implement --max-keepalive-requests (issue miyagawa#124)

lib/Starman/Server.pm

@@ -210,6 +210,8 @@ sub process_request {
             or die $!;
     }
 
+    my $keepalive_requests = 0;
+
     while ( $self->{client}->{keepalive} ) {
         last if !$conn->connected;
 
@@ -322,6 +324,10 @@ sub process_request {
                 }
             }
 
+	    if (exists $self->{options}->{max_keepalive_requests}) {
+		last if ++$keepalive_requests >= $self->{options}->{max_keepalive_requests};
+	    }
+
             DEBUG && warn "[$$] Waiting on previous connection for keep-alive request...\n";
 
             my $sel = IO::Select->new($conn);

script/starman

@@ -122,6 +122,16 @@ failover (see above).
 
 Number of the requests to process per one worker process. Defaults to 1000.
 
+Note that "requests" actually means "connections served by a worker".
+In presence of Keep-alive a worker process can actually serve more
+requests; this can only be limited with the
+C<--max-keepalive-requests> option.
+
+=item --max-keepalive-requests
+
+Maximum number of Keep-alive requests served for a connection. By
+default there's no limit.
+
 =item --preload-app
 
 This option lets Starman preload the specified PSGI application in the