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 () {
39 my $child = fork // fail_log("fork executor: $!");
42 open ::STDIN , "<& $call_fds[0]" or fail_log("dup for fd0");
43 open ::STDOUT, ">& $call_fds[1]" or fail_log("dup for fd1");
44 open ::STDERR, ">& $call_fds[2]" or fail_log("dup for fd2");
49 #---- monitor [2] ----
50 my $got = waitpid $child, 0 // fail_log("wait for executor: $!");
51 $got == $child or fail_log("wait for esecutor gave $got, expected $child");
53 protocol_write(pack "L", $?);
57 sub close_call_fds () {
65 sub protocol_write ($) {
67 return if (print CALL $d and flush CALL);
68 _exit(0) if $!==EPIPE || $!==ECONNRESET;
69 fail_log("protocol write: $!");
76 return $r if defined $r;
82 sub protocol_read_fail ($) {
84 _exit(0) if $!==ECONNRESET;
85 die("recv $what: $!");
88 sub protocol_exchange () {
95 $r = IO::FDPass::recv(fileno(CALL));
98 protocol_read_fail("fd $_");
104 $r = read(CALL, $len, 4) // protocol_read_fail("message length");
107 $len = unpack "L", $len;
109 $r = read(CALL, $data, $len) // protocol_read_fail("message data ($len)");
110 $r == $len or _exit(0);
112 @ARGV = split /\0/, $data;
113 @ARGV >= 2 or die("message data has too few strings");
114 length(pop(@ARGV)) and die("message data missing trailing nul");
116 while (my $s = shift @ARGV) {
118 $s =~ m/=/ or die("message data env var missing equals");
123 sub initialisation_complete {
126 # if env var not set, we're not running under prefork-interp
127 my @env_data = split / /, ($ENV{$env_name} // return), 3;
128 croak "$env_name has the wrong number of words" unless @env_data == 3;
129 my (@vsns) = split /,/, $env_data[0];
130 croak "$env_name doesn't offer protocol v1" unless grep { $_ eq 'v1' } @vsns;
131 my @env_fds = split /,/, $env_data[1];
132 croak "$env_name has too few fds" unless @env_fds >= 3;;
134 $socket_path = $env_data[2];
136 $num_servers = $opts{max_servers} // 4;
138 #---- setup (pm) [1] ----
141 $_ eq ($_+0) or croak "$env_name contains $_, not a number";
143 open LISTEN, "+>&=$env_fds[0]" or croak "listen fd: $!";
144 open CALL, "+>&=$env_fds[1]" or croak "listen fd: $!";
146 if (!$opts{no_openlog}) {
147 openlog("prefork-interp $0", 'ndelay,nofatal,pid',
148 $opts{log_facility} // 'log_user');
151 open NULL, "+>/dev/null" or croak "open /dev/null: $!";
153 #---- fork for server ----
155 my $child = fork // croak "first fork failed: $!";
157 #---- setup (pm) [2], exits ----
161 #---- server(pm) [1] ----
163 $child = fork // croak "second fork failed: $!";
165 # we are the child, i.e. the one fa-monitor
166 return become_monitor();
170 $children{$child} = 1;
172 # --- server(pm) [2] ----
175 setsid() > 0 or fail_log("setsid: $!");
176 open STDIN, "<&NULL" or fail_log("dup null onto stdin: $!");
177 open STDOUT, ">&NULL" or fail_log("dup null onto stdout: $!");
178 open STDERR, ">&NULL" or fail_log("dup null onto stderr: $!");
183 my $flags = fcntl(LISTEN, F_GETFL, 0)
184 or fail_log("F_GETFL listen socket: $!");
185 $flags |= O_NONBLOCK;
186 fcntl(LISTEN, F_SETFL, $flags)
187 or fail_log("F_SETFL listen socket: $!");
194 my $full = %children >= $num_servers;
195 my $got = waitpid -1, ($full ? 0 : WNOHANG);
198 "$0 prefork [$$]: monitor process [$got] failed with wait status $?");
200 if (!exists $children{$got}) {
202 "$0 prefork [$$]: monitor process [$got] wasn't one of ours?!");
204 delete $children{$got};
208 # select for accepting or housekeeping timeout
210 vec($rbits, fileno(LISTEN), 1) = 1;
212 my $nfound = select($rbits, '', $ebits, ($opts{check_interval} // 86400));
215 if (accept(CALL, LISTEN)) {
216 $child = fork // fail_log("fork for accepted call failed: $!");
218 #---- monitor [1] ----
220 eval { protocol_exchange(); 1; }
221 or fail_log("protocol exchange failed: $@");
222 return become_monitor();
226 $children{$child} = 1;
227 } elsif ($! == EINTR || $! == EAGAIN || $! == EWOULDBLOCK) {
229 syslog(LOG_WARNING, "$0 prefork [$$]: accept failed: $!");
230 if ($errcount > ($opts{max_errors} // 100)) {
232 "$0 prefork [$$]: too many accept failures, quitting");
240 my @st_listen = stat(LISTEN) // fail_log("fstat listening socket: $!");
241 my @st_socket = stat($socket_path) // do {
242 if ($! == ENOENT) { server_quit("socket $socket is ENOENT"); }
243 fail_log("stat socket $socket: $!");
245 if ("@st_listen[0..2]" ne "@st_socket[0..2]") {
246 server_quit("socket $socket is no longer ours");