> -----Original Message----- > From: Austin S. Hemmelgarn [mailto:ahferro...@gmail.com] > Sent: Friday, January 31, 2014 11:05 AM > To: Network Nut; 'Clemens Ladisch' > Cc: linux-kernel@vger.kernel.org > Subject: Re: WaitForMultipleObjects/etc. In Kernel
> >> Network Nut wrote: > > I was thinking that, rather than as for specifics, I should present my > > general > problem, and ask how long-time Linux experts would solve it. > > > > I have a master process M, that executes continually, from the birth to > death of user-session. > > > > I have many (distinct) processes that will be launched, and these > processes, P1, P2, ...Pn, expect to see that M is executing. These processes: > > > > 1. expect to have access to a shared-memory section that already exists > because M created it > > 2. expect to use a semaphore that already exists because M created it > > 3. expect to use a mutex that exists because M created it > > > > P1, P2, ...Pn all know the path of image on disk of M. They are also > permitted to maintain a fixed string that can be used to "get at" the mutex > and semaphore. > > > > How would P1, P2, ...Pn get at the semaphore that M created? > > > > Please note that M cannot have any prior knowledge at all of P1, P2, ...Pn. > P1...etc. must initiate communication with M. > > > > [I don't want to misuse/abuse linux-kernel with my personal questions, so > if there is a more appropriate group, please let me know.] > > > > Regards, > > > > -Net > Assuming that you're porting to mainline distributions (and not embedded > devices), named SHM segments are accessible (providing the accessing > process has correct permissions) under /dev/shm. You just need to make > sure that you create the segment with the right permissions for the > other processes to access it. Thanks, Austin. I already know how to do named shared memory between two processes. I only included that to describe my overall problem. The problem that I am having is how I can make three totally-independent processes interact: 1. M is a master process that creates a semaphore. 2. P1 is a process that operates against the semaphore. 3. P2 is a process that operates against the semaphore. 4. It is not permissible that M be responsible for launching P1 or P2. 5. The semaphore, one way or another, must allow itself to be specified as one of the synchronization primitives in epoll_wait() How do I do this? -Nut -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
