From b71f045b8b03f5add58603c1285aa7867d4c5547 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Fri, 4 Nov 2016 14:21:54 +0000
Subject: [PATCH] check parallel

---
 check | 47 ++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 40 insertions(+), 7 deletions(-)

diff --git a/check b/check
index a7ae489..7293371 100755
--- a/check
+++ b/check
@@ -19,21 +19,53 @@ perl -we '
 
     our $file;
     our $count;
+    our $batch=0;
+    our @tasks;
+
+    my $ncpus = eval {
+        require Sys::CPU;
+	Sys::CPU::cpu_count();
+    } // 3;
+
+$ncpus=1;
+    print STDERR "check using $ncpus cpus\n";
+
+    sub await_task () {
+	my ($pid, $oldbatch) = @{ shift @tasks };
+	waitpid $pid, 0 == $pid or die $!;
+	die "$oldbatch $?" if $?;
+	unlink $oldbatch or die "$oldbatch $!";
+        print STDERR "check completed $oldbatch [$pid]\n";
+    }
 
     sub complete_batch () {
-        if ($file) {
-            print STDERR "check completing batch\n";
-            close $file or die $!;
-	    system "git update-ref --stdin <batch"
-                and die $? < 0 ? $! : $?;
-        }
+        return unless $file;
+
+	close $file or die $!;
+
+        print STDERR "check closing $batch ($count)\n";
+
+	await_task if @tasks >= $ncpus;
+
+	my $pid = fork // die $!;
+	if (!$pid) {
+	    close STDIN;
+#            seek STDIN,0,1;
+#            flush STDIN;
+	    open STDIN, "<", $batch or die $batch;
+	    exec qw(git update-ref --stdin);
+	    die $!;
+	}
+        print STDERR "check spawned $batch ($count) [$pid]\n";
+    	push @tasks, [ $pid, $batch ];
+	$batch++;
 	$file = undef;
 	$count = 0;
     }
 
     while (<>) {
 #print STDERR ">$_<\n";
-        $file ||= new IO::File "batch", ">" or die $!;
+        $file ||= new IO::File $batch, ">" or die $!;
         chomp;
 	print $file "delete refs/tags/$_\n" or die $!;
 	$count++ < 100000 or complete_batch;
@@ -41,4 +73,5 @@ perl -we '
 #print STDERR "FOO\n";
     STDIN->error and die $!;
     complete_batch();
+    await_task while @tasks;
 '
-- 
2.30.2