From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: X-Spam-Status: No, score=-4.0 required=3.0 tests=ALL_TRUSTED,BAYES_00 shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from localhost (dcvr.yhbt.net [127.0.0.1]) by dcvr.yhbt.net (Postfix) with ESMTP id 100DC1F466 for ; Wed, 27 Nov 2019 01:33:35 +0000 (UTC) From: Eric Wong To: meta@public-inbox.org Subject: [PATCH 2/2] httpd|nntpd: avoid missed signal wakeups Date: Wed, 27 Nov 2019 01:33:33 +0000 Message-Id: <20191127013333.94381-3-e@80x24.org> In-Reply-To: <20191127013333.94381-1-e@80x24.org> References: <20191127013333.94381-1-e@80x24.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit List-Id: Our attempt at using a self-pipe in signal handlers was ineffective, since pure Perl code execution is deferred and Perl doesn't use an internal self-pipe/eventfd. In retrospect, I actually prefer the simplicity of Perl in this regard... We can use sigprocmask() from Perl, so we can introduce signalfd(2) and EVFILT_SIGNAL support on Linux and *BSD-based systems, respectively. These OS primitives allow us to avoid a race where Perl checks for signals right before epoll_wait() or kevent() puts the process to sleep. The (few) systems nowadays without signalfd(2) or IO::KQueue will now see wakeups every second to avoid missed signals. --- MANIFEST | 2 + lib/PublicInbox/DS.pm | 6 +- lib/PublicInbox/DSKQXS.pm | 103 +++++++++++++++++---- lib/PublicInbox/Daemon.pm | 183 ++++++++++++++++++------------------- lib/PublicInbox/Sigfd.pm | 63 +++++++++++++ lib/PublicInbox/Syscall.pm | 42 ++++++++- t/ds-kqxs.t | 28 ++++++ t/sigfd.t | 65 +++++++++++++ 8 files changed, 376 insertions(+), 116 deletions(-) create mode 100644 lib/PublicInbox/Sigfd.pm create mode 100644 t/sigfd.t diff --git a/MANIFEST b/MANIFEST index a50c1246..098e656d 100644 --- a/MANIFEST +++ b/MANIFEST @@ -141,6 +141,7 @@ lib/PublicInbox/SearchIdxShard.pm lib/PublicInbox/SearchMsg.pm lib/PublicInbox/SearchThread.pm lib/PublicInbox/SearchView.pm +lib/PublicInbox/Sigfd.pm lib/PublicInbox/SolverGit.pm lib/PublicInbox/Spamcheck.pm lib/PublicInbox/Spamcheck/Spamc.pm @@ -266,6 +267,7 @@ t/replace.t t/reply.t t/search-thr-index.t t/search.t +t/sigfd.t t/solve/0001-simple-mod.patch t/solve/0002-rename-with-modifications.patch t/solver_git.t diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm index 7f7cb85d..17c640f4 100644 --- a/lib/PublicInbox/DS.pm +++ b/lib/PublicInbox/DS.pm @@ -53,6 +53,7 @@ our ( $LoopTimeout, # timeout of event loop in milliseconds $DoneInit, # if we've done the one-time module init yet @Timers, # timers + $in_loop, ); Reset(); @@ -249,7 +250,7 @@ sub reap_pids { sub enqueue_reap ($) { push @$nextq, \&reap_pids }; sub EpollEventLoop { - local $SIG{CHLD} = \&enqueue_reap; + local $in_loop = 1; while (1) { my @events; my $i; @@ -628,8 +629,7 @@ sub shutdn ($) { # must be called with eval, PublicInbox::DS may not be loaded (see t/qspawn.t) sub dwaitpid ($$$) { my ($pid, $cb, $arg) = @_; - my $chld = $SIG{CHLD}; - if (defined($chld) && $chld eq \&enqueue_reap) { + if ($in_loop) { push @$WaitPids, [ $pid, $cb, $arg ]; # We could've just missed our SIGCHLD, cover it, here: diff --git a/lib/PublicInbox/DSKQXS.pm b/lib/PublicInbox/DSKQXS.pm index 84e146f8..a56079e2 100644 --- a/lib/PublicInbox/DSKQXS.pm +++ b/lib/PublicInbox/DSKQXS.pm @@ -8,18 +8,20 @@ # like epoll to simplify the code in DS.pm. This is NOT meant to be # an all encompassing emulation of epoll via IO::KQueue, but just to # support cases public-inbox-nntpd/httpd care about. -# A pure-Perl version using syscall() is planned, and it should be -# faster due to the lack of syscall overhead. +# +# It also implements signalfd(2) emulation via "tie". +# +# A pure-Perl version using syscall() is planned. package PublicInbox::DSKQXS; use strict; use warnings; -use parent qw(IO::KQueue); use parent qw(Exporter); +use Symbol qw(gensym); use IO::KQueue; +use Errno qw(EAGAIN); use PublicInbox::Syscall qw(EPOLLONESHOT EPOLLIN EPOLLOUT EPOLLET - EPOLL_CTL_ADD EPOLL_CTL_MOD EPOLL_CTL_DEL); + EPOLL_CTL_ADD EPOLL_CTL_MOD EPOLL_CTL_DEL SFD_NONBLOCK); our @EXPORT_OK = qw(epoll_ctl epoll_wait); -my $owner_pid = -1; # kqueue is close-on-fork (yes, fork, not exec) sub EV_DISPATCH () { 0x0080 } @@ -41,29 +43,90 @@ sub kq_flag ($$) { sub new { my ($class) = @_; - die 'non-singleton use not supported' if $owner_pid == $$; - $owner_pid = $$; - $class->SUPER::new; + bless { kq => IO::KQueue->new, owner_pid => $$ }, $class; +} + +# returns a new instance which behaves like signalfd on Linux. +# It's wasteful in that it uses another FD, but it simplifies +# our epoll-oriented code. +sub signalfd { + my ($class, $signo, $flags) = @_; + my $sym = gensym; + tie *$sym, $class, $signo, $flags; # calls TIEHANDLE + $sym +} + +sub TIEHANDLE { # similar to signalfd() + my ($class, $signo, $flags) = @_; + my $self = $class->new; + $self->{timeout} = ($flags & SFD_NONBLOCK) ? 0 : -1; + my $kq = $self->{kq}; + $kq->EV_SET($_, EVFILT_SIGNAL, EV_ADD) for @$signo; + $self; +} + +sub READ { # called by sysread() for signalfd compatibility + my ($self, undef, $len, $off) = @_; # $_[1] = buf + die "bad args for signalfd read" if ($len % 128) // defined($off); + my $timeout = $self->{timeout}; + my $sigbuf = $self->{sigbuf} //= []; + my $nr = $len / 128; + my $r = 0; + $_[1] = ''; + do { + while ($nr--) { + my $signo = shift(@$sigbuf) or last; + # caller only cares about signalfd_siginfo.ssi_signo: + $_[1] .= pack('L', $signo) . ("\0" x 124); + $r += 128; + } + return $r if $r; + my @events = eval { $self->{kq}->kevent($timeout) }; + # workaround https://rt.cpan.org/Ticket/Display.html?id=116615 + if ($@) { + next if $@ =~ /Interrupted system call/; + die; + } + if (!scalar(@events) && $timeout == 0) { + $! = EAGAIN; + return; + } + + # Grab the kevent.ident (signal number). The kevent.data + # field shows coalesced signals, and maybe we'll use it + # in the future... + @$sigbuf = map { $_->[0] } @events; + } while (1); } +# for fileno() calls in PublicInbox::DS +sub FILENO { ${$_[0]->{kq}} } + sub epoll_ctl { my ($self, $op, $fd, $ev) = @_; + my $kq = $self->{kq}; if ($op == EPOLL_CTL_MOD) { - $self->EV_SET($fd, EVFILT_READ, kq_flag(EPOLLIN, $ev)); - $self->EV_SET($fd, EVFILT_WRITE, kq_flag(EPOLLOUT, $ev)); + $kq->EV_SET($fd, EVFILT_READ, kq_flag(EPOLLIN, $ev)); + $kq->EV_SET($fd, EVFILT_WRITE, kq_flag(EPOLLOUT, $ev)); } elsif ($op == EPOLL_CTL_DEL) { - $self->EV_SET($fd, EVFILT_READ, EV_DISABLE); - $self->EV_SET($fd, EVFILT_WRITE, EV_DISABLE); - } else { - $self->EV_SET($fd, EVFILT_READ, EV_ADD|kq_flag(EPOLLIN, $ev)); - $self->EV_SET($fd, EVFILT_WRITE, EV_ADD|kq_flag(EPOLLOUT, $ev)); + $kq->EV_SET($fd, EVFILT_READ, EV_DISABLE); + $kq->EV_SET($fd, EVFILT_WRITE, EV_DISABLE); + } else { # EPOLL_CTL_ADD + $kq->EV_SET($fd, EVFILT_READ, EV_ADD|kq_flag(EPOLLIN, $ev)); + + # we call this blindly for read-only FDs such as tied + # DSKQXS (signalfd emulation) and Listeners + eval { + $kq->EV_SET($fd, EVFILT_WRITE, EV_ADD | + kq_flag(EPOLLOUT, $ev)); + }; } 0; } sub epoll_wait { my ($self, $maxevents, $timeout_msec, $events) = @_; - @$events = eval { $self->kevent($timeout_msec) }; + @$events = eval { $self->{kq}->kevent($timeout_msec) }; if (my $err = $@) { # workaround https://rt.cpan.org/Ticket/Display.html?id=116615 if ($err =~ /Interrupted system call/) { @@ -76,11 +139,13 @@ sub epoll_wait { scalar(@$events); } +# kqueue is close-on-fork (not exec), so we must not close it +# in forked processes: sub DESTROY { my ($self) = @_; - if ($owner_pid == $$) { - POSIX::close($$self); - $owner_pid = -1; + my $kq = delete $self->{kq} or return; + if (delete($self->{owner_pid}) == $$) { + POSIX::close($$kq); } } diff --git a/lib/PublicInbox/Daemon.pm b/lib/PublicInbox/Daemon.pm index 0e3b95d2..c7a71ba0 100644 --- a/lib/PublicInbox/Daemon.pm +++ b/lib/PublicInbox/Daemon.pm @@ -15,9 +15,11 @@ use Cwd qw/abs_path/; STDOUT->autoflush(1); STDERR->autoflush(1); use PublicInbox::DS qw(now); +use PublicInbox::Syscall qw(SFD_NONBLOCK); require PublicInbox::EvCleanup; require PublicInbox::Listener; require PublicInbox::ParentPipe; +require PublicInbox::Sigfd; my @CMD; my ($set_user, $oldset, $newset); my (@cfg_listen, $stdout, $stderr, $group, $user, $pid_file, $daemonize); @@ -74,12 +76,14 @@ sub accept_tls_opt ($) { { SSL_server => 1, SSL_startHandshake => 0, SSL_reuse_ctx => $ctx }; } +sub sig_setmask { sigprocmask(SIG_SETMASK, @_) or die "sigprocmask: $!" } + sub daemon_prepare ($) { my ($default_listen) = @_; $oldset = POSIX::SigSet->new(); $newset = POSIX::SigSet->new(); $newset->fillset or die "fillset: $!"; - sigprocmask(SIG_SETMASK, $newset, $oldset) or die "sigprocmask: $!"; + sig_setmask($newset, $oldset); @CMD = ($0, @ARGV); my %opts = ( 'l|listen=s' => \@cfg_listen, @@ -252,30 +256,12 @@ sub daemonize () { } } -sub shrink_pipes { - if ($^O eq 'linux') { # 1031: F_SETPIPE_SZ, 4096: page size - fcntl($_, 1031, 4096) for @_; - } -} - -sub worker_quit { +sub worker_quit { # $_[0] = signal name or number (unused) # killing again terminates immediately: exit unless @listeners; $_->close foreach @listeners; # call PublicInbox::DS::close @listeners = (); - - # create a lazy self-pipe which kicks us out of the EventLoop - # so DS::PostEventLoop can fire - if (pipe(my ($r, $w))) { - shrink_pipes($w); - - # shrink_pipes == noop - PublicInbox::ParentPipe->new($r, *shrink_pipes); - close $w; # wake up from the event loop - } else { - warn "E: pipe failed ($!), quit unreliable\n"; - } my $proc_name; my $warn = 0; # drop idle connections and try to quit gracefully @@ -398,7 +384,7 @@ processes when multiple service instances start. @rv } -sub upgrade () { +sub upgrade { # $_[0] = signal name or number (unused) if ($reexec_pid) { warn "upgrade in-progress: $reexec_pid\n"; return; @@ -453,7 +439,7 @@ sub upgrade_aborted ($) { warn $@, "\n" if $@; } -sub reap_children () { +sub reap_children { # $_[0] = 'CHLD' or POSIX::SIGCHLD() while (1) { my $p = waitpid(-1, WNOHANG) or return; if (defined $reexec_pid && $p == $reexec_pid) { @@ -483,60 +469,50 @@ sub unlink_pid_file_safe_ish ($$) { sub master_loop { pipe(my ($p0, $p1)) or die "failed to create parent-pipe: $!"; - pipe(my ($r, $w)) or die "failed to create self-pipe: $!"; - shrink_pipes($w, $p1); - - IO::Handle::blocking($w, 0); + # 1031: F_SETPIPE_SZ, 4096: page size + fcntl($p1, 1031, 4096) if $^O eq 'linux'; my $set_workers = $worker_processes; - my @caught; - my $master_pid = $$; - foreach my $s (qw(HUP CHLD QUIT INT TERM USR1 USR2 TTIN TTOU WINCH)) { - $SIG{$s} = sub { - return if $$ != $master_pid; - push @caught, $s; - syswrite($w, '.'); - }; - } - sigprocmask(SIG_SETMASK, $oldset) or die "sigprocmask: $!"; reopen_logs(); - # main loop my $quit = 0; - while (1) { - while (my $s = shift @caught) { - if ($s eq 'USR1') { - reopen_logs(); - kill_workers($s); - } elsif ($s eq 'USR2') { - upgrade(); - } elsif ($s =~ /\A(?:QUIT|TERM|INT)\z/) { - exit if $quit++; - kill_workers($s); - } elsif ($s eq 'WINCH') { - if (-t STDIN || -t STDOUT || -t STDERR) { - warn -"ignoring SIGWINCH since we are not daemonized\n"; - $SIG{WINCH} = 'IGNORE'; - } else { - $worker_processes = 0; - } - } elsif ($s eq 'HUP') { - $worker_processes = $set_workers; - kill_workers($s); - } elsif ($s eq 'TTIN') { - if ($set_workers > $worker_processes) { - ++$worker_processes; - } else { - $worker_processes = ++$set_workers; - } - } elsif ($s eq 'TTOU') { - if ($set_workers > 0) { - $worker_processes = --$set_workers; - } - } elsif ($s eq 'CHLD') { - reap_children(); + my $ignore_winch; + my $quit_cb = sub { exit if $quit++; kill_workers($_[0]) }; + my $sig = { + USR1 => sub { reopen_logs(); kill_workers($_[0]); }, + USR2 => \&upgrade, + QUIT => $quit_cb, + INT => $quit_cb, + TERM => $quit_cb, + WINCH => sub { + return if $ignore_winch; + if (-t STDIN || -t STDOUT || -t STDERR) { + $ignore_winch = 1; + warn < sub { + $worker_processes = $set_workers; + kill_workers($_[0]); + }, + TTIN => sub { + if ($set_workers > $worker_processes) { + ++$worker_processes; + } else { + $worker_processes = ++$set_workers; + } + }, + TTOU => sub { + $worker_processes = --$set_workers if $set_workers > 0; + }, + CHLD => \&reap_children, + }; + my $sigfd = PublicInbox::Sigfd->new($sig, 0); + local %SIG = (%SIG, %$sig) if !$sigfd; + sig_setmask($oldset) if !$sigfd; + while (1) { # main loop my $n = scalar keys %pids; if ($quit) { exit if $n == 0; @@ -549,22 +525,29 @@ sub master_loop { } $n = $worker_processes; } - sigprocmask(SIG_SETMASK, $newset) or die "sigprocmask: $!"; - foreach my $i ($n..($worker_processes - 1)) { - my $pid = fork; - if (!defined $pid) { - warn "failed to fork worker[$i]: $!\n"; - } elsif ($pid == 0) { - $set_user->() if $set_user; - return $p0; # run normal work code - } else { - warn "PID=$pid is worker[$i]\n"; - $pids{$pid} = $i; + my $want = $worker_processes - 1; + if ($n <= $want) { + sig_setmask($newset) if !$sigfd; + for my $i ($n..$want) { + my $pid = fork; + if (!defined $pid) { + warn "failed to fork worker[$i]: $!\n"; + } elsif ($pid == 0) { + $set_user->() if $set_user; + return $p0; # run normal work code + } else { + warn "PID=$pid is worker[$i]\n"; + $pids{$pid} = $i; + } } + sig_setmask($oldset) if !$sigfd; + } + + if ($sigfd) { # Linux and IO::KQueue users: + $sigfd->wait_once; + } else { # wake up every second + sleep(1); } - sigprocmask(SIG_SETMASK, $oldset) or die "sigprocmask: $!"; - # just wait on signal events here: - sysread($r, my $buf, 8); } exit # never gets here, just for documentation } @@ -606,6 +589,18 @@ sub daemon_loop ($$$$) { $nntpd->{accept_tls} = $v; } } + my $sig = { + HUP => $refresh, + INT => \&worker_quit, + QUIT => \&worker_quit, + TERM => \&worker_quit, + TTIN => 'IGNORE', + TTOU => 'IGNORE', + USR1 => \&reopen_logs, + USR2 => 'IGNORE', + WINCH => 'IGNORE', + CHLD => \&PublicInbox::DS::enqueue_reap, + }; my $parent_pipe; if ($worker_processes > 0) { $refresh->(); # preload by default @@ -614,16 +609,11 @@ sub daemon_loop ($$$$) { } else { reopen_logs(); $set_user->() if $set_user; - $SIG{USR2} = sub { worker_quit() if upgrade() }; + $sig->{USR2} = sub { worker_quit() if upgrade() }; $refresh->(); } $uid = $gid = undef; reopen_logs(); - $SIG{QUIT} = $SIG{INT} = $SIG{TERM} = *worker_quit; - $SIG{USR1} = *reopen_logs; - $SIG{HUP} = $refresh; - $SIG{CHLD} = 'DEFAULT'; - $SIG{$_} = 'IGNORE' for qw(USR2 TTIN TTOU WINCH); @listeners = map {; my $tls_cb = $post_accept{sockname($_)}; @@ -634,7 +624,14 @@ sub daemon_loop ($$$$) { # this calls epoll_create: PublicInbox::Listener->new($_, $tls_cb || $post_accept) } @listeners; - sigprocmask(SIG_SETMASK, $oldset) or die "sigprocmask: $!"; + my $sigfd = PublicInbox::Sigfd->new($sig, SFD_NONBLOCK); + local %SIG = (%SIG, %$sig) if !$sigfd; + if (!$sigfd) { + # wake up every second to accept signals if we don't + # have signalfd or IO::KQueue: + sig_setmask($oldset); + PublicInbox::DS->SetLoopTimeout(1000); + } PublicInbox::DS->EventLoop; $parent_pipe = undef; } diff --git a/lib/PublicInbox/Sigfd.pm b/lib/PublicInbox/Sigfd.pm new file mode 100644 index 00000000..ec5d7145 --- /dev/null +++ b/lib/PublicInbox/Sigfd.pm @@ -0,0 +1,63 @@ +# Copyright (C) 2019 all contributors +# License: AGPL-3.0+ +package PublicInbox::Sigfd; +use strict; +use parent qw(PublicInbox::DS); +use fields qw(sig); # hashref similar to %SIG, but signal numbers as keys +use PublicInbox::Syscall qw(signalfd EPOLLIN EPOLLET SFD_NONBLOCK); +use POSIX (); +use IO::Handle (); + +# returns a coderef to unblock signals if neither signalfd or kqueue +# are available. +sub new { + my ($class, $sig, $flags) = @_; + my $self = fields::new($class); + my %signo = map {; + my $cb = $sig->{$_}; + my $num = ($_ eq 'WINCH' && $^O =~ /linux|bsd/i) ? 28 : do { + my $m = "SIG$_"; + POSIX->$m; + }; + $num => $cb; + } keys %$sig; + my $io; + my $fd = signalfd(-1, [keys %signo], $flags); + if (defined $fd && $fd >= 0) { + $io = IO::Handle->new_from_fd($fd, 'r+'); + } elsif (eval { require PublicInbox::DSKQXS }) { + $io = PublicInbox::DSKQXS->signalfd([keys %signo], $flags); + } else { + return; # wake up every second to check for signals + } + if ($flags & SFD_NONBLOCK) { # it can go into the event loop + $self->SUPER::new($io, EPOLLIN | EPOLLET); + } else { # master main loop + $self->{sock} = $io; + } + $self->{sig} = \%signo; + $self; +} + +# PublicInbox::Daemon in master main loop (blocking) +sub wait_once ($) { + my ($self) = @_; + my $r = sysread($self->{sock}, my $buf, 128 * 64); + if (defined($r)) { + while (1) { + my $sig = unpack('L', $buf); + my $cb = $self->{sig}->{$sig}; + $cb->($sig) if $cb ne 'IGNORE'; + return $r if length($buf) == 128; + $buf = substr($buf, 128); + } + } + $r; +} + +# called by PublicInbox::DS in epoll_wait loop +sub event_step { + while (wait_once($_[0])) {} # non-blocking +} + +1; diff --git a/lib/PublicInbox/Syscall.pm b/lib/PublicInbox/Syscall.pm index da8a6c86..487013d5 100644 --- a/lib/PublicInbox/Syscall.pm +++ b/lib/PublicInbox/Syscall.pm @@ -24,7 +24,8 @@ $VERSION = "0.25"; @EXPORT_OK = qw(epoll_ctl epoll_create epoll_wait EPOLLIN EPOLLOUT EPOLLET EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD - EPOLLONESHOT EPOLLEXCLUSIVE); + EPOLLONESHOT EPOLLEXCLUSIVE + signalfd SFD_NONBLOCK); %EXPORT_TAGS = (epoll => [qw(epoll_ctl epoll_create epoll_wait EPOLLIN EPOLLOUT EPOLL_CTL_ADD EPOLL_CTL_DEL EPOLL_CTL_MOD @@ -42,6 +43,11 @@ use constant EPOLLET => (1 << 31); use constant EPOLL_CTL_ADD => 1; use constant EPOLL_CTL_DEL => 2; use constant EPOLL_CTL_MOD => 3; +use constant { + SFD_CLOEXEC => 02000000, + SFD_NONBLOCK => 00004000, +}; + our $loaded_syscall = 0; @@ -63,6 +69,7 @@ our ( $SYS_epoll_create, $SYS_epoll_ctl, $SYS_epoll_wait, + $SYS_signalfd4, ); our $no_deprecated = 0; @@ -88,63 +95,75 @@ if ($^O eq "linux") { $SYS_epoll_create = 254; $SYS_epoll_ctl = 255; $SYS_epoll_wait = 256; + $SYS_signalfd4 = 327; } elsif ($machine eq "x86_64") { $SYS_epoll_create = 213; $SYS_epoll_ctl = 233; $SYS_epoll_wait = 232; + $SYS_signalfd4 = 289; } elsif ($machine =~ m/^parisc/) { $SYS_epoll_create = 224; $SYS_epoll_ctl = 225; $SYS_epoll_wait = 226; $u64_mod_8 = 1; + $SYS_signalfd4 = 309; } elsif ($machine =~ m/^ppc64/) { $SYS_epoll_create = 236; $SYS_epoll_ctl = 237; $SYS_epoll_wait = 238; $u64_mod_8 = 1; + $SYS_signalfd4 = 313; } elsif ($machine eq "ppc") { $SYS_epoll_create = 236; $SYS_epoll_ctl = 237; $SYS_epoll_wait = 238; $u64_mod_8 = 1; + $SYS_signalfd4 = 313; } elsif ($machine =~ m/^s390/) { $SYS_epoll_create = 249; $SYS_epoll_ctl = 250; $SYS_epoll_wait = 251; $u64_mod_8 = 1; + $SYS_signalfd4 = 322; } elsif ($machine eq "ia64") { $SYS_epoll_create = 1243; $SYS_epoll_ctl = 1244; $SYS_epoll_wait = 1245; $u64_mod_8 = 1; + $SYS_signalfd4 = 289; } elsif ($machine eq "alpha") { # natural alignment, ints are 32-bits $SYS_epoll_create = 407; $SYS_epoll_ctl = 408; $SYS_epoll_wait = 409; $u64_mod_8 = 1; + $SYS_signalfd4 = 484; } elsif ($machine eq "aarch64") { $SYS_epoll_create = 20; # (sys_epoll_create1) $SYS_epoll_ctl = 21; $SYS_epoll_wait = 22; # (sys_epoll_pwait) $u64_mod_8 = 1; $no_deprecated = 1; + $SYS_signalfd4 = 74; } elsif ($machine =~ m/arm(v\d+)?.*l/) { # ARM OABI $SYS_epoll_create = 250; $SYS_epoll_ctl = 251; $SYS_epoll_wait = 252; $u64_mod_8 = 1; + $SYS_signalfd4 = 355; } elsif ($machine =~ m/^mips64/) { $SYS_epoll_create = 5207; $SYS_epoll_ctl = 5208; $SYS_epoll_wait = 5209; $u64_mod_8 = 1; + $SYS_signalfd4 = 5283; } elsif ($machine =~ m/^mips/) { $SYS_epoll_create = 4248; $SYS_epoll_ctl = 4249; $SYS_epoll_wait = 4250; $u64_mod_8 = 1; + $SYS_signalfd4 = 4324; } else { # as a last resort, try using the *.ph files which may not # exist or may be wrong @@ -152,6 +171,11 @@ if ($^O eq "linux") { $SYS_epoll_create = eval { &SYS_epoll_create; } || 0; $SYS_epoll_ctl = eval { &SYS_epoll_ctl; } || 0; $SYS_epoll_wait = eval { &SYS_epoll_wait; } || 0; + + # Note: do NOT add new syscalls to depend on *.ph, here. + # Better to miss syscalls (so we can fallback to IO::Poll) + # than to use wrong ones, since the names are not stable + # (at least not on FreeBSD), if the actual numbers are. } if ($u64_mod_8) { @@ -228,6 +252,22 @@ sub epoll_wait_mod8 { return $ct; } +sub signalfd ($$$) { + my ($fd, $signos, $flags) = @_; + if ($SYS_signalfd4) { + # Not sure if there's a way to get pack/unpack to get the + # contents of POSIX::SigSet to a buffer, but prepping the + # bitmap like one would for select() works: + my $buf = "\0" x 8; + vec($buf, $_ - 1, 1) = 1 for @$signos; + + syscall($SYS_signalfd4, $fd, $buf, 8, $flags|SFD_CLOEXEC); + } else { + $! = ENOSYS; + undef; + } +} + 1; =head1 WARRANTY diff --git a/t/ds-kqxs.t b/t/ds-kqxs.t index 785570c3..43b6333f 100644 --- a/t/ds-kqxs.t +++ b/t/ds-kqxs.t @@ -10,5 +10,33 @@ unless (eval { require IO::KQueue }) { : "no IO::KQueue, skipping $0: $@"; plan skip_all => $m; } + +if ('ensure nested kqueue works for signalfd emulation') { + require POSIX; + my $new = POSIX::SigSet->new(POSIX::SIGHUP()); + my $old = POSIX::SigSet->new; + my $hup = 0; + local $SIG{HUP} = sub { $hup++ }; + POSIX::sigprocmask(POSIX::SIG_SETMASK(), $new, $old) or die; + my $kqs = IO::KQueue->new or die; + $kqs->EV_SET(POSIX::SIGHUP(), IO::KQueue::EVFILT_SIGNAL(), + IO::KQueue::EV_ADD()); + kill('HUP', $$) or die; + my @events = $kqs->kevent(3000); + is(scalar(@events), 1, 'got one event'); + is($events[0]->[0], POSIX::SIGHUP(), 'got SIGHUP'); + my $parent = IO::KQueue->new or die; + my $kqfd = $$kqs; + $parent->EV_SET($kqfd, IO::KQueue::EVFILT_READ(), IO::KQueue::EV_ADD()); + kill('HUP', $$) or die; + @events = $parent->kevent(3000); + is(scalar(@events), 1, 'got one event'); + is($events[0]->[0], $kqfd, 'got kqfd'); + is($hup, 0, '$SIG{HUP} did not fire'); + POSIX::sigprocmask(POSIX::SIG_SETMASK(), $old) or die; + defined(POSIX::close($kqfd)) or die; + defined(POSIX::close($$parent)) or die; +} + local $ENV{TEST_IOPOLLER} = 'PublicInbox::DSKQXS'; require './t/ds-poll.t'; diff --git a/t/sigfd.t b/t/sigfd.t new file mode 100644 index 00000000..34f30de8 --- /dev/null +++ b/t/sigfd.t @@ -0,0 +1,65 @@ +# Copyright (C) 2019 all contributors +use strict; +use Test::More; +use IO::Handle; +use POSIX qw(:signal_h); +use Errno qw(ENOSYS); +use PublicInbox::Syscall qw(SFD_NONBLOCK); +require_ok 'PublicInbox::Sigfd'; + +SKIP: { + if ($^O ne 'linux' && !eval { require IO::KQueue }) { + skip 'signalfd requires Linux or IO::KQueue to emulate', 10; + } + my $new = POSIX::SigSet->new; + $new->fillset or die "sigfillset: $!"; + my $old = POSIX::SigSet->new; + sigprocmask(SIG_SETMASK, $new, $old) or die "sigprocmask $!"; + my $hit = {}; + my $sig = {}; + local $SIG{HUP} = sub { $hit->{HUP}->{normal}++ }; + local $SIG{TERM} = sub { $hit->{TERM}->{normal}++ }; + local $SIG{INT} = sub { $hit->{INT}->{normal}++ }; + for my $s (qw(HUP TERM INT)) { + $sig->{$s} = sub { $hit->{$s}->{sigfd}++ }; + } + my $sigfd = PublicInbox::Sigfd->new($sig, 0); + if ($sigfd) { + require PublicInbox::DS; + ok($sigfd, 'Sigfd->new works'); + kill('HUP', $$) or die "kill $!"; + kill('INT', $$) or die "kill $!"; + my $fd = fileno($sigfd->{sock}); + ok($fd >= 0, 'fileno(Sigfd->{sock}) works'); + my $rvec = ''; + vec($rvec, $fd, 1) = 1; + is(select($rvec, undef, undef, undef), 1, 'select() works'); + ok($sigfd->wait_once, 'wait_once reported success'); + for my $s (qw(HUP INT)) { + is($hit->{$s}->{sigfd}, 1, "sigfd fired $s"); + is($hit->{$s}->{normal}, undef, + 'normal $SIG{$s} not fired'); + } + $sigfd = undef; + + my $nbsig = PublicInbox::Sigfd->new($sig, SFD_NONBLOCK); + ok($nbsig, 'Sigfd->new SFD_NONBLOCK works'); + is($nbsig->wait_once, undef, 'nonblocking ->wait_once'); + ok($! == Errno::EAGAIN, 'got EAGAIN'); + kill('HUP', $$) or die "kill $!"; + PublicInbox::DS->SetPostLoopCallback(sub {}); # loop once + PublicInbox::DS->EventLoop; + is($hit->{HUP}->{sigfd}, 2, 'HUP sigfd fired in event loop'); + kill('TERM', $$) or die "kill $!"; + kill('HUP', $$) or die "kill $!"; + PublicInbox::DS->EventLoop; + PublicInbox::DS->Reset; + is($hit->{TERM}->{sigfd}, 1, 'TERM sigfd fired in event loop'); + is($hit->{HUP}->{sigfd}, 3, 'HUP sigfd fired in event loop'); + } else { + skip('signalfd disabled?', 10); + } + sigprocmask(SIG_SETMASK, $old) or die "sigprocmask $!"; +} + +done_testing;