4 our @ISA = qw(Exporter);
5 our @EXPORT = qw(initialisation_complete);
8 use Fcntl qw(F_GETFL F_SETFL O_NONBLOCK);
9 use POSIX qw(_exit setsid);
14 our $env_name = 'PREFORK_INTERP';
21 syslog(LOG_ERROR, "$0: prefork [$$]: error: $m");
27 syslog(LOG_INFO, "$0 prefork [$$]: $m, quitting");
31 # Returns in the executor process
32 sub become_monitor () {
33 my $child = fork // fail("fork executor: $!");
36 open ::STDIN , "<& $call_fds[0]" or fail_log("dup for fd0");
37 open ::STDOUT, ">& $call_fds[1]" or fail_log("dup for fd1");
38 open ::STDERR, ">& $call_fds[2]" or fail_log("dup for fd2");
39 POSIX::close($_) foreach @call_fds;
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", $?);
52 sub protocol_write ($) {
54 return if (print CALL $d and flush CALL);
55 _exit(0) if $!==EPIPE || $!==ECONNRESET;
56 fail_log("protocol write: $!");
63 return $r if defined $r;
69 sub protocol_read_fail ($) {
71 _exit(0) if $!==ECONNRESET;
72 fail_log("recv $what: $!");
75 sub protocol_exchange () {
82 $r = IO::FDPass::recv(fileno(CALL));
85 protocol_read_fail("fd $_");
91 $r = read(CALL, $len, 4) // protocol_read_fail("message length");
94 $len = unpack "L", $len;
96 $r = read(CALL, $data, $len) // protocol_read_fail("message data ($len)");
97 $r == $len or _exit(0);
99 @ARGV = split /\0/, $data;
100 @ARGV >= 2 or fail_log("message data has too few strings");
101 length(pop(@ARGV)) and fail_log("message data missing trailing nul");
103 while (my $s = shift @ARGV) {
105 $s =~ m/=/ or fail_log("message data env var missing equals");
110 sub initialisation_complete {
113 # if env var not set, we're not running under prefork-interp
114 my @env_params = split /,/, ($ENV{$env_name} // return), 5;
115 croak "$env_name has too few entries" unless @env_params == 5;
117 $num_servers = $opts{max_servers} // 4;
119 #---- setup (pm) [1] ----
121 $socket_path = pop @env_params;
122 foreach (@env_params) {
123 $_ eq ($_+0) or croak "$env_name contains $_, not a number";
125 open LISTEN, "+>&=$env_params[0]" or croak "listen fd: $!";
126 open CALL, "+>&=$env_params[1]" or croak "listen fd: $!";
127 @call_fds = ($env_params[2], $env_params[3], 2);
129 if (!$opts{no_openlog}) {
130 openlog("prefork-interp $0", 'ndelay,nofatal,pid',
131 $opts{log_facility} // 'log_user');
134 open NULL, "+>/dev/null" or croak "open /dev/null: $!";
136 #---- fork for server ----
138 my $child = fork // croak "first fork failed: $!";
140 #---- setup (pm) [2], exits ----
144 #---- server(pm) [1] ----
146 $child = fork // croak "second fork failed: $!";
148 # we are the child, i.e. the one fa-monitor
149 return become_monitor();
153 $children{$child} = 1;
155 # --- server(pm) [2] ----
157 setsid() > 0 or fail_log("setsid: $!");
158 open STDIN, "<&NULL" or fail_log("dup null onto stdin: $!");
159 open STDOUT, ">&NULL" or fail_log("dup null onto stdout: $!");
160 open STDERR, ">&NULL" or fail_log("dup null onto stderr: $!");
163 POSIX::close($_) foreach @call_fds;
166 my $flags = fcntl(LISTEN, F_GETFL, 0)
167 or fail_log("F_GETFL listen socket: $!");
168 $flags |= O_NONBLOCK;
169 fcntl(LISTEN, F_SETFL, $flags)
170 or fail_log("F_SETFL listen socket: $!");
177 my $full = %children >= $num_servers;
178 my $got = waitpid -1, ($full ? 0 : WNOHANG);
181 "$0 prefork [$$]: monitor process [$got] failed with wait status $?");
183 if (!exists $children{$got}) {
185 "$0 prefork [$$]: monitor process [$got] wasn't one of ours?!");
187 delete $children{$got};
191 # select for accepting or housekeeping timeout
193 vec($rbits, fileno(LISTEN), 1) = 1;
195 my $nfound = select($rbits, '', $ebits, ($opts{check_interval} // 86400));
198 if (accept(CALL, LISTEN)) {
199 $child = fork // fail_log("fork for accepted call failed: $!");
201 #---- monitor [1] ----
204 return become_monitor();
208 $children{$child} = 1;
209 } elsif ($! == EINTR || $! == EAGAIN || $! == EWOULDBLOCK) {
211 syslog(LOG_WARNING, "$0 prefork [$$]: accept failed: $!");
212 if ($errcount > ($opts{max_errors} // 100)) {
214 "$0 prefork [$$]: too many accept failures, quitting");
222 my @st_listen = stat(LISTEN) // fail_log("fstat listening socket: $!");
223 my @st_socket = stat($socket_path) // do {
224 if ($! == ENOENT) { server_quit("socket $socket is ENOENT"); }
225 fail_log("stat socket $socket: $!");
227 if ("@st_listen[0..2]" ne "@st_socket[0..2]") {
228 server_quit("socket $socket is no longer ours");