Boost C++ Libraries: Ticket #9181: memory leak in Date_Time

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gregory@… — Mon, 30 Sep 2013 12:43:46 GMT

attachment → bug.out

valgrind output

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Sun, 19 Jan 2014 22:41:43 GMT

cc mail@… added

I've reproduced your valgrind output on Fedora 19 (boost 1.53, gcc 4.8.2).

The source seems to be

/usr/include/boost/date_time/gregorian/gregorian_io.hpp:62

custom_date_facet* f = new custom_date_facet();

and

/usr/include/boost/date_time/posix_time/posix_time_io.hpp:59

custom_ptime_facet* f = new custom_ptime_facet();

inside a operator<<() definition.

But this memory leak is constant, i.e. it does not grow with the number of output operator calls - because it is guarded by:

if (std::has_facet<custom_ptime_facet>(os.getloc()))
{
 // use allocated facet
} else {
 // allocate facet
}

The else branch has a comment that reads:

//instantiate a custom facet for dealing with times since the user
//has not put one in the stream so far.  This is for efficiency
//since we would always need to reconstruct for every time period
//if the locale did not already exist.  Of course this will be overridden
//if the user imbues as some later point.

Andrey Semashev — Wed, 12 Mar 2014 16:33:09 GMT

Replying to Georg Sauthoff <mail@…>:

I've reproduced your valgrind output on Fedora 19 (boost 1.53, gcc 4.8.2).

The source seems to be

/usr/include/boost/date_time/gregorian/gregorian_io.hpp:62
custom_date_facet* f = new custom_date_facet();
and

/usr/include/boost/date_time/posix_time/posix_time_io.hpp:59
custom_ptime_facet* f = new custom_ptime_facet();
inside a operator<<() definition.

This is not a leak. The ownership of the facet is transferred to the locale object. The facet will be deleted when the locale is.

Regarding the valgrind report, I think this is due to the fact that the locale does not get deleted when valgrind makes its report. This is because standard streams are not destroyed at this point.

You can try adding "std::cout.imbue(std::locale())" at the end of your main() and see if the facet is deleted then.

status changed; resolution set

Andrey Semashev — Wed, 12 Mar 2014 19:42:23 GMT

status new → closed
resolution → invalid