mtr_im.pl

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# -*- cperl -*-
# Copyright (C) 2006 MySQL AB
# 
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 2 of the License.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

# This is a library file used by the Perl version of mysql-test-run,
# and is part of the translation of the Bourne shell script with the
# same name.

use strict;

# Private IM-related operations.

sub mtr_im_kill_process ($$$$);
sub mtr_im_load_pids ($);
sub mtr_im_terminate ($);
sub mtr_im_check_alive ($);
sub mtr_im_check_main_alive ($);
sub mtr_im_check_angel_alive ($);
sub mtr_im_check_mysqlds_alive ($);
sub mtr_im_check_mysqld_alive ($);
sub mtr_im_cleanup ($);
sub mtr_im_rm_file ($);
sub mtr_im_errlog ($);
sub mtr_im_kill ($);
sub mtr_im_wait_for_connection ($$$);
sub mtr_im_wait_for_mysqld($$$);

# Public IM-related operations.

sub mtr_im_start ($$);
sub mtr_im_stop ($);

##############################################################################
#
#  Private operations.
#
##############################################################################

sub mtr_im_kill_process ($$$$) {
  my $pid_lst= shift;
  my $signal= shift;
  my $total_retries= shift;
  my $timeout= shift;

  my %pids;

  foreach my $pid ( @{$pid_lst} )
  {
    $pids{$pid}= 1;
  }

  for ( my $cur_attempt= 1; $cur_attempt <= $total_retries; ++$cur_attempt )
  {
    foreach my $pid ( keys %pids )
    {
      mtr_debug("Sending $signal to $pid...");

      kill($signal, $pid);

      unless ( kill (0, $pid) )
      {
        mtr_debug("Process $pid died.");
        delete $pids{$pid};
      }
    }

    return if scalar keys %pids == 0;

    mtr_debug("Sleeping $timeout second(s) waiting for processes to die...");

    sleep($timeout);
  }

  mtr_debug("Process(es) " .
            join(' ', keys %pids) .
            " is still alive after $total_retries " .
            "of sending signal $signal.");
}

###########################################################################

sub mtr_im_load_pids($) {
  my $im= shift;

  mtr_debug("Loading PID files...");

  # Obtain mysqld-process pids.

  my $instances = $im->{'instances'};

  for ( my $idx= 0; $idx < 2; ++$idx )
  {
    mtr_debug("IM-guarded mysqld[$idx] PID file: '" .
              $instances->[$idx]->{'path_pid'} . "'.");

    my $mysqld_pid;

    if ( -r $instances->[$idx]->{'path_pid'} )
    {
      $mysqld_pid= mtr_get_pid_from_file($instances->[$idx]->{'path_pid'});
      mtr_debug("IM-guarded mysqld[$idx] PID: $mysqld_pid.");
    }
    else
    {
      $mysqld_pid= undef;
      mtr_debug("IM-guarded mysqld[$idx]: no PID file.");
    }

    $instances->[$idx]->{'pid'}= $mysqld_pid;
  }

  # Re-read Instance Manager PIDs from the file, since during tests Instance
  # Manager could have been restarted, so its PIDs could have been changed.

  #   - IM-main

  mtr_debug("IM-main PID file: '$im->{path_pid}'.");

  if ( -f $im->{'path_pid'} )
  {
    $im->{'pid'} =
      mtr_get_pid_from_file($im->{'path_pid'});

    mtr_debug("IM-main PID: $im->{pid}.");
  }
  else
  {
    mtr_debug("IM-main: no PID file.");
    $im->{'pid'}= undef;
  }

  #   - IM-angel

  mtr_debug("IM-angel PID file: '$im->{path_angel_pid}'.");

  if ( -f $im->{'path_angel_pid'} )
  {
    $im->{'angel_pid'} =
      mtr_get_pid_from_file($im->{'path_angel_pid'});

    mtr_debug("IM-angel PID: $im->{'angel_pid'}.");
  }
  else
  {
    mtr_debug("IM-angel: no PID file.");
    $im->{'angel_pid'} = undef;
  }
}

###########################################################################

sub mtr_im_terminate($) {
  my $im= shift;

  # Load pids from pid-files. We should do it first of all, because IM deletes
  # them on shutdown.

  mtr_im_load_pids($im);

  mtr_debug("Shutting Instance Manager down...");

  # Ignoring SIGCHLD so that all children could rest in peace.

  start_reap_all();

  # Send SIGTERM to IM-main.

  if ( defined $im->{'pid'} )
  {
    mtr_debug("IM-main pid: $im->{pid}.");
    mtr_debug("Stopping IM-main...");

    mtr_im_kill_process([ $im->{'pid'} ], 'TERM', 10, 1);
  }
  else
  {
    mtr_debug("IM-main pid: n/a.");
  }

  # If IM-angel was alive, wait for it to die.

  if ( defined $im->{'angel_pid'} )
  {
    mtr_debug("IM-angel pid: $im->{'angel_pid'}.");
    mtr_debug("Waiting for IM-angel to die...");

    my $total_attempts= 10;

    for ( my $cur_attempt=1; $cur_attempt <= $total_attempts; ++$cur_attempt )
    {
      unless ( kill (0, $im->{'angel_pid'}) )
      {
        mtr_debug("IM-angel died.");
        last;
      }

      sleep(1);
    }
  }
  else
  {
    mtr_debug("IM-angel pid: n/a.");
  }

  stop_reap_all();

  # Re-load PIDs.

  mtr_im_load_pids($im);
}

###########################################################################

sub mtr_im_check_alive($) {
  my $im= shift;

  mtr_debug("Checking whether IM-components are alive...");

  return 1 if mtr_im_check_main_alive($im);

  return 1 if mtr_im_check_angel_alive($im);

  return 1 if mtr_im_check_mysqlds_alive($im);

  return 0;
}

###########################################################################

sub mtr_im_check_main_alive($) {
  my $im= shift;

  # Check that the process, that we know to be IM's, is dead.

  if ( defined $im->{'pid'} )
  {
    if ( kill (0, $im->{'pid'}) )
    {
      mtr_debug("IM-main (PID: $im->{pid}) is alive.");
      return 1;
    }
    else
    {
      mtr_debug("IM-main (PID: $im->{pid}) is dead.");
    }
  }
  else
  {
    mtr_debug("No PID file for IM-main.");
  }

  # Check that IM does not accept client connections.

  if ( mtr_ping_port($im->{'port'}) )
  {
    mtr_debug("IM-main (port: $im->{port}) " .
              "is accepting connections.");

    mtr_im_errlog("IM-main is accepting connections on port " .
                  "$im->{port}, but there is no " .
                  "process information.");
    return 1;
  }
  else
  {
    mtr_debug("IM-main (port: $im->{port}) " .
              "does not accept connections.");
    return 0;
  }
}

###########################################################################

sub mtr_im_check_angel_alive($) {
  my $im= shift;

  # Check that the process, that we know to be the Angel, is dead.

  if ( defined $im->{'angel_pid'} )
  {
    if ( kill (0, $im->{'angel_pid'}) )
    {
      mtr_debug("IM-angel (PID: $im->{angel_pid}) is alive.");
      return 1;
    }
    else
    {
      mtr_debug("IM-angel (PID: $im->{angel_pid}) is dead.");
      return 0;
    }
  }
  else
  {
    mtr_debug("No PID file for IM-angel.");
    return 0;
  }
}

###########################################################################

sub mtr_im_check_mysqlds_alive($) {
  my $im= shift;

  mtr_debug("Checking for IM-guarded mysqld instances...");

  my $instances = $im->{'instances'};

  for ( my $idx= 0; $idx < 2; ++$idx )
  {
    mtr_debug("Checking mysqld[$idx]...");

    return 1
      if mtr_im_check_mysqld_alive($instances->[$idx]);
  }
}

###########################################################################

sub mtr_im_check_mysqld_alive($) {
  my $mysqld_instance= shift;

  # Check that the process is dead.

  if ( defined $mysqld_instance->{'pid'} )
  {
    if ( kill (0, $mysqld_instance->{'pid'}) )
    {
      mtr_debug("Mysqld instance (PID: $mysqld_instance->{pid}) is alive.");
      return 1;
    }
    else
    {
      mtr_debug("Mysqld instance (PID: $mysqld_instance->{pid}) is dead.");
    }
  }
  else
  {
    mtr_debug("No PID file for mysqld instance.");
  }

  # Check that mysqld does not accept client connections.

  if ( mtr_ping_port($mysqld_instance->{'port'}) )
  {
    mtr_debug("Mysqld instance (port: $mysqld_instance->{port}) " .
              "is accepting connections.");

    mtr_im_errlog("Mysqld is accepting connections on port " .
                  "$mysqld_instance->{port}, but there is no " .
                  "process information.");
    return 1;
  }
  else
  {
    mtr_debug("Mysqld instance (port: $mysqld_instance->{port}) " .
              "does not accept connections.");
    return 0;
  }
}

###########################################################################

sub mtr_im_cleanup($) {
  my $im= shift;

  mtr_im_rm_file($im->{'path_pid'});
  mtr_im_rm_file($im->{'path_sock'});

  mtr_im_rm_file($im->{'path_angel_pid'});

  for ( my $idx= 0; $idx < 2; ++$idx )
  {
    mtr_im_rm_file($im->{'instances'}->[$idx]->{'path_pid'});
    mtr_im_rm_file($im->{'instances'}->[$idx]->{'path_sock'});
  }
}