package SocketActivation;
# vim:ts=4:sw=4:expandtab
use strict;
use warnings;
use IO::Socket::UNIX; # core
use Cwd qw(abs_path); # core
use POSIX qw(:fcntl_h); # core
use AnyEvent::Handle; # not core
use AnyEvent::Util; # not core
use Exporter 'import';
use v5.10;
our @EXPORT = qw(activate_i3);
#
# Starts i3 using socket activation. Creates a listening socket (with bind +
# listen) which is then passed to i3, who in turn calls accept and handles the
# requests.
#
# Since the kernel buffers the connect, the parent process can connect to the
# socket immediately after forking. It then sends a request and waits until it
# gets an answer. Obviously, i3 has to be initialized to actually answer the
# request.
#
# This way, we can wait *precisely* the amount of time which i3 waits to get
# ready, which is a *HUGE* speed gain (and a lot more robust) in comparison to
# using sleep() with a fixed amount of time.
#
# unix_socket_path: Location of the socket to use for the activation
# display: X11 $ENV{DISPLAY}
# configfile: path to the configuration file to use
# logpath: path to the logfile to which i3 will append
# cv: an AnyEvent->condvar which will be triggered once i3 is ready
#
sub activate_i3 {
my %args = @_;
# remove the old unix socket
unlink($args{unix_socket_path});
my $socket = IO::Socket::UNIX->new(
Listen => 1,
Local => $args{unix_socket_path},
);
my $pid = fork;
if (!defined($pid)) {
die "could not fork()";
}
if ($pid == 0) {
# Start a process group so that in the parent, we can kill the entire
# process group and immediately kill i3bar and any other child
# processes.
setpgrp;
$ENV{LISTEN_PID} = $$;
$ENV{LISTEN_FDS} = 1;
delete $ENV{DESKTOP_STARTUP_ID};
delete $ENV{I3SOCK};
# $SHELL could be set to fish, which will horribly break running shell
# commands via i3’s exec feature. This happened e.g. when having
# “set-option -g default-shell "/usr/bin/fish"” in ~/.tmux.conf
delete $ENV{SHELL};
unless ($args{dont_create_temp_dir}) {
$ENV{XDG_RUNTIME_DIR} = '/tmp/i3-testsuite/';
mkdir $ENV{XDG_RUNTIME_DIR};
}
$ENV{DISPLAY} = $args{display};
# We are about to exec, but we did not modify $^F to include $socket
# when creating the socket (because the file descriptor could have a
# number != 3 which would lead to i3 leaking a file descriptor). This
# caused Perl to set the FD_CLOEXEC flag, which would close $socket on
# exec(), effectively *NOT* passing $socket to the new process.
# Therefore, we explicitly clear FD_CLOEXEC (the only flag right now)
# by setting the flags to 0.
POSIX::fcntl($socket, F_SETFD, 0) or die "Could not clear fd flags: $!";
# If the socket does not use file descriptor 3 by chance already, we
# close fd 3 and dup2() the socket to 3.
if (fileno($socket) != 3) {
POSIX::close(3);
POSIX::dup2(fileno($socket), 3);
POSIX::close(fileno($socket));
}
# Make sure no file descriptors are open. Strangely, I got an open file
# descriptor pointing to AnyEvent/Impl/EV.pm when testing.
AnyEvent::Util::close_all_fds_except(0, 1, 2, 3);
# Construct the command to launch i3. Use maximum debug level, disable
# the interactive signalhandler to make it crash immediately instead.
# Also disable logging to SHM since we redirect the logs anyways.
# Force Xinerama because we use Xdmx for multi-monitor tests.
my $i3cmd = q|i3 --shmlog-size=0 --disable-signalhandler|;
if (!defined($args{inject_randr15})) {
$i3cmd .= q| --force-xinerama|;
}
if (!$args{validate_config}) {
# We only set logging if i3 is actually started, but not if we only
# validate the config file. This is to keep logging to a minimum as
# such a test will likely want to inspect the log file.
$i3cmd .= q| -V -d all|;
}
# For convenience:
my $outdir = $args{outdir};
my $test = $args{testname};
if ($args{restart}) {
$i3cmd .= ' -L ' . abs_path('restart-state.golden');
}
if ($args{validate_config}) {
$i3cmd .= ' -C';
}
if ($args{valgrind}) {
$i3cmd =
qq|valgrind --log-file="$outdir/valgrind-for-$test.log" | .
qq|--suppressions="./valgrind.supp" | .
qq|--leak-check=full --track-origins=yes --num-callers=20 | .
qq|--tool=memcheck -- $i3cmd|;
}
my $logfile = "$outdir/i3-log-for-$test";
# Append to $logfile instead of overwriting because i3 might be
# run multiple times in one testcase.
my $cmd = "exec $i3cmd -c $args{configfile} >>$logfile 2>&1";
if ($args{strace}) {
my $out = "$outdir/strace-for-$test.log";
# We overwrite LISTEN_PID with the correct process ID to make
# socket activation work (LISTEN_PID has to match getpid(),
# otherwise the LISTEN_FDS will be treated as a left-over).
$cmd = qq|strace -fvy -s2048 -o "$out" -- | .
'sh -c "export LISTEN_PID=\$\$; ' . $cmd . '"';
}
if ($args{xtrace}) {
my $out = "$outdir/xtrace-for-$test.log";
# See comment in $args{strace} branch.
$cmd = qq|xtrace -n -o "$out" -- | .
'sh -c "export LISTEN_PID=\$\$; ' . $cmd . '"';
}
if ($args{inject_randr15}) {
# See comment in $args{strace} branch.
$cmd = 'test.inject_randr15 --getmonitors_reply="' .
$args{inject_randr15} . '" ' .
($args{inject_randr15_outputinfo}
? '--getoutputinfo_reply="' .
$args{inject_randr15_outputinfo} . '" '
: '') .
'-- ' .
'sh -c "export LISTEN_PID=\$\$; ' . $cmd . '"';
}
# We need to use the shell due to using output redirections.
exec '/bin/sh', '-c', $cmd;
# if we are still here, i3 could not be found or exec failed. bail out.
exit 1;
}
# close the socket, the child process should be the only one which keeps a file
# descriptor on the listening socket.
$socket->close;
if ($args{validate_config}) {
$args{cv}->send(1);
return $pid;
}
# We now connect (will succeed immediately) and send a request afterwards.
# As soon as the reply is there, i3 is considered ready.
my $cl = IO::Socket::UNIX->new(Peer => $args{unix_socket_path});
my $hdl;
$hdl = AnyEvent::Handle->new(
fh => $cl,
on_error => sub {
$hdl->destroy;
$args{cv}->send(0);
});
# send a get_tree message without payload
$hdl->push_write('i3-ipc' . pack("LL", 0, 4));
# wait for the reply
$hdl->push_read(chunk => 1, => sub {
my ($h, $line) = @_;
$args{cv}->send(1);
undef $hdl;
});
return $pid;
}
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