[snipped]
some clarification. I don't have any objections in general for having components pluggable. What I mean is this general work (moving to pluggable components) should not be necessarily connected with discussion/modification/switching the design or implementation of specific component
I agree, runtime pluggability is not very important for current development activities (provided that build-time switching is possible). However, here is the key difference with *certified* binary distribution and development builds, we hardly would afford certifying many build combinations. But distinctions in component characteristics (perf, footprint, etc) may become essential in specific environments/app domains (e.g. embedded systems); we should strive for max runtime adaptability in a long term. -- Alexey
Thanks, Mikhail We had several examples in Harmony when we had > alternative implementations of the same thing. In most of the cases > (e.g. Crypto, Math, RMI) we had a build switch, and only in case of GC > we had a runtime switch. > > GC is special because it was easy to identify where the bug is by > switching GC in runtime. Since almost all the verifier bugs can be > easily identified by "VerifyError" or by using "-noverify" option, I > think a build switch is enough here. > > The SPECs do not spend much time in verification, but I observe > Eclipse start time improvement on my laptop. > > Please let me know if it sounds reasonable > > Thanks, > Mikhail > > 2007/7/5, Xiao-Feng Li <[EMAIL PROTECTED]>: > > It's a wise choice for Java6 to decouple the type inferencing from > > online type checking. To decide which verifier to use, we probably > > need know which design is better for the type checking transition. > > > > Thanks, > > xiaofeng > > > > On 7/5/07, Alexei Fedotov <[EMAIL PROTECTED]> wrote: > > > Mikhail, > > > > > > Your verifier implemented very interesting algorithm. > > > > > > * We already started moving into Java 6.0 direction, and Java 6.0 > > > suggested a different verification scheme [1]. I see implementing this > > > scheme as more important task than switching between two old > > > verifiers. > > > > > > * When a new scheme is implemented the legacy scheme won't be used > > > often, this means performance considerations are of less importance > > > compared to minimal risk considerations and ease of bug fixing. Any > > > switching comes at the cost of risk and increase in maintenance > > > efforts. > > > > > > * The legacy scheme is to be completely removed from specification > > > soon, so the new verifier should be separate from the old code. I > > > found it more productive to decide which verifier code base should be > > > a base for new development. > > > > > > What do you think? > > > > > > [1] New Java SE 6 Feature: Type Checking Verifier, > > > https://jdk.dev.java.net/verifier.html > > > > > > > > > On 7/5/07, Mikhail Loenko <[EMAIL PROTECTED]> wrote: > > > > We have passed code and feature freeze recently and have a momentum for > > > > bigger changes in the code. > > > > > > > > We have recently accepted [1] a contribution of an alternative implementation of > > > > bytecode verifier [2] > > > > > > > > New implementation demonstrated pretty nice testing [3] and > > > > performance results [4]. > > > > > > > > Though many bugs in current implementation were fixed and it now also > > > > demonstrate good testing results, the performance difference remains the same. > > > > > > > > I suggest that we switch default implementation for Harmony > > > > > > > > Thanks, > > > > Mikhail > > > > > > > > [1] http://mail-archives.apache.org/mod_mbox/harmony-dev/200706.mbox/[EMAIL PROTECTED] > > > > > > > > [2] http://issues.apache.org/jira/browse/HARMONY-3363 > > > > > > > > [3] http://mail-archives.apache.org/mod_mbox/harmony-dev/200703.mbox/[EMAIL PROTECTED] > > > > > > > > [4] http://mail-archives.apache.org/mod_mbox/harmony-dev/200703.mbox/[EMAIL PROTECTED] > > > > > > > > > > > > > -- > > > With best regards, > > > Alexei, > > > ESSD, Intel > > > > > > > > > -- > > http://xiao-feng.blogspot.com > > >
