From patchwork Wed Dec 5 09:22:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tzvetomir Stoyanov X-Patchwork-Id: 10760133 Return-Path: Received: from mail-eopbgr710060.outbound.protection.outlook.com ([40.107.71.60]:45856 "EHLO NAM05-BY2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726918AbeLEJWP (ORCPT ); Wed, 5 Dec 2018 04:22:15 -0500 From: Tzvetomir Stoyanov To: "rostedt@goodmis.org" CC: "linux-trace-devel@vger.kernel.org" Subject: [PATCH 1/2] tools/lib/traceevent: make libtraceevent thread safe Date: Wed, 5 Dec 2018 09:22:12 +0000 Message-ID: <20181205092200.2291-2-tstoyanov@vmware.com> References: <20181205092200.2291-1-tstoyanov@vmware.com> In-Reply-To: <20181205092200.2291-1-tstoyanov@vmware.com> Content-Language: en-US MIME-Version: 1.0 Sender: linux-trace-devel-owner@vger.kernel.org List-ID: Content-Length: 7161 This patch begins tranformation of libtraceevent into a thread safe library. It implements per thread local storage of tep hadler thread sensitive data and internal APIs to access it. It covers tep->last_event cache, more library's thread sensitive data will be added with additional patches. Signed-off-by: Tzvetomir Stoyanov --- lib/traceevent/Makefile | 1 + lib/traceevent/event-parse-local.h | 15 +++++-- lib/traceevent/event-parse-thread.c | 63 +++++++++++++++++++++++++++++ lib/traceevent/event-parse.c | 39 +++++++++--------- 4 files changed, 97 insertions(+), 21 deletions(-) create mode 100644 lib/traceevent/event-parse-thread.c diff --git a/lib/traceevent/Makefile b/lib/traceevent/Makefile index bfbb6a3..8e34a97 100644 --- a/lib/traceevent/Makefile +++ b/lib/traceevent/Makefile @@ -14,6 +14,7 @@ OBJS += trace-seq.o OBJS += parse-filter.o OBJS += parse-utils.o OBJS += event-parse-api.o +OBJS += event-parse-thread.o # Additional util objects OBJS += str_error_r.o diff --git a/lib/traceevent/event-parse-local.h b/lib/traceevent/event-parse-local.h index 70693b8..2c75f9e 100644 --- a/lib/traceevent/event-parse-local.h +++ b/lib/traceevent/event-parse-local.h @@ -14,6 +14,12 @@ struct func_list; struct event_handler; struct func_resolver; +/* cache */ +struct tep_thread_data { + struct tep_handle *tep; + struct tep_event *last_event; +}; + struct tep_handle { int ref_count; @@ -85,9 +91,6 @@ struct tep_handle { int parsing_failures; - /* cache */ - struct tep_event *last_event; - char *trace_clock; }; @@ -98,4 +101,10 @@ unsigned short tep_data2host2(struct tep_handle *pevent, unsigned short data); unsigned int tep_data2host4(struct tep_handle *pevent, unsigned int data); unsigned long long tep_data2host8(struct tep_handle *pevent, unsigned long long data); +/* tep cache per thread */ +struct tep_event *get_thread_local_event_by_id(struct tep_handle *tep, int id); +struct tep_event * +get_thread_local_event_by_name(struct tep_handle *tep, const char *name, const char *sys); +void set_thread_local_event_cache(struct tep_handle *tep, struct tep_event *event); + #endif /* _PARSE_EVENTS_INT_H */ diff --git a/lib/traceevent/event-parse-thread.c b/lib/traceevent/event-parse-thread.c new file mode 100644 index 0000000..f846350 --- /dev/null +++ b/lib/traceevent/event-parse-thread.c @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * Copyright (C) 2009, 2010 Red Hat Inc, Steven Rostedt + * + */ + +#include "event-parse.h" +#include "event-parse-local.h" +#include "event-utils.h" + +static __thread struct tep_thread_data tep_thread_local; + +/** + * get_thread_local_event_by_id - Find event with given id in the cache + * @tep: a handle to the tep context + * @id: event's id + * + * Searches in the cache for event with given id + */ +struct tep_event *get_thread_local_event_by_id(struct tep_handle *tep, int id) +{ + + if (tep_thread_local.last_event && tep_thread_local.tep == tep && + tep_thread_local.last_event->id == id) + return tep_thread_local.last_event; + + return NULL; +} + +/** + * get_thread_local_event_by_name - Find event with given name and sys in the cache + * @tep: a handle to the tep context + * @name: event's name + * @sys: event's system + * + * Searches in the cache for event with given name and system + */ +struct tep_event * +get_thread_local_event_by_name(struct tep_handle *tep, const char *name, const char *sys) +{ + if (tep_thread_local.last_event && + tep_thread_local.tep == tep && + strcmp(tep_thread_local.last_event->name, name) == 0 && + (!sys || strcmp(tep_thread_local.last_event->system, sys) == 0)) + return tep_thread_local.last_event; + + return NULL; +} + +/** + * set_thread_local_event_cache - set last used event in the cache + * @tep: a handle to the tep context + * @event: pointer to the last used event + * + * Sets last used event in the cache, to speed up the next searches + */ +void set_thread_local_event_cache(struct tep_handle *tep, struct tep_event *event) +{ + tep_thread_local.tep = tep; + tep_thread_local.last_event = event; +} + + diff --git a/lib/traceevent/event-parse.c b/lib/traceevent/event-parse.c index bc35dc8..cacdcc4 100644 --- a/lib/traceevent/event-parse.c +++ b/lib/traceevent/event-parse.c @@ -3461,28 +3461,29 @@ static int events_id_cmp(const void *a, const void *b); /** * tep_find_event - find an event by given id - * @pevent: a handle to the pevent + * @tep: a handle to the tep context * @id: the id of the event * * Returns an event that has a given @id. */ -struct tep_event *tep_find_event(struct tep_handle *pevent, int id) +struct tep_event *tep_find_event(struct tep_handle *tep, int id) { struct tep_event **eventptr; struct tep_event key; struct tep_event *pkey = &key; + struct tep_event *event_cache = get_thread_local_event_by_id(tep, id); /* Check cache first */ - if (pevent->last_event && pevent->last_event->id == id) - return pevent->last_event; + if (event_cache) + return event_cache; key.id = id; - eventptr = bsearch(&pkey, pevent->events, pevent->nr_events, - sizeof(*pevent->events), events_id_cmp); + eventptr = bsearch(&pkey, tep->events, tep->nr_events, + sizeof(*tep->events), events_id_cmp); if (eventptr) { - pevent->last_event = *eventptr; + set_thread_local_event_cache(tep, *eventptr); return *eventptr; } @@ -3491,7 +3492,7 @@ struct tep_event *tep_find_event(struct tep_handle *pevent, int id) /** * tep_find_event_by_name - find an event by given name - * @pevent: a handle to the pevent + * @tep: a handle to the tep context * @sys: the system name to search for * @name: the name of the event to search for * @@ -3499,19 +3500,19 @@ struct tep_event *tep_find_event(struct tep_handle *pevent, int id) * @sys. If @sys is NULL the first event with @name is returned. */ struct tep_event * -tep_find_event_by_name(struct tep_handle *pevent, +tep_find_event_by_name(struct tep_handle *tep, const char *sys, const char *name) { - struct tep_event *event; int i; + struct tep_event *event = NULL; + struct tep_event *event_cache = get_thread_local_event_by_name(tep, name, sys); - if (pevent->last_event && - strcmp(pevent->last_event->name, name) == 0 && - (!sys || strcmp(pevent->last_event->system, sys) == 0)) - return pevent->last_event; + /* Check cache first */ + if (event_cache) + return event_cache; - for (i = 0; i < pevent->nr_events; i++) { - event = pevent->events[i]; + for (i = 0; i < tep->nr_events; i++) { + event = tep->events[i]; if (strcmp(event->name, name) == 0) { if (!sys) break; @@ -3519,10 +3520,12 @@ tep_find_event_by_name(struct tep_handle *pevent, break; } } - if (i == pevent->nr_events) + + if (i == tep->nr_events) event = NULL; + if (event) + set_thread_local_event_cache(tep, event); - pevent->last_event = event; return event; }