[LCP]Waking multiple processes on shared memory update

[Jack Lloyd]

On Tue, 2 Jul 2002, Brad Douglas wrote:

> Next (and a better solution had it worked) I tried including a shared
> conditional variable and mutex in the shared memory and created a array
> of update counters (one per table). My idea was to have update()
> increment the counter for the modified table and then signal the
> conditional variable, waking the waitForUpdate() processes so they
> could compare the modified update array against a local copy they mad
> before waiting. This all fell apart when I found out I could not share
> mutexs or conditional variables between processes under Linux.

Hrmm... are you refering to pthread mutexes here? [this seems likely, at
least as I read this]. Sharing those is not going to work.

Try "man semget", which may be what you are looking for.

Hope this helps,
 Jack