From patchwork Fri Nov 23 13:41:40 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tzvetomir Stoyanov X-Patchwork-Id: 10759857 Return-Path: Received: from mail-eopbgr740044.outbound.protection.outlook.com ([40.107.74.44]:1170 "EHLO NAM01-BN3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2410047AbeKXAZ7 (ORCPT ); Fri, 23 Nov 2018 19:25:59 -0500 From: Tzvetomir Stoyanov To: "rostedt@goodmis.org" CC: "linux-trace-devel@vger.kernel.org" Subject: [PATCH] tools/lib/traceevent: make libtraceevent thread safe Date: Fri, 23 Nov 2018 13:41:40 +0000 Message-ID: <20181123134130.16566-1-tstoyanov@vmware.com> Content-Language: en-US MIME-Version: 1.0 Sender: linux-trace-devel-owner@vger.kernel.org List-ID: Content-Length: 4576 This patch is a PoC about transforming libtraceevent into a thread safe library. It implements per thread local storage and internal APIs to access it. It covers only tep->last_event cache, but easily can be extended with all library's thread sensitive data. Signed-off-by: Tzvetomir Stoyanov --- tools/lib/traceevent/event-parse-local.h | 17 ++++++++++--- tools/lib/traceevent/event-parse-thread.c | 29 +++++++++++++++++++++++ tools/lib/traceevent/event-parse.c | 23 ++++++++++-------- 3 files changed, 56 insertions(+), 13 deletions(-) create mode 100644 tools/lib/traceevent/event-parse-thread.c diff --git a/tools/lib/traceevent/event-parse-local.h b/tools/lib/traceevent/event-parse-local.h index 9a092dd4a86d..11f71ef8850b 100644 --- a/tools/lib/traceevent/event-parse-local.h +++ b/tools/lib/traceevent/event-parse-local.h @@ -14,6 +14,17 @@ struct func_list; struct event_handler; struct func_resolver; +/* cache */ +struct tep_thread_data { + struct tep_event *last_event; +}; + +struct tep_thread_data_list { + pid_t tid; + struct tep_thread_data thr_data; + struct tep_thread_data_pool *next; +}; + struct tep_handle { int ref_count; @@ -83,9 +94,6 @@ struct tep_handle { struct event_handler *handlers; struct tep_function_handler *func_handlers; - /* cache */ - struct tep_event *last_event; - char *trace_clock; }; @@ -96,4 +104,7 @@ 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); +struct tep_thread_data *tep_get_thread_local(); +void tep_destroy_thread_local(); + #endif /* _PARSE_EVENTS_INT_H */ diff --git a/tools/lib/traceevent/event-parse-thread.c b/tools/lib/traceevent/event-parse-thread.c new file mode 100644 index 000000000000..775d953041ab --- /dev/null +++ b/tools/lib/traceevent/event-parse-thread.c @@ -0,0 +1,29 @@ +// 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; + + +struct tep_thread_data *tep_get_thread_local(struct tep_handle *tep __maybe_unused) +{ + if (tep_thread_local) + return tep_thread_local; + + tep_thread_local = calloc(1, sizeof(struct tep_thread_data)); + return tep_thread_local; +} + + +void tep_destroy_thread_local() +{ + free(tep_thread_local); + tep_thread_local = NULL; +} + diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c index a5048c1b9bec..25f4ceab9a58 100644 --- a/tools/lib/traceevent/event-parse.c +++ b/tools/lib/traceevent/event-parse.c @@ -3485,10 +3485,11 @@ struct tep_event *tep_find_event(struct tep_handle *pevent, int id) struct tep_event **eventptr; struct tep_event key; struct tep_event *pkey = &key; - + struct tep_thread_data *local = tep_get_thread_local(pevent); /* Check cache first */ - if (pevent->last_event && pevent->last_event->id == id) - return pevent->last_event; + + if (local && local->last_event && local->last_event->id == id) + return local->last_event; key.id = id; @@ -3496,7 +3497,8 @@ struct tep_event *tep_find_event(struct tep_handle *pevent, int id) sizeof(*pevent->events), events_id_cmp); if (eventptr) { - pevent->last_event = *eventptr; + if (local) + local->last_event = *eventptr; return *eventptr; } @@ -3516,13 +3518,14 @@ struct tep_event * tep_find_event_by_name(struct tep_handle *pevent, const char *sys, const char *name) { + struct tep_thread_data *local = tep_get_thread_local(pevent); struct tep_event *event = NULL; int i; - if (pevent->last_event && - strcmp(pevent->last_event->name, name) == 0 && - (!sys || strcmp(pevent->last_event->system, sys) == 0)) - return pevent->last_event; + if (local && local->last_event && + strcmp(local->last_event->name, name) == 0 && + (!sys || strcmp(local->last_event->system, sys) == 0)) + return local->last_event; for (i = 0; i < pevent->nr_events; i++) { event = pevent->events[i]; @@ -3535,8 +3538,8 @@ tep_find_event_by_name(struct tep_handle *pevent, } if (i == pevent->nr_events) event = NULL; - - pevent->last_event = event; + if (local) + local->last_event = event; return event; }