use Scalar::Util qw(blessed);
use PublicInbox::Syscall qw(:epoll);
use PublicInbox::Tmpfile;
-use Errno qw(EAGAIN EINVAL);
+use Errno qw(EAGAIN EINVAL ECHILD EINTR);
use Carp qw(carp croak);
-our @EXPORT_OK = qw(now msg_more dwaitpid add_timer add_uniq_timer);
+our @EXPORT_OK = qw(now msg_more awaitpid add_timer add_uniq_timer);
my %Stack;
my $nextq; # queue for next_tick
-my $wait_pids; # list of [ pid, callback, callback_arg ]
+my $AWAIT_PIDS; # pid => [ $callback, @args ]
my $reap_armed;
my $ToClose; # sockets to close when event loop is done
our (
# we may be iterating inside one of these on our stack
my @q = delete @Stack{keys %Stack};
for my $q (@q) { @$q = () }
- $wait_pids = $nextq = $ToClose = undef;
+ $AWAIT_PIDS = $nextq = $ToClose = undef;
$ep_io = undef; # closes real $Epoll FD
$Epoll = undef; # may call DSKQXS::DESTROY
- } while (@Timers || keys(%Stack) || $nextq || $wait_pids ||
+ } while (@Timers || keys(%Stack) || $nextq || $AWAIT_PIDS ||
$ToClose || keys(%DescriptorMap) ||
$PostLoopCallback || keys(%UniqTimer));
# caller sets return value to $Epoll
sub _InitPoller () {
- if (PublicInbox::Syscall::epoll_defined()) {
+ if (defined $PublicInbox::Syscall::SYS_epoll_create) {
my $fd = epoll_create();
die "epoll_create: $!" if $fd < 0;
open($ep_io, '+<&=', $fd) or return;
- my $fl = fcntl($ep_io, F_GETFD, 0);
- fcntl($ep_io, F_SETFD, $fl | FD_CLOEXEC);
+ fcntl($ep_io, F_SETFD, FD_CLOEXEC);
$fd;
} else {
my $cls;
$oldset;
}
-# We can't use waitpid(-1) safely here since it can hit ``, system(),
-# and other things. So we scan the $wait_pids list, which is hopefully
-# not too big. We keep $wait_pids small by not calling dwaitpid()
-# until we've hit EOF when reading the stdout of the child.
+sub await_cb ($;@) {
+ my ($pid, @cb_args) = @_;
+ my $cb = shift @cb_args or return;
+ eval { $cb->($pid, @cb_args) };
+ warn "E: awaitpid($pid): $@" if $@;
+}
+# This relies on our Perl process is single-threaded, or at least
+# no threads are spawning and waiting on processes (``, system(), etc...)
+# Threads are officially discouraged by the Perl5 team, and I expect
+# that to remain the case.
sub reap_pids {
$reap_armed = undef;
- my $tmp = $wait_pids or return;
- $wait_pids = undef;
- $Stack{reap_runq} = $tmp;
my $oldset = block_signals();
- foreach my $ary (@$tmp) {
- my ($pid, $cb, $arg) = @$ary;
- my $ret = waitpid($pid, WNOHANG);
- if ($ret == 0) {
- push @$wait_pids, $ary; # autovivifies @$wait_pids
- } elsif ($ret == $pid) {
- if ($cb) {
- eval { $cb->($arg, $pid) };
- warn "E: dwaitpid($pid) in_loop: $@" if $@;
- }
+ while (1) {
+ my $pid = waitpid(-1, WNOHANG) // last;
+ last if $pid <= 0;
+ if (defined(my $cb_args = delete $AWAIT_PIDS->{$pid})) {
+ await_cb($pid, @$cb_args) if $cb_args;
} else {
- warn "waitpid($pid, WNOHANG) = $ret, \$!=$!, \$?=$?";
+ warn "W: reaped unknown PID=$pid: \$?=$?\n";
}
}
sig_setmask($oldset);
- delete $Stack{reap_runq};
}
# reentrant SIGCHLD handler (since reap_pids is not reentrant)
undef;
}
-sub dwaitpid ($;$$) {
- my ($pid, $cb, $arg) = @_;
- if ($in_loop) {
- push @$wait_pids, [ $pid, $cb, $arg ];
- # We could've just missed our SIGCHLD, cover it, here:
- enqueue_reap();
- } else {
- my $ret = waitpid($pid, 0);
+sub awaitpid {
+ my ($pid, @cb_args) = @_; # @cb_args = ($cb, @args), $cb may be undef
+ $AWAIT_PIDS->{$pid} = \@cb_args if @cb_args;
+ # provide synchronous API
+ if (defined(wantarray) || (!$in_loop && !@cb_args)) {
+ my $ret;
+again:
+ $ret = waitpid($pid, 0) // -2;
if ($ret == $pid) {
- if ($cb) {
- eval { $cb->($arg, $pid) };
- carp "E: dwaitpid($pid) !in_loop: $@" if $@;
- }
+ my $cb_args = delete $AWAIT_PIDS->{$pid};
+ @cb_args = @$cb_args if !@cb_args && $cb_args;
+ await_cb($pid, @cb_args);
} else {
- carp "waitpid($pid, 0) = $ret, \$!=$!, \$?=$?";
+ goto again if $! == EINTR;
+ carp "waitpid($pid): $!";
+ delete $AWAIT_PIDS->{$pid};
}
+ return $ret;
+ } elsif ($in_loop) { # We could've just missed our SIGCHLD, cover it, here:
+ enqueue_reap();
}
}