# Public License, Version 2.1. Please read the important licensing and
# disclaimer information included below.
-# $Id: ProcManager.pm,v 1.17 2001/02/09 16:15:47 muaddie Exp $
+# $Id: ProcManager.pm,v 1.23 2001/04/23 16:10:11 muaddie Exp $
use strict;
use Exporter;
+use POSIX qw(:signal_h);
-use vars qw($VERSION @ISA @EXPORT_OK %EXPORT_TAGS $Q);
+use vars qw($VERSION @ISA @EXPORT_OK %EXPORT_TAGS $Q $SIG_CODEREF);
BEGIN {
- $VERSION = '0.16';
+ $VERSION = '0.17';
@ISA = qw(Exporter);
@EXPORT_OK = qw(pm_manage pm_die pm_wait
pm_write_pid_file pm_remove_pid_file
pm_pre_dispatch pm_post_dispatch
pm_change_process_name pm_received_signal pm_parameter
- pm_warn pm_notify pm_abort pm_exit);
+ pm_warn pm_notify pm_abort pm_exit
+ $SIG_CODEREF);
$EXPORT_TAGS{all} = \@EXPORT_OK;
$FCGI::ProcManager::Default = 'FCGI::ProcManager';
}
insert a call to C<pm_pre_dispatch> at the top of the loop, and then
7C<pm_post_dispatch> at the end of the loop.
+=head2 Signal Handling
+
+FCGI::ProcManager attempts to do the right thing for proper shutdowns now.
+
+When it receives a SIGHUP, it sends a SIGTERM to each of its children, and
+then resumes its normal operations.
+
+When it receives a SIGTERM, it sends a SIGTERM to each of its children, sets
+an alarm(3) "die timeout" handler, and waits for each of its children to
+die. If all children die before this timeout, process manager exits with
+return status 0. If all children do not die by the time the "die timeout"
+occurs, the process manager sends a SIGKILL to each of the remaining
+children, and exists with return status 1.
+
+In order to get FastCGI servers to exit upon receiving a signal, it is
+necessary to use its FAIL_ACCEPT_ON_INTR. See FCGI.pm's description of
+FAIL_ACCEPT_ON_INTR. Unfortunately, if you want/need to use CGI::Fast, it
+appears currently necessary to modify your installation of FCGI.pm, with
+something like the following:
+
+ -*- patch -*-
+ --- FCGI.pm 2001/03/09 01:44:00 1.1.1.3
+ +++ FCGI.pm 2001/03/09 01:47:32 1.2
+ @@ -24,7 +24,7 @@
+ *FAIL_ACCEPT_ON_INTR = sub() { 1 };
+
+ sub Request(;***$$$) {
+ - my @defaults = (\*STDIN, \*STDOUT, \*STDERR, \%ENV, 0, 0);
+ + my @defaults = (\*STDIN, \*STDOUT, \*STDERR, \%ENV, 0, FAIL_ACCEPT_ON_INTR());
+ splice @defaults,0,@_,@_;
+ RequestX(@defaults);
+ }
+ -*- end patch -*-
+
+Otherwise, if you don't, there is a loop around accept(2) which prevents
+os_unix.c OS_Accept() from returning the necessary error when FastCGI
+servers blocking on accept(2) receive the SIGTERM or SIGHUP.
+
+FCGI::ProcManager uses POSIX::sigaction() to override the default SA_RESTART
+policy used for perl's %SIG behavior. Specifically, the process manager
+never uses SA_RESTART, while the child FastCGI servers turn off SA_RESTART
+around the accept(2) loop, but re-enstate it otherwise.
+
+The desired (and implemented) effect is to give a request as big a chance as
+possible to succeed and to delay their exits until after their request,
+while allowing the FastCGI servers waiting for new requests to die right
+away.
=head1 METHODS
sub new {
my ($proto,$init) = @_;
+ $init ||= {};
my $this = {
role => "manager",
start_delay => 0,
- die_timeout => 60
+ die_timeout => 60,
+ %$init
};
- $init and %$this = %$init;
-
bless $this, ref($proto)||$proto;
$this->{PIDS} = {};
+ # initialize signal constructions.
+ unless ($this->no_signals()) {
+ $this->{sigaction_no_sa_restart} =
+ POSIX::SigAction->new('FCGI::ProcManager::sig_sub');
+ $this->{sigaction_sa_restart} =
+ POSIX::SigAction->new('FCGI::ProcManager::sig_sub',undef,POSIX::SA_RESTART);
+ }
+
return $this;
}
map { $this->pm_parameter($_,$values{$_}) } keys %values;
# skip to handling now if we won't be managing any processes.
- $this->n_processes() or goto HANDLING;
+ $this->n_processes() or return;
# call the (possibly overloaded) management initialization hook.
$this->role("manager");
return $this->pm_abort("fork: $!");
} else {
- $this->role("server");
$this->{MANAGER_PID} = $manager_pid;
# the server exits the managing loop.
last MANAGING_LOOP;
my ($this) = @_;
# begin to handle signals.
- $SIG{TERM} = sub { $this->sig_manager(@_) };
- $SIG{HUP} = sub { $this->sig_manager(@_) };
+ # We do NOT want SA_RESTART in the process manager.
+ # -- we want start the shutdown sequence immediately upon SIGTERM.
+ unless ($this->no_signals()) {
+ sigaction(SIGTERM, $this->{sigaction_no_sa_restart}) or
+ $this->pm_warn("sigaction: SIGTERM: $!");
+ sigaction(SIGHUP, $this->{sigaction_no_sa_restart}) or
+ $this->pm_warn("sigaction: SIGHUP: $!");
+ $SIG_CODEREF = sub { $this->sig_manager(@_) };
+ }
# change the name of this process as it appears in ps(1) output.
$this->pm_change_process_name("perl-fcgi-pm");
$this->pm_write_pid_file();
}
-
=head2 pm_die
instance or export
my ($this,$msg,$n) = self_or_default(@_);
# stop handling signals.
+ undef $SIG_CODEREF;
$SIG{HUP} = 'DEFAULT';
$SIG{TERM} = 'DEFAULT';
# prepare to die no matter what.
if (defined $this->die_timeout()) {
- $SIG{ARLM} = sub { $this->pm_abort("wait timeout") };
+ $SIG{ALRM} = sub { $this->pm_abort("wait timeout") };
alarm $this->die_timeout();
}
# send a TERM to each of the servers.
- kill "TERM", keys %{$this->{PIDS}};
+ if (my @pids = keys %{$this->{PIDS}}) {
+ $this->pm_notify("sending TERM to PIDs, @pids");
+ kill "TERM", @pids;
+ }
# wait for the servers to die.
while (%{$this->{PIDS}}) {
return $ret;
}
+=head2 sig_sub
+
+ instance
+ () sig_sub(string name)
+
+DESCRIPTION:
+
+The name of this method is passed to POSIX::sigaction(), and handles signals
+for the process manager. If $SIG_CODEREF is set, then the input arguments
+to this are passed to a call to that.
+
+=cut
+
+sub sig_sub {
+ $SIG_CODEREF->(@_) if ref $SIG_CODEREF;
+}
+
=head2 sig_manager
instance
sub sig_manager {
my ($this,$name) = @_;
- if ($name eq "TERM" or $name eq "HUP") {
+ if ($name eq "TERM") {
$this->pm_notify("received signal $name");
$this->pm_die("safe exit from signal $name");
+ } elsif ($name eq "HUP") {
+ # send a TERM to each of the servers, and pretend like nothing happened..
+ if (my @pids = keys %{$this->{PIDS}}) {
+ $this->pm_notify("sending TERM to PIDs, @pids");
+ kill "TERM", @pids;
+ }
} else {
$this->pm_notify("ignoring signal $name");
}
my ($this) = @_;
# begin to handle signals.
- $SIG{TERM} = sub { $this->sig_handler(@_) };
- $SIG{HUP} = sub { $this->sig_handler(@_) };
+ # We'll want accept(2) to return -1(EINTR) on caught signal..
+ unless ($this->no_signals()) {
+ sigaction(SIGTERM, $this->{sigaction_no_sa_restart}) or $this->pm_warn("sigaction: SIGTERM: $!");
+ sigaction(SIGHUP, $this->{sigaction_no_sa_restart}) or $this->pm_warn("sigaction: SIGHUP: $!");
+ $SIG_CODEREF = sub { $this->sig_handler(@_) };
+ }
# change the name of this process as it appears in ps(1) output.
$this->pm_change_process_name("perl-fcgi");
sub pm_pre_dispatch {
my ($this) = self_or_default(@_);
+
+ # Now, we want the request to continue unhindered..
+ unless ($this->no_signals()) {
+ sigaction(SIGTERM, $this->{sigaction_sa_restart}) or $this->pm_warn("sigaction: SIGTERM: $!");
+ sigaction(SIGHUP, $this->{sigaction_sa_restart}) or $this->pm_warn("sigaction: SIGHUP: $!");
+ }
}
=head2 pm_post_dispatch
if ($this->{MANAGER_PID} and getppid() != $this->{MANAGER_PID}) {
$this->pm_exit("safe exit: manager has died");
}
+ # We'll want accept(2) to return -1(EINTR) on caught signal..
+ unless ($this->no_signals()) {
+ sigaction(SIGTERM, $this->{sigaction_no_sa_restart}) or $this->pm_warn("sigaction: SIGTERM: $!");
+ sigaction(SIGHUP, $this->{sigaction_no_sa_restart}) or $this->pm_warn("sigaction: SIGHUP: $!");
+ }
}
=head2 sig_handler
projects / catagits/FCGI-ProcManager.git / commitdiff