Re: [Cppcms-users] reloading skins
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Re: [Cppcms-users] reloading skins
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From: Artyom B. <art...@ya...> - 2012-02-23 14:51:33
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Few points before I reply in detains. 1. What is wrong with current reload code? If the so changed it would be reloaded on the first access... Remind me :-) 2. Your code is wrong, you can't call "reload" function from signal handler. This may lead to undefined behavior. In fact there are very few functions you can call. And shutdown() is explicitly created as signal safe function. 3. If you want to implement your own "skin" reloader you can just unload all the skin shared object and load them once again upon signal. You don't really need CppCMS for - just don't list the skins in the skins list. I'll take a look on it in more details later. Artyom Beilis -------------- CppCMS - C++ Web Framework: http://cppcms.com/ CppDB - C++ SQL Connectivity: http://cppcms.com/sql/cppdb/ >________________________________ > From: Marcel Hellwig <ke...@co...> >To: cpp...@li... >Sent: Thursday, February 23, 2012 4:42 PM >Subject: [Cppcms-users] reloading skins > > >I hope this will will not be ugly tu read. A lot of code may be inside of this. So hold on (: >Hi everyone, >first: congrats for v1.0 artyom. You still haven't announced it, but svn already knows it :) >It is such a great framework. I never want to miss it and never go back to PHP or similar. >Now my request. >I am not happy with the solution of the auto reload skin function atm. As I mentioned long long time ago, I'd like to control it over Signals, and that's why I searched in your code and found this: >src/service.cpp:366 >void handler(int /*nothing*/) { if(the_service) the_service->shutdown(); } > >so I changed it a bit and now it looks like this: > >void handler(int sig) >{ > BOOSTER_DEBUG("cppcms") << "Signal " << sig << " received."; > if (the_service) > switch (sig) { > case 10: the_service->views_pool().reloadSkins(); break; > default: the_service->shutdown(); > } > >} > >signal 10 is, aymk, the USR1 sig and if you send that sig to the prog, it should reload all the skins, no matter if they are outdated or not. >So I changed: > >cppcms/views_pool.h:192 (reloadSkins() is public) >/// > /// Reload the Skins, when they are loaded via library. > /// > void reloadSkins(); > >and also >src/views_pool.cpp:336 > // reload all if needed > reloadSkins(); > pool::instance().render(skin_name,template_name,out,content); //as far as I see, render don't need a mutex lock > return; >...... > >void manager::reloadSkins() >{ > booster::unique_lock<booster::recursive_shared_mutex> lock(d->lock); > for(size_t i=0;i<d->skins.size();i++) { > impl::skin ¤t = d->skins[i]; > time_t mtime = impl::get_mtime(current.file_name); > //skip time checking > BOOSTER_DEBUG("cppcms") << "Reloading shared object/dll " << current.file_name; > current.so.reset(); > current.mtime = mtime; > current.so.reset(new impl::shared_object(current.file_name,true)); > } > return; >} > >What I did is to outsource the whole block, what is now inside of reloadSkins(), nothing more. Now the signal handler can access the method. > >Next step was to build cppcms again and run the messageboard example. I edited the config.js a bit, namely: >added "auto_reload" to views (just for testing) and changed the logging level to debug. > >Make the example will run, and work as expected. >Now, to my changes. >Here is the output: > >2012-02-23 15:20:43; cppcms_http, info: GET / (http_api.cpp:251) >2012-02-23 15:20:43; cppcms_http, info: GET /media/style.css (http_api.cpp:251) >2012-02-23 15:20:43; cppcms_http, info: GET /media/style-ltr.css (http_api.cpp:251) >now editing the template and compile it again, without restarting the prog >2012-02-23 15:21:23; cppcms_http, info: GET / (http_api.cpp:251) >2012-02-23 15:21:23; cppcms_http, info: GET /media/style.css (http_api.cpp:251) >2012-02-23 15:21:23; cppcms_http, info: GET /media/style-ltr.css (http_api.cpp:251) >nothing happens, as you see. Now the signal >2012-02-23 15:21:45; cppcms, debug: Signal 10 received. (service.cpp:368) >2012-02-23 15:21:45; cppcms, debug: Reloading shared object/dll .//libsimple.so (views_pool.cpp:351) >Arrived and reloaded >2012-02-23 15:21:55; cppcms_http, info: GET / (http_api.cpp:251) >2012-02-23 15:21:55; cppcms_http, info: GET /media/style.css (http_api.cpp:251) >2012-02-23 15:21:55; cppcms_http, info: GET /media/style-ltr.css (http_api.cpp:251) >but still there isn't any change > >Okay I thought, it is my fault and checked out the svn repo again and build the example again, but still there is the same error. >So whats next. I started to figure out, if the prog really uses the library I override. >lsof examples/message_board/build/libsimple.so > > Output information may be incomplete. >COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME >mb 11567 xxx mem REG 8,6 154864 5636786 ./examples/message_board/build/libsimple.so > >so yes, it loads the right library and uses it. And I checked it twice, that the time of the library is newer than the date of the program so that he should reload the lib. > >So two major things: >- I think your implementation of the time checking is invalid (it should load it before I'll give him the signal >- there is a huge mistake anywhere, so that he does not reload the skin and print that out. Maybe a caching error? > > > >When I wrote the last sentence I had an idea and tried to prove that. And bäm, I was right. >It was an "error" with the caching mechanism. I would suggest, that if you reload the skins, the whole cache should be reset. >I'd like you (artyom) to implement the following into cppcms with cache resetting, of cource. Oh and don't forget my "patch" ticket in sourceforge. (just two missing whitespaces) > > >Regards > >Marcel Hellwig > >------------------------------------------------------------------------------ >Virtualization & Cloud Management Using Capacity Planning >Cloud computing makes use of virtualization - but cloud computing >also focuses on allowing computing to be delivered as a service. >http://www.accelacomm.com/jaw/sfnl/114/51521223/ >_______________________________________________ >Cppcms-users mailing list >Cpp...@li... >https://lists.sourceforge.net/lists/listinfo/cppcms-users > > > |
