-pthread option

[Jonathan Wakely]

On 16 January 2011 08:50, ali hagigat wrote:
> Add support for multithreading using the POSIX threads library.  This
> option sets flags for both the preprocessor and linker.  It does not
> affect the thread safety of object code produced by the compiler or
> that of libraries supplied with it.
> --------------------------------------------------------------
> What is the meaning of thread safety? I wonder if anybody knows what
> flags are set and please write a simple example of a multi-thread
> code.

The flags are platform-specific.  For GNU/Linux it passes -D_REENTRANT
 to the preprocessor and -lpthread to the linker.

This list really isn't the place to learn what thread-safety means, or
to learn about multithreading in general.  There are lots of books and
online documentation covering it.