Hello! On Wed, Oct 06, 2021 at 07:53:00PM +0000, Eran Kornblau wrote:
> > > > -----Original Message----- > > From: nginx-devel <nginx-devel-boun...@nginx.org> On Behalf Of Maxim Dounin > > Sent: Wednesday, 6 October 2021 16:12 > > To: nginx-devel@nginx.org > > Subject: Re: Sending a notification to the main nginx thread > > > > Hello! > > > > First of all, you may want to take a look at this warning in the > > development guide: > > > > https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fnginx.org%2Fen%2Fdocs%2Fdev%2Fdevelopment_guide.html%23threads_pitfalls&data=04%7C01%7C%7Cd0de648d5c294e07aac008d988cae55b%7C0c503748de3f4e2597e26819d53a42b6%7C1%7C1%7C637691227285308685%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=%2BiDgCqNY6Wtl0elz%2FYAG7UvdOmoW%2BsZg9v0i5Oicc%2FY%3D&reserved=0 > > > > Quoting it here: > > > > It is recommended to avoid using threads in nginx because it will > > definitely break things: most nginx functions are not thread-safe. It is > > expected that a thread will be executing only system calls and thread-safe > > library functions. > > If you need to run some code that is not related to client request > > processing, the proper way is to schedule a timer in the init_process > > module handler and perform required actions in timer handler. Internally > > nginx makes use of threads to boost IO-related operations, but this is a > > special case with a lot of limitations. > > > Thanks Maxim, I completely get that, that is the reason I was looking for way > to send a notification to the main thread, and didn't just try to call nginx > functions from some other thread. > In my case, I need to integrate with some 3rd party library that has its own > event loop, it would require significant changes to the library to make it > run inside nginx's event loop... > So, my plan is to run it on a side thread, and send notifications between the > threads, which would trigger some handler on the main thread whenever new > data arrives. > I can use ngx_notify for this, but if someone will use the module and also > nginx's thread pool or some 3rd party module that uses ngx_notify, it will > break. > I think I can live with that, but would be nice to have a solution that is > complete. To re-iterate: inside a "side thread" you are not allowed to call any non-thread-safe libc functions. It is reasonable to assume this excludes all 3rd party libraries with their own even loops. -- Maxim Dounin http://mdounin.ru/ _______________________________________________ nginx-devel mailing list nginx-devel@nginx.org http://mailman.nginx.org/mailman/listinfo/nginx-devel
