[boost] Re: Smart Pointers - (many) thanks and (some) questions

From: scleary_at_[hidden]
Date: 1999-12-28 08:32:53

Giora Unger wrote:

> 1. As far as I understand, the library is NOT thread safe.
>    Am I wrong ?
>    For example, let's examine line 169 in smart_ptr.h:
>       if (--*pn == 0) { delete px; }
>    I believe, that in case of two threads concurrently accessing
>    this line (the reset() method), and an initial reference count==2,
>    then a crash is possible: if both decrements occur before both
>    comparisons, resulting in two deletion attempts.

The smart pointers are just as thread-safe as integers.  To use them in a
thread-safe way, protect them just as you would any other non-thread-safe
fundamental type/class/library.

Should we look at doing a portable multi-threading library?  I have the
beginnings of one, but it doesn't allow timed waits or waiting for multiple
objects -- would these be considered essential or optional?

        -Steve