Re: Testing "Brazil" on Cygwin... is that expected?

[Achim Gratz]

Achim Gratz <Stromeko <at> nexgo.de> writes:
> That's actually an issue with the NetApp support in Cygwin.  NetApp
> produces unstable inode numbers and therefore Cygwin fakes stable inode
> numbers by doing some hashing.  While that removes problems like the
> inode changing underneath a cp in progress, it necessarily makes all
> link counts 1.  The hard links themselves are fine, you can write to any
> of the linked files and the contents shows up in the others, but you
> don't get to see how many files are linked.

The following patch makes GNU parallel work correctly on systems that report
bogus link counts on hard-linked files.  The output from the test is now as
expected:

First started
Second started
Third started
The third finished
The second finished
Fourth started
The first finished
The fourth finished
All finished.

--- /bin/parallel       2014-07-22 16:15:08.000000000 +0200
+++ /bin/sem    2014-08-15 11:22:26.630801200 +0200
@@ -7109,16 +7109,20 @@

 sub release {
     my $self = shift;
-    unlink $self->{'pidfile'};
-    if($self->nlinks() == 1) {
-       # This is the last link, so atomic cleanup
-       $self->lock();
-       if($self->nlinks() == 1) {
-           unlink $self->{'idfile'};
-           rmdir $self->{'lockdir'};
-       }
-       $self->unlock();
+    $self->lock();
+    my $nlinks = $self->nlinks();
+    ::debug($nlinks, "<", $self->{'count'});
+    if($nlinks-- > 1) {
+       unlink $self->{'idfile'};
+       open (my $fh, ">", $self->{'idfile'}) or
+           ::die_bug("write_idfile: $self->{'idfile'}");
+       print $fh "#"x$nlinks;
+       close $fh;
+    } else {
+       unlink $self->{'idfile'};
+       rmdir $self->{'lockdir'};
     }
+    $self->unlock();
     ::debug("run", "released $self->{'pid'}\n");
 }

@@ -7127,14 +7131,14 @@
     my $self = shift;
     my $retval = 0;
     $self->lock();
-    ::debug($self->nlinks(), "<", $self->{'count'});
-    if($self->nlinks() < $self->{'count'}) {
+    my $nlinks = $self->nlinks();
+    ::debug($nlinks, "<", $self->{'count'});
+    if($nlinks++ < $self->{'count'}) {
        -d $self->{'lockdir'} or mkdir_or_die($self->{'lockdir'});
-       if(not -e $self->{'idfile'}) {
-           open (my $fh, ">", $self->{'idfile'}) or
-               ::die_bug("write_idfile: $self->{'idfile'}");
-           close $fh;
-       }
+       open (my $fh, ">", $self->{'idfile'}) or
+           ::die_bug("write_idfile: $self->{'idfile'}");
+       print $fh "#"x$nlinks;
+       close $fh;
        $retval = link $self->{'idfile'}, $self->{'pidfile'};
     }
     $self->unlock();
@@ -7145,8 +7149,8 @@
 sub nlinks {
     my $self = shift;
     if(-e $self->{'idfile'}) {
-       ::debug("run", "nlinks", (stat(_))[3], "\n");
-       return (stat(_))[3];
+       ::debug("run", "nlinks", (stat(_))[3], "size", (stat(_))[7], "\n");
+       return (stat(_))[7];
     } else {
        return 0;
     }


Regards,
Achim.