* dprintf(3) portability? [was [02/19] spawn: pi_fork_exec: support "pgid"]
2021-02-07 8:51 4% ` [PATCH 02/19] spawn: pi_fork_exec: support "pgid" Eric Wong
@ 2021-02-07 23:10 6% ` Eric Wong
0 siblings, 0 replies; 3+ results
From: Eric Wong @ 2021-02-07 23:10 UTC (permalink / raw)
To: meta
Eric Wong <e@80x24.org> wrote:
> +++ b/lib/PublicInbox/Spawn.pm
> + /* continue message started by exit_err in child */
> + dprintf(err_fd, ": %s\n", strerror(cerrnum));
dprintf(3) is POSIX.1-2008 and we already depend on Perl 5.10.1
from 2009, so no concerns there, right?
I remember it being a portability problem around 2004, but it's
probably not an issue today. This usage is trivial enough to
replace with writev(2), though.
^ permalink raw reply [relevance 6%]
* [PATCH 00/19] lei import Maildir, remote mboxrd fixes
@ 2021-02-07 8:51 7% Eric Wong
2021-02-07 8:51 4% ` [PATCH 02/19] spawn: pi_fork_exec: support "pgid" Eric Wong
0 siblings, 1 reply; 3+ results
From: Eric Wong @ 2021-02-07 8:51 UTC (permalink / raw)
To: meta
"lei q" with remote mboxrd + early MUA spawning is
nicer, too. Several risky constructs eliminated,
Interrupting "add-external --mirror" is less bad, now;
though it could probably support indexlevel=none in
case somebody wants to run index themselves.
Eric Wong (19):
spawn: pi_fork_exec: restore parent sigmask in child
spawn: pi_fork_exec: support "pgid"
lei add-external: handle interrupts with --mirror
spawn_pp: die more consistently in child
ipc: do not die inside wq_worker child process
ipc: trim down the Storable checks
Makefile.PL: depend on IO::Uncompress::Gunzip
xapcmd: avoid potential die surprise in children
tests: guard setup_public_inboxes for SQLite and Xapian
Revert "ipc: add support for asynchronous callbacks"
ipc: wq_do => wq_io_do
lei: more consistent IPC exit and error handling
lei: remove --mua-cmd alias for --mua
lei: replace --thread with --threads
lei q: improve remote mboxrd UX
lei q: SIGWINCH process group with the terminal
lei import: support Maildirs
imap: avoid unnecessary delete on stack
httpd/async: avoid unnecessary on-stack delete
Documentation/lei-q.pod | 4 +-
MANIFEST | 1 +
Makefile.PL | 1 +
lib/PublicInbox/HTTPD/Async.pm | 2 +-
lib/PublicInbox/IMAP.pm | 6 +-
lib/PublicInbox/IPC.pm | 105 +++++++-----------------
lib/PublicInbox/LEI.pm | 49 +++++++----
lib/PublicInbox/LeiCurl.pm | 11 ++-
lib/PublicInbox/LeiHelp.pm | 6 +-
lib/PublicInbox/LeiImport.pm | 38 ++++++---
lib/PublicInbox/LeiMirror.pm | 75 ++++++++++-------
lib/PublicInbox/LeiOverview.pm | 7 +-
lib/PublicInbox/LeiQuery.pm | 4 +-
lib/PublicInbox/LeiStore.pm | 8 +-
lib/PublicInbox/LeiToMail.pm | 37 ++++-----
lib/PublicInbox/LeiXSearch.pm | 143 ++++++++++++++++++++-------------
lib/PublicInbox/Mbox.pm | 2 +-
lib/PublicInbox/OnDestroy.pm | 2 +-
lib/PublicInbox/Search.pm | 2 +-
lib/PublicInbox/SearchView.pm | 2 +-
lib/PublicInbox/Spawn.pm | 63 +++++++++------
lib/PublicInbox/SpawnPP.pm | 44 +++++-----
lib/PublicInbox/Xapcmd.pm | 11 +--
script/lei | 8 +-
t/ipc.t | 39 ++-------
t/lei-externals.t | 2 +
t/lei-import-maildir.t | 33 ++++++++
t/lei-mirror.t | 14 ++++
t/lei.t | 2 +-
t/lei_to_mail.t | 6 +-
t/spawn.t | 18 +++++
xt/stress-sharedkv.t | 6 +-
32 files changed, 433 insertions(+), 318 deletions(-)
create mode 100644 t/lei-import-maildir.t
^ permalink raw reply [relevance 7%]
* [PATCH 02/19] spawn: pi_fork_exec: support "pgid"
2021-02-07 8:51 7% [PATCH 00/19] lei import Maildir, remote mboxrd fixes Eric Wong
@ 2021-02-07 8:51 4% ` Eric Wong
2021-02-07 23:10 6% ` dprintf(3) portability? [was [02/19] spawn: pi_fork_exec: support "pgid"] Eric Wong
0 siblings, 1 reply; 3+ results
From: Eric Wong @ 2021-02-07 8:51 UTC (permalink / raw)
To: meta
We'll be using this to allow the "git clone" process hierarchy
to be killed via Ctrl-C. This also fixes a long-standing bug
in error reporting for the Inline::C version, because we're
actually testing for errors, now!
n.b. strlen(3) is officially async-signal-safe as of
POSIX.1-2016, but I can't think of a reason any previous
implementation prior to that wouldn't be.
---
lib/PublicInbox/Spawn.pm | 37 +++++++++++++++++++++++++------------
lib/PublicInbox/SpawnPP.pm | 24 ++++++++++++++----------
t/spawn.t | 18 ++++++++++++++++++
3 files changed, 57 insertions(+), 22 deletions(-)
diff --git a/lib/PublicInbox/Spawn.pm b/lib/PublicInbox/Spawn.pm
index bac24dd1..00e6829e 100644
--- a/lib/PublicInbox/Spawn.pm
+++ b/lib/PublicInbox/Spawn.pm
@@ -61,9 +61,10 @@ my $all_libc = <<'ALL_LIBC'; # all *nix systems we support
} while (0)
/* needs to be safe inside a vfork'ed process */
-static void exit_err(int *cerrnum)
+static void exit_err(const char *fn, volatile int *cerrnum)
{
*cerrnum = errno;
+ write(2, fn, strlen(fn));
_exit(1);
}
@@ -73,7 +74,7 @@ static void exit_err(int *cerrnum)
* Be sure to update PublicInbox::SpawnPP if this changes
*/
int pi_fork_exec(SV *redirref, SV *file, SV *cmdref, SV *envref, SV *rlimref,
- const char *cd)
+ const char *cd, int pgid)
{
AV *redir = (AV *)SvRV(redirref);
AV *cmd = (AV *)SvRV(cmdref);
@@ -83,8 +84,10 @@ int pi_fork_exec(SV *redirref, SV *file, SV *cmdref, SV *envref, SV *rlimref,
pid_t pid;
char **argv, **envp;
sigset_t set, old;
- int ret, perrnum, cerrnum = 0;
+ int ret, perrnum;
+ volatile int cerrnum = 0; /* shared due to vfork */
int chld_is_member;
+ I32 max_fd = av_len(redir);
AV2C_COPY(argv, cmd);
AV2C_COPY(envp, env);
@@ -99,23 +102,25 @@ int pi_fork_exec(SV *redirref, SV *file, SV *cmdref, SV *envref, SV *rlimref,
pid = vfork();
if (pid == 0) {
int sig;
- I32 i, child_fd, max = av_len(redir);
+ I32 i, child_fd, max_rlim;
- for (child_fd = 0; child_fd <= max; child_fd++) {
+ for (child_fd = 0; child_fd <= max_fd; child_fd++) {
SV **parent = av_fetch(redir, child_fd, 0);
int parent_fd = SvIV(*parent);
if (parent_fd == child_fd)
continue;
if (dup2(parent_fd, child_fd) < 0)
- exit_err(&cerrnum);
+ exit_err("dup2", &cerrnum);
}
+ if (pgid >= 0 && setpgid(0, pgid) < 0)
+ exit_err("setpgid", &cerrnum);
for (sig = 1; sig < NSIG; sig++)
signal(sig, SIG_DFL); /* ignore errors on signals */
if (*cd && chdir(cd) < 0)
- exit_err(&cerrnum);
+ exit_err("chdir", &cerrnum);
- max = av_len(rlim);
- for (i = 0; i < max; i += 3) {
+ max_rlim = av_len(rlim);
+ for (i = 0; i < max_rlim; i += 3) {
struct rlimit rl;
SV **res = av_fetch(rlim, i, 0);
SV **soft = av_fetch(rlim, i + 1, 0);
@@ -124,12 +129,12 @@ int pi_fork_exec(SV *redirref, SV *file, SV *cmdref, SV *envref, SV *rlimref,
rl.rlim_cur = SvIV(*soft);
rl.rlim_max = SvIV(*hard);
if (setrlimit(SvIV(*res), &rl) < 0)
- exit_err(&cerrnum);
+ exit_err("setrlimit", &cerrnum);
}
(void)sigprocmask(SIG_SETMASK, &old, NULL);
execve(filename, argv, envp);
- exit_err(&cerrnum);
+ exit_err("execve", &cerrnum);
}
perrnum = errno;
if (chld_is_member > 0)
@@ -137,9 +142,16 @@ int pi_fork_exec(SV *redirref, SV *file, SV *cmdref, SV *envref, SV *rlimref,
ret = sigprocmask(SIG_SETMASK, &old, NULL);
assert(ret == 0 && "BUG calling sigprocmask to restore");
if (cerrnum) {
+ int err_fd = STDERR_FILENO;
+ if (err_fd <= max_fd) {
+ SV **parent = av_fetch(redir, err_fd, 0);
+ err_fd = SvIV(*parent);
+ }
if (pid > 0)
waitpid(pid, NULL, 0);
pid = -1;
+ /* continue message started by exit_err in child */
+ dprintf(err_fd, ": %s\n", strerror(cerrnum));
errno = cerrnum;
} else if (perrnum) {
errno = perrnum;
@@ -373,7 +385,8 @@ sub spawn ($;$$) {
push @$rlim, $r, @$v;
}
my $cd = $opts->{'-C'} // ''; # undef => NULL mapping doesn't work?
- my $pid = pi_fork_exec($redir, $f, $cmd, \@env, $rlim, $cd);
+ my $pgid = $opts->{pgid} // -1;
+ my $pid = pi_fork_exec($redir, $f, $cmd, \@env, $rlim, $cd, $pgid);
die "fork_exec @$cmd failed: $!\n" unless $pid > 0;
$pid;
}
diff --git a/lib/PublicInbox/SpawnPP.pm b/lib/PublicInbox/SpawnPP.pm
index f64b95dc..401cb78d 100644
--- a/lib/PublicInbox/SpawnPP.pm
+++ b/lib/PublicInbox/SpawnPP.pm
@@ -5,12 +5,12 @@
# of vfork, so no speedups under Linux for spawning from large processes.
package PublicInbox::SpawnPP;
use strict;
-use warnings;
-use POSIX qw(dup2 :signal_h);
+use v5.10.1;
+use POSIX qw(dup2 _exit setpgid :signal_h);
# Pure Perl implementation for folks that do not use Inline::C
-sub pi_fork_exec ($$$$$$) {
- my ($redir, $f, $cmd, $env, $rlim, $cd) = @_;
+sub pi_fork_exec ($$$$$$$) {
+ my ($redir, $f, $cmd, $env, $rlim, $cd, $pgid) = @_;
my $old = POSIX::SigSet->new();
my $set = POSIX::SigSet->new();
$set->fillset or die "fillset failed: $!";
@@ -22,21 +22,25 @@ sub pi_fork_exec ($$$$$$) {
$pid = -1;
}
if ($pid == 0) {
- while (@$rlim) {
- my ($r, $soft, $hard) = splice(@$rlim, 0, 3);
- BSD::Resource::setrlimit($r, $soft, $hard) or
- warn "failed to set $r=[$soft,$hard]\n";
- }
for my $child_fd (0..$#$redir) {
my $parent_fd = $redir->[$child_fd];
next if $parent_fd == $child_fd;
dup2($parent_fd, $child_fd) or
die "dup2($parent_fd, $child_fd): $!\n";
}
+ if ($pgid >= 0 && !defined(setpgid(0, $pgid))) {
+ warn "setpgid: $!";
+ _exit(1);
+ }
+ $SIG{$_} = 'DEFAULT' for keys %SIG;
if ($cd ne '') {
chdir $cd or die "chdir $cd: $!";
}
- $SIG{$_} = 'DEFAULT' for keys %SIG;
+ while (@$rlim) {
+ my ($r, $soft, $hard) = splice(@$rlim, 0, 3);
+ BSD::Resource::setrlimit($r, $soft, $hard) or
+ warn "failed to set $r=[$soft,$hard]\n";
+ }
$old->delset(POSIX::SIGCHLD) or die "delset SIGCHLD: $!";
sigprocmask(SIG_SETMASK, $old) or die "SETMASK: ~SIGCHLD: $!";
if ($ENV{MOD_PERL}) {
diff --git a/t/spawn.t b/t/spawn.t
index 6f811ec1..a17b72d9 100644
--- a/t/spawn.t
+++ b/t/spawn.t
@@ -18,6 +18,24 @@ use PublicInbox::Sigfd;
is($?, 0, 'true exited successfully');
}
+SKIP: {
+ my $pid = spawn(['true'], undef, { pgid => 0 });
+ ok($pid, 'spawned process with new pgid');
+ is(waitpid($pid, 0), $pid, 'waitpid succeeds on spawned process');
+ is($?, 0, 'true exited successfully');
+ pipe(my ($r, $w)) or BAIL_OUT;
+ $pid = eval { spawn(['true'], undef, { pgid => 1, 2 => $w }) };
+ close $w;
+ my $err = do { local $/; <$r> };
+ # diag "$err ($@)";
+ if (defined $pid) {
+ waitpid($pid, 0) if defined $pid;
+ isnt($?, 0, 'child error (pure-Perl)');
+ } else {
+ ok($@, 'exception raised');
+ }
+}
+
{ # ensure waitpid(-1, 0) and SIGCHLD works in spawned process
my $script = <<'EOF';
$| = 1; # unbuffer stdout
^ permalink raw reply related [relevance 4%]
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2021-02-07 8:51 7% [PATCH 00/19] lei import Maildir, remote mboxrd fixes Eric Wong
2021-02-07 8:51 4% ` [PATCH 02/19] spawn: pi_fork_exec: support "pgid" Eric Wong
2021-02-07 23:10 6% ` dprintf(3) portability? [was [02/19] spawn: pi_fork_exec: support "pgid"] Eric Wong
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