Re: condition variables and signals

Thanks Greg for the insight into the problem. The fact that the signal handler runs in the same thread was not something I thought. Also I think it confirms using SIGEV_THREAD for this is the safe approach in this scenario. Best, Matias On Wed, Jan 13, 2021, at 19:06, Gregory Nutt wrote: > > >

Re: Milestone: 40,000th Commit

Cheers! On Wed, Jan 13, 2021 at 10:37 PM Nathan Hartman wrote: > > We have surpassed our 40,000th commit in the main NuttX repository. > > Many thanks to all of our past and present contributors who helped get > us this far over the years. > > Here's to the next 40,000 commits! > > Cheers, > Nath

Re: condition variables and signals

I am thinking that there must be some race condition:  When the condition variable is created the cond->sem value will be set to zero.  While waiting for cond->sem, it will be set to -1. If you see cond->sem equal to zero, my guess would be that the signal was received and cond->sem was incre

Milestone: 40,000th Commit

We have surpassed our 40,000th commit in the main NuttX repository. Many thanks to all of our past and present contributors who helped get us this far over the years. Here's to the next 40,000 commits! Cheers, Nathan

Re: condition variables and signals

Thanks. I'm using FLAT mode so no problem. Best, Matias On Wed, Jan 13, 2021, at 11:40, Gregory Nutt wrote: > Just beware of https://github.com/apache/incubator-nuttx/issues/1352 > > On 1/13/2021 8:09 AM, Matias N. wrote: >> Hi, >> thanks for your responses. Yes, upon more reading I realized mix

Re: condition variables and signals

Just beware of https://github.com/apache/incubator-nuttx/issues/1352 On 1/13/2021 8:09 AM, Matias N. wrote: Hi, thanks for your responses. Yes, upon more reading I realized mixing signals with pthread mutexes was not safe. I guess I was getting a race condition inside the mutex locking. As a

Re: condition variables and signals

Hi, thanks for your responses. Yes, upon more reading I realized mixing signals with pthread mutexes was not safe. I guess I was getting a race condition inside the mutex locking. As a workaround, I resorted to using SIGEV_THREAD notification for POSIX timers. This appears to work and I guess it

Re: condition variables and signals

BTW, looking at the spec for pthread_cond_wait, there's actually no mention about a limitation regarding using pthread_cond_signal invoked from within a signal handler to unblock a pthread_cond_wait. The restriction is elsewhere. pthread_cond_signal() is not in the list of async-signal-safe func