1 files changed, 41 insertions, 0 deletions
diff --git a/src/commands/1plus1 b/src/commands/1plus1
new file mode 100755
index 0000000..897d235
--- /dev/null
+++ b/src/commands/1plus1
@@ -0,0 +1,41 @@
+#!/usr/bin/perl
+use strict;
+use warnings;
+
+# import LOCK_*
+use Fcntl qw(:flock);
+
+my $lockbase      = shift;    # suggested: $GL_REPO_BASE/$GL_REPO.git/.gl-mirror-push-lock.$SLAVE_NAME
+my @cmd_plus_args = @ARGV;    # the actual 'gitolite mirror ...' command
+@ARGV = ();
+
+# ----------------------------------------------------------------------
+
+open( my $fhrun, ">", "$lockbase.run" ) or die "open '$lockbase.run' failed: $!";
+if ( flock( $fhrun, LOCK_EX | LOCK_NB ) ) {
+    # got run lock; you're good to go
+
+    system(@cmd_plus_args);
+
+    flock( $fhrun, LOCK_UN );
+    exit 0;
+}
+
+# "run" lock failed; someone is already running the command
+
+open( my $fhqueue, ">", "$lockbase.queue" ) or die "open '$lockbase.queue' failed: $!";
+if ( flock( $fhqueue, LOCK_EX | LOCK_NB ) ) {
+    # got queue lock, now block waiting for "run" lock
+    flock( $fhrun, LOCK_EX );
+    # got run lock, so take yourself out of "queue" state, then run
+    flock( $fhqueue, LOCK_UN );
+
+    system(@cmd_plus_args);
+
+    flock( $fhrun, LOCK_UN );
+    exit 0;
+}
+
+# "queue" lock also failed; someone is running AND someone is queued; we can go home
+say STDERR "INFO: nothing to do/queue; '$lockbase' already running and 1 in queue";
+exit 0;