X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=lib%2FPublicInbox%2FSpawn.pm;h=3f69108a094d3dc1e61aa667927edbdf232ec7f9;hb=23af251dd607c4e75ab1e68063f2c885c48cc035;hp=6493ad387cdbcb915ca71fcbdc325f0ce673f768;hpb=b82e6c82aedb58309bdcdd041cabb5f82ec62234;p=public-inbox.git diff --git a/lib/PublicInbox/Spawn.pm b/lib/PublicInbox/Spawn.pm index 6493ad38..3f69108a 100644 --- a/lib/PublicInbox/Spawn.pm +++ b/lib/PublicInbox/Spawn.pm @@ -1,32 +1,42 @@ -# Copyright (C) 2016-2019 all contributors +# Copyright (C) all contributors # License: AGPL-3.0+ # # This allows vfork to be used for spawning subprocesses if -# PERL_INLINE_DIRECTORY is explicitly defined in the environment. +# ~/.cache/public-inbox/inline-c is writable or if PERL_INLINE_DIRECTORY +# is explicitly defined in the environment (and writable). # 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. +# +# There'll probably be more OS-level C stuff here, down the line. +# We don't want too many DSOs: https://udrepper.livejournal.com/8790.html package PublicInbox::Spawn; -use strict; -use warnings; -use base qw(Exporter); +use v5.12; +use parent qw(Exporter); use Symbol qw(gensym); -use IO::Handle; +use Fcntl qw(LOCK_EX SEEK_SET); +use IO::Handle (); use PublicInbox::ProcessPipe; -our @EXPORT_OK = qw/which spawn popen_rd/; -sub RLIMITS () { qw(RLIMIT_CPU RLIMIT_CORE RLIMIT_DATA) } +our @EXPORT_OK = qw(which spawn popen_rd run_die); +our @RLIMITS = qw(RLIMIT_CPU RLIMIT_CORE RLIMIT_DATA); -my $vfork_spawn = <<'VFORK_SPAWN'; +BEGIN { + my $all_libc = <<'ALL_LIBC'; # all *nix systems we support +#include +#include #include -#include #include -#include +#include #include #include +#include +#include +#include +#include /* some platforms need alloca.h, but some don't */ #if defined(__GNUC__) && !defined(alloca) @@ -56,43 +66,23 @@ my $vfork_spawn = <<'VFORK_SPAWN'; dst[real_len] = 0; \ } while (0) -static void *deconst(const char *s) -{ - union { const char *in; void *out; } u; - u.in = s; - return u.out; -} - /* needs to be safe inside a vfork'ed process */ -static void xerr(const char *msg) +static void exit_err(const char *fn, volatile int *cerrnum) { - struct iovec iov[3]; - const char *err = strerror(errno); /* should be safe in practice */ - - iov[0].iov_base = deconst(msg); - iov[0].iov_len = strlen(msg); - iov[1].iov_base = deconst(err); - iov[1].iov_len = strlen(err); - iov[2].iov_base = deconst("\n"); - iov[2].iov_len = 1; - writev(2, iov, 3); + *cerrnum = errno; + write(2, fn, strlen(fn)); _exit(1); } -#define REDIR(var,fd) do { \ - if (var != fd && dup2(var, fd) < 0) \ - xerr("error redirecting std"#var ": "); \ -} while (0) - /* - * unstable internal API. This was easy to implement but does not - * support arbitrary redirects. It'll be updated depending on + * unstable internal API. It'll be updated depending on * whatever we'll need in the future. * Be sure to update PublicInbox::SpawnPP if this changes */ -int pi_fork_exec(int in, int out, int err, - SV *file, SV *cmdref, SV *envref, SV *rlimref) +int pi_fork_exec(SV *redirref, SV *file, SV *cmdref, SV *envref, SV *rlimref, + const char *cd, int pgid) { + AV *redir = (AV *)SvRV(redirref); AV *cmd = (AV *)SvRV(cmdref); AV *env = (AV *)SvRV(envref); AV *rlim = (AV *)SvRV(rlimref); @@ -100,28 +90,43 @@ int pi_fork_exec(int in, int out, int err, pid_t pid; char **argv, **envp; sigset_t set, old; - int ret, errnum; + 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); - ret = sigfillset(&set); - assert(ret == 0 && "BUG calling sigfillset"); - ret = sigprocmask(SIG_SETMASK, &set, &old); - assert(ret == 0 && "BUG calling sigprocmask to block"); + if (sigfillset(&set)) return -1; + if (sigprocmask(SIG_SETMASK, &set, &old)) return -1; + chld_is_member = sigismember(&old, SIGCHLD); + if (chld_is_member < 0) return -1; + if (chld_is_member > 0) + sigdelset(&old, SIGCHLD); + pid = vfork(); if (pid == 0) { int sig; - I32 i, max; + I32 i, child_fd, max_rlim; - REDIR(in, 0); - REDIR(out, 1); - REDIR(err, 2); + 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("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("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); @@ -130,56 +135,183 @@ int pi_fork_exec(int in, int out, int err, rl.rlim_cur = SvIV(*soft); rl.rlim_max = SvIV(*hard); if (setrlimit(SvIV(*res), &rl) < 0) - xerr("sertlimit"); + exit_err("setrlimit", &cerrnum); } - /* - * don't bother unblocking, we don't want signals - * to the group taking out a subprocess - */ + (void)sigprocmask(SIG_SETMASK, &old, NULL); execve(filename, argv, envp); - xerr("execve failed"); + exit_err("execve", &cerrnum); } - errnum = errno; + perrnum = errno; + if (chld_is_member > 0) + sigaddset(&old, SIGCHLD); ret = sigprocmask(SIG_SETMASK, &old, NULL); assert(ret == 0 && "BUG calling sigprocmask to restore"); - errno = errnum; - + 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; + } return (int)pid; } -VFORK_SPAWN - -my $inline_dir = $ENV{PERL_INLINE_DIRECTORY}; -$vfork_spawn = undef unless defined $inline_dir && -d $inline_dir && -w _; -if (defined $vfork_spawn) { - # Inline 0.64 or later has locking in multi-process env, - # but we support 0.5 on Debian wheezy - use Fcntl qw(:flock); - eval { - 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'; #, 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"; - $vfork_spawn = undef; + +static int sleep_wait(unsigned *tries, int err) +{ + const struct timespec req = { 0, 100000000 }; /* 100ms */ + switch (err) { + case ENOBUFS: case ENOMEM: case ETOOMANYREFS: + if (++*tries < 50) { + fprintf(stderr, "sleeping on sendmsg: %s (#%u)\n", + strerror(err), *tries); + nanosleep(&req, NULL); + return 1; + } + default: + return 0; + } +} + +#if defined(CMSG_SPACE) && defined(CMSG_LEN) +#define SEND_FD_CAPA 10 +#define SEND_FD_SPACE (SEND_FD_CAPA * sizeof(int)) +union my_cmsg { + struct cmsghdr hdr; + char pad[sizeof(struct cmsghdr) + 16 + SEND_FD_SPACE]; +}; + +SV *send_cmd4(PerlIO *s, SV *svfds, SV *data, int flags) +{ + struct msghdr msg = { 0 }; + union my_cmsg cmsg = { 0 }; + STRLEN dlen = 0; + struct iovec iov; + ssize_t sent; + AV *fds = (AV *)SvRV(svfds); + I32 i, nfds = av_len(fds) + 1; + int *fdp; + unsigned tries = 0; + + if (SvOK(data)) { + iov.iov_base = SvPV(data, dlen); + iov.iov_len = dlen; + } + if (!dlen) { /* must be non-zero */ + iov.iov_base = &msg.msg_namelen; /* whatever */ + iov.iov_len = 1; + } + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + if (nfds) { + if (nfds > SEND_FD_CAPA) { + fprintf(stderr, "FIXME: bump SEND_FD_CAPA=%d\n", nfds); + nfds = SEND_FD_CAPA; + } + msg.msg_control = &cmsg.hdr; + msg.msg_controllen = CMSG_SPACE(nfds * sizeof(int)); + cmsg.hdr.cmsg_level = SOL_SOCKET; + cmsg.hdr.cmsg_type = SCM_RIGHTS; + cmsg.hdr.cmsg_len = CMSG_LEN(nfds * sizeof(int)); + fdp = (int *)CMSG_DATA(&cmsg.hdr); + for (i = 0; i < nfds; i++) { + SV **fd = av_fetch(fds, i, 0); + *fdp++ = SvIV(*fd); + } } + do { + sent = sendmsg(PerlIO_fileno(s), &msg, flags); + } while (sent < 0 && sleep_wait(&tries, errno)); + return sent >= 0 ? newSViv(sent) : &PL_sv_undef; } -unless (defined $vfork_spawn) { - require PublicInbox::SpawnPP; - no warnings 'once'; - *pi_fork_exec = *PublicInbox::SpawnPP::pi_fork_exec +void recv_cmd4(PerlIO *s, SV *buf, STRLEN n) +{ + union my_cmsg cmsg = { 0 }; + struct msghdr msg = { 0 }; + struct iovec iov; + ssize_t i; + Inline_Stack_Vars; + Inline_Stack_Reset; + + if (!SvOK(buf)) + sv_setpvn(buf, "", 0); + iov.iov_base = SvGROW(buf, n + 1); + iov.iov_len = n; + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + msg.msg_control = &cmsg.hdr; + msg.msg_controllen = CMSG_SPACE(SEND_FD_SPACE); + + i = recvmsg(PerlIO_fileno(s), &msg, 0); + if (i < 0) + Inline_Stack_Push(&PL_sv_undef); + else + SvCUR_set(buf, i); + if (i > 0 && cmsg.hdr.cmsg_level == SOL_SOCKET && + cmsg.hdr.cmsg_type == SCM_RIGHTS) { + size_t len = cmsg.hdr.cmsg_len; + int *fdp = (int *)CMSG_DATA(&cmsg.hdr); + for (i = 0; CMSG_LEN((i + 1) * sizeof(int)) <= len; i++) + Inline_Stack_Push(sv_2mortal(newSViv(*fdp++))); + } + Inline_Stack_Done; } +#endif /* defined(CMSG_SPACE) && defined(CMSG_LEN) */ +ALL_LIBC + + my $inline_dir = $ENV{PERL_INLINE_DIRECTORY} //= ( + $ENV{XDG_CACHE_HOME} // + ( ($ENV{HOME} // '/nonexistent').'/.cache' ) + ).'/public-inbox/inline-c'; + warn "$inline_dir exists, not writable\n" if -e $inline_dir && !-w _; + $all_libc = undef unless -d _ && -w _; + if (defined $all_libc) { + my $f = "$inline_dir/.public-inbox.lock"; + open my $oldout, '>&', \*STDOUT or die "dup(1): $!"; + open my $olderr, '>&', \*STDERR or die "dup(2): $!"; + open my $fh, '+>', $f or die "open($f): $!"; + open STDOUT, '>&', $fh or die "1>$f: $!"; + open STDERR, '>&', $fh or die "2>$f: $!"; + STDERR->autoflush(1); + STDOUT->autoflush(1); + + # CentOS 7.x ships Inline 0.53, 0.64+ has built-in locking + flock($fh, LOCK_EX) or die "LOCK_EX($f): $!"; + eval <<'EOM'; +use Inline C => $all_libc, BUILD_NOISY => 1; +EOM + my $err = $@; + my $ndc_err = ''; + $err = $@; + open(STDERR, '>&', $olderr) or warn "restore stderr: $!"; + open(STDOUT, '>&', $oldout) or warn "restore stdout: $!"; + if ($err) { + seek($fh, 0, SEEK_SET); + my @msg = <$fh>; + warn "Inline::C build failed:\n", + $ndc_err, $err, "\n", @msg; + $all_libc = undef; + } + } + unless ($all_libc) { + require PublicInbox::SpawnPP; + *pi_fork_exec = \&PublicInbox::SpawnPP::pi_fork_exec + } +} # /BEGIN sub which ($) { my ($file) = @_; return $file if index($file, '/') >= 0; - foreach my $p (split(':', $ENV{PATH})) { + for my $p (split(/:/, $ENV{PATH})) { $p .= "/$file"; return $p if -x $p; } @@ -188,22 +320,27 @@ sub which ($) { sub spawn ($;$$) { my ($cmd, $env, $opts) = @_; - my $f = which($cmd->[0]); - defined $f or die "$cmd->[0]: command not found\n"; + my $f = which($cmd->[0]) // die "$cmd->[0]: command not found\n"; my @env; $opts ||= {}; - - my %env = $env ? (%ENV, %$env) : %ENV; + my %env = (%ENV, $env ? %$env : ()); while (my ($k, $v) = each %env) { - push @env, "$k=$v"; + push @env, "$k=$v" if defined($v); + } + my $redir = []; + for my $child_fd (0..2) { + my $parent_fd = $opts->{$child_fd}; + if (defined($parent_fd) && $parent_fd !~ /\A[0-9]+\z/) { + my $fd = fileno($parent_fd) // + die "$parent_fd not an IO GLOB? $!"; + $parent_fd = $fd; + } + $redir->[$child_fd] = $parent_fd // $child_fd; } - my $in = $opts->{0} || 0; - my $out = $opts->{1} || 1; - my $err = $opts->{2} || 2; my $rlim = []; - foreach my $l (RLIMITS()) { - defined(my $v = $opts->{$l}) or next; + foreach my $l (@RLIMITS) { + my $v = $opts->{$l} // next; my $r = eval "require BSD::Resource; BSD::Resource::$l();"; unless (defined $r) { warn "$l undefined by BSD::Resource: $@\n"; @@ -211,21 +348,30 @@ sub spawn ($;$$) { } push @$rlim, $r, @$v; } - my $pid = pi_fork_exec($in, $out, $err, $f, $cmd, \@env, $rlim); - $pid < 0 ? undef : $pid; + my $cd = $opts->{'-C'} // ''; # undef => NULL mapping doesn't work? + 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; + $pid; } sub popen_rd { - my ($cmd, $env, $opts) = @_; + my ($cmd, $env, $opt) = @_; pipe(my ($r, $w)) or die "pipe: $!\n"; - $opts ||= {}; - $opts->{1} = fileno($w); - my $pid = spawn($cmd, $env, $opts); - return unless defined $pid; + $opt ||= {}; + $opt->{1} = fileno($w); + my $pid = spawn($cmd, $env, $opt); return ($r, $pid) if wantarray; my $ret = gensym; - tie *$ret, 'PublicInbox::ProcessPipe', $pid, $r; + tie *$ret, 'PublicInbox::ProcessPipe', $pid, $r, @$opt{qw(cb arg)}; $ret; } +sub run_die ($;$$) { + my ($cmd, $env, $rdr) = @_; + my $pid = spawn($cmd, $env, $rdr); + waitpid($pid, 0) == $pid or die "@$cmd did not finish"; + $? == 0 or die "@$cmd failed: \$?=$?\n"; +} + 1;