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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 D0DB8C43381 for ; Mon, 1 Apr 2019 16:44:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A8259208E4 for ; Mon, 1 Apr 2019 16:44:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728928AbfDAQoq (ORCPT ); Mon, 1 Apr 2019 12:44:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:60092 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728255AbfDAQnp (ORCPT ); Mon, 1 Apr 2019 12:43:45 -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 1480921905; Mon, 1 Apr 2019 16:43:44 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.92) (envelope-from ) id 1hB02B-0004rI-7Q; Mon, 01 Apr 2019 12:43:43 -0400 Message-Id: <20190401164343.117437443@goodmis.org> User-Agent: quilt/0.65 Date: Mon, 01 Apr 2019 12:43:08 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Arnaldo Carvalho de Melo , Ingo Molnar , Jiri Olsa , Namhyung Kim , Andrew Morton , Tzvetomir Stoyanov Subject: [PATCH 03/15] tools lib traceevent: Implement a new API, tep_list_events_copy() References: <20190401164305.359125441@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Archived-At: List-Archive: List-Post: From: Tzvetomir Stoyanov Existing API tep_list_events() is not thread safe, it uses the internal array sort_events to keep cache of the sorted events and reuses it. This patch implements a new API, tep_list_events_copy(), which allocates new sorted array each time it is called. It could be used when a sorted events functionality is needed in thread safe use cases. It is up to the caller to free the array. Link: http://lore.kernel.org/linux-trace-devel/20181218133013.31094-1-tstoyanov@vmware.com Signed-off-by: Tzvetomir Stoyanov Signed-off-by: Steven Rostedt (VMware) --- tools/lib/traceevent/event-parse.c | 109 +++++++++++++++++++++++------ tools/lib/traceevent/event-parse.h | 5 +- 2 files changed, 91 insertions(+), 23 deletions(-) diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c index 666e23ded6ed..c00aebab3c33 100644 --- a/tools/lib/traceevent/event-parse.c +++ b/tools/lib/traceevent/event-parse.c @@ -5651,32 +5651,26 @@ static int events_system_cmp(const void *a, const void *b) return events_id_cmp(a, b); } -struct tep_event **tep_list_events(struct tep_handle *pevent, enum tep_event_sort_type sort_type) +static struct tep_event **list_events_copy(struct tep_handle *tep) { struct tep_event **events; - int (*sort)(const void *a, const void *b); - - events = pevent->sort_events; - - if (events && pevent->last_type == sort_type) - return events; - if (!events) { - events = malloc(sizeof(*events) * (pevent->nr_events + 1)); - if (!events) - return NULL; + if (!tep) + return NULL; - memcpy(events, pevent->events, sizeof(*events) * pevent->nr_events); - events[pevent->nr_events] = NULL; + events = malloc(sizeof(*events) * (tep->nr_events + 1)); + if (!events) + return NULL; - pevent->sort_events = events; + memcpy(events, tep->events, sizeof(*events) * tep->nr_events); + events[tep->nr_events] = NULL; + return events; +} - /* the internal events are sorted by id */ - if (sort_type == TEP_EVENT_SORT_ID) { - pevent->last_type = sort_type; - return events; - } - } +static void list_events_sort(struct tep_event **events, int nr_events, + enum tep_event_sort_type sort_type) +{ + int (*sort)(const void *a, const void *b); switch (sort_type) { case TEP_EVENT_SORT_ID: @@ -5689,11 +5683,82 @@ struct tep_event **tep_list_events(struct tep_handle *pevent, enum tep_event_sor sort = events_system_cmp; break; default: + sort = NULL; + } + + if (sort) + qsort(events, nr_events, sizeof(*events), sort); +} + +/** + * tep_list_events - Get events, sorted by given criteria. + * @tep: a handle to the tep context + * @sort_type: desired sort order of the events in the array + * + * Returns an array of pointers to all events, sorted by the given + * @sort_type criteria. The last element of the array is NULL. The returned + * memory must not be freed, it is managed by the library. + * The function is not thread safe. + */ +struct tep_event **tep_list_events(struct tep_handle *tep, + enum tep_event_sort_type sort_type) +{ + struct tep_event **events; + + if (!tep) + return NULL; + + events = tep->sort_events; + if (events && tep->last_type == sort_type) return events; + + if (!events) { + events = list_events_copy(tep); + if (!events) + return NULL; + + tep->sort_events = events; + + /* the internal events are sorted by id */ + if (sort_type == TEP_EVENT_SORT_ID) { + tep->last_type = sort_type; + return events; + } } - qsort(events, pevent->nr_events, sizeof(*events), sort); - pevent->last_type = sort_type; + list_events_sort(events, tep->nr_events, sort_type); + tep->last_type = sort_type; + + return events; +} + + +/** + * tep_list_events_copy - Thread safe version of tep_list_events() + * @tep: a handle to the tep context + * @sort_type: desired sort order of the events in the array + * + * Returns an array of pointers to all events, sorted by the given + * @sort_type criteria. The last element of the array is NULL. The returned + * array is newly allocated inside the function and must be freed by the caller + */ +struct tep_event **tep_list_events_copy(struct tep_handle *tep, + enum tep_event_sort_type sort_type) +{ + struct tep_event **events; + + if (!tep) + return NULL; + + events = list_events_copy(tep); + if (!events) + return NULL; + + /* the internal events are sorted by id */ + if (sort_type == TEP_EVENT_SORT_ID) + return events; + + list_events_sort(events, tep->nr_events, sort_type); return events; } diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h index aec48f2aea8a..41159358abc2 100644 --- a/tools/lib/traceevent/event-parse.h +++ b/tools/lib/traceevent/event-parse.h @@ -544,7 +544,10 @@ void tep_event_info(struct trace_seq *s, struct tep_event *event, int tep_strerror(struct tep_handle *pevent, enum tep_errno errnum, char *buf, size_t buflen); -struct tep_event **tep_list_events(struct tep_handle *pevent, enum tep_event_sort_type); +struct tep_event **tep_list_events(struct tep_handle *tep, + enum tep_event_sort_type); +struct tep_event **tep_list_events_copy(struct tep_handle *tep, + enum tep_event_sort_type); struct tep_format_field **tep_event_common_fields(struct tep_event *event); struct tep_format_field **tep_event_fields(struct tep_event *event); -- 2.20.1