-# Copyright (C) 2016 all contributors <meta@public-inbox.org>
+# Copyright (C) 2016-2018 all contributors <meta@public-inbox.org>
# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+#
+# This allows vfork to be used for spawning subprocesses if
+# PERL_INLINE_DIRECTORY is explicitly defined in the environment.
+# Under Linux, vfork can make a big difference in spawning performance
+# as process size increases (fork still needs to mark pages for CoW use).
+# Currently, we only use this for code intended for long running
+# daemons (inside the PSGI code (-httpd) and -nntpd). The short-lived
+# scripts (-mda, -index, -learn, -init) either use IPC::run or standard
+# Perl routines.
+
package PublicInbox::Spawn;
use strict;
use warnings;
use base qw(Exporter);
-our @EXPORT_OK = qw/which spawn/;
+use Symbol qw(gensym);
+use IO::Handle;
+use PublicInbox::ProcessPipe;
+our @EXPORT_OK = qw/which spawn popen_rd/;
my $vfork_spawn = <<'VFORK_SPAWN';
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#include <alloca.h>
+#include <signal.h>
+#include <assert.h>
#define AV_ALLOCA(av, max) alloca((max = (av_len((av)) + 1)) * sizeof(char *))
pid_t pid;
char **argv, **envp;
I32 max;
+ sigset_t set, old;
+ int ret, errnum;
argv = AV_ALLOCA(cmd, max);
av2c_copy(argv, cmd, max);
envp = AV_ALLOCA(env, max);
av2c_copy(envp, env, max);
+ ret = sigfillset(&set);
+ assert(ret == 0 && "BUG calling sigfillset");
+ ret = sigprocmask(SIG_SETMASK, &set, &old);
+ assert(ret == 0 && "BUG calling sigprocmask to block");
pid = vfork();
if (pid == 0) {
+ int sig;
+
REDIR(in, 0);
REDIR(out, 1);
REDIR(err, 2);
+ for (sig = 1; sig < NSIG; sig++)
+ signal(sig, SIG_DFL); /* ignore errors on signals */
+ /*
+ * don't bother unblocking, we don't want signals
+ * to the group taking out a subprocess
+ */
execve(filename, argv, envp);
xerr("execve failed");
}
+ errnum = errno;
+ ret = sigprocmask(SIG_SETMASK, &old, NULL);
+ assert(ret == 0 && "BUG calling sigprocmask to restore");
+ errno = errnum;
return (int)pid;
}
my $f = "$inline_dir/.public-inbox.lock";
open my $fh, '>', $f or die "failed to open $f: $!\n";
flock($fh, LOCK_EX) or die "LOCK_EX failed on $f: $!\n";
- eval 'use Inline C => $vfork_spawn';
+ eval 'use Inline C => $vfork_spawn'; #, BUILD_NOISY => 1';
+ my $err = $@;
flock($fh, LOCK_UN) or die "LOCK_UN failed on $f: $!\n";
+ die $err if $err;
};
if ($@) {
warn "Inline::C failed for vfork: $@\n";
*public_inbox_fork_exec = *PublicInbox::SpawnPP::public_inbox_fork_exec
}
+# n.b. we never use absolute paths with this
sub which ($) {
my ($file) = @_;
foreach my $p (split(':', $ENV{PATH})) {
my $in = $opts->{0} || 0;
my $out = $opts->{1} || 1;
my $err = $opts->{2} || 2;
- public_inbox_fork_exec($in, $out, $err, $f, $cmd, \@env);
+ my $pid = public_inbox_fork_exec($in, $out, $err, $f, $cmd, \@env);
+ $pid < 0 ? undef : $pid;
+}
+
+sub popen_rd {
+ my ($cmd, $env, $opts) = @_;
+ pipe(my ($r, $w)) or die "pipe: $!\n";
+ $opts ||= {};
+ my $blocking = $opts->{Blocking};
+ IO::Handle::blocking($r, $blocking) if defined $blocking;
+ $opts->{1} = fileno($w);
+ my $pid = spawn($cmd, $env, $opts);
+ return unless defined $pid;
+ return ($r, $pid) if wantarray;
+ my $ret = gensym;
+ tie *$ret, 'PublicInbox::ProcessPipe', $pid, $r;
+ $ret;
}
1;