ds: introduce and use do_fork helper

This ensures we handle RNG reseeding and resetting the event
loop properly in child processes after forking.

6 files changed, 24 insertions, 35 deletions

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index eefbdcc3..9960937d 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -34,6 +34,7 @@ use PublicInbox::Tmpfile;
 use PublicInbox::Select;
 use Errno qw(EAGAIN EINVAL ECHILD);
 use Carp qw(carp croak);
+use autodie qw(fork);
 our @EXPORT_OK = qw(now msg_more awaitpid add_timer add_uniq_timer);
 
 my $nextq; # queue for next_tick
@@ -737,6 +738,17 @@ sub awaitpid {
         }
 }
 
+sub do_fork () {
+        my $seed = rand(0xffffffff);
+        my $pid = fork;
+        if ($pid == 0) {
+                srand($seed);
+                eval { Net::SSLeay::randomize() };
+                Reset();
+        }
+        $pid;
+}
+
 package PublicInbox::DummyPoller; # only used during Reset
 use v5.12;
 
diff --git a/lib/PublicInbox/Daemon.pm b/lib/PublicInbox/Daemon.pm
index 520cef72..f33f6f17 100644
--- a/lib/PublicInbox/Daemon.pm
+++ b/lib/PublicInbox/Daemon.pm
@@ -541,17 +541,11 @@ sub reap_worker { # awaitpid CB
 
 sub start_worker ($) {
         my ($nr) = @_;
-        my $seed = rand(0xffffffff);
         return unless @listeners;
-        my $pid = fork;
-        if (!defined($pid)) {
-                warn "fork: $!";
-        } elsif ($pid == 0) {
+        my $pid = PublicInbox::DS::do_fork;
+        if ($pid == 0) {
                 undef %WORKERS;
-                PublicInbox::DS::Reset();
                 local $PublicInbox::DS::Poller; # allow epoll/kqueue
-                srand($seed);
-                eval { Net::SSLeay::randomize() };
                 $set_user->() if $set_user;
                 PublicInbox::EOFpipe->new($parent_pipe, \&worker_quit);
                 worker_loop();
@@ -563,9 +557,9 @@ sub start_worker ($) {
 }
 
 sub start_workers {
-        for my $nr (grep { !defined($WORKERS{$_}) } (0..($nworker - 1))) {
-                start_worker($nr);
-        }
+        my @idx = grep { !defined($WORKERS{$_}) } (0..($nworker - 1)) or return;
+        eval { start_worker($_) for @idx };
+        warn "E: $@\n" if $@;
 }
 
 sub trim_workers {
diff --git a/lib/PublicInbox/IPC.pm b/lib/PublicInbox/IPC.pm
index 5964645e..3292d960 100644
--- a/lib/PublicInbox/IPC.pm
+++ b/lib/PublicInbox/IPC.pm
@@ -102,12 +102,8 @@ sub ipc_worker_spawn {
         pipe(my $r_res, my $w_res);
         my $sigset = $oldset // PublicInbox::DS::block_signals();
         $self->ipc_atfork_prepare;
-        my $seed = rand(0xffffffff);
-        my $pid = fork;
+        my $pid = PublicInbox::DS::do_fork;
         if ($pid == 0) {
-                srand($seed);
-                eval { Net::SSLeay::randomize() };
-                eval { PublicInbox::DS->Reset };
                 delete @$self{qw(-wq_s1 -wq_s2 -wq_workers -wq_ppid)};
                 $w_req = $r_res = undef;
                 $w_res->autoflush(1);
@@ -341,13 +337,9 @@ sub _wq_worker_start {
         my ($self, $oldset, $fields, $one, @cb_args) = @_;
         my ($bcast1, $bcast2);
         $one or socketpair($bcast1, $bcast2, AF_UNIX, SOCK_SEQPACKET, 0);
-        my $seed = rand(0xffffffff);
-        my $pid = fork;
+        my $pid = PublicInbox::DS::do_fork;
         if ($pid == 0) {
-                srand($seed);
-                eval { Net::SSLeay::randomize() };
                 undef $bcast1;
-                eval { PublicInbox::DS->Reset };
                 delete @$self{qw(-wq_s1 -wq_ppid)};
                 $self->{-wq_worker_nr} =
                                 keys %{delete($self->{-wq_workers}) // {}};
diff --git a/lib/PublicInbox/TestCommon.pm b/lib/PublicInbox/TestCommon.pm
index 323152b4..77da822b 100644
--- a/lib/PublicInbox/TestCommon.pm
+++ b/lib/PublicInbox/TestCommon.pm
@@ -549,9 +549,8 @@ sub start_script {
         require PublicInbox::OnDestroy;
         my $tmp_mask = PublicInbox::OnDestroy->new(
                                         \&PublicInbox::DS::sig_setmask, $oset);
-        my $pid = fork // die "fork: $!";
+        my $pid = PublicInbox::DS::do_fork();
         if ($pid == 0) {
-                eval { PublicInbox::DS->Reset };
                 for (@{delete($opt->{-CLOFORK}) // []}) {
                         close($_) or die "close $!";
                 }
diff --git a/lib/PublicInbox/Watch.pm b/lib/PublicInbox/Watch.pm
index 3426d4a7..41b77dc1 100644
--- a/lib/PublicInbox/Watch.pm
+++ b/lib/PublicInbox/Watch.pm
@@ -385,7 +385,6 @@ sub watch_atfork_child ($) {
         my ($self) = @_;
         delete $self->{pids};
         delete $self->{opendirs};
-        PublicInbox::DS->Reset;
         my $sig = delete $self->{sig};
         $sig->{CHLD} = $sig->{HUP} = $sig->{USR1} = 'DEFAULT';
         # TERM/QUIT/INT call ->quit, which works in both parent+child
@@ -413,11 +412,8 @@ sub imap_idle_reap { # awaitpid callback
 sub imap_idle_fork {
         my ($self, $uri, $intvl) = @_;
         return if $self->{quit};
-        my $seed = rand(0xffffffff);
-        my $pid = fork // die "fork: $!";
+        my $pid = PublicInbox::DS::do_fork;
         if ($pid == 0) {
-                srand($seed);
-                eval { Net::SSLeay::randomize() };
                 watch_atfork_child($self);
                 watch_imap_idle_1($self, $uri, $intvl);
                 _exit(0);
@@ -477,11 +473,8 @@ sub poll_fetch_fork { # DS::add_timer callback
         my @imap = grep { # push() always returns > 0
                 $_->scheme =~ m!\Aimaps?!i ? 1 : (push(@nntp, $_) < 0)
         } @$uris;
-        my $seed = rand(0xffffffff);
-        my $pid = fork // die "fork: $!";
+        my $pid = PublicInbox::DS::do_fork;
         if ($pid == 0) {
-                srand($seed);
-                eval { Net::SSLeay::randomize() };
                 watch_atfork_child($self);
                 watch_imap_fetch_all($self, \@imap) if @imap;
                 watch_nntp_fetch_all($self, \@nntp) if @nntp;
diff --git a/lib/PublicInbox/Xapcmd.pm b/lib/PublicInbox/Xapcmd.pm
index 4e055acf..c2b66e69 100644
--- a/lib/PublicInbox/Xapcmd.pm
+++ b/lib/PublicInbox/Xapcmd.pm
@@ -11,6 +11,7 @@ use PublicInbox::SearchIdx;
 use File::Temp 0.19 (); # ->newdir
 use File::Path qw(remove_tree);
 use POSIX qw(WNOHANG _exit);
+use PublicInbox::DS;
 
 # support testing with dev versions of Xapian which installs
 # commands with a version number suffix (e.g. "xapian-compact-1.5")
@@ -102,10 +103,8 @@ sub commit_changes ($$$$) {
 
 sub cb_spawn {
         my ($cb, $args, $opt) = @_; # $cb = cpdb() or compact()
-        my $seed = rand(0xffffffff);
-        my $pid = fork // die "fork: $!";
+        my $pid = PublicInbox::DS::do_fork;
         return $pid if $pid > 0;
-        srand($seed);
         $SIG{__DIE__} = sub { warn @_; _exit(1) }; # don't jump up stack
         $cb->($args, $opt);
         _exit(0);