recv_cmd: do not undef recvmsg buffer arg on errors

[public-inbox.git] / lib / PublicInbox / CmdIPC4.pm

diff --git a/lib/PublicInbox/CmdIPC4.pm b/lib/PublicInbox/CmdIPC4.pm
index 74dbf8a12ee4a8090a16d75a8ddbcaee6271cf3b..76938b6d36dc4c16a89ecf63be1ff487a2e6217d 100644 (file)
--- a/lib/PublicInbox/CmdIPC4.pm
+++ b/lib/PublicInbox/CmdIPC4.pm
@@ -1,4 +1,4 @@
-# Copyright (C) 2020-2021 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>
 
 # callers should use PublicInbox::CmdIPC4->can('send_cmd4') (or recv_cmd4)
@@ -17,13 +17,22 @@ no warnings 'once';
        my ($sock, $fds, undef, $flags) = @_;
        my $mh = Socket::MsgHdr->new(buf => $_[2]);
        $mh->cmsghdr(SOL_SOCKET, SCM_RIGHTS, pack('i' x scalar(@$fds), @$fds));
-       Socket::MsgHdr::sendmsg($sock, $mh, $flags);
+       my $s;
+       my $try = 0;
+       do {
+               $s = Socket::MsgHdr::sendmsg($sock, $mh, $flags);
+       } while (!defined($s) &&
+                       ($!{ENOBUFS} || $!{ENOMEM} || $!{ETOOMANYREFS}) &&
+                       (++$try < 50) &&
+                       warn "sleeping on sendmsg: $! (#$try)\n" &&
+                       select(undef, undef, undef, 0.1) == 0);
+       $s;
 };
 
 *recv_cmd4 = sub ($$$) {
        my ($s, undef, $len) = @_; # $_[1] = destination buffer
        my $mh = Socket::MsgHdr->new(buflen => $len, controllen => 256);
-       my $r = Socket::MsgHdr::recvmsg($s, $mh, 0) // return ($_[1] = undef);
+       my $r = Socket::MsgHdr::recvmsg($s, $mh, 0) // return (undef);
        $_[1] = $mh->buf;
        return () if $r == 0;
        my (undef, undef, $data) = $mh->cmsghdr;