On 5/8/16, 5:21 AM, "Christofer Dutz" <christofer.d...@c-ware.de> wrote:
> >Hi Alex, > >well actually the Ant build doesn't destroy the compiler, but the entire >VM. To me it seems that for every compilation and every Unit test a new >VM is forked. This is extremely expensive and time consuming. If you have >a look at the Flex Jenkins and compare the build time of Falcon with Ant >and with Maven, you will see that the Maven build runs in half the time >while still executing all Unit and Integration tests except the hand full >that need externs or the flex-sdk to run. Most of this speedup is due to >the fact that I don't fork a new VM for everything. Interesting. I occasionally run into a problem on my system where the Unit Tests run from Ant get real slow. In searching the internet, it appeared that a new VM was being created for each Unit Test even though I think the settings tell Junit not to do that, and I think after a restart my system suddenly runs the Ant tests much faster. So maybe somehow Ant + Junit + low memory doesn't allow a VM to be shared. > >Actually needing to fork is a measure of last resort. I know you might >need to pass things through the compiler and access that state from >different parts without wanting to pass along everything with each method >invocation. Usually you use Threadlocals for this. I haven't come across >this design pattern in Flex-related code. Perhaps it's worth having a >look at it [1]. It's a variable that each thread has it's own value. So >as soon as the same thread accesses the variable, it will get the same >result, but another thread has it's own value. As Threadlocals were >introduced with Java 7 you can still use what was used earlier ... A >singleton that manages a Map of Thread-Object pairs does the same thing >and you no longer need to worry about leaking states between instances >[2]. Then you could also utilize Maven concurrent builds and Surefires >multiple test execution in which you can build multiple Maven modules or >just Unit/Integration-tests in parallel, which dramatically speeds up >build time, if CPU utilization is the limiting factor. Before we go and remove all public statics, please take a moment to think about the Workspace class and read about it on this page: https://cwiki.apache.org/confluence/display/FLEX/How+Falcon+Creates+SWFs and the page it links to. I didn't work on this code, but it appears there is intention here to share stuff between instances of the compilers. I still think we need things to be efficient when the compilers are used outside of Maven like in some IDE so I think we want to make sure there is some way to share things. Thanks, -Alex
