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<div style="direction: ltr;font-family: Tahoma;color: #000000;font-size: 10pt;"><font size="2"><span style="font-size:10pt;">Hello,<br>
<br>
I am Yang Wang, I am currently using lttng to trace my JVM.<br>
<br>
During my using lttng in tracing JVM, I found three problems,<br>
<br>
1) in </span></font><font size="2"><span style="font-size:10pt;">lttng-ust-2.1.0/include/lttng/ust-tracepoint-event.h</span></font><br>
<br>
why using an assertion "<font size="2"><span style="font-size:10pt;">assert(!ret);" (Line676)?<br>
not allowing double registering and init?<br>
if double registering or initialization (provider), why not allowed just returning silently instead
<br>
of aborting"? How about </span></font><b><font size="2"><span style="font-size:10pt;">comments assert(!ret); ==>//assert(!ret);</span></font></b> what is the side-effects<br>
of doing this?<br>
<font size="2"><span style="font-size:10pt;"> <br>
2) The other problem is in .<b>/userspace-rcu-0.7.5/urcu/list.h Line85</b><br>
<br>
I have to add a guard "if" statement as the assertion in my program fails otherwise<br>
<br>
static inline void<br>
__cds_list_del (struct cds_list_head *prev, struct cds_list_head *next)<br>
{<br>
<b> if (prev != NULL && next != NULL) {</b><br>
//assert(prev != NULL && next != NULL);<br>
next->prev = prev;<br>
prev->next = next;<br>
}<br>
<br>
3) Now my instrumented prog is ready to run. Here is my commands:<br>
lttng create<br>
lttng enable-event -u -a<br>
lttng start<br>
./prog <br>
<br>
The (lttng) instrumented prog is stuck there without any outputs related to lttng tracing, how can I know what happen inside.<br>
In other words, does lttng have any mechanism to trace itself?<br>
<br>
Thanks<br>
<br>
Yang<br>
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