[lttng-dev] [PATCH lttng-ust] Add trace instrumentation for some pthread functions.
Mathieu Desnoyers
mathieu.desnoyers at efficios.com
Wed Aug 7 10:33:47 EDT 2013
* Stefan Seefeld (stefan_seefeld at mentor.com) wrote:
> On 08/07/2013 09:14 AM, Stefan Seefeld wrote:
> > Mathieu,
> >
> > please find attached a revised patch.
> >
> > On 08/06/2013 09:32 PM, Mathieu Desnoyers wrote:
> >> +#include <lttng/tracepoint.h>
> >> +
> >> +TRACEPOINT_EVENT(ust_pthread, pthread_mutex_lock_req,
> >> + TP_ARGS(pthread_mutex_t *, mutex),
> >> + TP_FIELDS(
> >> + ctf_integer_hex(unsigned long, mutex, (unsigned long) mutex)
> >> I'm curious (and I honestly don't remember): does it work if we put
> >> "void *" as type rather than "unsigned long" here ?
> > It seems to work fine - I applied the suggested change (see the current
> > patch) and I see the same traces.
>
> Sorry, the patch was incomplete. Here is the complete one (including the
> revised ust_pthread.h code.
We're getting close with this patch, still a few questions below.
>
> Stefan
>
> --
> Stefan Seefeld
> CodeSourcery / Mentor Graphics
> http://www.mentor.com/embedded-software/
>
> From 204a0821918ee826a19ad3e01d1ada69d9ece395 Mon Sep 17 00:00:00 2001
> From: Stefan Seefeld <stefan_seefeld at mentor.com>
> Date: Wed, 31 Jul 2013 16:35:31 -0400
> Subject: [PATCH] Add tracing instrumentation for pthread mutex lock functions.
>
> Signed-off-by: Stefan Seefeld <stefan_seefeld at mentor.com>
> ---
> liblttng-ust-libc-wrapper/Makefile.am | 12 +++-
> liblttng-ust-libc-wrapper/lttng-ust-pthread.c | 97 +++++++++++++++++++++++++++
> liblttng-ust-libc-wrapper/ust_pthread.h | 76 +++++++++++++++++++++
> 3 files changed, 184 insertions(+), 1 deletion(-)
> create mode 100644 liblttng-ust-libc-wrapper/lttng-ust-pthread.c
> create mode 100644 liblttng-ust-libc-wrapper/ust_pthread.h
>
> diff --git a/liblttng-ust-libc-wrapper/Makefile.am b/liblttng-ust-libc-wrapper/Makefile.am
> index 4fdcedb..d402d53 100644
> --- a/liblttng-ust-libc-wrapper/Makefile.am
> +++ b/liblttng-ust-libc-wrapper/Makefile.am
> @@ -1,7 +1,8 @@
> AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_builddir)/include
> AM_CFLAGS = -fno-strict-aliasing
>
> -lib_LTLIBRARIES = liblttng-ust-libc-wrapper.la
> +lib_LTLIBRARIES = liblttng-ust-libc-wrapper.la \
> + liblttng-ust-pthread-wrapper.la
> liblttng_ust_libc_wrapper_la_SOURCES = \
> lttng-ust-malloc.c \
> ust_libc.h
> @@ -9,11 +10,20 @@ liblttng_ust_libc_wrapper_la_LIBADD = \
> -L$(top_builddir)/liblttng-ust/.libs \
> -llttng-ust
>
> +liblttng_ust_pthread_wrapper_la_SOURCES = \
> + lttng-ust-pthread.c \
> + ust_pthread.h
> +liblttng_ust_pthread_wrapper_la_LIBADD = \
> + -L$(top_builddir)/liblttng-ust/.libs \
> + -llttng-ust
> +
> if LTTNG_UST_BUILD_WITH_LIBDL
> liblttng_ust_libc_wrapper_la_LIBADD += -ldl
> +liblttng_ust_pthread_wrapper_la_LIBADD += -ldl
> endif
> if LTTNG_UST_BUILD_WITH_LIBC_DL
> liblttng_ust_libc_wrapper_la_LIBADD += -lc
> +liblttng_ust_pthread_wrapper_la_LIBADD += -lc
> endif
>
> noinst_SCRIPTS = run
> diff --git a/liblttng-ust-libc-wrapper/lttng-ust-pthread.c b/liblttng-ust-libc-wrapper/lttng-ust-pthread.c
> new file mode 100644
> index 0000000..53230e1
> --- /dev/null
> +++ b/liblttng-ust-libc-wrapper/lttng-ust-pthread.c
> @@ -0,0 +1,97 @@
> +/*
> + * Copyright (C) 2013 Mentor Graphics
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +#define _GNU_SOURCE
> +#include <dlfcn.h>
> +#include <pthread.h>
> +
> +#define TRACEPOINT_DEFINE
> +#define TRACEPOINT_CREATE_PROBES
> +#include "ust_pthread.h"
> +
> +static __thread int thread_in_trace;
> +
> +int pthread_mutex_lock(pthread_mutex_t *mutex)
> +{
> + static int (*mutex_lock)(pthread_mutex_t *);
> + int retval;
> +
> + if (!mutex_lock) {
> + mutex_lock = dlsym(RTLD_NEXT, "pthread_mutex_lock");
> + if (!mutex_lock && !thread_in_trace) {
I'd rather see:
if (!mutex_lock) {
if (thread_in_trace) {
abort();
}
fprintf(stderr, "unable to initialize pthread wrapper library.\n");
return EINVAL;
}
because in that situation, there is not much we can do anyway.
> + fprintf(stderr, "unable to initialize pthread wrapper library.\n");
> + return EINVAL;
> + }
> + }
> + if (thread_in_trace) {
> + return mutex_lock(mutex);
> + }
> +
> + thread_in_trace = 1;
> + tracepoint(ust_pthread, pthread_mutex_lock_req, mutex);
> + retval = mutex_lock(mutex);
> + tracepoint(ust_pthread, pthread_mutex_lock_acq, mutex, retval);
> + thread_in_trace = 0;
> + return retval;
> +}
> +
> +int pthread_mutex_trylock(pthread_mutex_t *mutex)
> +{
> + static int (*mutex_trylock)(pthread_mutex_t *);
> + int retval;
> +
> + if (!mutex_trylock) {
> + mutex_trylock = dlsym(RTLD_NEXT, "pthread_mutex_trylock");
> + if (!mutex_trylock && !thread_in_trace) {
> + fprintf(stderr, "unable to initialize pthread wrapper library.\n");
> + return EINVAL;
> + }
> + }
> + if (thread_in_trace) {
> + return mutex_trylock(mutex);
> + }
> +
> + thread_in_trace = 1;
> + retval = mutex_trylock(mutex);
> + tracepoint(ust_pthread, pthread_mutex_trylock, mutex, retval);
> + thread_in_trace = 0;
> + return retval;
> +}
> +
> +int pthread_mutex_unlock(pthread_mutex_t *mutex)
> +{
> + static int (*mutex_unlock)(pthread_mutex_t *);
> + int retval;
> +
> + if (!mutex_unlock) {
> + mutex_unlock = dlsym(RTLD_NEXT, "pthread_mutex_unlock");
> + if (!mutex_unlock && !thread_in_trace) {
> + fprintf(stderr, "unable to initialize pthread wrapper library.\n");
> + return EINVAL;
> + }
> + }
> + if (thread_in_trace) {
> + return mutex_unlock(mutex);
> + }
> +
> + thread_in_trace = 1;
> + retval = mutex_unlock(mutex);
> + tracepoint(ust_pthread, pthread_mutex_unlock, mutex, retval);
> + thread_in_trace = 0;
> + return retval;
> +}
> diff --git a/liblttng-ust-libc-wrapper/ust_pthread.h b/liblttng-ust-libc-wrapper/ust_pthread.h
> new file mode 100644
> index 0000000..a1be974
> --- /dev/null
> +++ b/liblttng-ust-libc-wrapper/ust_pthread.h
> @@ -0,0 +1,76 @@
> +#undef TRACEPOINT_PROVIDER
> +#define TRACEPOINT_PROVIDER ust_pthread
> +
> +#if !defined(_TRACEPOINT_UST_PTHREAD_H) || defined(TRACEPOINT_HEADER_MULTI_READ)
> +#define _TRACEPOINT_UST_PTHREAD_H
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +/*
> + * Copyright (C) 2013 Mentor Graphics
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
> + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
> + * SOFTWARE.
> + */
> +
> +#include <lttng/tracepoint.h>
> +
> +TRACEPOINT_EVENT(ust_pthread, pthread_mutex_lock_req,
> + TP_ARGS(pthread_mutex_t *, mutex),
> + TP_FIELDS(
> + ctf_integer_hex(void *, mutex, (void *) mutex)
I think the (void *) cast can be removed here: an implicit cast from
pthread_mutex_t * to void * should be fine.
Thanks,
Mathieu
> + )
> +)
> +
> +TRACEPOINT_EVENT(ust_pthread, pthread_mutex_lock_acq,
> + TP_ARGS(pthread_mutex_t *, mutex, int, status),
> + TP_FIELDS(
> + ctf_integer_hex(void *, mutex, (void *) mutex)
> + ctf_integer(int, status, status)
> + )
> +)
> +
> +TRACEPOINT_EVENT(ust_pthread, pthread_mutex_trylock,
> + TP_ARGS(pthread_mutex_t *, mutex, int, status),
> + TP_FIELDS(
> + ctf_integer_hex(void *, mutex, (void *) mutex)
> + ctf_integer(int, status, status)
> + )
> +)
> +
> +TRACEPOINT_EVENT(ust_pthread, pthread_mutex_unlock,
> + TP_ARGS(pthread_mutex_t *, mutex, int, status),
> + TP_FIELDS(
> + ctf_integer_hex(void *, mutex, (void *) mutex)
> + ctf_integer(int, status, status)
> + )
> +)
> +
> +#endif /* _TRACEPOINT_UST_PTHREAD_H */
> +
> +#undef TRACEPOINT_INCLUDE
> +#define TRACEPOINT_INCLUDE "./ust_pthread.h"
> +
> +/* This part must be outside ifdef protection */
> +#include <lttng/tracepoint-event.h>
> +
> +#ifdef __cplusplus
> +}
> +#endif
> --
> 1.8.3.1
>
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--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
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