daemon: share and allow configuring Xapian helpers

Xapian helper processes are disabled by default once again.
However, they can be enabled via the new `-X INTEGER' parameter.
One big positive is the Xapian helpers being spawned by the
top-level daemon means they can be shared freely across all
workers for improved load balancing and memory reduction.

1 files changed, 4 insertions, 3 deletions

diff --git a/lib/PublicInbox/XapClient.pm b/lib/PublicInbox/XapClient.pm
index f0270091..24b3f45e 100644
--- a/lib/PublicInbox/XapClient.pm
+++ b/lib/PublicInbox/XapClient.pm
@@ -12,6 +12,7 @@ use PublicInbox::Spawn qw(spawn);
 use Socket qw(AF_UNIX SOCK_SEQPACKET);
 use PublicInbox::IPC;
 use autodie qw(pipe socketpair);
+our $tries = 50;
 
 sub mkreq {
         my ($self, $ios, @arg) = @_;
@@ -19,13 +20,13 @@ sub mkreq {
         pipe($r, $ios->[0]) if !defined($ios->[0]);
         my @fds = map fileno($_), @$ios;
         my $buf = join("\0", @arg, '');
-        $n = $PublicInbox::IPC::send_cmd->($self->{io}, \@fds, $buf, 0) //
-                die "send_cmd: $!";
+        $n = $PublicInbox::IPC::send_cmd->($self->{io}, \@fds, $buf, 0, $tries)
+                // die "send_cmd: $!";
         $n == length($buf) or die "send_cmd: $n != ".length($buf);
         $r;
 }
 
-sub start_helper {
+sub start_helper (@) {
         $PublicInbox::IPC::send_cmd or return; # can't work w/o SCM_RIGHTS
         my @argv = @_;
         socketpair(my $sock, my $in, AF_UNIX, SOCK_SEQPACKET, 0);