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List:       opensolaris-dtrace-discuss
Subject:    Re: [dtrace-discuss] pid provider to trace all function calls from
From:       Kodnani_Mohnish () emc ! com
Date:       2009-05-11 17:42:46
Message-ID: 1BE2A7C9899B074DAE9B4B1B7E95F40508CEB0BE () CORPUSMX60C ! corp ! emc ! com
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Thanks Pramod, 
I will try this out and see how it goes.  


Mohnish Kodnani

EMC CORPORATION
Ph: 925-600-6067

-----Original Message-----
From: Pramod.Batni@Sun.COM [mailto:Pramod.Batni@Sun.COM] 
Sent: Saturday, May 09, 2009 00:08
To: Kodnani, Mohnish
Cc: dtrace-discuss@opensolaris.org
Subject: Re: [dtrace-discuss] pid provider to trace all function calls
from aparticular function

Pramod Batni wrote:
> mohnish wrote:
>> Hi, We have a c++ application and I want to time all function calls, 
>> called from within a function. For Ex:
>> Lets say there is a function funcA and it calls funcB funC etc.. Now 
>> other functions can also call funcB and funcC, but I only want to 
>> trace them when they are called from within funcA. My psuedocode 
>> snippet :
>>
>> pid$target::<MANGLED FUNCA>:entry
>> {
>>  self->go_in = 1;
>>  self->ts[probefunc] = timestamp;
>> }
>> pid$target:::entry
>> /self->go_in/
>> {
>>   self->ts[probefunc] = timestamp;
>> }
>> pid$target:::return
>> /self->go_in/
>> {
>>  this->tmp = timestamp - self->ts[probefunc];
>>  this->tmp =0;
>> }
>> pid$target::<MANGLED FUNCA>:return
>> {
>>  this->tmp = timestamp - self->ts[probefunc];
>>  self->go_in = 0;
>>  this->tmp = 0;
>> }
>>
>>
>> This doesnt seem to work and ends up matching and printing all 
>> function calls. Can you please help me and see what I am doing wrong.

>
> You are not seeing any timing information because you are  recording 
> the timing information in a associative array and
> these arrays are not printed when you terminate the D script.
>
> Here's an attempt to rectify your script, keeping in mind that one of 
> the functions called from <func a> can be called
> multiple times.
>
> #!/usr/sbin/dtrace -s
>
> pid$target::<MANGLED FUNCA>:entry
> {
>   self->in = 1;
>   self->depth = 0;
> }
>
> pid$target:::entry
> /self->in/
> {
>        self->ts[self->depth++] = timestamp;
> }
>
> pid$target:::return
> /self->in  && self->ts[--self->depth] != 0/
> {
>        @a[probefunc] = avg(timestamp - self->ts[self->depth]);
>        @calls[probefunc] = count();
>        self->ts[self->depth] = 0;
> }
>
> pid$target::<MANGLED_FUNCA>:return
> /self->in/
> {
>   printf("TIMESTAMP");
>   printa("%s -> %@d\n", @a);
>
>   printf("FUNC_CALLS");
>   printa("%s -> %@d\n", @calls);
    /* returning from the function of interest, set self->in to zero to 
stop collecting information */

       self->in = 0;
>
> }
>


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