From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A56E0C43458 for ; Wed, 22 Jul 2020 01:18:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C97022D6E for ; Wed, 22 Jul 2020 01:18:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731774AbgGVBS3 (ORCPT ); Tue, 21 Jul 2020 21:18:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:36994 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731654AbgGVBR4 (ORCPT ); Tue, 21 Jul 2020 21:17:56 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D409522CF6; Wed, 22 Jul 2020 01:17:55 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.93) (envelope-from ) id 1jy3OM-005sFa-R8; Tue, 21 Jul 2020 21:17:54 -0400 Message-ID: <20200722011754.720060785@goodmis.org> User-Agent: quilt/0.66 Date: Tue, 21 Jul 2020 21:16:44 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-trace-devel@vger.kernel.org Cc: Arnaldo Carvalho de Melo , Ingo Molnar , Jiri Olsa , Namhyung Kim , Andrew Morton , "Tzvetomir Stoyanov (VMware)" Subject: [PATCH 16/23 v3] tools lib traceevent: Document tep_load_plugins_hook() References: <20200722011628.925541477@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org From: "Tzvetomir Stoyanov (VMware)" Add description of tep_load_plugins_hook() traceevent API. Updated library man pages with description of the tep_load_plugins_hook() API. Link: https://lore.kernel.org/r/CAM9d7cgLBWCrEHwz+Lhv5x5EXGcNWB0QQoeGh3OKh2JfR=dV9Q@mail.gmail.com Link: https://lore.kernel.org/linux-trace-devel/20200714103027.2477584-2-tz.stoyanov@gmail.com Link: https://lore.kernel.org/linux-trace-devel/20200716092014.2613403-2-tz.stoyanov@gmail.com Suggested-by: Namhyung Kim Acked-by: Namhyung Kim Signed-off-by: Tzvetomir Stoyanov (VMware) Signed-off-by: Steven Rostedt (VMware) --- .../Documentation/libtraceevent-plugins.txt | 25 ++++++++++++++++++- tools/lib/traceevent/event-plugin.c | 16 ++++++++++++ 2 files changed, 40 insertions(+), 1 deletion(-) diff --git a/tools/lib/traceevent/Documentation/libtraceevent-plugins.txt b/tools/lib/traceevent/Documentation/libtraceevent-plugins.txt index 596032ade31f..4d6394397d92 100644 --- a/tools/lib/traceevent/Documentation/libtraceevent-plugins.txt +++ b/tools/lib/traceevent/Documentation/libtraceevent-plugins.txt @@ -3,7 +3,7 @@ libtraceevent(3) NAME ---- -tep_load_plugins, tep_unload_plugins - Load / unload traceevent plugins. +tep_load_plugins, tep_unload_plugins, tep_load_plugins_hook - Load / unload traceevent plugins. SYNOPSIS -------- @@ -13,6 +13,12 @@ SYNOPSIS struct tep_plugin_list pass:[*]*tep_load_plugins*(struct tep_handle pass:[*]_tep_); void *tep_unload_plugins*(struct tep_plugin_list pass:[*]_plugin_list_, struct tep_handle pass:[*]_tep_); +void *tep_load_plugins_hook*(struct tep_handle pass:[*]_tep_, const char pass:[*]_suffix_, + void (pass:[*]_load_plugin_)(struct tep_handle pass:[*]tep, + const char pass:[*]path, + const char pass:[*]name, + void pass:[*]data), + void pass:[*]_data_); -- DESCRIPTION @@ -22,11 +28,13 @@ directories. The _tep_ argument is trace event parser context. The plugin directories are : [verse] -- + - Directories, specified in _tep_->plugins_dir with priority TEP_PLUGIN_FIRST - System's plugin directory, defined at the library compile time. It depends on the library installation prefix and usually is _(install_preffix)/lib/traceevent/plugins_ - Directory, defined by the environment variable _TRACEEVENT_PLUGIN_DIR_ - User's plugin directory, located at _~/.local/lib/traceevent/plugins_ + - Directories, specified in _tep_->plugins_dir with priority TEP_PLUGIN_LAST -- Loading of plugins can be controlled by the _tep_flags_, using the _tep_set_flag()_ API: @@ -44,6 +52,12 @@ _tep_load_plugins()_. The _tep_ argument is trace event parser context. The _plugin_list_ is the list of loaded plugins, returned by the _tep_load_plugins()_ function. +The _tep_load_plugins_hook_ function walks through all directories with plugins +and calls user specified _load_plugin()_ hook for each plugin file. Only files +with given _suffix_ are considered to be plugins. The _data_ is a user specified +context, passed to _load_plugin()_. Directories and the walk order are the same +as in _tep_load_plugins()_ API. + RETURN VALUE ------------ The _tep_load_plugins()_ function returns a list of successfully loaded plugins, @@ -63,6 +77,15 @@ if (plugins == NULL) { } ... tep_unload_plugins(plugins, tep); +... +void print_plugin(struct tep_handle *tep, const char *path, + const char *name, void *data) +{ + pritnf("Found libtraceevent plugin %s/%s\n", path, name); +} +... +tep_load_plugins_hook(tep, ".so", print_plugin, NULL); +... -- FILES diff --git a/tools/lib/traceevent/event-plugin.c b/tools/lib/traceevent/event-plugin.c index 1d4f1809cf17..aa6f43290cd3 100644 --- a/tools/lib/traceevent/event-plugin.c +++ b/tools/lib/traceevent/event-plugin.c @@ -543,6 +543,22 @@ load_plugins_dir(struct tep_handle *tep, const char *suffix, closedir(dir); } +/** + * tep_load_plugins_hook - call a user specified callback to load a plugin + * @tep: handler to traceevent context + * @suffix: filter only plugin files with given suffix + * @load_plugin: user specified callback, called for each plugin file + * @data: custom context, passed to @load_plugin + * + * Searches for traceevent plugin files and calls @load_plugin for each + * The order of plugins search is: + * - Directories, specified in @tep->plugins_dir and priority TEP_PLUGIN_FIRST + * - Directory, specified at compile time with PLUGIN_TRACEEVENT_DIR + * - Directory, specified by environment variable TRACEEVENT_PLUGIN_DIR + * - In user's home: ~/.local/lib/traceevent/plugins/ + * - Directories, specified in @tep->plugins_dir and priority TEP_PLUGIN_LAST + * + */ void tep_load_plugins_hook(struct tep_handle *tep, const char *suffix, void (*load_plugin)(struct tep_handle *tep, const char *path, -- 2.26.2