* Re: Tracepoints for pthreads conditional variables
[not found] <CAC-H6tv29C9RdoquefmAs6s-kM6o-RyYFMAYF1a1Vqk0PYX9dQ@mail.gmail.com>
@ 2018-05-01 14:39 ` Jonathan Rajotte-Julien
[not found] ` <20180501143953.GA26829@joraj-alpa>
1 sibling, 0 replies; 6+ messages in thread
From: Jonathan Rajotte-Julien @ 2018-05-01 14:39 UTC (permalink / raw)
To: Shehab Elsayed; +Cc: lttng-dev
Hi Shehab,
Please provide a link to a lttng-ust git tree or an actual patch (git format-patch).
This will help any person who might be interested in helping you including
myself.
Cheers
On Tue, May 01, 2018 at 09:31:52AM -0400, Shehab Elsayed wrote:
> Hi,
>
> I am trying to create wrappers for pthreads conditional variables functions
> (wait, signal and broadcast) to insert tracepoints. I followed the same
> approach done for the mutex functions already provided with lttng, however
> I am running into some problems. Mainly the applications seem to get stuck
> when the conditional variable wrappers are enabled.
>
> Here is my implementation for the wrapper functions:
> int pthread_cond_wait(pthread_cond_t *condition, pthread_mutex_t
> *mutex)
>
> {
>
> static int (*cond_wait)(pthread_cond_t *, pthread_mutex_t
> *);
> int retval;
>
>
>
> if (!cond_wait)
> {
>
> cond_wait = dlsym(RTLD_NEXT, "pthread_cond_wait");
>
> if (!cond_wait)
> {
>
> if (thread_in_trace)
> {
>
>
> abort();
>
>
> }
>
> fprintf(stderr, "unable to initialize pthread wrapper
> library.\n");
> return EINVAL;
>
>
> }
>
>
> }
>
> if (thread_in_trace)
> {
>
> return cond_wait(condition, mutex);
>
>
> }
>
>
>
> thread_in_trace =
> 1;
>
> tracepoint(lttng_ust_pthread, pthread_cond_wait_begin, condition,
> mutex,
>
> LTTNG_UST_CALLER_IP());
>
> retval = cond_wait(condition, mutex);
>
> tracepoint(lttng_ust_pthread, pthread_cond_wait_end, condition,
> mutex,
>
> LTTNG_UST_CALLER_IP());
>
> thread_in_trace =
> 0;
>
> return retval;
>
> }
>
>
>
> int pthread_cond_signal(pthread_cond_t
> *condition)
>
> {
>
> static int (*cond_signal)(pthread_cond_t
> *);
>
> int retval;
>
>
>
> if (!cond_signal)
> {
>
> cond_signal = dlsym(RTLD_NEXT, "pthread_cond_signal");
>
> if (!cond_signal)
> {
>
> if (thread_in_trace)
> {
>
>
> abort();
>
>
> }
>
> fprintf(stderr, "unable to initialize pthread wrapper
> library.\n");
> return EINVAL;
>
>
> }
>
>
> }
>
> if (thread_in_trace)
> {
>
> return cond_signal(condition);
>
>
> }
>
>
>
> thread_in_trace =
> 1;
>
> tracepoint(lttng_ust_pthread, pthread_cond_signal_begin,
> condition,
> LTTNG_UST_CALLER_IP());
>
> retval = cond_signal(condition);
>
> tracepoint(lttng_ust_pthread, pthread_cond_signal_end,
> condition,
> LTTNG_UST_CALLER_IP());
>
> thread_in_trace =
> 0;
>
> return retval;
>
> }
>
>
>
> int pthread_cond_broadcast(pthread_cond_t
> *condition)
>
> {
>
> static int (*cond_broadcast)(pthread_cond_t
> *);
> int retval;
>
>
>
> if (!cond_broadcast)
> {
>
> cond_broadcast = dlsym(RTLD_NEXT, "pthread_cond_broadcast");
>
> if (!cond_broadcast)
> {
>
> if (thread_in_trace)
> {
>
>
> abort();
>
>
> }
>
> fprintf(stderr, "unable to initialize pthread wrapper
> library.\n");
> return EINVAL;
>
>
> }
>
>
> }
>
> if (thread_in_trace)
> {
>
> return cond_broadcast(condition);
>
>
> }
>
>
>
> thread_in_trace =
> 1;
>
> tracepoint(lttng_ust_pthread, pthread_cond_broadcast_begin,
> condition,
> LTTNG_UST_CALLER_IP());
>
> retval = cond_broadcast(condition);
>
> tracepoint(lttng_ust_pthread, pthread_cond_broadcast_end,
> condition,
> LTTNG_UST_CALLER_IP());
>
> thread_in_trace =
> 0;
>
> return retval;
>
> }
>
> Things I have tried:
> 1- Comment out pthread_cond_wait function --> segmentation fault
> 2- Comment out pthread_cond_signal and _broadcast --> stuck (I can see the
> program is still running but nor forward progress is being made) compared
> to the case when the wrappers are not preloaded.
> 3- Comment out all tracepoint related code (basically the wrapper just call
> the corresponding pthreads function) --> same results as points 1 and 2.
>
> Any idea what might be causing this or how I could debug this problem?
>
> Thank you very much in advance.
>
> Best Regards,
> Shehab
> int pthread_cond_wait(pthread_cond_t *condition, pthread_mutex_t *mutex)
> {
> static int (*cond_wait)(pthread_cond_t *, pthread_mutex_t *);
> int retval;
>
> if (!cond_wait) {
> cond_wait = dlsym(RTLD_NEXT, "pthread_cond_wait");
> if (!cond_wait) {
> if (thread_in_trace) {
> abort();
> }
> fprintf(stderr, "unable to initialize pthread wrapper library.\n");
> return EINVAL;
> }
> }
> if (thread_in_trace) {
> return cond_wait(condition, mutex);
> }
>
> thread_in_trace = 1;
> tracepoint(lttng_ust_pthread, pthread_cond_wait_begin, condition, mutex,
> LTTNG_UST_CALLER_IP());
> retval = cond_wait(condition, mutex);
> tracepoint(lttng_ust_pthread, pthread_cond_wait_end, condition, mutex,
> LTTNG_UST_CALLER_IP());
> thread_in_trace = 0;
> return retval;
> }
>
> int pthread_cond_signal(pthread_cond_t *condition)
> {
> static int (*cond_signal)(pthread_cond_t *);
> int retval;
>
> if (!cond_signal) {
> cond_signal = dlsym(RTLD_NEXT, "pthread_cond_signal");
> if (!cond_signal) {
> if (thread_in_trace) {
> abort();
> }
> fprintf(stderr, "unable to initialize pthread wrapper library.\n");
> return EINVAL;
> }
> }
> if (thread_in_trace) {
> return cond_signal(condition);
> }
>
> thread_in_trace = 1;
> tracepoint(lttng_ust_pthread, pthread_cond_signal_begin, condition,
> LTTNG_UST_CALLER_IP());
> retval = cond_signal(condition);
> tracepoint(lttng_ust_pthread, pthread_cond_signal_end, condition,
> LTTNG_UST_CALLER_IP());
> thread_in_trace = 0;
> return retval;
> }
>
> int pthread_cond_broadcast(pthread_cond_t *condition)
> {
> static int (*cond_broadcast)(pthread_cond_t *);
> int retval;
>
> if (!cond_broadcast) {
> cond_broadcast = dlsym(RTLD_NEXT, "pthread_cond_broadcast");
> if (!cond_broadcast) {
> if (thread_in_trace) {
> abort();
> }
> fprintf(stderr, "unable to initialize pthread wrapper library.\n");
> return EINVAL;
> }
> }
> if (thread_in_trace) {
> return cond_broadcast(condition);
> }
>
> thread_in_trace = 1;
> tracepoint(lttng_ust_pthread, pthread_cond_broadcast_begin, condition,
> LTTNG_UST_CALLER_IP());
> retval = cond_broadcast(condition);
> tracepoint(lttng_ust_pthread, pthread_cond_broadcast_end, condition,
> LTTNG_UST_CALLER_IP());
> thread_in_trace = 0;
> return retval;
> }
> _______________________________________________
> lttng-dev mailing list
> lttng-dev@lists.lttng.org
> https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
--
Jonathan Rajotte-Julien
EfficiOS
_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Tracepoints for pthreads conditional variables
[not found] ` <20180501143953.GA26829@joraj-alpa>
@ 2018-05-03 20:37 ` Shehab Elsayed
[not found] ` <CAC-H6tuewaghma5hN3R2iCGvpcYVMph1uwti3u0+1ZhZEn44-A@mail.gmail.com>
1 sibling, 0 replies; 6+ messages in thread
From: Shehab Elsayed @ 2018-05-03 20:37 UTC (permalink / raw)
To: Jonathan Rajotte-Julien; +Cc: lttng-dev
[-- Attachment #1.1: Type: text/plain, Size: 7966 bytes --]
Thanks for the reply. Here is a link to the repo
https://github.com/ShehabElsayed/LTTng_debugging.git
It contains the LTTng source code I am using and one of the benchmarks that
is causing problems.
Shehab Y. Elsayed, MSc.
PhD Student
The Edwards S. Rogers Sr. Dept. of Electrical and Computer Engineering
University of Toronto
E-mail: shehabyomn@gmail.com
<https://webmail.rice.edu/imp/message.php?mailbox=INBOX&index=11#>
On Tue, May 1, 2018 at 10:39 AM, Jonathan Rajotte-Julien <
jonathan.rajotte-julien@efficios.com> wrote:
> Hi Shehab,
>
> Please provide a link to a lttng-ust git tree or an actual patch (git
> format-patch).
> This will help any person who might be interested in helping you including
> myself.
>
> Cheers
>
> On Tue, May 01, 2018 at 09:31:52AM -0400, Shehab Elsayed wrote:
> > Hi,
> >
> > I am trying to create wrappers for pthreads conditional variables
> functions
> > (wait, signal and broadcast) to insert tracepoints. I followed the same
> > approach done for the mutex functions already provided with lttng,
> however
> > I am running into some problems. Mainly the applications seem to get
> stuck
> > when the conditional variable wrappers are enabled.
> >
> > Here is my implementation for the wrapper functions:
> > int pthread_cond_wait(pthread_cond_t *condition, pthread_mutex_t
> > *mutex)
> >
> > {
> >
> > static int (*cond_wait)(pthread_cond_t *, pthread_mutex_t
> > *);
> > int retval;
> >
> >
> >
> > if (!cond_wait)
> > {
> >
> > cond_wait = dlsym(RTLD_NEXT, "pthread_cond_wait");
> >
> > if (!cond_wait)
> > {
> >
> > if (thread_in_trace)
> > {
> >
> >
> > abort();
> >
> >
> > }
> >
> > fprintf(stderr, "unable to initialize pthread wrapper
> > library.\n");
> > return EINVAL;
> >
> >
> > }
> >
> >
> > }
> >
> > if (thread_in_trace)
> > {
> >
> > return cond_wait(condition, mutex);
> >
> >
> > }
> >
> >
> >
> > thread_in_trace =
> > 1;
> >
> > tracepoint(lttng_ust_pthread, pthread_cond_wait_begin, condition,
> > mutex,
> >
> > LTTNG_UST_CALLER_IP());
> >
> > retval = cond_wait(condition, mutex);
> >
> > tracepoint(lttng_ust_pthread, pthread_cond_wait_end, condition,
> > mutex,
> >
> > LTTNG_UST_CALLER_IP());
> >
> > thread_in_trace =
> > 0;
> >
> > return retval;
> >
> > }
> >
> >
> >
> > int pthread_cond_signal(pthread_cond_t
> > *condition)
> >
> > {
> >
> > static int (*cond_signal)(pthread_cond_t
> > *);
> >
> > int retval;
> >
> >
> >
> > if (!cond_signal)
> > {
> >
> > cond_signal = dlsym(RTLD_NEXT, "pthread_cond_signal");
> >
> > if (!cond_signal)
> > {
> >
> > if (thread_in_trace)
> > {
> >
> >
> > abort();
> >
> >
> > }
> >
> > fprintf(stderr, "unable to initialize pthread wrapper
> > library.\n");
> > return EINVAL;
> >
> >
> > }
> >
> >
> > }
> >
> > if (thread_in_trace)
> > {
> >
> > return cond_signal(condition);
> >
> >
> > }
> >
> >
> >
> > thread_in_trace =
> > 1;
> >
> > tracepoint(lttng_ust_pthread, pthread_cond_signal_begin,
> > condition,
> > LTTNG_UST_CALLER_IP());
> >
> > retval = cond_signal(condition);
> >
> > tracepoint(lttng_ust_pthread, pthread_cond_signal_end,
> > condition,
> > LTTNG_UST_CALLER_IP());
> >
> > thread_in_trace =
> > 0;
> >
> > return retval;
> >
> > }
> >
> >
> >
> > int pthread_cond_broadcast(pthread_cond_t
> > *condition)
> >
> > {
> >
> > static int (*cond_broadcast)(pthread_cond_t
> > *);
> > int retval;
> >
> >
> >
> > if (!cond_broadcast)
> > {
> >
> > cond_broadcast = dlsym(RTLD_NEXT, "pthread_cond_broadcast");
> >
> > if (!cond_broadcast)
> > {
> >
> > if (thread_in_trace)
> > {
> >
> >
> > abort();
> >
> >
> > }
> >
> > fprintf(stderr, "unable to initialize pthread wrapper
> > library.\n");
> > return EINVAL;
> >
> >
> > }
> >
> >
> > }
> >
> > if (thread_in_trace)
> > {
> >
> > return cond_broadcast(condition);
> >
> >
> > }
> >
> >
> >
> > thread_in_trace =
> > 1;
> >
> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_begin,
> > condition,
> > LTTNG_UST_CALLER_IP());
> >
> > retval = cond_broadcast(condition);
> >
> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_end,
> > condition,
> > LTTNG_UST_CALLER_IP());
> >
> > thread_in_trace =
> > 0;
> >
> > return retval;
> >
> > }
> >
> > Things I have tried:
> > 1- Comment out pthread_cond_wait function --> segmentation fault
> > 2- Comment out pthread_cond_signal and _broadcast --> stuck (I can see
> the
> > program is still running but nor forward progress is being made) compared
> > to the case when the wrappers are not preloaded.
> > 3- Comment out all tracepoint related code (basically the wrapper just
> call
> > the corresponding pthreads function) --> same results as points 1 and 2.
> >
> > Any idea what might be causing this or how I could debug this problem?
> >
> > Thank you very much in advance.
> >
> > Best Regards,
> > Shehab
>
> > int pthread_cond_wait(pthread_cond_t *condition, pthread_mutex_t
> *mutex)
> > {
>
>
>
> > static int (*cond_wait)(pthread_cond_t *, pthread_mutex_t *);
>
> > int retval;
>
> >
>
> > if (!cond_wait) {
>
> > cond_wait = dlsym(RTLD_NEXT, "pthread_cond_wait");
>
> > if (!cond_wait) {
>
> > if (thread_in_trace) {
>
> > abort();
>
> > }
>
> > fprintf(stderr, "unable to initialize pthread wrapper
> library.\n");
> > return EINVAL;
>
> > }
>
> > }
>
> > if (thread_in_trace) {
>
> > return cond_wait(condition, mutex);
>
> > }
>
> >
>
> > thread_in_trace = 1;
>
> > tracepoint(lttng_ust_pthread, pthread_cond_wait_begin, condition,
> mutex,
> > LTTNG_UST_CALLER_IP());
>
> > retval = cond_wait(condition, mutex);
>
> > tracepoint(lttng_ust_pthread, pthread_cond_wait_end, condition,
> mutex,
> > LTTNG_UST_CALLER_IP());
>
> > thread_in_trace = 0;
>
> > return retval;
>
> > }
>
> >
>
> > int pthread_cond_signal(pthread_cond_t *condition)
>
> > {
>
> > static int (*cond_signal)(pthread_cond_t *);
>
> > int retval;
>
> >
>
> > if (!cond_signal) {
>
> > cond_signal = dlsym(RTLD_NEXT, "pthread_cond_signal");
>
> > if (!cond_signal) {
>
> > if (thread_in_trace) {
>
> > abort();
>
> > }
>
> > fprintf(stderr, "unable to initialize pthread wrapper
> library.\n");
> > return EINVAL;
>
> > }
>
> > }
>
> > if (thread_in_trace) {
>
> > return cond_signal(condition);
>
> > }
>
> >
>
> > thread_in_trace = 1;
>
> > tracepoint(lttng_ust_pthread, pthread_cond_signal_begin, condition,
>
> > LTTNG_UST_CALLER_IP());
>
> > retval = cond_signal(condition);
>
> > tracepoint(lttng_ust_pthread, pthread_cond_signal_end, condition,
>
> > LTTNG_UST_CALLER_IP());
>
> > thread_in_trace = 0;
>
> > return retval;
>
> > }
>
> >
>
> > int pthread_cond_broadcast(pthread_cond_t *condition)
>
> > {
>
> > static int (*cond_broadcast)(pthread_cond_t *);
>
> > int retval;
>
> >
>
> > if (!cond_broadcast) {
>
> > cond_broadcast = dlsym(RTLD_NEXT, "pthread_cond_broadcast");
>
> > if (!cond_broadcast) {
>
> > if (thread_in_trace) {
>
> > abort();
>
> > }
>
> > fprintf(stderr, "unable to initialize pthread wrapper
> library.\n");
> > return EINVAL;
>
> > }
>
> > }
>
> > if (thread_in_trace) {
>
> > return cond_broadcast(condition);
>
> > }
>
> >
>
> > thread_in_trace = 1;
>
> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_begin,
> condition,
> > LTTNG_UST_CALLER_IP());
>
> > retval = cond_broadcast(condition);
>
> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_end, condition,
>
> > LTTNG_UST_CALLER_IP());
>
> > thread_in_trace = 0;
>
> > return retval;
>
> > }
>
> > _______________________________________________
> > lttng-dev mailing list
> > lttng-dev@lists.lttng.org
> > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>
>
> --
> Jonathan Rajotte-Julien
> EfficiOS
>
[-- Attachment #1.2: Type: text/html, Size: 23544 bytes --]
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_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Tracepoints for pthreads conditional variables
[not found] ` <CAC-H6tuewaghma5hN3R2iCGvpcYVMph1uwti3u0+1ZhZEn44-A@mail.gmail.com>
@ 2018-05-29 14:36 ` Shehab Elsayed
[not found] ` <CAC-H6tu3wfE-LJWCTL8+rggLkyJ75yjMEmi=rWGsWspWkaaoGg@mail.gmail.com>
1 sibling, 0 replies; 6+ messages in thread
From: Shehab Elsayed @ 2018-05-29 14:36 UTC (permalink / raw)
To: Jonathan Rajotte-Julien; +Cc: lttng-dev
[-- Attachment #1.1: Type: text/plain, Size: 8810 bytes --]
I was wondering if you had a chance to look over this issue. Thanks!
Shehab Y. Elsayed, MSc.
PhD Student
The Edwards S. Rogers Sr. Dept. of Electrical and Computer Engineering
University of Toronto
E-mail: shehabyomn@gmail.com
<https://webmail.rice.edu/imp/message.php?mailbox=INBOX&index=11#>
On Thu, May 3, 2018 at 4:37 PM, Shehab Elsayed <shehabyomn@gmail.com> wrote:
> Thanks for the reply. Here is a link to the repo https://github.com/
> ShehabElsayed/LTTng_debugging.git
>
> It contains the LTTng source code I am using and one of the benchmarks
> that is causing problems.
>
> Shehab Y. Elsayed, MSc.
> PhD Student
> The Edwards S. Rogers Sr. Dept. of Electrical and Computer Engineering
> University of Toronto
> E-mail: shehabyomn@gmail.com
> <https://webmail.rice.edu/imp/message.php?mailbox=INBOX&index=11#>
>
> On Tue, May 1, 2018 at 10:39 AM, Jonathan Rajotte-Julien <
> jonathan.rajotte-julien@efficios.com> wrote:
>
>> Hi Shehab,
>>
>> Please provide a link to a lttng-ust git tree or an actual patch (git
>> format-patch).
>> This will help any person who might be interested in helping you including
>> myself.
>>
>> Cheers
>>
>> On Tue, May 01, 2018 at 09:31:52AM -0400, Shehab Elsayed wrote:
>> > Hi,
>> >
>> > I am trying to create wrappers for pthreads conditional variables
>> functions
>> > (wait, signal and broadcast) to insert tracepoints. I followed the same
>> > approach done for the mutex functions already provided with lttng,
>> however
>> > I am running into some problems. Mainly the applications seem to get
>> stuck
>> > when the conditional variable wrappers are enabled.
>> >
>> > Here is my implementation for the wrapper functions:
>> > int pthread_cond_wait(pthread_cond_t *condition, pthread_mutex_t
>> > *mutex)
>> >
>> > {
>> >
>> > static int (*cond_wait)(pthread_cond_t *, pthread_mutex_t
>> > *);
>> > int retval;
>> >
>> >
>> >
>> > if (!cond_wait)
>> > {
>> >
>> > cond_wait = dlsym(RTLD_NEXT, "pthread_cond_wait");
>> >
>> > if (!cond_wait)
>> > {
>> >
>> > if (thread_in_trace)
>> > {
>> >
>> >
>> > abort();
>> >
>> >
>> > }
>> >
>> > fprintf(stderr, "unable to initialize pthread wrapper
>> > library.\n");
>> > return EINVAL;
>> >
>> >
>> > }
>> >
>> >
>> > }
>> >
>> > if (thread_in_trace)
>> > {
>> >
>> > return cond_wait(condition, mutex);
>> >
>> >
>> > }
>> >
>> >
>> >
>> > thread_in_trace =
>> > 1;
>> >
>> > tracepoint(lttng_ust_pthread, pthread_cond_wait_begin, condition,
>> > mutex,
>> >
>> > LTTNG_UST_CALLER_IP());
>> >
>> > retval = cond_wait(condition, mutex);
>> >
>> > tracepoint(lttng_ust_pthread, pthread_cond_wait_end, condition,
>> > mutex,
>> >
>> > LTTNG_UST_CALLER_IP());
>> >
>> > thread_in_trace =
>> > 0;
>> >
>> > return retval;
>> >
>> > }
>> >
>> >
>> >
>> > int pthread_cond_signal(pthread_cond_t
>> > *condition)
>> >
>> > {
>> >
>> > static int (*cond_signal)(pthread_cond_t
>> > *);
>> >
>> > int retval;
>> >
>> >
>> >
>> > if (!cond_signal)
>> > {
>> >
>> > cond_signal = dlsym(RTLD_NEXT, "pthread_cond_signal");
>> >
>> > if (!cond_signal)
>> > {
>> >
>> > if (thread_in_trace)
>> > {
>> >
>> >
>> > abort();
>> >
>> >
>> > }
>> >
>> > fprintf(stderr, "unable to initialize pthread wrapper
>> > library.\n");
>> > return EINVAL;
>> >
>> >
>> > }
>> >
>> >
>> > }
>> >
>> > if (thread_in_trace)
>> > {
>> >
>> > return cond_signal(condition);
>> >
>> >
>> > }
>> >
>> >
>> >
>> > thread_in_trace =
>> > 1;
>> >
>> > tracepoint(lttng_ust_pthread, pthread_cond_signal_begin,
>> > condition,
>> > LTTNG_UST_CALLER_IP());
>> >
>> > retval = cond_signal(condition);
>> >
>> > tracepoint(lttng_ust_pthread, pthread_cond_signal_end,
>> > condition,
>> > LTTNG_UST_CALLER_IP());
>> >
>> > thread_in_trace =
>> > 0;
>> >
>> > return retval;
>> >
>> > }
>> >
>> >
>> >
>> > int pthread_cond_broadcast(pthread_cond_t
>> > *condition)
>> >
>> > {
>> >
>> > static int (*cond_broadcast)(pthread_cond_t
>> > *);
>> > int retval;
>> >
>> >
>> >
>> > if (!cond_broadcast)
>> > {
>> >
>> > cond_broadcast = dlsym(RTLD_NEXT, "pthread_cond_broadcast");
>> >
>> > if (!cond_broadcast)
>> > {
>> >
>> > if (thread_in_trace)
>> > {
>> >
>> >
>> > abort();
>> >
>> >
>> > }
>> >
>> > fprintf(stderr, "unable to initialize pthread wrapper
>> > library.\n");
>> > return EINVAL;
>> >
>> >
>> > }
>> >
>> >
>> > }
>> >
>> > if (thread_in_trace)
>> > {
>> >
>> > return cond_broadcast(condition);
>> >
>> >
>> > }
>> >
>> >
>> >
>> > thread_in_trace =
>> > 1;
>> >
>> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_begin,
>> > condition,
>> > LTTNG_UST_CALLER_IP());
>> >
>> > retval = cond_broadcast(condition);
>> >
>> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_end,
>> > condition,
>> > LTTNG_UST_CALLER_IP());
>> >
>> > thread_in_trace =
>> > 0;
>> >
>> > return retval;
>> >
>> > }
>> >
>> > Things I have tried:
>> > 1- Comment out pthread_cond_wait function --> segmentation fault
>> > 2- Comment out pthread_cond_signal and _broadcast --> stuck (I can see
>> the
>> > program is still running but nor forward progress is being made)
>> compared
>> > to the case when the wrappers are not preloaded.
>> > 3- Comment out all tracepoint related code (basically the wrapper just
>> call
>> > the corresponding pthreads function) --> same results as points 1 and 2.
>> >
>> > Any idea what might be causing this or how I could debug this problem?
>> >
>> > Thank you very much in advance.
>> >
>> > Best Regards,
>> > Shehab
>>
>> > int pthread_cond_wait(pthread_cond_t *condition, pthread_mutex_t
>> *mutex)
>> > {
>>
>>
>>
>> > static int (*cond_wait)(pthread_cond_t *, pthread_mutex_t *);
>>
>> > int retval;
>>
>> >
>>
>> > if (!cond_wait) {
>>
>> > cond_wait = dlsym(RTLD_NEXT, "pthread_cond_wait");
>>
>> > if (!cond_wait) {
>>
>> > if (thread_in_trace) {
>>
>> > abort();
>>
>> > }
>>
>> > fprintf(stderr, "unable to initialize pthread wrapper
>> library.\n");
>> > return EINVAL;
>>
>> > }
>>
>> > }
>>
>> > if (thread_in_trace) {
>>
>> > return cond_wait(condition, mutex);
>>
>> > }
>>
>> >
>>
>> > thread_in_trace = 1;
>>
>> > tracepoint(lttng_ust_pthread, pthread_cond_wait_begin, condition,
>> mutex,
>> > LTTNG_UST_CALLER_IP());
>>
>> > retval = cond_wait(condition, mutex);
>>
>> > tracepoint(lttng_ust_pthread, pthread_cond_wait_end, condition,
>> mutex,
>> > LTTNG_UST_CALLER_IP());
>>
>> > thread_in_trace = 0;
>>
>> > return retval;
>>
>> > }
>>
>> >
>>
>> > int pthread_cond_signal(pthread_cond_t *condition)
>>
>> > {
>>
>> > static int (*cond_signal)(pthread_cond_t *);
>>
>> > int retval;
>>
>> >
>>
>> > if (!cond_signal) {
>>
>> > cond_signal = dlsym(RTLD_NEXT, "pthread_cond_signal");
>>
>> > if (!cond_signal) {
>>
>> > if (thread_in_trace) {
>>
>> > abort();
>>
>> > }
>>
>> > fprintf(stderr, "unable to initialize pthread wrapper
>> library.\n");
>> > return EINVAL;
>>
>> > }
>>
>> > }
>>
>> > if (thread_in_trace) {
>>
>> > return cond_signal(condition);
>>
>> > }
>>
>> >
>>
>> > thread_in_trace = 1;
>>
>> > tracepoint(lttng_ust_pthread, pthread_cond_signal_begin, condition,
>>
>> > LTTNG_UST_CALLER_IP());
>>
>> > retval = cond_signal(condition);
>>
>> > tracepoint(lttng_ust_pthread, pthread_cond_signal_end, condition,
>>
>> > LTTNG_UST_CALLER_IP());
>>
>> > thread_in_trace = 0;
>>
>> > return retval;
>>
>> > }
>>
>> >
>>
>> > int pthread_cond_broadcast(pthread_cond_t *condition)
>>
>> > {
>>
>> > static int (*cond_broadcast)(pthread_cond_t *);
>>
>> > int retval;
>>
>> >
>>
>> > if (!cond_broadcast) {
>>
>> > cond_broadcast = dlsym(RTLD_NEXT, "pthread_cond_broadcast");
>>
>> > if (!cond_broadcast) {
>>
>> > if (thread_in_trace) {
>>
>> > abort();
>>
>> > }
>>
>> > fprintf(stderr, "unable to initialize pthread wrapper
>> library.\n");
>> > return EINVAL;
>>
>> > }
>>
>> > }
>>
>> > if (thread_in_trace) {
>>
>> > return cond_broadcast(condition);
>>
>> > }
>>
>> >
>>
>> > thread_in_trace = 1;
>>
>> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_begin,
>> condition,
>> > LTTNG_UST_CALLER_IP());
>>
>> > retval = cond_broadcast(condition);
>>
>> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_end, condition,
>>
>> > LTTNG_UST_CALLER_IP());
>>
>> > thread_in_trace = 0;
>>
>> > return retval;
>>
>> > }
>>
>> > _______________________________________________
>> > lttng-dev mailing list
>> > lttng-dev@lists.lttng.org
>> > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>
>>
>> --
>> Jonathan Rajotte-Julien
>> EfficiOS
>>
>
>
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_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Tracepoints for pthreads conditional variables
[not found] ` <CAC-H6tu3wfE-LJWCTL8+rggLkyJ75yjMEmi=rWGsWspWkaaoGg@mail.gmail.com>
@ 2018-07-05 21:36 ` Shehab Elsayed
[not found] ` <CAC-H6tv5KPAYwg_ZxjUva95g2wZpZm8Oi_Q5Pve+Ow4jDcGfxw@mail.gmail.com>
1 sibling, 0 replies; 6+ messages in thread
From: Shehab Elsayed @ 2018-07-05 21:36 UTC (permalink / raw)
To: Jonathan Rajotte-Julien; +Cc: lttng-dev
[-- Attachment #1.1: Type: text/plain, Size: 9746 bytes --]
Any suggestions where I should investigate to fix this bug? Also, please
let me know whether the git repo I shared is sufficient.
Thanks,
Shehab
Shehab Y. Elsayed, MSc.
PhD Student
The Edwards S. Rogers Sr. Dept. of Electrical and Computer Engineering
University of Toronto
E-mail: shehabyomn@gmail.com
<https://webmail.rice.edu/imp/message.php?mailbox=INBOX&index=11#>
On Tue, May 29, 2018 at 10:36 AM, Shehab Elsayed <shehabyomn@gmail.com>
wrote:
> I was wondering if you had a chance to look over this issue. Thanks!
>
> Shehab Y. Elsayed, MSc.
> PhD Student
> The Edwards S. Rogers Sr. Dept. of Electrical and Computer Engineering
> University of Toronto
> E-mail: shehabyomn@gmail.com
> <https://webmail.rice.edu/imp/message.php?mailbox=INBOX&index=11#>
>
> On Thu, May 3, 2018 at 4:37 PM, Shehab Elsayed <shehabyomn@gmail.com>
> wrote:
>
>> Thanks for the reply. Here is a link to the repo
>> https://github.com/ShehabElsayed/LTTng_debugging.git
>>
>> It contains the LTTng source code I am using and one of the benchmarks
>> that is causing problems.
>>
>> Shehab Y. Elsayed, MSc.
>> PhD Student
>> The Edwards S. Rogers Sr. Dept. of Electrical and Computer Engineering
>> University of Toronto
>> E-mail: shehabyomn@gmail.com
>> <https://webmail.rice.edu/imp/message.php?mailbox=INBOX&index=11#>
>>
>> On Tue, May 1, 2018 at 10:39 AM, Jonathan Rajotte-Julien <
>> jonathan.rajotte-julien@efficios.com> wrote:
>>
>>> Hi Shehab,
>>>
>>> Please provide a link to a lttng-ust git tree or an actual patch (git
>>> format-patch).
>>> This will help any person who might be interested in helping you
>>> including
>>> myself.
>>>
>>> Cheers
>>>
>>> On Tue, May 01, 2018 at 09:31:52AM -0400, Shehab Elsayed wrote:
>>> > Hi,
>>> >
>>> > I am trying to create wrappers for pthreads conditional variables
>>> functions
>>> > (wait, signal and broadcast) to insert tracepoints. I followed the same
>>> > approach done for the mutex functions already provided with lttng,
>>> however
>>> > I am running into some problems. Mainly the applications seem to get
>>> stuck
>>> > when the conditional variable wrappers are enabled.
>>> >
>>> > Here is my implementation for the wrapper functions:
>>> > int pthread_cond_wait(pthread_cond_t *condition, pthread_mutex_t
>>> > *mutex)
>>> >
>>> > {
>>> >
>>> > static int (*cond_wait)(pthread_cond_t *, pthread_mutex_t
>>> > *);
>>> > int retval;
>>> >
>>> >
>>> >
>>> > if (!cond_wait)
>>> > {
>>> >
>>> > cond_wait = dlsym(RTLD_NEXT, "pthread_cond_wait");
>>> >
>>> > if (!cond_wait)
>>> > {
>>> >
>>> > if (thread_in_trace)
>>> > {
>>> >
>>> >
>>> > abort();
>>> >
>>> >
>>> > }
>>> >
>>> > fprintf(stderr, "unable to initialize pthread wrapper
>>> > library.\n");
>>> > return EINVAL;
>>> >
>>> >
>>> > }
>>> >
>>> >
>>> > }
>>> >
>>> > if (thread_in_trace)
>>> > {
>>> >
>>> > return cond_wait(condition, mutex);
>>> >
>>> >
>>> > }
>>> >
>>> >
>>> >
>>> > thread_in_trace =
>>> > 1;
>>> >
>>> > tracepoint(lttng_ust_pthread, pthread_cond_wait_begin, condition,
>>> > mutex,
>>> >
>>> > LTTNG_UST_CALLER_IP());
>>> >
>>> > retval = cond_wait(condition, mutex);
>>> >
>>> > tracepoint(lttng_ust_pthread, pthread_cond_wait_end, condition,
>>> > mutex,
>>> >
>>> > LTTNG_UST_CALLER_IP());
>>> >
>>> > thread_in_trace =
>>> > 0;
>>> >
>>> > return retval;
>>> >
>>> > }
>>> >
>>> >
>>> >
>>> > int pthread_cond_signal(pthread_cond_t
>>> > *condition)
>>> >
>>> > {
>>> >
>>> > static int (*cond_signal)(pthread_cond_t
>>> > *);
>>> >
>>> > int retval;
>>> >
>>> >
>>> >
>>> > if (!cond_signal)
>>> > {
>>> >
>>> > cond_signal = dlsym(RTLD_NEXT, "pthread_cond_signal");
>>> >
>>> > if (!cond_signal)
>>> > {
>>> >
>>> > if (thread_in_trace)
>>> > {
>>> >
>>> >
>>> > abort();
>>> >
>>> >
>>> > }
>>> >
>>> > fprintf(stderr, "unable to initialize pthread wrapper
>>> > library.\n");
>>> > return EINVAL;
>>> >
>>> >
>>> > }
>>> >
>>> >
>>> > }
>>> >
>>> > if (thread_in_trace)
>>> > {
>>> >
>>> > return cond_signal(condition);
>>> >
>>> >
>>> > }
>>> >
>>> >
>>> >
>>> > thread_in_trace =
>>> > 1;
>>> >
>>> > tracepoint(lttng_ust_pthread, pthread_cond_signal_begin,
>>> > condition,
>>> > LTTNG_UST_CALLER_IP());
>>> >
>>> > retval = cond_signal(condition);
>>> >
>>> > tracepoint(lttng_ust_pthread, pthread_cond_signal_end,
>>> > condition,
>>> > LTTNG_UST_CALLER_IP());
>>> >
>>> > thread_in_trace =
>>> > 0;
>>> >
>>> > return retval;
>>> >
>>> > }
>>> >
>>> >
>>> >
>>> > int pthread_cond_broadcast(pthread_cond_t
>>> > *condition)
>>> >
>>> > {
>>> >
>>> > static int (*cond_broadcast)(pthread_cond_t
>>> > *);
>>> > int retval;
>>> >
>>> >
>>> >
>>> > if (!cond_broadcast)
>>> > {
>>> >
>>> > cond_broadcast = dlsym(RTLD_NEXT, "pthread_cond_broadcast");
>>> >
>>> > if (!cond_broadcast)
>>> > {
>>> >
>>> > if (thread_in_trace)
>>> > {
>>> >
>>> >
>>> > abort();
>>> >
>>> >
>>> > }
>>> >
>>> > fprintf(stderr, "unable to initialize pthread wrapper
>>> > library.\n");
>>> > return EINVAL;
>>> >
>>> >
>>> > }
>>> >
>>> >
>>> > }
>>> >
>>> > if (thread_in_trace)
>>> > {
>>> >
>>> > return cond_broadcast(condition);
>>> >
>>> >
>>> > }
>>> >
>>> >
>>> >
>>> > thread_in_trace =
>>> > 1;
>>> >
>>> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_begin,
>>> > condition,
>>> > LTTNG_UST_CALLER_IP());
>>> >
>>> > retval = cond_broadcast(condition);
>>> >
>>> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_end,
>>> > condition,
>>> > LTTNG_UST_CALLER_IP());
>>> >
>>> > thread_in_trace =
>>> > 0;
>>> >
>>> > return retval;
>>> >
>>> > }
>>> >
>>> > Things I have tried:
>>> > 1- Comment out pthread_cond_wait function --> segmentation fault
>>> > 2- Comment out pthread_cond_signal and _broadcast --> stuck (I can see
>>> the
>>> > program is still running but nor forward progress is being made)
>>> compared
>>> > to the case when the wrappers are not preloaded.
>>> > 3- Comment out all tracepoint related code (basically the wrapper just
>>> call
>>> > the corresponding pthreads function) --> same results as points 1 and
>>> 2.
>>> >
>>> > Any idea what might be causing this or how I could debug this problem?
>>> >
>>> > Thank you very much in advance.
>>> >
>>> > Best Regards,
>>> > Shehab
>>>
>>> > int pthread_cond_wait(pthread_cond_t *condition, pthread_mutex_t
>>> *mutex)
>>> > {
>>>
>>>
>>>
>>> > static int (*cond_wait)(pthread_cond_t *, pthread_mutex_t *);
>>>
>>> > int retval;
>>>
>>> >
>>>
>>> > if (!cond_wait) {
>>>
>>> > cond_wait = dlsym(RTLD_NEXT, "pthread_cond_wait");
>>>
>>> > if (!cond_wait) {
>>>
>>> > if (thread_in_trace) {
>>>
>>> > abort();
>>>
>>> > }
>>>
>>> > fprintf(stderr, "unable to initialize pthread wrapper
>>> library.\n");
>>> > return EINVAL;
>>>
>>> > }
>>>
>>> > }
>>>
>>> > if (thread_in_trace) {
>>>
>>> > return cond_wait(condition, mutex);
>>>
>>> > }
>>>
>>> >
>>>
>>> > thread_in_trace = 1;
>>>
>>> > tracepoint(lttng_ust_pthread, pthread_cond_wait_begin, condition,
>>> mutex,
>>> > LTTNG_UST_CALLER_IP());
>>>
>>> > retval = cond_wait(condition, mutex);
>>>
>>> > tracepoint(lttng_ust_pthread, pthread_cond_wait_end, condition,
>>> mutex,
>>> > LTTNG_UST_CALLER_IP());
>>>
>>> > thread_in_trace = 0;
>>>
>>> > return retval;
>>>
>>> > }
>>>
>>> >
>>>
>>> > int pthread_cond_signal(pthread_cond_t *condition)
>>>
>>> > {
>>>
>>> > static int (*cond_signal)(pthread_cond_t *);
>>>
>>> > int retval;
>>>
>>> >
>>>
>>> > if (!cond_signal) {
>>>
>>> > cond_signal = dlsym(RTLD_NEXT, "pthread_cond_signal");
>>>
>>> > if (!cond_signal) {
>>>
>>> > if (thread_in_trace) {
>>>
>>> > abort();
>>>
>>> > }
>>>
>>> > fprintf(stderr, "unable to initialize pthread wrapper
>>> library.\n");
>>> > return EINVAL;
>>>
>>> > }
>>>
>>> > }
>>>
>>> > if (thread_in_trace) {
>>>
>>> > return cond_signal(condition);
>>>
>>> > }
>>>
>>> >
>>>
>>> > thread_in_trace = 1;
>>>
>>> > tracepoint(lttng_ust_pthread, pthread_cond_signal_begin, condition,
>>>
>>> > LTTNG_UST_CALLER_IP());
>>>
>>> > retval = cond_signal(condition);
>>>
>>> > tracepoint(lttng_ust_pthread, pthread_cond_signal_end, condition,
>>>
>>> > LTTNG_UST_CALLER_IP());
>>>
>>> > thread_in_trace = 0;
>>>
>>> > return retval;
>>>
>>> > }
>>>
>>> >
>>>
>>> > int pthread_cond_broadcast(pthread_cond_t *condition)
>>>
>>> > {
>>>
>>> > static int (*cond_broadcast)(pthread_cond_t *);
>>>
>>> > int retval;
>>>
>>> >
>>>
>>> > if (!cond_broadcast) {
>>>
>>> > cond_broadcast = dlsym(RTLD_NEXT, "pthread_cond_broadcast");
>>>
>>> > if (!cond_broadcast) {
>>>
>>> > if (thread_in_trace) {
>>>
>>> > abort();
>>>
>>> > }
>>>
>>> > fprintf(stderr, "unable to initialize pthread wrapper
>>> library.\n");
>>> > return EINVAL;
>>>
>>> > }
>>>
>>> > }
>>>
>>> > if (thread_in_trace) {
>>>
>>> > return cond_broadcast(condition);
>>>
>>> > }
>>>
>>> >
>>>
>>> > thread_in_trace = 1;
>>>
>>> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_begin,
>>> condition,
>>> > LTTNG_UST_CALLER_IP());
>>>
>>> > retval = cond_broadcast(condition);
>>>
>>> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_end,
>>> condition,
>>> > LTTNG_UST_CALLER_IP());
>>>
>>> > thread_in_trace = 0;
>>>
>>> > return retval;
>>>
>>> > }
>>>
>>> > _______________________________________________
>>> > lttng-dev mailing list
>>> > lttng-dev@lists.lttng.org
>>> > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>>
>>>
>>> --
>>> Jonathan Rajotte-Julien
>>> EfficiOS
>>>
>>
>>
>
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_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Tracepoints for pthreads conditional variables
[not found] ` <CAC-H6tv5KPAYwg_ZxjUva95g2wZpZm8Oi_Q5Pve+Ow4jDcGfxw@mail.gmail.com>
@ 2019-04-26 20:44 ` Shehab Elsayed
0 siblings, 0 replies; 6+ messages in thread
From: Shehab Elsayed @ 2019-04-26 20:44 UTC (permalink / raw)
To: Jonathan Rajotte-Julien; +Cc: lttng-dev
[-- Attachment #1.1: Type: text/plain, Size: 11083 bytes --]
I came across something some time ago that I think might solve this
problem. It goes back to making sure that the version of the
synchronization function called from the wrapper is the same that would be
called without the wrapper.
To specify the version the following instruction can be used:
....... = dlvsym(RTLD_NEXT, "function_name", "GLIBC_2.3.2")
To know which version is normally used, you can use the following:
objdump -t <bin_name> | grep <func_name>
where <bin_name> is the name of the program to be run, and <func_name> is
the name of the function to be called from the wrapper.
For more information, check this
link:
http://blog.fesnel.com/blog/2009/08/25/preloading-with-multiple-symbol-versions/
I hope this helps.
On Thu, Jul 5, 2018 at 5:36 PM Shehab Elsayed <shehabyomn@gmail.com> wrote:
> Any suggestions where I should investigate to fix this bug? Also, please
> let me know whether the git repo I shared is sufficient.
>
> Thanks,
> Shehab
>
> Shehab Y. Elsayed, MSc.
> PhD Student
> The Edwards S. Rogers Sr. Dept. of Electrical and Computer Engineering
> University of Toronto
> E-mail: shehabyomn@gmail.com
> <https://webmail.rice.edu/imp/message.php?mailbox=INBOX&index=11#>
>
> On Tue, May 29, 2018 at 10:36 AM, Shehab Elsayed <shehabyomn@gmail.com>
> wrote:
>
>> I was wondering if you had a chance to look over this issue. Thanks!
>>
>> Shehab Y. Elsayed, MSc.
>> PhD Student
>> The Edwards S. Rogers Sr. Dept. of Electrical and Computer Engineering
>> University of Toronto
>> E-mail: shehabyomn@gmail.com
>> <https://webmail.rice.edu/imp/message.php?mailbox=INBOX&index=11#>
>>
>> On Thu, May 3, 2018 at 4:37 PM, Shehab Elsayed <shehabyomn@gmail.com>
>> wrote:
>>
>>> Thanks for the reply. Here is a link to the repo
>>> https://github.com/ShehabElsayed/LTTng_debugging.git
>>>
>>> It contains the LTTng source code I am using and one of the benchmarks
>>> that is causing problems.
>>>
>>> Shehab Y. Elsayed, MSc.
>>> PhD Student
>>> The Edwards S. Rogers Sr. Dept. of Electrical and Computer Engineering
>>> University of Toronto
>>> E-mail: shehabyomn@gmail.com
>>> <https://webmail.rice.edu/imp/message.php?mailbox=INBOX&index=11#>
>>>
>>> On Tue, May 1, 2018 at 10:39 AM, Jonathan Rajotte-Julien <
>>> jonathan.rajotte-julien@efficios.com> wrote:
>>>
>>>> Hi Shehab,
>>>>
>>>> Please provide a link to a lttng-ust git tree or an actual patch (git
>>>> format-patch).
>>>> This will help any person who might be interested in helping you
>>>> including
>>>> myself.
>>>>
>>>> Cheers
>>>>
>>>> On Tue, May 01, 2018 at 09:31:52AM -0400, Shehab Elsayed wrote:
>>>> > Hi,
>>>> >
>>>> > I am trying to create wrappers for pthreads conditional variables
>>>> functions
>>>> > (wait, signal and broadcast) to insert tracepoints. I followed the
>>>> same
>>>> > approach done for the mutex functions already provided with lttng,
>>>> however
>>>> > I am running into some problems. Mainly the applications seem to get
>>>> stuck
>>>> > when the conditional variable wrappers are enabled.
>>>> >
>>>> > Here is my implementation for the wrapper functions:
>>>> > int pthread_cond_wait(pthread_cond_t *condition, pthread_mutex_t
>>>> > *mutex)
>>>> >
>>>> > {
>>>> >
>>>> > static int (*cond_wait)(pthread_cond_t *, pthread_mutex_t
>>>> > *);
>>>> > int retval;
>>>> >
>>>> >
>>>> >
>>>> > if (!cond_wait)
>>>> > {
>>>> >
>>>> > cond_wait = dlsym(RTLD_NEXT, "pthread_cond_wait");
>>>> >
>>>> > if (!cond_wait)
>>>> > {
>>>> >
>>>> > if (thread_in_trace)
>>>> > {
>>>> >
>>>> >
>>>> > abort();
>>>> >
>>>> >
>>>> > }
>>>> >
>>>> > fprintf(stderr, "unable to initialize pthread wrapper
>>>> > library.\n");
>>>> > return EINVAL;
>>>> >
>>>> >
>>>> > }
>>>> >
>>>> >
>>>> > }
>>>> >
>>>> > if (thread_in_trace)
>>>> > {
>>>> >
>>>> > return cond_wait(condition, mutex);
>>>> >
>>>> >
>>>> > }
>>>> >
>>>> >
>>>> >
>>>> > thread_in_trace =
>>>> > 1;
>>>> >
>>>> > tracepoint(lttng_ust_pthread, pthread_cond_wait_begin, condition,
>>>> > mutex,
>>>> >
>>>> > LTTNG_UST_CALLER_IP());
>>>> >
>>>> > retval = cond_wait(condition, mutex);
>>>> >
>>>> > tracepoint(lttng_ust_pthread, pthread_cond_wait_end, condition,
>>>> > mutex,
>>>> >
>>>> > LTTNG_UST_CALLER_IP());
>>>> >
>>>> > thread_in_trace =
>>>> > 0;
>>>> >
>>>> > return retval;
>>>> >
>>>> > }
>>>> >
>>>> >
>>>> >
>>>> > int pthread_cond_signal(pthread_cond_t
>>>> > *condition)
>>>> >
>>>> > {
>>>> >
>>>> > static int (*cond_signal)(pthread_cond_t
>>>> > *);
>>>> >
>>>> > int retval;
>>>> >
>>>> >
>>>> >
>>>> > if (!cond_signal)
>>>> > {
>>>> >
>>>> > cond_signal = dlsym(RTLD_NEXT, "pthread_cond_signal");
>>>> >
>>>> > if (!cond_signal)
>>>> > {
>>>> >
>>>> > if (thread_in_trace)
>>>> > {
>>>> >
>>>> >
>>>> > abort();
>>>> >
>>>> >
>>>> > }
>>>> >
>>>> > fprintf(stderr, "unable to initialize pthread wrapper
>>>> > library.\n");
>>>> > return EINVAL;
>>>> >
>>>> >
>>>> > }
>>>> >
>>>> >
>>>> > }
>>>> >
>>>> > if (thread_in_trace)
>>>> > {
>>>> >
>>>> > return cond_signal(condition);
>>>> >
>>>> >
>>>> > }
>>>> >
>>>> >
>>>> >
>>>> > thread_in_trace =
>>>> > 1;
>>>> >
>>>> > tracepoint(lttng_ust_pthread, pthread_cond_signal_begin,
>>>> > condition,
>>>> > LTTNG_UST_CALLER_IP());
>>>> >
>>>> > retval = cond_signal(condition);
>>>> >
>>>> > tracepoint(lttng_ust_pthread, pthread_cond_signal_end,
>>>> > condition,
>>>> > LTTNG_UST_CALLER_IP());
>>>> >
>>>> > thread_in_trace =
>>>> > 0;
>>>> >
>>>> > return retval;
>>>> >
>>>> > }
>>>> >
>>>> >
>>>> >
>>>> > int pthread_cond_broadcast(pthread_cond_t
>>>> > *condition)
>>>> >
>>>> > {
>>>> >
>>>> > static int (*cond_broadcast)(pthread_cond_t
>>>> > *);
>>>> > int retval;
>>>> >
>>>> >
>>>> >
>>>> > if (!cond_broadcast)
>>>> > {
>>>> >
>>>> > cond_broadcast = dlsym(RTLD_NEXT, "pthread_cond_broadcast");
>>>> >
>>>> > if (!cond_broadcast)
>>>> > {
>>>> >
>>>> > if (thread_in_trace)
>>>> > {
>>>> >
>>>> >
>>>> > abort();
>>>> >
>>>> >
>>>> > }
>>>> >
>>>> > fprintf(stderr, "unable to initialize pthread wrapper
>>>> > library.\n");
>>>> > return EINVAL;
>>>> >
>>>> >
>>>> > }
>>>> >
>>>> >
>>>> > }
>>>> >
>>>> > if (thread_in_trace)
>>>> > {
>>>> >
>>>> > return cond_broadcast(condition);
>>>> >
>>>> >
>>>> > }
>>>> >
>>>> >
>>>> >
>>>> > thread_in_trace =
>>>> > 1;
>>>> >
>>>> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_begin,
>>>> > condition,
>>>> > LTTNG_UST_CALLER_IP());
>>>> >
>>>> > retval = cond_broadcast(condition);
>>>> >
>>>> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_end,
>>>> > condition,
>>>> > LTTNG_UST_CALLER_IP());
>>>> >
>>>> > thread_in_trace =
>>>> > 0;
>>>> >
>>>> > return retval;
>>>> >
>>>> > }
>>>> >
>>>> > Things I have tried:
>>>> > 1- Comment out pthread_cond_wait function --> segmentation fault
>>>> > 2- Comment out pthread_cond_signal and _broadcast --> stuck (I can
>>>> see the
>>>> > program is still running but nor forward progress is being made)
>>>> compared
>>>> > to the case when the wrappers are not preloaded.
>>>> > 3- Comment out all tracepoint related code (basically the wrapper
>>>> just call
>>>> > the corresponding pthreads function) --> same results as points 1 and
>>>> 2.
>>>> >
>>>> > Any idea what might be causing this or how I could debug this problem?
>>>> >
>>>> > Thank you very much in advance.
>>>> >
>>>> > Best Regards,
>>>> > Shehab
>>>>
>>>> > int pthread_cond_wait(pthread_cond_t *condition, pthread_mutex_t
>>>> *mutex)
>>>> > {
>>>>
>>>>
>>>>
>>>> > static int (*cond_wait)(pthread_cond_t *, pthread_mutex_t *);
>>>>
>>>> > int retval;
>>>>
>>>> >
>>>>
>>>> > if (!cond_wait) {
>>>>
>>>> > cond_wait = dlsym(RTLD_NEXT, "pthread_cond_wait");
>>>>
>>>> > if (!cond_wait) {
>>>>
>>>> > if (thread_in_trace) {
>>>>
>>>> > abort();
>>>>
>>>> > }
>>>>
>>>> > fprintf(stderr, "unable to initialize pthread wrapper
>>>> library.\n");
>>>> > return EINVAL;
>>>>
>>>> > }
>>>>
>>>> > }
>>>>
>>>> > if (thread_in_trace) {
>>>>
>>>> > return cond_wait(condition, mutex);
>>>>
>>>> > }
>>>>
>>>> >
>>>>
>>>> > thread_in_trace = 1;
>>>>
>>>> > tracepoint(lttng_ust_pthread, pthread_cond_wait_begin, condition,
>>>> mutex,
>>>> > LTTNG_UST_CALLER_IP());
>>>>
>>>> > retval = cond_wait(condition, mutex);
>>>>
>>>> > tracepoint(lttng_ust_pthread, pthread_cond_wait_end, condition,
>>>> mutex,
>>>> > LTTNG_UST_CALLER_IP());
>>>>
>>>> > thread_in_trace = 0;
>>>>
>>>> > return retval;
>>>>
>>>> > }
>>>>
>>>> >
>>>>
>>>> > int pthread_cond_signal(pthread_cond_t *condition)
>>>>
>>>> > {
>>>>
>>>> > static int (*cond_signal)(pthread_cond_t *);
>>>>
>>>> > int retval;
>>>>
>>>> >
>>>>
>>>> > if (!cond_signal) {
>>>>
>>>> > cond_signal = dlsym(RTLD_NEXT, "pthread_cond_signal");
>>>>
>>>> > if (!cond_signal) {
>>>>
>>>> > if (thread_in_trace) {
>>>>
>>>> > abort();
>>>>
>>>> > }
>>>>
>>>> > fprintf(stderr, "unable to initialize pthread wrapper
>>>> library.\n");
>>>> > return EINVAL;
>>>>
>>>> > }
>>>>
>>>> > }
>>>>
>>>> > if (thread_in_trace) {
>>>>
>>>> > return cond_signal(condition);
>>>>
>>>> > }
>>>>
>>>> >
>>>>
>>>> > thread_in_trace = 1;
>>>>
>>>> > tracepoint(lttng_ust_pthread, pthread_cond_signal_begin,
>>>> condition,
>>>> > LTTNG_UST_CALLER_IP());
>>>>
>>>> > retval = cond_signal(condition);
>>>>
>>>> > tracepoint(lttng_ust_pthread, pthread_cond_signal_end, condition,
>>>>
>>>> > LTTNG_UST_CALLER_IP());
>>>>
>>>> > thread_in_trace = 0;
>>>>
>>>> > return retval;
>>>>
>>>> > }
>>>>
>>>> >
>>>>
>>>> > int pthread_cond_broadcast(pthread_cond_t *condition)
>>>>
>>>> > {
>>>>
>>>> > static int (*cond_broadcast)(pthread_cond_t *);
>>>>
>>>> > int retval;
>>>>
>>>> >
>>>>
>>>> > if (!cond_broadcast) {
>>>>
>>>> > cond_broadcast = dlsym(RTLD_NEXT, "pthread_cond_broadcast");
>>>>
>>>> > if (!cond_broadcast) {
>>>>
>>>> > if (thread_in_trace) {
>>>>
>>>> > abort();
>>>>
>>>> > }
>>>>
>>>> > fprintf(stderr, "unable to initialize pthread wrapper
>>>> library.\n");
>>>> > return EINVAL;
>>>>
>>>> > }
>>>>
>>>> > }
>>>>
>>>> > if (thread_in_trace) {
>>>>
>>>> > return cond_broadcast(condition);
>>>>
>>>> > }
>>>>
>>>> >
>>>>
>>>> > thread_in_trace = 1;
>>>>
>>>> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_begin,
>>>> condition,
>>>> > LTTNG_UST_CALLER_IP());
>>>>
>>>> > retval = cond_broadcast(condition);
>>>>
>>>> > tracepoint(lttng_ust_pthread, pthread_cond_broadcast_end,
>>>> condition,
>>>> > LTTNG_UST_CALLER_IP());
>>>>
>>>> > thread_in_trace = 0;
>>>>
>>>> > return retval;
>>>>
>>>> > }
>>>>
>>>> > _______________________________________________
>>>> > lttng-dev mailing list
>>>> > lttng-dev@lists.lttng.org
>>>> > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
>>>>
>>>>
>>>> --
>>>> Jonathan Rajotte-Julien
>>>> EfficiOS
>>>>
>>>
>>>
>>
>
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_______________________________________________
lttng-dev mailing list
lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
^ permalink raw reply [flat|nested] 6+ messages in thread
* Tracepoints for pthreads conditional variables
@ 2018-05-01 13:31 Shehab Elsayed
0 siblings, 0 replies; 6+ messages in thread
From: Shehab Elsayed @ 2018-05-01 13:31 UTC (permalink / raw)
To: lttng-dev
[-- Attachment #1.1: Type: text/plain, Size: 3292 bytes --]
Hi,
I am trying to create wrappers for pthreads conditional variables functions
(wait, signal and broadcast) to insert tracepoints. I followed the same
approach done for the mutex functions already provided with lttng, however
I am running into some problems. Mainly the applications seem to get stuck
when the conditional variable wrappers are enabled.
Here is my implementation for the wrapper functions:
int pthread_cond_wait(pthread_cond_t *condition, pthread_mutex_t
*mutex)
{
static int (*cond_wait)(pthread_cond_t *, pthread_mutex_t
*);
int retval;
if (!cond_wait)
{
cond_wait = dlsym(RTLD_NEXT, "pthread_cond_wait");
if (!cond_wait)
{
if (thread_in_trace)
{
abort();
}
fprintf(stderr, "unable to initialize pthread wrapper
library.\n");
return EINVAL;
}
}
if (thread_in_trace)
{
return cond_wait(condition, mutex);
}
thread_in_trace =
1;
tracepoint(lttng_ust_pthread, pthread_cond_wait_begin, condition,
mutex,
LTTNG_UST_CALLER_IP());
retval = cond_wait(condition, mutex);
tracepoint(lttng_ust_pthread, pthread_cond_wait_end, condition,
mutex,
LTTNG_UST_CALLER_IP());
thread_in_trace =
0;
return retval;
}
int pthread_cond_signal(pthread_cond_t
*condition)
{
static int (*cond_signal)(pthread_cond_t
*);
int retval;
if (!cond_signal)
{
cond_signal = dlsym(RTLD_NEXT, "pthread_cond_signal");
if (!cond_signal)
{
if (thread_in_trace)
{
abort();
}
fprintf(stderr, "unable to initialize pthread wrapper
library.\n");
return EINVAL;
}
}
if (thread_in_trace)
{
return cond_signal(condition);
}
thread_in_trace =
1;
tracepoint(lttng_ust_pthread, pthread_cond_signal_begin,
condition,
LTTNG_UST_CALLER_IP());
retval = cond_signal(condition);
tracepoint(lttng_ust_pthread, pthread_cond_signal_end,
condition,
LTTNG_UST_CALLER_IP());
thread_in_trace =
0;
return retval;
}
int pthread_cond_broadcast(pthread_cond_t
*condition)
{
static int (*cond_broadcast)(pthread_cond_t
*);
int retval;
if (!cond_broadcast)
{
cond_broadcast = dlsym(RTLD_NEXT, "pthread_cond_broadcast");
if (!cond_broadcast)
{
if (thread_in_trace)
{
abort();
}
fprintf(stderr, "unable to initialize pthread wrapper
library.\n");
return EINVAL;
}
}
if (thread_in_trace)
{
return cond_broadcast(condition);
}
thread_in_trace =
1;
tracepoint(lttng_ust_pthread, pthread_cond_broadcast_begin,
condition,
LTTNG_UST_CALLER_IP());
retval = cond_broadcast(condition);
tracepoint(lttng_ust_pthread, pthread_cond_broadcast_end,
condition,
LTTNG_UST_CALLER_IP());
thread_in_trace =
0;
return retval;
}
Things I have tried:
1- Comment out pthread_cond_wait function --> segmentation fault
2- Comment out pthread_cond_signal and _broadcast --> stuck (I can see the
program is still running but nor forward progress is being made) compared
to the case when the wrappers are not preloaded.
3- Comment out all tracepoint related code (basically the wrapper just call
the corresponding pthreads function) --> same results as points 1 and 2.
Any idea what might be causing this or how I could debug this problem?
Thank you very much in advance.
Best Regards,
Shehab
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[-- Attachment #2: cond_variables.c --]
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int pthread_cond_wait(pthread_cond_t *condition, pthread_mutex_t *mutex)
{
static int (*cond_wait)(pthread_cond_t *, pthread_mutex_t *);
int retval;
if (!cond_wait) {
cond_wait = dlsym(RTLD_NEXT, "pthread_cond_wait");
if (!cond_wait) {
if (thread_in_trace) {
abort();
}
fprintf(stderr, "unable to initialize pthread wrapper library.\n");
return EINVAL;
}
}
if (thread_in_trace) {
return cond_wait(condition, mutex);
}
thread_in_trace = 1;
tracepoint(lttng_ust_pthread, pthread_cond_wait_begin, condition, mutex,
LTTNG_UST_CALLER_IP());
retval = cond_wait(condition, mutex);
tracepoint(lttng_ust_pthread, pthread_cond_wait_end, condition, mutex,
LTTNG_UST_CALLER_IP());
thread_in_trace = 0;
return retval;
}
int pthread_cond_signal(pthread_cond_t *condition)
{
static int (*cond_signal)(pthread_cond_t *);
int retval;
if (!cond_signal) {
cond_signal = dlsym(RTLD_NEXT, "pthread_cond_signal");
if (!cond_signal) {
if (thread_in_trace) {
abort();
}
fprintf(stderr, "unable to initialize pthread wrapper library.\n");
return EINVAL;
}
}
if (thread_in_trace) {
return cond_signal(condition);
}
thread_in_trace = 1;
tracepoint(lttng_ust_pthread, pthread_cond_signal_begin, condition,
LTTNG_UST_CALLER_IP());
retval = cond_signal(condition);
tracepoint(lttng_ust_pthread, pthread_cond_signal_end, condition,
LTTNG_UST_CALLER_IP());
thread_in_trace = 0;
return retval;
}
int pthread_cond_broadcast(pthread_cond_t *condition)
{
static int (*cond_broadcast)(pthread_cond_t *);
int retval;
if (!cond_broadcast) {
cond_broadcast = dlsym(RTLD_NEXT, "pthread_cond_broadcast");
if (!cond_broadcast) {
if (thread_in_trace) {
abort();
}
fprintf(stderr, "unable to initialize pthread wrapper library.\n");
return EINVAL;
}
}
if (thread_in_trace) {
return cond_broadcast(condition);
}
thread_in_trace = 1;
tracepoint(lttng_ust_pthread, pthread_cond_broadcast_begin, condition,
LTTNG_UST_CALLER_IP());
retval = cond_broadcast(condition);
tracepoint(lttng_ust_pthread, pthread_cond_broadcast_end, condition,
LTTNG_UST_CALLER_IP());
thread_in_trace = 0;
return retval;
}
[-- Attachment #3: Type: text/plain, Size: 156 bytes --]
_______________________________________________
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lttng-dev@lists.lttng.org
https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2019-04-26 20:44 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
[not found] <CAC-H6tv29C9RdoquefmAs6s-kM6o-RyYFMAYF1a1Vqk0PYX9dQ@mail.gmail.com>
2018-05-01 14:39 ` Tracepoints for pthreads conditional variables Jonathan Rajotte-Julien
[not found] ` <20180501143953.GA26829@joraj-alpa>
2018-05-03 20:37 ` Shehab Elsayed
[not found] ` <CAC-H6tuewaghma5hN3R2iCGvpcYVMph1uwti3u0+1ZhZEn44-A@mail.gmail.com>
2018-05-29 14:36 ` Shehab Elsayed
[not found] ` <CAC-H6tu3wfE-LJWCTL8+rggLkyJ75yjMEmi=rWGsWspWkaaoGg@mail.gmail.com>
2018-07-05 21:36 ` Shehab Elsayed
[not found] ` <CAC-H6tv5KPAYwg_ZxjUva95g2wZpZm8Oi_Q5Pve+Ow4jDcGfxw@mail.gmail.com>
2019-04-26 20:44 ` Shehab Elsayed
2018-05-01 13:31 Shehab Elsayed
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