Boost C++ Libraries: Ticket #4089: Memory leak in Boost.Signals2 when the signal is not invoked

attachment set

dan.berindei@… — Mon, 12 Apr 2010 16:57:17 GMT

attachment → aaa.cpp

Leak Test

Frank Mori Hess — Tue, 13 Apr 2010 13:02:19 GMT

(In [61243]) Fix for uncontrolled growth of slot list under certain patterns of connection/disconnection without invocation. Refs #4089.

status changed; resolution set

Frank Mori Hess — Wed, 14 Apr 2010 20:30:39 GMT

status new → closed
resolution → fixed

(In [61278]) Merged from trunk to release. Fixes #4089.

status, version, milestone changed; resolution deleted

julien.puydt@… — Fri, 27 Jun 2014 14:48:45 GMT

status closed → reopened
version Boost 1.42.0 → Boost 1.55.0
resolution fixed
milestone Boost 1.43.0 → To Be Determined

The following code gives wrong results with 1.55.0 ; it shows kept references trough a disconnection, which get released only if the signal is triggered :

#include <boost/smart_ptr.hpp>
#include <boost/signals2.hpp>
#include <iostream>
void
print (boost::shared_ptr<int> & ptr)
{
  std::cout << "Pointer has use count: " << ptr.use_count () << std::endl;
}
int
main (int argc,
      char* argv[])
{
  boost::signals2::signal<void(void)> sig;
  boost::shared_ptr<int> ptr(new int);
  // one ref here: should be 1
  print (ptr);
  boost::signals2::connection conn = sig.connect (boost::bind (&print, ptr));
  // one ref here, one in the bind: should be 2
  print (ptr);
  // is supposed to release the bind reference
  conn.disconnect ();
  // one ref here: should be 1
  print (ptr);
  // this isn't supposed to release a reference!
  sig ();
  // one ref here: should be 1
  print (ptr);
  return 0;
}

Frank Mori Hess — Fri, 27 Jun 2014 18:16:45 GMT

The behavior described by the most recent comment is by design and not a memory leak. There is already a ticket (#8533) to change the designed behavior to what you were expecting.

julien.puydt@… — Fri, 27 Jun 2014 19:12:47 GMT

It's what I was expecting because that's what I used to have. Though I can't tell if it was with signals v1 or v2...

status changed; resolution set

Frank Mori Hess — Fri, 15 Aug 2014 21:32:46 GMT

status reopened → closed
resolution → invalid