From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Monjalon <thomas.monjalon@6wind.com>
Subject: Re: [PATCH v4] log: respect rte_openlog_stream calls
	before rte_eal_init
Date: Wed, 12 Oct 2016 21:47:32 +0200
Message-ID: <2906824.LEp5vtMuTD@xps13>
References: <20160928204244.8288-1-ouster@cs.stanford.edu>
 <20161012193832.5016-1-ouster@cs.stanford.edu>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7Bit
Cc: dev@dpdk.org
To: John Ousterhout <ouster@cs.stanford.edu>
Return-path: <dev-bounces@dpdk.org>
Received: from mail-lf0-f54.google.com (mail-lf0-f54.google.com
 [209.85.215.54]) by dpdk.org (Postfix) with ESMTP id 14FC437B4
 for <dev@dpdk.org>; Wed, 12 Oct 2016 21:47:34 +0200 (CEST)
Received: by mail-lf0-f54.google.com with SMTP id x79so94680453lff.0
 for <dev@dpdk.org>; Wed, 12 Oct 2016 12:47:34 -0700 (PDT)
In-Reply-To: <20161012193832.5016-1-ouster@cs.stanford.edu>
List-Id: patches and discussions about DPDK <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

2016-10-12 12:38, John Ousterhout:
> @@ -127,6 +125,19 @@ rte_vlog(uint32_t level, uint32_t logtype, const char *format, va_list ap)
>  {
>  	int ret;
>  	FILE *f = rte_logs.file;
> +	if (f == NULL) {
> +		f = default_log_stream;
> +		if (f == NULL) {
> +			/*
> +			 * Grab the current value of stderr here, rather than
> +			 * just initializing default_log_stream to stderr. This
> +			 * ensures that we will always use the current value
> +			 * of stderr, even if the application closes and
> +			 * reopens it.
> +			 */
> +			f = stderr;
> +		}
> +	}

I don't understand this big comment.
What is the difference with initializing default_log_stream to stderr?
What do you mean by "if the application closes and reopens it"?