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From: Namhyung Kim <namhyung@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Paul Mackerras <paulus@samba.org>, Ingo Molnar <mingo@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Namhyung Kim <namhyung.kim@lge.com>
Subject: Re: [PATCH 3/3] tools lib traceevent: Introduce pevent_strerror
References: <1339486959-25241-1-git-send-email-namhyung@kernel.org>
	<1339486959-25241-4-git-send-email-namhyung@kernel.org>
	<1339524114.13377.140.camel@gandalf.stny.rr.com>
Date: Wed, 13 Jun 2012 12:02:51 +0900
In-Reply-To: <1339524114.13377.140.camel@gandalf.stny.rr.com> (Steven
	Rostedt's message of "Tue, 12 Jun 2012 14:01:54 -0400")
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Hi,

On Tue, 12 Jun 2012 14:01:54 -0400, Steven Rostedt wrote:
> On Tue, 2012-06-12 at 16:42 +0900, Namhyung Kim wrote:
>> +int pevent_strerror(struct pevent *pevent, enum pevent_errno errnum,
>> +		    char *buf, size_t buflen)
>
> Hmm, actually I wonder if we should put the error into the pevent
> structure. Then we wouldn't even need to waste time to pass the data
> through.
>
> That is, you can simply do:
>
> 	ret = pevent_foo();
> 	if (ret < 0) {
> 		pevent_strerr(pevent, buf, buflen);
> 		printf("%s\n", buf);
> 	}
>
> Perhaps even include a pevent_perror(), to just do:
>
> 	if (ret < 0) {
> 		pevent_perror(pevent);
> 		return ret;
> 	}
>

I thought something like this, but worried about the thread-safety. What
about if more than one thread call pevent functions for a same pevent
concurrently?  Should we make the pevent->errno TLS?

Thanks,
Namhyung