Re: [cdi-dev] Enhancing SPI to support async operation for contexts

Even in Servlets-3.0 a ‚Request‘ is only attached to exactly one single thread AT THE SAME TIME afaik. So they can switch a Request from one thread to another one, but there is always just a single one accessing it at the same time. At least that is what I did understand. LieGrue, strub > Am 19.02.2015 um 17:33 schrieb Sven Linstaedt <sven.linstaedt(a)gmail.com&gt;: > > Hi, > > and sorry for spontaneously dropping in. Just to clarify some personal questions/assumptions: > > 1. Regarding threading the current spec only states that "A context may be associated with one or more threads". > > 2. It is nowhere stated that @RequestScoped beans are inherently thread safe. Thread safety was implied from the servlet spec, because the scope backing container (ServletRequest#attributes) was executed single threaded. > > 3. With Servlet 3.0 the same ServletRequest#attributes is available for access from multiple threads via ServletRequest#startAsync(), so containing objects may have a need for synchronization. > > 4. Why does CDI 2.0 has to care about thread safety of @RequestScoped beans? If the application is for some reason setting the request in async mode, the application must also ensure, it's containing and accessed beans are thread safe. > > > Best regards > Sven > > 2015-02-19 11:22 GMT+01:00 Romain Manni-Bucau <rmannibucau(a)gmail.com&gt;: > Hi > > I'm +1 for it but it needs important changes (= surely new contexts). > Typically we can't change today @RequestScoped (which has no link with > a request but only with a thread!). > > So we could have @RequestScoped (~ @ThreadLocalScoped) and > @InheritedRequestScoped which would be a real request scope (but not > an InheritedThreadLocal please) > > For the request it makes a lot of sense since you need to stay thread > safe even accross threads (servlet spec) and avoids to be forced to > use message passing which - even if a good pattern - adds boilerplate > code for simple async needs. > > For JAXRS I dont know since it is really suspend/resume semantic so > request scope maybe doesnt makes much sense here (there is a break in > the flow). > > > > Romain Manni-Bucau > @rmannibucau > http://www.tomitribe.com > http://rmannibucau.wordpress.com > https://github.com/rmannibucau > > > 2015-02-19 10:32 GMT+01:00 Antoine Sabot-Durand <antoine(a)sabot-durand.net&gt;: > > Hi All, > > > > Beyond the asynchronous event case, shouldn’t we provide a way for user to launch async treatments in CDI with the possibility to keep the existing contexts at the moment of async operation launch? > > Today servlet or JAX-RS spec support async call without the loss of request for instance. Shouldn’t we think to something like that? > > > > Thanks for your input on that point. > > > > Antoine > > > > > > > > > > > > _______________________________________________ > > cdi-dev mailing list > > cdi-dev(a)lists.jboss.org > > https://lists.jboss.org/mailman/listinfo/cdi-dev > > > > Note that for all code provided on this list, the provider licenses the code under the Apache License, Version 2 (http://www.apache.org/licenses/LICENSE-2.0.html). For all other ideas provided on this list, the provider waives all patent and other intellectual property rights inherent in such information. > > _______________________________________________ > cdi-dev mailing list > cdi-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/cdi-dev > > Note that for all code provided on this list, the provider licenses the code under the Apache License, Version 2 (http://www.apache.org/licenses/LICENSE-2.0.html). For all other ideas provided on this list, the provider waives all patent and other intellectual property rights inherent in such information. > > _______________________________________________ > cdi-dev mailing list > cdi-dev(a)lists.jboss.org > https://lists.jboss.org/mailman/listinfo/cdi-dev > > Note that for all code provided on this list, the provider licenses the code under the Apache License, Version 2 (http://www.apache.org/licenses/LICENSE-2.0.html). For all other ideas provided on this list, the provider waives all patent and other intellectual property rights inherent in such information. _______________________________________________ cdi-dev mailing list cdi-dev(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/cdi-dev Note that for all code provided on this list, the provider licenses the code under the Apache License, Version 2 (http://www.apache.org/licenses/LICENSE-2.0.html). For all other ideas provided on this list, the provider waives all patent and other intellectual property rights inherent in such information.