Hi, there is in gr-osmosdr a lot of code like: hackrf_source_c::~hackrf_source_c () { ... free(_buf); _buf = NULL; } } Setting value in destructor have sense in two case: - they are used in some way in destructor of parent class - You set then to something like 0xDEADBEEF and when pointer from already destroyed class is used it will cause segfault. Setting value to NULL is contraproductive because there is a lot of checks if value is not NULL, this actually can hide some troubles of calling something using already freed pointer. I'm suggesting to remove this kind of code. I will prepare patch but now I'm waiting if those two pending patches I have send before would be accepter or not. Is there any opinion which oppose previous claim? With best regards, JP.