From 4efca15bb2136c3e226eb4e372776fad95a955c9 Mon Sep 17 00:00:00 2001 From: ndparker <> Date: Wed, 20 Jun 2001 20:34:11 +0000 Subject: [PATCH 1/1] added submodules of new Lock.pm --- selfforum-cgi/shared/Lock/API.pm | 288 ++++++++++++++++++++ selfforum-cgi/shared/Lock/Exclusive.pm | 123 +++++++++ selfforum-cgi/shared/Lock/Handle.pm | 62 +++++ selfforum-cgi/shared/Lock/Symlink.pm | 121 +++++++++ selfforum-cgi/shared/Lock/Unlink.pm | 124 +++++++++ selfforum-cgi/shared/Lock/_simple.pm | 351 +++++++++++++++++++++++++ selfforum-cgi/shared/Lock/_static.pm | 184 +++++++++++++ 7 files changed, 1253 insertions(+) create mode 100644 selfforum-cgi/shared/Lock/API.pm create mode 100644 selfforum-cgi/shared/Lock/Exclusive.pm create mode 100644 selfforum-cgi/shared/Lock/Handle.pm create mode 100644 selfforum-cgi/shared/Lock/Symlink.pm create mode 100644 selfforum-cgi/shared/Lock/Unlink.pm create mode 100644 selfforum-cgi/shared/Lock/_simple.pm create mode 100644 selfforum-cgi/shared/Lock/_static.pm diff --git a/selfforum-cgi/shared/Lock/API.pm b/selfforum-cgi/shared/Lock/API.pm new file mode 100644 index 0000000..21f3ecf --- /dev/null +++ b/selfforum-cgi/shared/Lock/API.pm @@ -0,0 +1,288 @@ +package Lock::API; + +################################################################################ +# # +# File: shared/Lock/API.pm # +# # +# Authors: Andre Malo , 2001-05-25 # +# # +# Description: system independent part of Locking and Filehandle class # +# NOT FOR PUBLIC USE # +# # +################################################################################ + +use strict; +use vars qw( + $VERSION +); + +use Carp; + +use base qw( + Lock::Handle + Lock::_simple +); + +################################################################################ +# +# Version check +# +$VERSION = do { my @r =(q$Revision$ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r }; + +### sub lock ################################################################### +# +# set a lock on the file +# +# Params: $locktype - what kind of locking? +# $timeout - (optional) Timeout +# +# Return: success (boolean) +# +sub lock { + my $self = shift; + my $locktype = shift; + + return if $self -> masterlocked; + + ########################################### + # shared lock + # + if ($locktype == $self -> LH_SHARED) { + return 1 if $self -> locked_shared; + return if $self -> locked_exclusive; + + my $timeout = shift || $self -> timeout ('shared'); + + # try to increase the reference counter + # + if ($self -> add_ref($timeout)) { + $self -> set_static (locked_shared => 1); + return 1; + } + } + + + ########################################### + # exclusive lock + # + elsif ($locktype == $self -> LH_EXCL) { + return 1 if $self -> locked_exclusive; + + my $timeout = shift || $self -> timeout ('exclusive'); + + ##################### + # transform exclusive shared lock into exclusive lock + # + if ($self -> locked_exsh) { + my $reflock = new Lock::Handle ($self -> reflock); + + for (0..$timeout) { + if ($self -> set_excl_announce and $self -> _simple_lock ($reflock)) { + if ($self -> get_ref == 1) { + $self -> set_ref(0); + $self -> remove_exsh_announce; + $self -> set_static (locked_exsh => 0); + $self -> set_static (locked_exclusive => 1); + return 1; + } + + last unless ($self -> _simple_unlock ($reflock->filename)); + } + + sleep 1; + } + $self -> remove_excl_announce; + } + + ##################### + # set exclusive lock + # + else { + my $reflock = new Lock::Handle ($self -> reflock); + + for (0..$timeout) { + if ($self -> set_excl_announce and $self -> _simple_lock ($reflock)) { + if ($self -> get_ref == 0) { + $self -> set_static (locked_exclusive => 1); + return 1; + } + + last unless ($self -> _simple_unlock ($reflock->filename)); + } + + sleep 1; + } + $self -> remove_excl_announce; + } + } + + + ########################################### + # exclusive shared lock + # + elsif ($locktype == $self -> LH_EXSH) { + return 1 if $self -> locked_exsh; + return if ($self -> locked_shared or $self -> locked_exclusive); + + my $timeout = shift || $self -> timeout ('shared'); + + # try to increase the reference counter + # + if ($self -> es_add_ref($timeout)) { + $self -> set_static (locked_exsh => 1); + return 1; + } + } + + + ########################################### + # master lock + # + elsif ($locktype == $self -> LH_MASTER) { + $self -> lock ($self->LH_EXCL, $self -> timeout('master')) and + $self -> _simple_lock (new Lock::Handle ($self->masterlock)) and + return 1; + } + + ########################################### + # unknown locking type + # + else { + croak "unknown locking type '$locktype'"; + } + + # timeout + # + $self -> unlock_violent; + return; +} + +### sub unlock ################################################################# +# +# remove shared or exclusive lock +# +# Params: $timeout - (optional) Timeout +# +# Return: success (boolean) +# +sub unlock { + my $self = shift; + my $timeout = shift || $self -> timeout ('shared'); + + return if $self -> masterlocked; + + ########################################### + # shared lock + # + if ($self -> locked_shared) { + # try to decrease the reference counter + # + if ($self -> sub_ref($timeout)) { + $self -> set_static (locked_shared => 0); + return 1; + } + } + + + ########################################### + # exclusive lock + # + elsif ($self -> locked_exclusive) { + my $reflock = new Lock::Handle ($self -> reflock); + + for (0..$timeout) { + if ($self -> _simple_unlock ($reflock->filename)) { + $self -> remove_excl_announce; + $self -> set_static (locked_exclusive => 0); + return 1; + } + + sleep 1; + } + } + + + ########################################### + # exclusive shared lock + # + elsif ($self -> locked_exsh) { + # try to decrease the reference counter + # + if ($self -> es_sub_ref($timeout)) { + $self -> remove_exsh_announce; + $self -> set_static (locked_exsh => 0); + return 1; + } + } + + + ########################################### + # not locked + # + else { + return 1; + } + + # unlocking failed + # + $self -> unlock_violent; + return; +} + +### sub unlock_violent ######################################################### +# +# remove any lock violently (excludes master lock) +# +# Params: ~none~ +# +# Return: -none- (the success is undefined) +# +sub unlock_violent { + my $self = shift; + + unless ($self -> masterlocked) { + + # find out last modification time + # and do nothing unless 'violent-timout' is over + # + my $time = $self -> _reftime; + + if ($time) { + return if ((time - $time) < $self -> timeout('violent')); + } + + $self -> set_ref (0); # reference counter = 0 + $self -> _simple_unlock ($self -> reflock); # release reference counter file + $self -> _simple_unlock ($self -> exshlock); # remove excl shared lock + $self -> _simple_unlock ($self -> lockfile); # release file + } + + return; +} + +### sub release ################################################################ +# +# release a file +# +# Params: ~none~ +# +# Return: ~none~ +# +sub release { + my $self = shift; + + $self -> set_ref (0); # reference counter = 0 + $self -> _simple_unlock ($self -> reflock); # release reference counter + $self -> _simple_unlock ($self -> lockfile); # remove any write lock announce + $self -> _simple_unlock ($self -> exshlock); # remove any excl shared lock + $self -> _simple_unlock ($self -> masterlock); # remove master lock + + return; +} + +# keep 'require' happy +1; + +# +# +### end of Lock::API ########################################################### \ No newline at end of file diff --git a/selfforum-cgi/shared/Lock/Exclusive.pm b/selfforum-cgi/shared/Lock/Exclusive.pm new file mode 100644 index 0000000..d6243ec --- /dev/null +++ b/selfforum-cgi/shared/Lock/Exclusive.pm @@ -0,0 +1,123 @@ +package Lock::Exclusive; + +################################################################################ +# # +# File: shared/Lock/Exclusive.pm # +# # +# Authors: Andre Malo , 2001-05-25 # +# # +# Description: Locking and Filehandle class # +# using O_EXCL and lock files # +# # +################################################################################ + +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_lock ########################################################### +# +# simple file lock +# (create lock file) +# +# Params: $filename - file to lock +# $timeout - timeout +# +# Return: success (boolean) +# +sub _simple_lock { + my ($self, $fh) = @_; + + sysopen ($fh, $fh->filename, O_CREAT | O_EXCL | O_WRONLY) + and close $fh + and return 1; + + return; +} + +### sub _simple_unlock ######################################################### +# +# simple file unlock +# (unlink lock file) +# +# Params: $filename - lockfile name +# ^^^^^^^^ +# +# Return: success (boolean) +# +sub _simple_unlock { + my ($self, $filename) = @_; + + return 1 if (!-f $filename or unlink $filename); + + # not able to unlink lock file, hmmm... + # + return; +} + +### sub _reftime ############################################################### +# +# determine reference time for violent unlock +# +# Params: ~none~ +# +# Return: time or zero, if no reference file found +# +sub _reftime { + my $self = shift; + my ($time, $reffile) = 0; + + if (-f ($reffile = $self -> filename)) { + $time = (stat $reffile)[9];} + + elsif (-f ($reffile = $self -> lockfile)) { + $time = (stat $reffile)[9];} + + $time; +} + +### sub masterlocked ########################################################### +# +# check on master lock status of the file +# +# Params: ~none~ +# +# Return: status (boolean) +# +sub masterlocked {-f shift -> masterlock} + +### sub excl_announced ######################################################### +# +# check on exclusive lock announced status of the file +# +# Params: ~none~ +# +# Return: status (boolean) +# +sub excl_announced {-f shift -> lockfile} + +### sub exsh_announced ######################################################### +# +# check on exclusive shared lock status of the file +# +# Params: ~none~ +# +# Return: status (boolean) +# +sub exsh_announced {-f shift -> exshlock} + +# keep 'require' happy +1; + +# +# +### end of Lock::Exclusive ##################################################### \ No newline at end of file diff --git a/selfforum-cgi/shared/Lock/Handle.pm b/selfforum-cgi/shared/Lock/Handle.pm new file mode 100644 index 0000000..e5a749e --- /dev/null +++ b/selfforum-cgi/shared/Lock/Handle.pm @@ -0,0 +1,62 @@ +package Lock::Handle; + +################################################################################ +# # +# File: shared/Lock/Handle.pm # +# # +# Authors: Andre Malo , 2001-05-30 # +# # +# Description: belongs to Locking and Filehandle class # +# NOT FOR PUBLIC USE # +# # +################################################################################ + +use strict; +use vars qw( + $VERSION +); + +use base qw(Lock::_static); + +use Symbol qw(gensym); + +################################################################################ +# +# Version check +# +$VERSION = do { my @r =(q$Revision$ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r }; + +### sub new #################################################################### +# +# constructor +# +# Params: $file - filename +# +# Return: Lock object +# +sub new { + my ($instance, $file) = @_; + my $class = ref($instance) || $instance; + my $self = bless $class -> _create_handle => $class; + + $self -> set_static (filename => $file); + + $self; +} + +### sub _create_handle ######################################################### +# +# create a globref +# +# Params: ~none~ +# +# Return: globref +# +sub _create_handle {gensym} + +# keep 'require' happy +1; + +# +# +### end of Lock::Handle ######################################################## \ No newline at end of file diff --git a/selfforum-cgi/shared/Lock/Symlink.pm b/selfforum-cgi/shared/Lock/Symlink.pm new file mode 100644 index 0000000..82ea283 --- /dev/null +++ b/selfforum-cgi/shared/Lock/Symlink.pm @@ -0,0 +1,121 @@ +package Lock::Symlink; + +################################################################################ +# # +# File: shared/Lock/Symlink.pm # +# # +# Authors: Andre Malo , 2001-05-25 # +# # +# Description: Locking and Filehandle class # +# using symlinks # +# # +################################################################################ + +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_lock ########################################################### +# +# simple file lock +# (create lock file) +# +# Params: $filename - file to lock +# $timeout - timeout +# +# Return: success (boolean) +# +sub _simple_lock { + my ($self, $fh) = @_; + + symlink $self->filename, $fh->filename and return 1; + + return; +} + +### sub _simple_unlock ######################################################### +# +# simple file unlock +# (unlink lock file) +# +# Params: $filename - lockfile name +# ^^^^^^^^ +# +# Return: success (boolean) +# +sub _simple_unlock { + my ($self, $filename) = @_; + + return 1 if (!-l $filename or unlink $filename); + + # not able to unlink symlink, hmmm... + # + return; +} + +### sub _reftime ############################################################### +# +# determine reference time for violent unlock +# +# Params: ~none~ +# +# Return: time or zero, if no reference file found +# +sub _reftime { + my $self = shift; + my ($time, $reffile) = 0; + + if (-f ($reffile = $self -> filename)) { + $time = (stat $reffile)[9];} + + elsif (-l ($reffile = $self -> lockfile)) { + $time = (lstat $reffile)[9];} + + $time; +} + +### sub masterlocked ########################################################### +# +# check on master lock status of the file +# +# Params: ~none~ +# +# Return: status (boolean) +# +sub masterlocked {-l shift -> masterlock} + +### sub excl_announced ######################################################### +# +# check on exclusive lock announced status of the file +# +# Params: ~none~ +# +# Return: status (boolean) +# +sub excl_announced {-l shift -> lockfile} + +### sub exsh_announced ######################################################### +# +# check on exclusive shared lock status of the file +# +# Params: ~none~ +# +# Return: status (boolean) +# +sub exsh_announced {-l shift -> exshlock} + +# keep 'require' happy +1; + +# +# +### end of Lock::Symlink ####################################################### diff --git a/selfforum-cgi/shared/Lock/Unlink.pm b/selfforum-cgi/shared/Lock/Unlink.pm new file mode 100644 index 0000000..d7bd6ec --- /dev/null +++ b/selfforum-cgi/shared/Lock/Unlink.pm @@ -0,0 +1,124 @@ +package Lock::Unlink; + +################################################################################ +# # +# File: shared/Lock/Unlink.pm # +# # +# Authors: Andre Malo , 2001-05-25 # +# # +# Description: Locking and Filehandle class # +# using the atomic behavior of unlinkig files # +# # +################################################################################ + +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_lock ########################################################### +# +# simple file lock +# (unlink lock file) +# +# Params: $filename - file to lock +# $timeout - timeout +# +# Return: success (boolean) +# +sub _simple_lock { + my ($self, $fh) = @_; + + unlink $fh -> filename and return 1; + + return; +} + +### sub _simple_unlock ######################################################### +# +# simple file unlock +# (create lock file) +# +# Params: $filename - lockfile name +# ^^^^^^^^ +# +# Return: success (boolean) +# +sub _simple_unlock { + my ($self, $filename) = @_; + local *LF; + + sysopen (LF, $filename, O_WRONLY | O_CREAT | O_TRUNC) + and close LF + and return 1; + + # not able to create lock file, hmmm... + # + return; +} + +### sub _reftime ############################################################### +# +# determine reference time for violent unlock +# +# Params: ~none~ +# +# Return: time or zero, if no reference file found +# +sub _reftime { + my $self = shift; + my ($time, $reffile) = 0; + + if (-f ($reffile = $self -> filename)) { + $time = (stat $reffile)[9];} + + elsif (-f ($reffile = $self -> lockfile)) { + $time = (stat $reffile)[9];} + + $time; +} + +### sub masterlocked ########################################################### +# +# check on master lock status of the file +# +# Params: ~none~ +# +# Return: status (boolean) +# +sub masterlocked {not -f shift -> masterlock} + +### sub excl_announced ######################################################### +# +# check on exclusive lock announced status of the file +# +# Params: ~none~ +# +# Return: status (boolean) +# +sub excl_announced {not -f shift -> lockfile} + +### sub exsh_announced ######################################################### +# +# check on exclusive shared lock status of the file +# +# Params: ~none~ +# +# Return: status (boolean) +# +sub exsh_announced {not -f shift -> exshlock} + +# keep 'require' happy +1; + +# +# +### end of Lock::Unlink ######################################################## diff --git a/selfforum-cgi/shared/Lock/_simple.pm b/selfforum-cgi/shared/Lock/_simple.pm new file mode 100644 index 0000000..7aae43a --- /dev/null +++ b/selfforum-cgi/shared/Lock/_simple.pm @@ -0,0 +1,351 @@ +package Lock::_simple; + +################################################################################ +# # +# File: shared/Lock/_simple.pm # +# # +# Authors: Andre Malo , 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 diff --git a/selfforum-cgi/shared/Lock/_static.pm b/selfforum-cgi/shared/Lock/_static.pm new file mode 100644 index 0000000..37233de --- /dev/null +++ b/selfforum-cgi/shared/Lock/_static.pm @@ -0,0 +1,184 @@ +package Lock::_static; + +################################################################################ +# # +# File: shared/Lock/_static.pm # +# # +# Authors: Andre Malo , 2001-05-25 # +# # +# Description: belongs to Locking and Filehandle class # +# NO PUBLIC USE # +# save the lock object static information # +# (because the lock object is a blessed file handle) # +# # +################################################################################ + +use strict; +use vars qw( + $VERSION +); + +use Carp; + +################################################################################ +# +# Version check +# +$VERSION = do { my @r =(q$Revision$ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r }; + +################################################################################ +# +# Variables +# +my (%static, %access); + +# define standard timeouts +# (seconds) +# +my %timeout = ( + shared => 10, # for shared and exclusive shared locks + exclusive => 10, # for exclusive locks + violent => 600, # for violent unlocks (10 minutes should justify a process abort) + master => 20 # for master locks +); + +### timeout #################################################################### +# +# set and read out the timeout +# +# Params: $type - timeout type (defined in %timeout, see above) +# in this case, the specified timeout will be returned +# OR +# %hash - (type => time) pairs +# the specified timouts will be set +# +# Return: specified timeout or nothing +# +sub timeout { + my ($self, @ary) = @_; + + return if (@ary == 0); + + if (@ary == 1) { + my $type = shift @ary; + my $hash = $self -> get_static('timeout') || {}; + + return defined $hash->{$type} + ? $hash -> {$type} + : $timeout {$type}; + } + + my %hash = @ary; + $self->set_static(timeout => {%{$self -> get_static('timeout') || {}},%hash}); + + return; +} + +### set_static ################################################################# +# +# set an object property +# +# Params: $key - property and method name +# $value - property +# +# Return: $value or nothing +# +sub set_static { + my ($self, $key, $value) = @_; + + $static{$self}={} unless exists($static{$self}); + $static{$self}->{$key} = $value; + + defined wantarray and return $value; + return; +} + +### get_static ################################################################# +# +# read out an object property +# +# Params: $key - property name +# +# Return: value or false +# +sub get_static { + my ($self, $key) = @_; + + return unless exists($static{$self}); + $static{$self}->{$key}; +} + +################################################################################ +# +# define the lock file names +# +sub reffile {shift -> filename . '.lock.ref'} +sub lockfile {shift -> filename . '.lock'} +sub reflock {shift -> filename . '.lock.ref.lock'} +sub exshlock {shift -> filename . '.exshlock'} +sub masterlock {shift -> filename . '.masterlock'} + +################################################################################ +# +# autoload the general access methods +# +BEGIN { + %access = map {$_=>1} qw( + filename + locked_shared + locked_exclusive + locked_exsh + es_announced + announced + ); +} +AUTOLOAD { + my $self = shift; + (my $attr = $Lock::_static::AUTOLOAD) =~ s/.*:://; + return if ($attr eq 'DESTROY'); + + if ($access{$attr}) { + return $self -> get_static($attr); + } + else { + eval { + local $SIG{__DIE__}; + my $sup = "SUPER::$attr"; + return $self -> $sup(@_); + }; + croak $@; + } +} + +################################################################################ +# +# destrcutor - try to unlock, if neccessary and possible +# +DESTROY { + my $self = shift; + + $self -> unlock if ($self =~ /^Lock=/); + delete $static{$self}; +} + +################################################################################ +# +# terminator, catch sigTERM and (try to) destroy all objects +# +sub destroy_all { + $SIG{TERM} = \&destroy_all; + + $_ -> unlock for (grep ((ref $_ and /^Lock=/) => keys %static)); + + exit (0); +} +BEGIN { + $SIG{TERM} = \&destroy_all; +} + +# keep 'require' happy +1; + +# +# +### end of Lock::_static ####################################################### \ No newline at end of file -- 2.34.1