searchidxshard: reuse $SIG{__WARN__} callback from Admin

We don't want to define $SIG{__WARN__} in the worker to call an
existing non-default callback.  Instead update ->{current_info}
the same way the V2Writable master process does.

I noticed this while reindexing with a large XAPIAN_FLUSH_THRESHOLD
and seeing the wrong epoch on my terminal from a shard because the
shard worker was spawned while reindexing a higher-numbered epoch.

diff --git a/lib/PublicInbox/SearchIdxShard.pm b/lib/PublicInbox/SearchIdxShard.pm
index e27d0e64851eb975751f5f184988d362818c8d5d..b22e51dcdbb408f04effaa83d156d0f9fbe45a81 100644 (file)
--- a/lib/PublicInbox/SearchIdxShard.pm
+++ b/lib/PublicInbox/SearchIdxShard.pm
@@ -19,7 +19,7 @@ sub new {
 }
 
 sub spawn_worker {
-       my ($self, $v2writable, $shard) = @_;
+       my ($self, $v2w, $shard) = @_;
        my ($r, $w);
        pipe($r, $w) or die "pipe failed: $!\n";
        binmode $r, ':raw';
@@ -27,15 +27,14 @@ sub spawn_worker {
        my $pid = fork;
        defined $pid or die "fork failed: $!\n";
        if ($pid == 0) {
-               my $bnote = $v2writable->atfork_child;
-               $v2writable = undef;
+               my $bnote = $v2w->atfork_child;
                close $w or die "failed to close: $!";
 
                # F_SETPIPE_SZ = 1031 on Linux; increasing the pipe size here
                # speeds V2Writable batch imports across 8 cores by nearly 20%
                fcntl($r, 1031, 1048576) if $^O eq 'linux';
 
-               eval { shard_worker_loop($self, $r, $shard, $bnote) };
+               eval { shard_worker_loop($self, $v2w, $r, $shard, $bnote) };
                die "worker $shard died: $@\n" if $@;
                die "unexpected MM $self->{mm}" if $self->{mm};
                exit;
@@ -45,18 +44,12 @@ sub spawn_worker {
        close $r or die "failed to close: $!";
 }
 
-sub shard_worker_loop ($$$$) {
-       my ($self, $r, $shard, $bnote) = @_;
+sub shard_worker_loop ($$$$$) {
+       my ($self, $v2w, $r, $shard, $bnote) = @_;
        $0 = "pi-v2-shard[$shard]";
-       my $current_info = '';
-       my $warn_cb = $SIG{__WARN__} || sub { print STDERR @_ };
-       local $SIG{__WARN__} = sub {
-               chomp $current_info;
-               $warn_cb->("[$shard] $current_info: ", @_);
-       };
        $self->begin_txn_lazy;
        while (my $line = $r->getline) {
-               $current_info = $line;
+               $v2w->{current_info} = "[$shard] $line";
                if ($line eq "commit\n") {
                        $self->commit_txn_lazy;
                } elsif ($line eq "close\n") {