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Date: Sat, 6 Oct 2018 21:29:00 -0400
From: "Emilio G. Cota" <cota@braap.org>
Message-ID: <20181007012900.GB23787@flamenco>
References: <20181005154910.3099-1-alex.bennee@linaro.org>
	<20181005154910.3099-15-alex.bennee@linaro.org>
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In-Reply-To: <20181005154910.3099-15-alex.bennee@linaro.org>
Subject: Re: [Qemu-devel] [RFC PATCH 14/21] trace: add support for plugin
 infrastructure
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To: Alex =?iso-8859-1?Q?Benn=E9e?= <alex.bennee@linaro.org>
Cc: qemu-devel@nongnu.org, Pavel.Dovgaluk@ispras.ru, vilanova@ac.upc.edu, Stefan Hajnoczi <stefanha@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>

On Fri, Oct 05, 2018 at 16:49:03 +0100, Alex Bennée wrote:
(snip)
> +static int bind_to_tracepoints(GModule *g_module, GPtrArray *events)
> +{
> +    int count = 0;
> +    TraceEventIter iter;
> +    TraceEvent *ev;
> +
> +    trace_event_iter_init(&iter, "*");
> +    while ((ev = trace_event_iter_next(&iter)) != NULL) {
> +        const char *name = trace_event_get_name(ev);
> +        gpointer fn;
> +
> +        if (g_module_symbol(g_module, name, &fn)) {
> +            ev->plugin = (uintptr_t) fn;
> +            trace_event_set_state_dynamic(ev, true);
> +            count++;
> +        }
> +    }

I'd rather have subscription functions exposed to the
plugins via an API, so that
- Plugins can turn on and off subscriptions to callbacks
  as they see fit, instead of "being called from
  the very beginning, and then disable forever"
- We can have compile-time failures when doing something
  wrong with callback names :-)

Thanks,

		E.