Opened 3 years ago

Last modified 3 years ago

#10337 new Bugs

weak_ptr & shared_ptr causes double "delete" -> crash

Reported by: thesaint1987@… Owned by: Peter Dimov
Milestone: To Be Determined Component: smart_ptr
Version: Boost 1.53.0 Severity: Problem
Keywords: Cc:


I am not sure why this happens (VS2005 - VS2013) and specifically on windows (code compiles and runs fine on linux)...

The following is the boost code that is responsible:

void sp_counted_impl_p<T>::release() nothrow {

if( BOOST_INTERLOCKED_DECREMENT( &use_count_ ) == 0 ) {

dispose(); weak_release();



void sp_counted_impl_p<T>::weak_release() nothrow {

if( BOOST_INTERLOCKED_DECREMENT( &weak_count_ ) == 0 ) {




Look what MUST happen, when "use_count = 1" and "weak_count = 1".. It causes a double release which crashes the application. That was a real pain in the ass to track down and unfortunately I have nothing to specifically trigger this issue either. Just look at the code and it should be obvious that this is a race condition.

Attachments (0)

Change History (1)

comment:1 Changed 3 years ago by anonymous

Yeah I can now tell this issue persists in 1.56... Also I found a bug in my code. The issue was that I had two shared_ptr of which one was using a weak_ptr to the other. Then the one the weak_ptr pointed to got release by C++ before the other, so that the race condition above happened. I still think this should be fixed, because its obviously a race condition in boost too.

I solved the issue on my end by simply turning the weak_ptr into a shared_ptr and the original shared_ptr that the weak_ptr pointed to into a weak_ptr. This will force the correct release order at application exit upon boost and prevents the race condition from happening.

Modify Ticket

Change Properties
Set your email in Preferences
as new The owner will remain Peter Dimov.

Add Comment

E-mail address and name can be saved in the Preferences.

Note: See TracTickets for help on using tickets.