4 our @ISA = qw(Exporter);
5 our @EXPORT = qw(initialisation_complete);
8 use Fcntl qw(F_GETFL F_SETFL O_NONBLOCK);
10 use POSIX qw(_exit setsid);
15 our $env_name = 'PREFORK_INTERP';
24 syslog(LOG_ERR, "$0: prefork [$$]: error: $m");
26 croak "$0: prefork: initialisation error: $m";
33 syslog(LOG_INFO, "$0 prefork [$$]: $m, quitting");
37 # Returns in the executor process
38 sub become_monitor () {
40 eval { protocol_exchange(); 1; }
41 or fail_log("protocol exchange failed: $@");
43 my $child = fork // fail_log("fork executor: $!");
46 open ::STDIN , "<& $call_fds[0]" or fail_log("dup for fd0");
47 open ::STDOUT, ">& $call_fds[1]" or fail_log("dup for fd1");
48 open ::STDERR, ">& $call_fds[2]" or fail_log("dup for fd2");
54 #---- monitor [2] ----
55 my $got = waitpid $child, 0 // fail_log("wait for executor: $!");
56 $got == $child or fail_log("wait for esecutor gave $got, expected $child");
58 protocol_write(pack "L", $?);
62 sub close_call_fds () {
69 sub protocol_write ($) {
71 return if (print CALL $d and flush CALL);
72 _exit(0) if $!==EPIPE || $!==ECONNRESET;
73 fail_log("protocol write: $!");
80 return $r if defined $r;
86 sub protocol_read_fail ($) {
88 _exit(0) if $!==ECONNRESET;
89 die("recv $what: $!");
92 sub protocol_exchange () {
93 my $greeting = "PFI\n\0\0\0\0";
94 protocol_write($greeting);
100 $r = IO::FDPass::recv(fileno(CALL));
103 protocol_read_fail("fd $_");
109 $r = read(CALL, $len, 4) // protocol_read_fail("message length");
112 $len = unpack "L", $len;
114 $r = read(CALL, $data, $len) // protocol_read_fail("message data ($len)");
115 $r == $len or _exit(0);
117 @ARGV = split /\0/, $data;
118 @ARGV >= 2 or die("message data has too few strings (".(scalar @ARGV).")");
119 length(pop(@ARGV)) and die("message data missing trailing nul");
121 while (my $s = shift @ARGV) {
123 $s =~ m/=/ or die("message data env var missing equals");
128 sub initialisation_complete {
131 # if env var not set, we're not running under prefork-interp
132 my @env_data = split / /, ($ENV{$env_name} // return), 3;
133 croak "$env_name has the wrong number of words" unless @env_data == 3;
134 my (@vsns) = split /,/, $env_data[0];
135 croak "$env_name doesn't offer protocol v1" unless grep { $_ eq 'v1' } @vsns;
136 my @env_fds = split /,/, $env_data[1];
137 croak "$env_name has too few fds" unless @env_fds >= 2;;
139 $socket_path = $env_data[2];
141 $num_servers = $opts{max_servers} // 4;
143 #---- setup (pm) [1] ----
146 $_ eq ($_+0) or croak "$env_name contains $_, not a number";
148 open LISTEN, "+>&=$env_fds[0]" or croak "listen fd: $!";
149 open CALL, "+>&=$env_fds[1]" or croak "listen fd: $!";
151 if (!$opts{no_openlog}) {
152 openlog("prefork-interp $0", 'ndelay,nofatal,pid',
153 $opts{log_facility} // 'log_user');
156 open NULL, "+>/dev/null" or croak "open /dev/null: $!";
158 #---- fork for server ----
160 my $child = fork // croak "first fork failed: $!";
162 #---- setup (pm) [2], exits ----
165 setsid() > 0 or fail_log("setsid: $!");
166 # The server will be a session leader, but it won't open ttys,
169 #---- server(pm) [1] ----
171 $child = fork // croak "second fork failed: $!";
173 # we are the child, i.e. the one fa-monitor
174 return become_monitor();
178 $children{$child} = 1;
180 # --- server(pm) [2] ----
183 open STDIN, "<&NULL" or fail_log("dup null onto stdin: $!");
184 open STDOUT, ">&NULL" or fail_log("dup null onto stdout: $!");
185 open STDERR, ">&NULL" or fail_log("dup null onto stderr: $!");
190 my $flags = fcntl(LISTEN, F_GETFL, 0)
191 or fail_log("F_GETFL listen socket: $!");
192 $flags |= O_NONBLOCK;
193 fcntl(LISTEN, F_SETFL, $flags)
194 or fail_log("F_SETFL listen socket: $!");
201 my $full = %children >= $num_servers;
202 my $got = waitpid -1, ($full ? 0 : WNOHANG);
205 "$0 prefork [$$]: monitor process [$got] failed with wait status $?");
207 if (!exists $children{$got}) {
209 "$0 prefork [$$]: monitor process [$got] wasn't one of ours?!");
211 delete $children{$got};
215 # select for accepting or housekeeping timeout
217 vec($rbits, fileno(LISTEN), 1) = 1;
219 my $nfound = select($rbits, '', $ebits, ($opts{check_interval} // 86400));
222 if (accept(CALL, LISTEN)) {
223 $child = fork // fail_log("fork for accepted call failed: $!");
225 #---- monitor [1] ----
230 $children{$child} = 1;
231 } elsif ($! == EINTR || $! == EAGAIN || $! == EWOULDBLOCK) {
233 syslog(LOG_WARNING, "$0 prefork [$$]: accept failed: $!");
234 if ($errcount > ($opts{max_errors} // 100)) {
236 "$0 prefork [$$]: too many accept failures, quitting");
244 my @st_listen = stat(LISTEN) // fail_log("fstat listening socket: $!");
245 my @st_socket = stat($socket_path) // do {
246 if ($! == ENOENT) { server_quit("socket $socket is ENOENT"); }
247 fail_log("stat socket $socket: $!");
249 if ("@st_listen[0..2]" ne "@st_socket[0..2]") {
250 server_quit("socket $socket is no longer ours");