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';
22 syslog(LOG_ERR, "$0: prefork [$$]: error: $m");
28 syslog(LOG_INFO, "$0 prefork [$$]: $m, quitting");
32 # Returns in the executor process
33 sub become_monitor () {
34 my $child = fork // fail("fork executor: $!");
37 open ::STDIN , "<& $call_fds[0]" or fail_log("dup for fd0");
38 open ::STDOUT, ">& $call_fds[1]" or fail_log("dup for fd1");
39 open ::STDERR, ">& $call_fds[2]" or fail_log("dup for fd2");
44 #---- monitor [2] ----
45 my $got = waitpid $child, 0 // fail_log("wait for executor: $!");
46 $got == $child or fail_log("wait for esecutor gave $got, expected $child");
48 protocol_write(pack "L", $?);
52 sub close_call_fds () {
60 sub protocol_write ($) {
62 return if (print CALL $d and flush CALL);
63 _exit(0) if $!==EPIPE || $!==ECONNRESET;
64 fail_log("protocol write: $!");
71 return $r if defined $r;
77 sub protocol_read_fail ($) {
79 _exit(0) if $!==ECONNRESET;
80 die("recv $what: $!");
83 sub protocol_exchange () {
90 $r = IO::FDPass::recv(fileno(CALL));
93 protocol_read_fail("fd $_");
99 $r = read(CALL, $len, 4) // protocol_read_fail("message length");
102 $len = unpack "L", $len;
104 $r = read(CALL, $data, $len) // protocol_read_fail("message data ($len)");
105 $r == $len or _exit(0);
107 @ARGV = split /\0/, $data;
108 @ARGV >= 2 or die("message data has too few strings");
109 length(pop(@ARGV)) and die("message data missing trailing nul");
111 while (my $s = shift @ARGV) {
113 $s =~ m/=/ or die("message data env var missing equals");
118 sub initialisation_complete {
121 # if env var not set, we're not running under prefork-interp
122 my @env_data = split / /, ($ENV{$env_name} // return), 3;
123 croak "$env_name has the wrong number of words" unless @env_data == 3;
124 my (@vsns) = split /,/, $env_data[0];
125 croak "$env_name doesn't offer protocol v1" unless grep { $_ eq 'v1' } @vsns;
126 my @env_fds = split /,/, $env_data[1];
127 croak "$env_name has too few fds" unless @env_fds >= 3;;
129 $socket_path = $env_data[2];
131 $num_servers = $opts{max_servers} // 4;
133 #---- setup (pm) [1] ----
136 $_ eq ($_+0) or croak "$env_name contains $_, not a number";
138 open LISTEN, "+>&=$env_fds[0]" or croak "listen fd: $!";
139 open CALL, "+>&=$env_fds[1]" or croak "listen fd: $!";
141 if (!$opts{no_openlog}) {
142 openlog("prefork-interp $0", 'ndelay,nofatal,pid',
143 $opts{log_facility} // 'log_user');
146 open NULL, "+>/dev/null" or croak "open /dev/null: $!";
148 #---- fork for server ----
150 my $child = fork // croak "first fork failed: $!";
152 #---- setup (pm) [2], exits ----
156 #---- server(pm) [1] ----
158 $child = fork // croak "second fork failed: $!";
160 # we are the child, i.e. the one fa-monitor
161 return become_monitor();
165 $children{$child} = 1;
167 # --- server(pm) [2] ----
169 setsid() > 0 or fail_log("setsid: $!");
170 open STDIN, "<&NULL" or fail_log("dup null onto stdin: $!");
171 open STDOUT, ">&NULL" or fail_log("dup null onto stdout: $!");
172 open STDERR, ">&NULL" or fail_log("dup null onto stderr: $!");
177 my $flags = fcntl(LISTEN, F_GETFL, 0)
178 or fail_log("F_GETFL listen socket: $!");
179 $flags |= O_NONBLOCK;
180 fcntl(LISTEN, F_SETFL, $flags)
181 or fail_log("F_SETFL listen socket: $!");
188 my $full = %children >= $num_servers;
189 my $got = waitpid -1, ($full ? 0 : WNOHANG);
192 "$0 prefork [$$]: monitor process [$got] failed with wait status $?");
194 if (!exists $children{$got}) {
196 "$0 prefork [$$]: monitor process [$got] wasn't one of ours?!");
198 delete $children{$got};
202 # select for accepting or housekeeping timeout
204 vec($rbits, fileno(LISTEN), 1) = 1;
206 my $nfound = select($rbits, '', $ebits, ($opts{check_interval} // 86400));
209 if (accept(CALL, LISTEN)) {
210 $child = fork // fail_log("fork for accepted call failed: $!");
212 #---- monitor [1] ----
214 eval { protocol_exchange(); 1; }
215 or fail_log("protocol exchange failed: $@");
216 return become_monitor();
220 $children{$child} = 1;
221 } elsif ($! == EINTR || $! == EAGAIN || $! == EWOULDBLOCK) {
223 syslog(LOG_WARNING, "$0 prefork [$$]: accept failed: $!");
224 if ($errcount > ($opts{max_errors} // 100)) {
226 "$0 prefork [$$]: too many accept failures, quitting");
234 my @st_listen = stat(LISTEN) // fail_log("fstat listening socket: $!");
235 my @st_socket = stat($socket_path) // do {
236 if ($! == ENOENT) { server_quit("socket $socket is ENOENT"); }
237 fail_log("stat socket $socket: $!");
239 if ("@st_listen[0..2]" ne "@st_socket[0..2]") {
240 server_quit("socket $socket is no longer ours");