* [PATCH 6/7] git: improve coupling with {sock} and {inflight} fields
2023-11-26 2:10 7% [PATCH 0/7] more I/O + process reliability and cleanups Eric Wong
@ 2023-11-26 2:11 5% ` Eric Wong
0 siblings, 0 replies; 2+ results
From: Eric Wong @ 2023-11-26 2:11 UTC (permalink / raw)
To: meta
While the {inflight} array should be tied to the IO object even
more tightly, that's not an easy task with our current code. So
take some small steps by introducing a gcf_inflight helper to
validate the ownership of the process and to drain the inflight
array via the awaitpid callback.
This hopefully fix problems with t/lei-q-save.t (still) hanging
occasionally on v2 outputs since git->cleanup/->DESTROY was getting
called in v2 shard workers.
---
lib/PublicInbox/Gcf2Client.pm | 6 ++-
lib/PublicInbox/Git.pm | 79 ++++++++++++++++++++--------------
lib/PublicInbox/GitAsyncCat.pm | 2 +-
lib/PublicInbox/IO.pm | 17 ++++++--
4 files changed, 65 insertions(+), 39 deletions(-)
diff --git a/lib/PublicInbox/Gcf2Client.pm b/lib/PublicInbox/Gcf2Client.pm
index 19d77e32..07ff7dcb 100644
--- a/lib/PublicInbox/Gcf2Client.pm
+++ b/lib/PublicInbox/Gcf2Client.pm
@@ -31,15 +31,16 @@ sub new {
$opt->{0} = $opt->{1} = $s2;
my $cmd = [$^X, $^W ? ('-w') : (),
qw[-MPublicInbox::Gcf2 -e PublicInbox::Gcf2::loop]];
- PublicInbox::IO::attach_pid($s1, spawn($cmd, $env, $opt));
$self->{inflight} = [];
+ PublicInbox::IO::attach_pid($s1, spawn($cmd, $env, $opt),
+ \&PublicInbox::Git::gcf_drain, $self->{inflight});
$self->{epwatch} = \undef; # for Git->cleanup
$self->SUPER::new($s1, EPOLLIN);
}
sub gcf2_async ($$$;$) {
my ($self, $req, $cb, $arg) = @_;
- my $inflight = $self->{inflight} or return $self->close;
+ my $inflight = $self->gcf_inflight or return;
PublicInbox::Git::write_all($self, $req, \&cat_async_step, $inflight);
push @$inflight, \$req, $cb, $arg; # ref prevents Git.pm retries
}
@@ -49,6 +50,7 @@ sub alternates_changed {}
no warnings 'once';
+*gcf_inflight = \&PublicInbox::Git::gcf_inflight; # for event_step
*cat_async_step = \&PublicInbox::Git::cat_async_step; # for event_step
*event_step = \&PublicInbox::Git::event_step;
*fail = \&PublicInbox::Git::fail;
diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index 93736cf0..fe834210 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -140,6 +140,18 @@ sub last_check_err {
$buf;
}
+sub gcf_drain { # awaitpid cb
+ my ($pid, $inflight, $bc) = @_;
+ while (@$inflight) {
+ my ($req, $cb, $arg) = splice(@$inflight, 0, 3);
+ $req = $$req if ref($req);
+ $bc and $req =~ s/\A(?:contents|info) //;
+ $req =~ s/ .*//; # drop git_dir for Gcf2Client
+ eval { $cb->(undef, $req, undef, undef, $arg) };
+ warn "E: (in abort) $req: $@" if $@;
+ }
+}
+
sub _sock_cmd {
my ($self, $batch, $err_c) = @_;
$self->{sock} and Carp::confess('BUG: {sock} exists');
@@ -162,8 +174,11 @@ sub _sock_cmd {
$self->{err_c} = $opt->{2} = tmpfile($id, undef, 1) or
$self->fail("tmpfile($id): $!");
}
+ my $inflight = []; # TODO consider moving this into the IO object
my $pid = spawn(\@cmd, undef, $opt);
- $self->{sock} = PublicInbox::IO::attach_pid($s1, $pid);
+ $self->{sock} = PublicInbox::IO::attach_pid($s1, $pid,
+ \&gcf_drain, $inflight, $self->{-bc});
+ $self->{inflight} = $inflight;
}
sub cat_async_retry ($$) {
@@ -171,8 +186,8 @@ sub cat_async_retry ($$) {
# {inflight} may be non-existent, but if it isn't we delete it
# here to prevent cleanup() from waiting:
- delete $self->{inflight};
- cleanup($self);
+ my ($sock, $epwatch) = delete @$self{qw(sock epwatch inflight)};
+ $self->SUPER::close if $epwatch;
my $new_inflight = batch_prepare($self);
while (my ($oid, $cb, $arg) = splice(@$old_inflight, 0, 3)) {
@@ -180,13 +195,25 @@ sub cat_async_retry ($$) {
$oid = \$oid if !@$new_inflight; # to indicate oid retried
push @$new_inflight, $oid, $cb, $arg;
}
+ $sock->close if $sock; # only safe once old_inflight is empty
cat_async_step($self, $new_inflight); # take one step
}
+sub gcf_inflight ($) {
+ my ($self) = @_;
+ if ($self->{sock}) {
+ return $self->{inflight} if $self->{sock}->owner_pid == $$;
+ delete @$self{qw(sock inflight)};
+ } else {
+ $self->close;
+ }
+ undef;
+}
+
# returns true if prefetch is successful
sub async_prefetch {
my ($self, $oid, $cb, $arg) = @_;
- my $inflight = $self->{inflight} or return;
+ my $inflight = gcf_inflight($self) or return;
return if @$inflight;
substr($oid, 0, 0) = 'contents ' if $self->{-bc};
write_all($self, "$oid\n", \&cat_async_step, $inflight);
@@ -195,7 +222,7 @@ sub async_prefetch {
sub cat_async_step ($$) {
my ($self, $inflight) = @_;
- die 'BUG: inflight empty or odd' if scalar(@$inflight) < 3;
+ croak 'BUG: inflight empty or odd' if scalar(@$inflight) < 3;
my ($req, $cb, $arg) = @$inflight[0, 1, 2];
my ($bref, $oid, $type, $size);
my $head = $self->{sock}->my_readline;
@@ -237,11 +264,8 @@ sub cat_async_step ($$) {
sub cat_async_wait ($) {
my ($self) = @_;
- return $self->close if !$self->{sock};
- my $inflight = $self->{inflight} or return;
- while (scalar(@$inflight)) {
- cat_async_step($self, $inflight);
- }
+ my $inflight = gcf_inflight($self) or return;
+ cat_async_step($self, $inflight) while (scalar(@$inflight));
}
sub batch_prepare ($) {
@@ -253,7 +277,6 @@ sub batch_prepare ($) {
} else {
_sock_cmd($self, 'batch');
}
- $self->{inflight} = [];
}
sub _cat_file_cb {
@@ -271,7 +294,7 @@ sub cat_file {
sub check_async_step ($$) {
my ($ck, $inflight) = @_;
- die 'BUG: inflight empty or odd' if scalar(@$inflight) < 3;
+ croak 'BUG: inflight empty or odd' if scalar(@$inflight) < 3;
my ($req, $cb, $arg) = @$inflight[0, 1, 2];
chomp(my $line = $ck->{sock}->my_readline);
my ($hex, $type, $size) = split(/ /, $line);
@@ -291,8 +314,7 @@ sub check_async_wait ($) {
my ($self) = @_;
return cat_async_wait($self) if $self->{-bc};
my $ck = $self->{ck} or return;
- return $ck->close if !$ck->{sock};
- my $inflight = $ck->{inflight} or return;
+ my $inflight = gcf_inflight($ck) or return;
check_async_step($ck, $inflight) while (scalar(@$inflight));
}
@@ -312,7 +334,6 @@ sub check_async_begin ($) {
} else {
_sock_cmd($self = ck($self), 'batch-check', 1);
}
- $self->{inflight} = [];
}
sub write_all {
@@ -337,12 +358,13 @@ sub check_async ($$$$) {
my $inflight;
if ($self->{-bc}) { # likely as time goes on
batch_command:
- $inflight = $self->{inflight} // cat_async_begin($self);
+ $inflight = gcf_inflight($self) // cat_async_begin($self);
substr($oid, 0, 0) = 'info ';
write_all($self, "$oid\n", \&cat_async_step, $inflight);
} else { # accounts for git upgrades while we're running:
my $ck = $self->{ck}; # undef OK, maybe set in check_async_begin
- $inflight = $ck->{inflight} // check_async_begin($self);
+ $inflight = ($ck ? gcf_inflight($ck) : undef)
+ // check_async_begin($self);
goto batch_command if $self->{-bc};
write_all($self->{ck}, "$oid\n", \&check_async_step, $inflight);
}
@@ -417,8 +439,8 @@ sub date_parse {
}
sub _active ($) {
- scalar(@{$_[0]->{inflight} // []}) ||
- ($_[0]->{ck} && scalar(@{$_[0]->{ck}->{inflight} // []}))
+ scalar(@{gcf_inflight($_[0]) // []}) ||
+ ($_[0]->{ck} && scalar(@{gcf_inflight($_[0]->{ck}) // []}))
}
# check_async and cat_async may trigger the other, so ensure they're
@@ -493,13 +515,13 @@ sub pub_urls {
sub cat_async_begin {
my ($self) = @_;
cleanup($self) if $self->alternates_changed;
- die 'BUG: already in async' if $self->{inflight};
+ die 'BUG: already in async' if gcf_inflight($self);
batch_prepare($self);
}
sub cat_async ($$$;$) {
my ($self, $oid, $cb, $arg) = @_;
- my $inflight = $self->{inflight} // cat_async_begin($self);
+ my $inflight = gcf_inflight($self) // cat_async_begin($self);
substr($oid, 0, 0) = 'contents ' if $self->{-bc};
write_all($self, $oid."\n", \&cat_async_step, $inflight);
push(@$inflight, $oid, $cb, $arg);
@@ -596,8 +618,7 @@ sub cleanup_if_unlinked {
sub event_step {
my ($self) = @_;
- $self->close if !$self->{sock}; # process died while requeued
- my $inflight = $self->{inflight};
+ my $inflight = gcf_inflight($self);
if ($inflight && @$inflight) {
$self->cat_async_step($inflight);
return $self->close unless $self->{sock};
@@ -619,18 +640,10 @@ sub watch_async ($) {
sub close {
my ($self) = @_;
- if (my $q = $self->{inflight}) { # abort inflight requests
- while (@$q) {
- my ($req, $cb, $arg) = splice(@$q, 0, 3);
- $req = $$req if ref($req);
- $self->{-bc} and $req =~ s/\A(?:contents|info) //;
- $req =~ s/ .*//; # drop git_dir for Gcf2Client
- eval { $cb->(undef, $req, undef, undef, $arg) };
- warn "E: (in abort) $req: $@" if $@;
- }
- }
+ my $sock = $self->{sock};
delete @$self{qw(-bc err_c inflight)};
delete($self->{epwatch}) ? $self->SUPER::close : delete($self->{sock});
+ $sock->close if $sock; # calls gcf_drain via awaitpid
}
package PublicInbox::GitCheck; # only for git <2.36
diff --git a/lib/PublicInbox/GitAsyncCat.pm b/lib/PublicInbox/GitAsyncCat.pm
index f8b2a9fc..09744b34 100644
--- a/lib/PublicInbox/GitAsyncCat.pm
+++ b/lib/PublicInbox/GitAsyncCat.pm
@@ -40,7 +40,7 @@ sub ibx_async_prefetch {
my ($ibx, $oid, $cb, $arg) = @_;
my $git = $ibx->git;
if (!defined($ibx->{topdir}) && $GCF2C) {
- if (!@{$GCF2C->{inflight} // []}) {
+ if (!@{$GCF2C->gcf_inflight // []}) {
$oid .= " $git->{git_dir}\n";
return $GCF2C->gcf2_async($oid, $cb, $arg); # true
}
diff --git a/lib/PublicInbox/IO.pm b/lib/PublicInbox/IO.pm
index fcebac59..6593dcdf 100644
--- a/lib/PublicInbox/IO.pm
+++ b/lib/PublicInbox/IO.pm
@@ -15,8 +15,10 @@ use Errno qw(EINTR EAGAIN);
sub waitcb { # awaitpid callback
my ($pid, $errref, $cb, @args) = @_;
+ $errref //= \my $workaround_await_pids_clobbered;
$$errref = $?; # sets .cerr for _close
- $cb->($pid, @args) if $cb;
+ $cb->($pid, @args) if $cb; # may clobber $?
+ $? = $$errref;
}
sub attach_pid {
@@ -33,6 +35,11 @@ sub attached_pid {
${${*$io}{pi_io_reap} // []}[1];
}
+sub owner_pid {
+ my ($io) = @_;
+ ${${*$io}{pi_io_reap} // [-1]}[0];
+}
+
# caller cares about error result if they call close explicitly
# reap->[2] may be set before this is called via waitcb
sub close {
@@ -40,8 +47,12 @@ sub close {
my $ret = $io->SUPER::close;
my $reap = delete ${*$io}{pi_io_reap};
return $ret unless $reap && $reap->[0] == $$;
- ${$reap->[2]} // (my $w = awaitpid($reap->[1])); # sets [2]
- ($? = ${$reap->[2]}) ? '' : $ret;
+ if (defined ${$reap->[2]}) { # reap_pids already reaped asynchronously
+ $? = ${$reap->[2]};
+ } else { # wait synchronously
+ my $w = awaitpid($reap->[1]);
+ }
+ $? ? '' : $ret; # use $?, AWAIT_PIDS may be cleared on ->Reset (FIXME?)
}
sub DESTROY {
^ permalink raw reply related [relevance 5%]
* [PATCH 0/7] more I/O + process reliability and cleanups
@ 2023-11-26 2:10 7% Eric Wong
2023-11-26 2:11 5% ` [PATCH 6/7] git: improve coupling with {sock} and {inflight} fields Eric Wong
0 siblings, 1 reply; 2+ results
From: Eric Wong @ 2023-11-26 2:10 UTC (permalink / raw)
To: meta
6/7 ought to fix another hang in t/lei-q-save.t when writing to
v2 outputs.
Much of this stuff will be relevant to code search since Xapian
searches will be moved to C++ (if available) to support features
which aren't usable from Perl bindings and allow more
predictable performance anyways.
Eric Wong (7):
xap_helper_cxx: do not copy xap_helper.h source
xap_client: attach PID to the IO object
xap_client: pass arguments to top-level xap_helper
xap_helper: allow PI_NO_CXX to disable C++ in more places
git: move rbuf handling to PublicInbox::IO
git: improve coupling with {sock} and {inflight} fields
drop redundant calls to DS->Reset
lib/PublicInbox/CodeSearchIdx.pm | 11 +--
lib/PublicInbox/Daemon.pm | 1 -
lib/PublicInbox/Gcf2Client.pm | 7 +-
lib/PublicInbox/Git.pm | 138 ++++++++++++-------------------
lib/PublicInbox/GitAsyncCat.pm | 2 +-
lib/PublicInbox/IO.pm | 70 ++++++++++++++--
lib/PublicInbox/TestCommon.pm | 2 +-
lib/PublicInbox/Watch.pm | 6 +-
lib/PublicInbox/XapClient.pm | 9 +-
lib/PublicInbox/XapHelperCxx.pm | 11 +--
lib/PublicInbox/Xapcmd.pm | 6 +-
t/xap_helper.t | 5 +-
12 files changed, 145 insertions(+), 123 deletions(-)
^ permalink raw reply [relevance 7%]
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