Very Computer

Hi,

I'm concerned about the thread safety of the STL supplied with gcc.

So my question is basically : is it thread safe or not ? ;-)

By that I mean: do I have to protect calls to (for instance, could be any
read/write operation on an STL component) avector.push_back() myself using
mutex-operations (and the like) or will push_back protect itself from
another push_back (from another thread) on the same vector?

Since there's something out there called STLport, which claims to be
thread-safe, I've got a bad feeling about the STL that ships with gcc.

Pieter

The answer isn't a simple yes or no, and it may depend on the
version of gcc.

See <http://gcc.gnu.org/onlinedocs/libstdc++/17_intro/howto.html#3>.

Quote:> By that I mean: do I have to protect calls to (for instance, could be any
> read/write operation on an STL component) avector.push_back() myself using
> mutex-operations (and the like) or will push_back protect itself from
> another push_back (from another thread) on the same vector?

> Since there's something out there called STLport, which claims to be
> thread-safe, I've got a bad feeling about the STL that ships with gcc.

The standard C++ library container are supposed to be pretty
lightweight, so few if any implementations will use mutexes to support
multiple writers.  In any case, mutexes on basic operations won't help
to deal with problems such as invalidated iterators.  So, yes, you do
have to use your own mutexes, whichever library you use.