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 :signal_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 [$$]: error: $m");
28 carp "$0: prefork: initialisation error: $m";
35 syslog(LOG_INFO, "$0 prefork [$$]: $m, quitting");
39 # Returns in the executor process
40 sub become_monitor () {
45 # Make a process group for this call
46 setpgrp or fail_log("setpgrp failed: $!");
48 eval { protocol_exchange(); 1; }
49 or fail_log("protocol exchange failed: $@");
51 pipe EXECTERM, EXECTERMW or fail_log("pipe: $!");
53 my $child = fork // fail_log("fork executor: $!");
56 open ::STDIN , "<& $call_fds[0]" or fail_log("dup for fd0");
57 open ::STDOUT, ">& $call_fds[1]" or fail_log("dup for fd1");
58 open ::STDERR, ">& $call_fds[2]" or fail_log("dup for fd2");
66 #---- monitor [2] ----
69 vec($rbits, fileno(CALL), 1) = 1;
70 vec($rbits, fileno(EXECTERM), 1) = 1;
72 my $nfound = select($rbits, '', $ebits, undef);
74 # Either the child has just died, or the caller has gone away
77 kill 'INT', 0 or fail_log("kill executor [$child]: $!");
79 my $got = waitpid $child, 0;
80 $got >= 0 // fail_log("wait for executor [$child] (2): $!");
81 $got == $child or fail_log("wait for esecutor [$child] gave [$got]");
83 protocol_write(pack "N", $?);
87 sub close_call_fds () {
94 sub protocol_write ($) {
96 return if (print CALL $d and flush CALL);
97 _exit(0) if $!==EPIPE || $!==ECONNRESET;
98 fail_log("protocol write: $!");
101 sub eintr_retry ($) {
105 return $r if defined $r;
111 sub protocol_read_fail ($) {
113 _exit(0) if $!==ECONNRESET;
114 die("recv $what: $!");
117 sub protocol_exchange () {
118 my $greeting = "PFI\n\0\0\0\0";
119 protocol_write($greeting);
125 $r = IO::FDPass::recv(fileno(CALL));
128 protocol_read_fail("fd $_");
134 my $r = read(CALL, $len, 4) // protocol_read_fail("message length");
137 $len = unpack "N", $len;
139 $r = read(CALL, $data, $len) // protocol_read_fail("message data ($len)");
140 $r == $len or _exit(0);
142 @ARGV = split /\0/, $data, -1;
143 @ARGV >= 2 or die("message data has too few strings (".(scalar @ARGV).")");
144 length(pop(@ARGV)) and die("message data missing trailing nul");
146 while (my $s = shift @ARGV) {
148 $s =~ m/=/ or die("message data env var missing equals");
153 sub initialisation_complete {
156 # if env var not set, we're not running under prefork-interp
157 my @env_data = split / /, ($ENV{$env_name} // return);
158 croak "$env_name has too few words" unless @env_data >= 2;
159 my (@vsns) = split /,/, $env_data[0];
160 croak "$env_name doesn't offer protocol v1" unless grep { $_ eq 'v1' } @vsns;
161 my @env_fds = split /,/, $env_data[1];
162 croak "$env_name has too few fds" unless @env_fds >= 4;;
165 my $num_servers = $opts{max_servers} // 4;
167 #---- setup (pm) [1] ----
170 $_ eq ($_+0) or croak "$env_name contains $_, not a number";
172 open LISTEN, "+>&=$env_fds[0]" or croak "listen fd: $!";
173 open CALL, "+>&=$env_fds[1]" or croak "call fd: $!";
174 open WATCHI, "+>&=$env_fds[2]" or croak "call fd: $!";
175 open WATCHE, "+>&=$env_fds[3]" or croak "watch stderr fd: $!";
177 if (!$opts{no_openlog}) {
178 openlog("prefork-interp $0", 'ndelay,nofatal,pid',
179 $opts{log_facility} // 'log_user');
182 open NULL, "+>/dev/null" or croak "open /dev/null: $!";
184 #---- fork for server ----
186 my $child = fork // croak "first fork failed: $!";
188 #---- setup (pm) [2], exits ----
191 setsid() > 0 or fail_log("setsid: $!");
192 # The server will be a session leader, but it won't open ttys,
195 #---- server(pm) [1] ----
197 $child = fork // croak "second fork failed: $!";
199 # we are the child, i.e. the one fa-monitor
200 local $0 = "$0 [monitor(init)]";
201 return become_monitor();
206 $children{$child} = 1;
208 # --- server(pm) [2] ----
210 local $0 = "$0 [server]";
213 open STDIN, "<&NULL" or fail_log("dup null onto stdin: $!");
214 open STDOUT, ">&NULL" or fail_log("dup null onto stdout: $!");
215 open STDERR, ">&NULL" or fail_log("dup null onto stderr: $!");
223 my $full = %children >= $num_servers;
224 my $got = waitpid -1, ($full ? 0 : WNOHANG);
225 $got >= 0 or fail_log("failed to wait for monitor(s): $!");
227 if ($? && $? != SIGPIPE) {
229 "$0 prefork [$$]: monitor process [$got] failed with wait status $?");
231 if (!exists $children{$got}) {
233 "$0 prefork [$$]: monitor process [$got] wasn't one of ours?!");
235 delete $children{$got};
240 # select for accepting or housekeeping timeout
242 vec($rbits, fileno(LISTEN), 1) = 1;
243 vec($rbits, fileno(WATCHE), 1) = 1;
245 my $nfound = select($rbits, '', $ebits, ($opts{idle_timeout} // 1000000));
248 last if $nfound == 0;
251 fail_log("select failed: $!");
254 # Has the watcher told us to shut down, or died with a message ?
256 my $r = sysread WATCHE, $msgbuf, 2048;
259 fail_log("watcher: $msgbuf");
260 } elsif (defined $r) {
262 } elsif ($! == EINTR || $! == EAGAIN || $! == EWOULDBLOCK) {
264 fail_log("watcher stderr read: $!");
267 # TODO stat checking, quit here if we are stale
269 # Anything to accept ?
270 if (accept(CALL, LISTEN)) {
271 $child = fork // fail_log("fork for accepted call failed: $!");
273 #---- monitor [1] ----
274 local $0 = "$0 [monitor]";
275 return become_monitor();
279 $children{$child} = 1;
280 } elsif ($! == EINTR || $! == EAGAIN || $! == EWOULDBLOCK) {
282 syslog(LOG_WARNING, "$0 prefork [$$]: accept failed: $!");
283 if ($errcount > ($opts{max_errors} // 100)) {
284 fail_log("too many accept failures, quitting");