test/lock_file.pl

   1 #!/usr/bin/perl
   2
   3 use lib '../src';
   4 use strict;
   5 use warnings;
   6
   7 use Socket;
   8 use POSIX (); # don't import assert()
   9
  10 use PVE::Tools 'lock_file_full';
  11
  12 my $name = "test.lockfile.$$-";
  13
  14 END {
  15         system("rm $name*");
  16 };
  17
  18 # Utilities:
  19
  20 sub forked($$) {
  21     my ($code1, $code2) = @_;
  22
  23     pipe(my $except_r, my $except_w) or die "pipe: $!\n";
  24
  25     my $pid = fork();
  26     die "fork failed: $!\n" if !defined($pid);
  27
  28     if ($pid == 0) {
  29         close($except_r);
  30         eval { $code1->() };
  31         if ($@) {
  32             print {$except_w} $@;
  33             $except_w->flush();
  34             POSIX::_exit(1);
  35         }
  36         POSIX::_exit(0);
  37     }
  38     close($except_w);
  39
  40     eval { $code2->() };
  41     my $err = $@;
  42     if ($err) {
  43         kill(15, $pid);
  44     } else {
  45         my $err = do { local $/ = undef; <$except_r> };
  46     }
  47     die "interrupted\n" if waitpid($pid, 0) != $pid;
  48     die $err if $err;
  49
  50     # Check exit code:
  51     my $status = POSIX::WEXITSTATUS($?);
  52     if ($? == -1) {
  53         die "failed to execute\n";
  54     } elsif (POSIX::WIFSIGNALED($?)) {
  55         my $sig = POSIX::WTERMSIG($?);
  56         die "got signal $sig\n";
  57     } elsif ($status != 0) {
  58         die "exit code $status\n";
  59     }
  60 }
  61
  62 # Book-keeping:
  63
  64 my %_ran;
  65 sub new {
  66         %_ran = ();
  67 }
  68 sub ran {
  69         my ($what) = @_;
  70         $_ran{$what} = 1;
  71 }
  72 sub assert {
  73         my ($what) = @_;
  74         die "code didn't run: $what\n" if !$_ran{$what};
  75 }
  76 sub assert_not {
  77         my ($what) = @_;
  78         die "code shouldn't have run: $what\n" if $_ran{$what};
  79 }
  80
  81 # Regular lock:
  82 new();
  83 lock_file_full($name, 10, 0, sub { ran('single lock') });
  84 assert('single lock');
  85
  86 # Lock multiple times in a row:
  87 new();
  88 lock_file_full($name, 10, 0, sub { ran('lock A') });
  89 assert('lock A');
  90 lock_file_full($name, 10, 0, sub { ran('lock B') });
  91 assert('lock B');
  92
  93 # Nested lock:
  94 new();
  95 lock_file_full($name, 10, 0, sub {
  96         ran('lock A');
  97         lock_file_full($name, 10, 0, sub { ran('lock B') });
  98         assert('lock B');
  99         ran('lock C');
 100 });
 101 assert('lock A');
 102 assert('lock B');
 103 assert('lock C');
 104
 105 # Independent locks:
 106 new();
 107 lock_file_full($name, 10, 0, sub {
 108         ran('lock A');
 109         # locks file "${name}2"
 110         lock_file_full($name.2, 10, 0, sub { ran('lock B') });
 111         assert('lock B');
 112         ran('lock C');
 113 });
 114 assert('lock A');
 115 assert('lock B');
 116 assert('lock C');
 117
 118 # Does it actually lock? (shared=0)
 119 # Can we get two simultaneous shared locks? (shared=1)
 120 sub forktest1($) {
 121     my ($shared) = @_;
 122     new();
 123     # socket pair for synchronization
 124     socketpair(my $fmain, my $fother, AF_UNIX, SOCK_STREAM, PF_UNSPEC)
 125         or die "socketpair(): $!\n";
 126     forked sub {
 127             # other side
 128             close($fmain);
 129             my $line;
 130             lock_file_full($name, 60, $shared, sub {
 131                 ran('other side');
 132                 # tell parent we've acquired the lock
 133                 print {$fother} "1\n";
 134                 $fother->flush();
 135                 # wait for parent to be done trying to lock
 136                 $line = <$fother>;
 137             });
 138             die $@ if $@;
 139             die "parent failed\n" if !$line || $line ne "2\n";
 140             assert('other side');
 141     }, sub {
 142             # main process
 143             # Wait for our child to lock:
 144             close($fother);
 145             my $line = <$fmain>;
 146             die "child failed to acquire a lock\n" if !$line || $line ne "1\n";
 147             lock_file_full($name, 1, $shared, sub {
 148                 ran('local side');
 149             });
 150             if ($shared) {
 151                 assert('local side');
 152             } else {
 153                 assert_not('local side');
 154             }
 155             print {$fmain} "2\n";
 156             $fmain->flush();
 157     };
 158     close($fmain);
 159 }
 160 forktest1(0);
 161 forktest1(1);