Re: [PATCH V2 3/9] New commands `enable probe' and `disable probe'.

[jose.marchesi@oracle.com (Jose E. Marchesi)]

Hi Doug.

    Would it be useful to have "info probes" show
    the enable/disable state of each probe?
    Or at least know which ones have been disabled.

Right, `info probes' actually tells you the "Enabled" status of the
probes, provided there is at least one dtrace probe in the executable.
For example:

(gdb) info probes
Provider Name             Where              Semaphore Enabled Object                         
demo     am-main          0x0000000000400c96           n/a     /home/jemarch/oracle/usdt/demo 
demo     another          0x0000000000400c8b n/a       always  /home/jemarch/oracle/usdt/demo 
demo     progress-counter 0x0000000000400c81 n/a       no      /home/jemarch/oracle/usdt/demo

In the example above demo:am-main is a systemtap probe, for which
"Enabled" reads n/a.  demo:another is a dtrace probe which cannot be
disabled (it does not have any associated enabler) and
demo:progress-counter is a dtrace probe which is disabled.

This is the source code used for the example above:

#include "stap-sdt.h"
#include "demo.h"

int main(int argc, char *argv[]) {
  int i=0;
  long int foo = 666;
  char *jaja = "oh yeah";

   while (i < 10) {
      i++;
      if (DEMO_PROGRESS_COUNTER_ENABLED())
        DEMO_PROGRESS_COUNTER (i, foo, jaja);
      DEMO_ANOTHER (i);
   }

   STAP_PROBE3(demo, am-main, i, foo, jaja);
   i = 0;
}