4 our @ISA = qw(Exporter);
5 our @EXPORT = qw(initialisation_complete);
10 use Fcntl qw(F_GETFL F_SETFL O_NONBLOCK);
12 use POSIX qw(_exit setsid :sys_wait_h :errno_h);
13 use Sys::Syslog qw(openlog syslog LOG_INFO LOG_ERR LOG_WARNING);
17 our $env_name = 'PREFORK_INTERP';
26 syslog(LOG_ERR, "$0: prefork [$$]: error: $m");
28 croak "$0: prefork: initialisation error: $m";
35 syslog(LOG_INFO, "$0 prefork [$$]: $m, quitting");
39 # Returns in the executor process
40 sub become_monitor () {
43 # Make a process group for this call
44 setpgrp or fail_log("setpgrp failed: $!");
46 eval { protocol_exchange(); 1; }
47 or fail_log("protocol exchange failed: $@");
49 pipe EXECTERM, EXECTERMW or fail_log("pipe: $!");
51 my $child = fork // fail_log("fork executor: $!");
54 open ::STDIN , "<& $call_fds[0]" or fail_log("dup for fd0");
55 open ::STDOUT, ">& $call_fds[1]" or fail_log("dup for fd1");
56 open ::STDERR, ">& $call_fds[2]" or fail_log("dup for fd2");
64 #---- monitor [2] ----
67 vec($rbits, fileno(CALL), 1) = 1;
68 vec($rbits, fileno(EXECTERM), 1) = 1;
70 my $nfound = select($rbits, '', $ebits, undef);
72 # Either the child has just died, or the caller has gone away
75 kill 'INT', 0 or fail_log("kill executor [$child]: $!");
77 my $got = waitpid $child, 0;
78 $got >= 0 // fail_log("wait for executor [$child] (2): $!");
79 $got == $child or fail_log("wait for esecutor [$child] gave [$got]");
81 protocol_write(pack "N", $?);
85 sub close_call_fds () {
92 sub protocol_write ($) {
94 return if (print CALL $d and flush CALL);
95 _exit(0) if $!==EPIPE || $!==ECONNRESET;
96 fail_log("protocol write: $!");
103 return $r if defined $r;
109 sub protocol_read_fail ($) {
111 _exit(0) if $!==ECONNRESET;
112 die("recv $what: $!");
115 sub protocol_exchange () {
116 my $greeting = "PFI\n\0\0\0\0";
117 protocol_write($greeting);
123 $r = IO::FDPass::recv(fileno(CALL));
126 protocol_read_fail("fd $_");
132 my $r = read(CALL, $len, 4) // protocol_read_fail("message length");
135 $len = unpack "N", $len;
137 $r = read(CALL, $data, $len) // protocol_read_fail("message data ($len)");
138 $r == $len or _exit(0);
140 @ARGV = split /\0/, $data, -1;
141 @ARGV >= 2 or die("message data has too few strings (".(scalar @ARGV).")");
142 length(pop(@ARGV)) and die("message data missing trailing nul");
144 while (my $s = shift @ARGV) {
146 $s =~ m/=/ or die("message data env var missing equals");
151 sub initialisation_complete {
154 # if env var not set, we're not running under prefork-interp
155 my @env_data = split / /, ($ENV{$env_name} // return);
156 croak "$env_name has too few words" unless @env_data >= 2;
157 my (@vsns) = split /,/, $env_data[0];
158 croak "$env_name doesn't offer protocol v1" unless grep { $_ eq 'v1' } @vsns;
159 my @env_fds = split /,/, $env_data[1];
160 croak "$env_name has too few fds" unless @env_fds >= 4;;
163 my $num_servers = $opts{max_servers} // 4;
165 #---- setup (pm) [1] ----
168 $_ eq ($_+0) or croak "$env_name contains $_, not a number";
170 open LISTEN, "+>&=$env_fds[0]" or croak "listen fd: $!";
171 open CALL, "+>&=$env_fds[1]" or croak "call fd: $!";
172 open WATCHE, ">+&=$env_fds[3]" or croak "watch stderr fd: $!";
174 if (!$opts{no_openlog}) {
175 openlog("prefork-interp $0", 'ndelay,nofatal,pid',
176 $opts{log_facility} // 'log_user');
179 open NULL, "+>/dev/null" or croak "open /dev/null: $!";
181 #---- fork for server ----
183 my $child = fork // croak "first fork failed: $!";
185 #---- setup (pm) [2], exits ----
188 setsid() > 0 or fail_log("setsid: $!");
189 # The server will be a session leader, but it won't open ttys,
192 #---- server(pm) [1] ----
194 $child = fork // croak "second fork failed: $!";
196 # we are the child, i.e. the one fa-monitor
197 local $0 = "$0 [monitor(init)]";
198 return become_monitor();
202 $children{$child} = 1;
204 # --- server(pm) [2] ----
207 open STDIN, "<&NULL" or fail_log("dup null onto stdin: $!");
208 open STDOUT, ">&NULL" or fail_log("dup null onto stdout: $!");
209 open STDERR, ">&NULL" or fail_log("dup null onto stderr: $!");
216 local $0 = "$0 [server]";
221 my $full = %children >= $num_servers;
222 my $got = waitpid -1, ($full ? 0 : WNOHANG);
223 $got >= 0 or fail_log("failed to wait for monitor(s)");
227 "$0 prefork [$$]: monitor process [$got] failed with wait status $?");
229 if (!exists $children{$got}) {
231 "$0 prefork [$$]: monitor process [$got] wasn't one of ours?!");
233 delete $children{$got};
238 # select for accepting or housekeeping timeout
240 vec($rbits, fileno(LISTEN), 1) = 1;
241 vec($rbits, fileno(WATCHE), 1) = 1;
243 my $nfound = select($rbits, '', $ebits, ($opts{idle_timeout} // 1000000));
246 last if $nfound == 0;
249 fail_log("select failed: $!");
252 # Has the watcher told us to shut down, or died with a message ?
254 my $r = sysread WATCHE, $msgbuf, 2048;
257 fail_log("watcher: $msgbuf");
260 } elsif ($! == EINTR || $! == EAGAIN || $! == EWOULDBLOCK) {
262 fail_log("watcher stderr read: $!");
265 # TODO stat checking, quit here if we are stale
267 # Anything to accept ?
268 if (accept(CALL, LISTEN)) {
269 $child = fork // fail_log("fork for accepted call failed: $!");
271 #---- monitor [1] ----
272 local $0 = "$0 [monitor]";
277 $children{$child} = 1;
278 } elsif ($! == EINTR || $! == EAGAIN || $! == EWOULDBLOCK) {
280 syslog(LOG_WARNING, "$0 prefork [$$]: accept failed: $!");
281 if ($errcount > ($opts{max_errors} // 100)) {
282 fail_log("too many accept failures, quitting");