-# Copyright (C) 2016-2021 all contributors <meta@public-inbox.org>
+# Copyright (C) all contributors <meta@public-inbox.org>
# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
# Like most Perl modules in public-inbox, this is internal and
# operate in. This can be useful to ensure smaller inboxes can
# be cloned while cloning of large inboxes is maxed out.
#
-# This does not depend on the PublicInbox::DS->EventLoop or any
+# This does not depend on the PublicInbox::DS::event_loop or any
# other external scheduling mechanism, you just need to call
# start() and finish() appropriately. However, public-inbox-httpd
# (which uses PublicInbox::DS) will be able to schedule this
# processes such as git-apply(1).
package PublicInbox::Qspawn;
-use strict;
+use v5.12;
use PublicInbox::Spawn qw(popen_rd);
use PublicInbox::GzipFilter;
+use Scalar::Util qw(blessed);
# n.b.: we get EAGAIN with public-inbox-httpd, and EINTR on other PSGI servers
use Errno qw(EAGAIN EINTR);
# $cmd is the command to spawn
# $cmd_env is the environ for the child process (not PSGI env)
# $opt can include redirects and perhaps other process spawning options
-sub new ($$$;) {
+# {qsp_err} is an optional error buffer callers may access themselves
+sub new {
my ($class, $cmd, $cmd_env, $opt) = @_;
bless { args => [ $cmd, $cmd_env, $opt ] }, $class;
}
$o{$k} = $rlimit;
}
}
- $self->{cmd} = $o{quiet} ? undef : $cmd;
+ $self->{cmd} = $cmd;
+ $self->{-quiet} = 1 if $o{quiet};
+ $o{cb_arg} = [ \&waitpid_err, $self ];
eval {
# popen_rd may die on EMFILE, ENFILE
- $self->{rpipe} = popen_rd($cmd, $cmd_env, \%o);
-
- die "E: $!" unless defined($self->{rpipe});
-
+ $self->{rpipe} = popen_rd($cmd, $cmd_env, \%o) // die "E: $!";
$limiter->{running}++;
$start_cb->($self); # EPOLL_CTL_ADD may ENOSPC/ENOMEM
};
finish($self, $@) if $@;
}
-sub child_err ($) {
- my ($child_error) = @_; # typically $?
- my $exitstatus = ($child_error >> 8) or return;
- my $sig = $child_error & 127;
- my $msg = "exit status=$exitstatus";
- $msg .= " signal=$sig" if $sig;
- $msg;
-}
-
-sub log_err ($$) {
- my ($env, $msg) = @_;
- $env->{'psgi.errors'}->print($msg, "\n");
-}
-
-sub finalize ($$) {
- my ($self, $err) = @_;
-
- my ($env, $qx_cb, $qx_arg, $qx_buf) =
- delete @$self{qw(psgi_env qx_cb qx_arg qx_buf)};
+sub finalize ($) {
+ my ($self) = @_;
- # done, spawn whatever's in the queue
- my $limiter = $self->{limiter};
+ # process is done, spawn whatever's in the queue
+ my $limiter = delete $self->{limiter} or return;
my $running = --$limiter->{running};
if ($running < $limiter->{max}) {
_do_spawn(@$next, $limiter);
}
}
-
- if ($err) {
- if (defined $self->{err}) {
- $self->{err} .= "; $err";
- } else {
- $self->{err} = $err;
- }
- if ($env && $self->{cmd}) {
- log_err($env, join(' ', @{$self->{cmd}}) . ": $err");
+ if (my $err = $self->{_err}) { # set by finish or waitpid_err
+ utf8::decode($err);
+ if (my $dst = $self->{qsp_err}) {
+ $$dst .= $$dst ? " $err" : "; $err";
}
+ warn "@{$self->{cmd}}: $err\n" if !$self->{-quiet};
}
+
+ my ($env, $qx_cb, $qx_arg, $qx_buf) =
+ delete @$self{qw(psgi_env qx_cb qx_arg qx_buf)};
if ($qx_cb) {
eval { $qx_cb->($qx_buf, $qx_arg) };
- } elsif (my $wcb = delete $env->{'qspawn.wcb'}) {
+ return unless $@;
+ warn "E: $@"; # hope qspawn.wcb can handle it
+ }
+ return if $self->{passed}; # another command chained it
+ if (my $wcb = delete $env->{'qspawn.wcb'}) {
# have we started writing, yet?
+ my $code = delete $env->{'qspawn.fallback'} // 500;
require PublicInbox::WwwStatic;
- $wcb->(PublicInbox::WwwStatic::r(500));
+ $wcb->(PublicInbox::WwwStatic::r($code));
}
}
-# callback for dwaitpid or ProcessPipe
-sub waitpid_err { finalize($_[0], child_err($?)) }
+sub DESTROY { finalize($_[0]) } # ->finalize is idempotent
+
+sub waitpid_err { # callback for awaitpid
+ my (undef, $self) = @_; # $_[0]: pid
+ $self->{_err} = ''; # for defined check in ->finish
+ if ($?) {
+ my $status = $? >> 8;
+ my $sig = $? & 127;
+ $self->{_err} .= "exit status=$status";
+ $self->{_err} .= " signal=$sig" if $sig;
+ }
+ finalize($self) if !$self->{rpipe};
+}
sub finish ($;$) {
my ($self, $err) = @_;
- my $tied_pp = delete($self->{rpipe}) or return finalize($self, $err);
- my PublicInbox::ProcessPipe $pp = tied *$tied_pp;
- @$pp{qw(cb arg)} = (\&waitpid_err, $self); # for ->DESTROY
+ $self->{_err} //= $err; # only for $@
+
+ # we can safely finalize if pipe was closed before, or if
+ # {_err} is defined by waitpid_err. Deleting {rpipe} will
+ # trigger PublicInbox::ProcessPipe::DESTROY -> waitpid_err,
+ # but it may not fire right away if inside the event loop.
+ my $closed_before = !delete($self->{rpipe});
+ finalize($self) if $closed_before || defined($self->{_err});
}
sub start ($$$) {
}
}
-sub psgi_qx_init_cb {
+sub psgi_qx_init_cb { # this may be PublicInbox::HTTPD::Async {cb}
my ($self) = @_;
- my $async = delete $self->{async};
my ($r, $buf);
- my $qx_fh = $self->{qx_fh};
reread:
$r = sysread($self->{rpipe}, $buf, 65536);
- if ($async) {
- $async->async_pass($self->{psgi_env}->{'psgix.io'},
- $qx_fh, \$buf);
- } elsif (defined $r) {
- $r ? (print $qx_fh $buf) : event_step($self, undef);
- } else {
+ if (!defined($r)) {
return if $! == EAGAIN; # try again when notified
goto reread if $! == EINTR;
event_step($self, $!);
+ } elsif (my $as = delete $self->{async}) { # PublicInbox::HTTPD::Async
+ $as->async_pass($self->{psgi_env}->{'psgix.io'},
+ $self->{qx_fh}, \$buf);
+ } elsif ($r) { # generic PSGI:
+ print { $self->{qx_fh} } $buf;
+ } else { # EOF
+ event_step($self, undef);
}
}
# PSGI servers.
sub event_step {
my ($self, $err) = @_; # $err: $!
- log_err($self->{psgi_env}, "psgi_{return,qx} $err") if defined($err);
+ warn "psgi_{return,qx} $err" if defined($err);
finish($self);
- my ($fh, $qx_fh) = delete(@$self{qw(fh qx_fh)});
+ my ($fh, $qx_fh) = delete(@$self{qw(qfh qx_fh)});
$fh->close if $fh; # async-only (psgi_return)
}
sub rd_hdr ($) {
my ($self) = @_;
# typically used for reading CGI headers
- # we must loop until EAGAIN for EPOLLET in HTTPD/Async.pm
# We also need to check EINTR for generic PSGI servers.
my $ret;
my $total_rd = 0;
my $hdr_buf = $self->{hdr_buf};
my ($ph_cb, $ph_arg) = @{$self->{parse_hdr}};
- do {
+ until (defined($ret)) {
my $r = sysread($self->{rpipe}, $$hdr_buf, 4096,
length($$hdr_buf));
if (defined($r)) {
$total_rd += $r;
eval { $ret = $ph_cb->($total_rd, $hdr_buf, $ph_arg) };
if ($@) {
- log_err($self->{psgi_env}, "parse_hdr: $@");
+ warn "parse_hdr: $@";
+ $ret = [ 500, [], [ "Internal error\n" ] ];
+ } elsif (!defined($ret) && !$r) {
+ warn <<EOM;
+EOF parsing headers from @{$self->{cmd}} ($self->{psgi_env}->{REQUEST_URI})
+EOM
$ret = [ 500, [], [ "Internal error\n" ] ];
}
} else {
# caller should notify us when it's ready:
return if $! == EAGAIN;
next if $! == EINTR; # immediate retry
- log_err($self->{psgi_env}, "error reading header: $!");
+ warn "error reading header: $!";
$ret = [ 500, [], [ "Internal error\n" ] ];
}
- } until (defined $ret);
+ }
delete $self->{parse_hdr}; # done parsing headers
$ret;
}
-sub psgi_return_init_cb {
+sub psgi_return_init_cb { # this may be PublicInbox::HTTPD::Async {cb}
my ($self) = @_;
my $r = rd_hdr($self) or return;
my $env = $self->{psgi_env};
- my $filter = delete $env->{'qspawn.filter'} //
- PublicInbox::GzipFilter::qsp_maybe($r->[1], $env);
+ my $filter;
+
+ # this is for RepoAtom since that can fire after parse_cgi_headers
+ if (ref($r) eq 'ARRAY' && blessed($r->[2]) && $r->[2]->can('attach')) {
+ $filter = pop @$r;
+ }
+ $filter //= delete($env->{'qspawn.filter'}) // (ref($r) eq 'ARRAY' ?
+ PublicInbox::GzipFilter::qsp_maybe($r->[1], $env) : undef);
my $wcb = delete $env->{'qspawn.wcb'};
- my $async = delete $self->{async};
- if (scalar(@$r) == 3) { # error
- if ($async) {
- # calls rpipe->close && ->event_step
- $async->close;
- } else {
- $self->{rpipe}->close;
+ my $async = delete $self->{async}; # PublicInbox::HTTPD::Async
+ if (ref($r) ne 'ARRAY' || scalar(@$r) == 3) { # error
+ if ($async) { # calls rpipe->close && ->event_step
+ $async->close; # PublicInbox::HTTPD::Async::close
+ } else { # generic PSGI, use PublicInbox::ProcessPipe::CLOSE
+ delete($self->{rpipe})->close;
event_step($self);
}
- $wcb->($r);
+ if (ref($r) eq 'ARRAY') { # error
+ $wcb->($r)
+ } elsif (ref($r) eq 'CODE') { # chain another command
+ $r->($wcb);
+ $self->{passed} = 1;
+ }
+ # else do nothing
} elsif ($async) {
# done reading headers, handoff to read body
my $fh = $wcb->($r); # scalar @$r == 2
$fh = $filter->attach($fh) if $filter;
- $self->{fh} = $fh;
+ $self->{qfh} = $fh;
$async->async_pass($env->{'psgix.io'}, $fh,
delete($self->{hdr_buf}));
} else { # for synchronous PSGI servers
require PublicInbox::GetlineBody;
+ my $buf = delete $self->{hdr_buf};
$r->[2] = PublicInbox::GetlineBody->new($self->{rpipe},
- \&event_step, $self,
- ${$self->{hdr_buf}}, $filter);
+ \&event_step, $self, $$buf, $filter);
$wcb->($r);
}
}
sub psgi_return_start { # may run later, much later...
my ($self) = @_;
- if (my $async = $self->{psgi_env}->{'pi-httpd.async'}) {
+ if (my $cb = $self->{psgi_env}->{'pi-httpd.async'}) {
# PublicInbox::HTTPD::Async->new(rpipe, $cb, $cb_arg, $end_obj)
- $self->{async} = $async->($self->{rpipe},
+ $self->{async} = $cb->($self->{rpipe},
\&psgi_return_init_cb, $self, $self);
} else { # generic PSGI
psgi_return_init_cb($self) while $self->{parse_hdr};
}
package PublicInbox::Qspawn::Limiter;
-use strict;
-use warnings;
+use v5.12;
sub new {
my ($class, $max) = @_;