"system" call in multithreading env

[Fedele Giuseppe]

Hi all,

I have a program in C code in which I would introduce the thread mechanisms.

The program uses "system" call and I know that it is not thread-safe.

My question is: can I use "system" in main-thread only? Or is it forbidden also here?

Thanks and Regards

Giuseppe

[Dennis Handly]

The problem with system(3) is that is calls fork/exec. This means the atfork handlers have to fire off and any signal handling required to wait for the child has to be done.

That said, I don't know if limiting it to the main thread will be good enough.

[Fedele Giuseppe]

Hi,
could you better explain how to manage signals in such a context?

The standard signal handling must be modified?

Thanks

Giuseppe

[Dennis Handly]

>could you better explain how to manage signals in such a context?

You may not able to do that because system(3) has to handle SIGCHLD and may mess up your handler.

[Fedele Giuseppe]

Can I use fork/execl instead of "system" ?

I know these two calls are thread safe ...

Giuseppe

[Dennis Handly]

>Can I use fork/execl instead of "system"?

Sure. Provided you know how to implement what you are passing to system(3).