I would like to see the updated source code. Even if boost vault is deprecated and moved to github, it is still a good place to post files. Two more remarks: 1) it would be great to use auto_ptr for instance_ptr_type. It will make sure that the resource is deleted and the constructor called. 2) 2011/6/25 Ben Robinson <icaretaker@gmail.com>:
Singularity, I feel I still must make "instance_ptr" volatile for thread safety. If I do not, the compiler can store the pointer in a register, and other threads of execution will not see changes to its value. The linked article seems mostly concerned with fencing access to the variable, which I am achieving by using a mutex object. I only need volatile to prevent effectively reading a "cached" value for the pointer. I found the following article by Andrei Alexandrescu especially interesting: http://drdobbs.com/cpp/184403766
It is not thread safe. Consider the article http://www.aristeia.com/Papers/DDJ_Jul_Aug_2004_revised.pdf by Scott Meyers and Andrei Alexandrescu. In the article by Andrei Alexandrescu at http://drdobbs.com/cpp/184403766 there is no construction of object in LockingPtr, and that makes a big difference! Best regards, Antony Polukhin