::_simple;
+
+################################################################################
+# #
+# File: shared/Lock/_simple.pm #
+# #
+# Authors: Andre Malo <nd@o3media.de>, 2001-05-25 #
+# #
+# Description: belongs to Locking and Filehandle class #
+# NOT FOR PUBLIC USE #
+# #
+################################################################################
+
+use strict;
+use vars qw(
+ $VERSION
+);
+
+use Fcntl;
+
+################################################################################
+#
+# Version check
+#
+$VERSION = do { my @r =(q$Revision$ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
+
+### sub _simple_esna ###########################################################
+#
+# simple file lock
+# excl shared lock announced, no locking possible
+#
+# Params: $filename - filename
+# $timeout - timeout
+#
+# Return: success code (boolean)
+#
+sub _simple_esna {
+ my ($self, $filename, $timeout) = @_;
+ my $fh = new Lock::Handle ($filename);
+
+ for (0..$timeout) {
+ unless ($self -> exsh_announced) {
+ $self -> _simple_lock ($fh) and return 1;
+ }
+ sleep 1;
+ }
+
+ # timeout
+ return;
+}
+
+### sub _simple_ana ############################################################
+#
+# simple file lock
+# while excl lock announced, no locking possible
+#
+# Params: $filename - filename
+# $timeout - timeout
+#
+# Return: success code (boolean)
+#
+sub _simple_ana {
+ my ($self, $filename, $timeout) = @_;
+ my $fh = new Lock::Handle ($filename);
+
+ for (0..$timeout) {
+ unless ($self -> excl_announced) {
+ $self -> _simple_lock ($fh) and return 1;
+ }
+ sleep 1;
+ }
+
+ # timeout
+ return;
+}
+
+### sub _simple_aa #############################################################
+#
+# simple file lock
+# while excl lock announced, locking is possible
+#
+# Params: $filename - filename
+# $timeout - timeout
+#
+# Return: success code (boolean)
+#
+sub _simple_aa {
+ my ($self, $filename, $timeout) = @_;
+ my $fh = new Lock::Handle ($filename);
+
+ for (0..$timeout) {
+ $self -> _simple_lock ($fh) and return 1;
+ sleep 1;
+ }
+
+ # timeout
+ return;
+}
+
+### sub es_add_ref #############################################################
+#
+# increase shared lock reference counter
+# (for excl shared lock)
+#
+# Params: $timeout - timeout
+#
+# Return: success code (boolean)
+#
+sub es_add_ref {
+ my ($self, $timeout) = @_;
+
+ # lock reference counter file
+ # increase reference counter
+ # set excl shared lock
+ # release ref. counter file
+ #
+ return unless($self -> _simple_esna ($self->reflock, $timeout));
+ $self -> set_ref ($self -> get_ref + 1) or return;
+ $self -> set_exsh_announce or return;
+ $self -> _simple_unlock ($self -> reflock) or return;
+
+ # successfully done
+ 1;
+}
+
+### sub es_sub_ref #############################################################
+#
+# decrease shared lock reference counter
+# (of an excl shared locked file)
+#
+# Params: $timeout - timeout
+#
+# Return: success code (boolean)
+#
+sub es_sub_ref {
+ my ($self, $timeout) = @_;
+
+ # lock reference counter file
+ # increase reference counter
+ # release ref. counter file
+ #
+ return unless($self -> _simple_aa ($self->reflock, $timeout));
+ $self -> set_ref ($self -> get_ref - 1) or return;
+ $self -> remove_exsh_announce;
+ $self -> _simple_unlock ($self -> reflock) or return;
+
+ # successfully done
+ 1;
+}
+
+### sub add_ref ################################################################
+#
+# increase shared lock reference counter
+#
+# Params: $timeout - timeout
+#
+# Return: success code (boolean)
+#
+sub add_ref {
+ my ($self, $timeout) = @_;
+
+ # lock reference counter file
+ # increase reference counter
+ # release ref. counter file
+ #
+ return unless($self -> _simple_ana ($self->reflock, $timeout));
+ $self -> set_ref ($self -> get_ref + 1) or return;
+ $self -> _simple_unlock ($self -> reflock) or return;
+
+ # successfully done
+ 1;
+}
+
+### sub sub_ref ################################################################
+#
+# decrease shared lock reference counter
+#
+# Params: $timeout - timeout
+#
+# Return: success code (boolean)
+#
+sub sub_ref {
+ my ($self, $timeout) = @_;
+
+ # lock reference counter file
+ # increase reference counter
+ # release ref. counter file
+ #
+ return unless($self -> _simple_aa ($self->reflock, $timeout));
+ $self -> set_ref ($self -> get_ref - 1) or return;
+ $self -> _simple_unlock ($self -> reflock) or return;
+
+ # successfully done
+ 1;
+}
+
+### sub get_ref ################################################################
+#
+# read out the reference counter
+# NO LOCKING HERE!
+#
+# Params: ~none~
+#
+# Return: counter value
+#
+sub get_ref {
+ my $self = shift;
+ my ($fh, $val) = new Lock::Handle ($self -> reffile);
+
+ {
+ local $/;
+ sysopen ($fh, $fh->filename, O_RDONLY) or return 0;
+ $val = <$fh>;
+ close $fh;
+ }
+
+ # return value
+ #
+ $val;
+}
+
+### sub set_ref ################################################################
+#
+# write reference counter into file
+# NO LOCKING HERE!
+#
+# Params: counter value
+#
+# Return: success code (boolean)
+#
+sub set_ref {
+ my ($self, $val) = @_;
+ my $fh = new Lock::Handle ($self -> reffile);
+
+ if ($val == 0) {
+ if (-f $fh->filename) {
+ unlink $fh->filename or return;
+ }
+ }
+ else {
+ local $\;
+ sysopen ($fh, $fh->filename, O_WRONLY | O_TRUNC | O_CREAT) or return;
+ print $fh $val or do {
+ close $fh;
+ unlink $fh->filename;
+ return;
+ };
+
+ close $fh or do {
+ unlink $fh->filename;
+ return;
+ };
+ }
+
+ # successfully done
+ #
+ 1;
+}
+
+### sub set_excl_announce ######################################################
+#
+# try to announce an exclusive lock
+#
+# Params: ~none~
+#
+# Return: status (boolean)
+#
+sub set_excl_announce {
+ my $self = shift;
+
+ if ($self -> excl_announced) {
+ return ($self -> announced) ? 1 : return;
+ }
+
+ if ($self -> _simple_lock (new Lock::Handle ($self -> lockfile))) {
+ $self -> set_static (announced => 1);
+ return 1;
+ }
+
+ return;
+}
+
+### sub remove_excl_announce ###################################################
+#
+# remove announce of an exclusive lock, if it's set by ourself
+#
+# Params: ~none~
+#
+# Return: ~none~
+#
+sub remove_excl_announce {
+ my $self = shift;
+
+ if ($self -> excl_announced and $self -> announced) {
+ $self -> _simple_unlock ($self -> lockfile);
+ }
+
+ $self -> set_static (announced => 0);
+
+ return;
+}
+
+### sub set_exsh_announce ######################################################
+#
+# try to announce an exclusive shared lock
+#
+# Params: ~none~
+#
+# Return: status (boolean)
+#
+sub set_exsh_announce {
+ my $self = shift;
+
+ if ($self -> exsh_announced) {
+ return ($self -> es_announced) ? 1 : return;
+ }
+
+ if ($self -> _simple_lock (new Lock::Handle ($self -> exshlock))) {
+ $self -> set_static (es_announced => 1);
+ return 1;
+ }
+
+ return;
+}
+
+### sub remove_exsh_announce ###################################################
+#
+# remove an exclusive shared lock, if it's set by ourself
+#
+# Params: ~none~
+#
+# Return: ~none~
+#
+sub remove_exsh_announce {
+ my $self = shift;
+
+ if ($self -> exsh_announced and $self -> es_announced) {
+ $self -> _simple_unlock ($self -> exshlock);
+ }
+
+ $self -> set_static (es_announced => 0);
+
+ return;
+}
+
+# keep 'require' happy
+1;
+
+#
+#
+### end of Lock::_simple #######################################################
\ No newline at end of file
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