I understand that CLR in its current state is bound to windows OS and provides various services by using Win32 APIs internally.
Since .NET Core is platform independent, this basically implies the same IL code can run on different OS. Is CoreCLR OS specific? Or is CoreCLR code written to take different execution paths depending upon current execution environment/OS ?
From the discussion in coreclr repository:
As far as I am aware the CLR in this repo [coreclr] is identical to the CLR in full .NET and the only differences are in the available API set in corefx.
... but seems like there is at least C++/CLI that is missing...
To answer some of the other questions:
Since .NET Core is platform independent, this basically implies the same IL code can run on different OS
Yes. IL is a custom "language". You can write an interpreter/runtime for it that can run on any platform. This is true for other intermediate representations in other languages too, including java bytecode, llvm ir, python bytecode and so on.
Is CoreCLR OS specific? Or is CoreCLR code written to take different execution paths depending upon current execution environment/OS ?
It's a mix. A particular build of coreclr will only work on one OS, because it has been compiled to use features from that OS (including the OS-specific compiler, linking against the right OS-specific libraries, and running code specific to handle that OS). There is also a Platform Abstraction Layer in CoreCLR so that developers can code against one API - based on the Win32 API - and the PAL layer converts it to the right syscalls on Linux and Mac. As pointed out in a comment by #HansPassant, there's a large number of #ifdefs - both on native side and the managed side of CoreCLR.
We're converting quite a large Flex project from a monolithic web application project type to multiple projects where most of the existing files (~2000) will newly live under a Library project and there will be multiple runnable projects beside it (like web version and a desktop version).
What concerns us is the compilation time. It used to be something like a minute (already more that we would have liked) but now it easily takes ~10 minutes which is unacceptable.
Is it expected to see such a big difference when moving from MXMLC compiler to COMPC? I know MXMLC optimizes its usage and will skip files that are not used in the application it is expected that the COMPC build would be slightly slower as it compiles more files but I don't think the difference should be 10 fold, should it?
Is there a way to complie code directly into Native Code instead of MSIL so that we can bypass JIT while executing the code on machine. If its possible. Please let me know the technique also.
Thanks
Compiling MSIL to Native Code Ngen.exe
SUMMARY:
The runtime supplies another mode of
compilation called install-time code
generation. The install-time code
generation mode converts MSIL to
native code just as the regular JIT
compiler does, but it converts larger
units of code at a time, storing the
resulting native code for use when the
assembly is subsequently loaded and
run. When using install-time code
generation, the entire assembly that
is being installed is converted into
native code, taking into account what
is known about other assemblies that
are already installed.
Take look at - How to compile a .NET application to native code?
In the .NET languages I'm familiar with, the source is compiled directly to MSIL. What the JIT does is subsequently compile the IL code to native code.
What is default type of JIT compiler is used in .Net (visual studio)
out of (Pre-JIT,Econo-JIT,Normal-JIT)?
As far as I know default JIT is Pre-JIT but ASP.NET Does Not Support Pre-Just-In-Time (JIT) Compilation Through Native Image Generator.
A little bit of background on the various JIT types:
PRE-JIT: Compiles complete source code to native code in a single operation.
ECONO-JIT: Compiles only methods called at Runtime.
NORMAL-JIT: Compiles only methods called at Runtime and stored in cache.
I run Flex Builder 3 on a mac and as my project grows - the compile time gets longer and longer and longer. I am using some SWC's and there is a fair amount of code but it shouldn't take minutes to build and crash daily should it?
First of all, comments on some of the response:
There is no need to explicitly specify -incremental in Flex Builder because it uses incremental compilation by default.
-keep-generated-actionscript is a performance killer because it instructs the compiler to write out AS3 codes generated for MXML components in the middle of the compilation. File I/O in the middle of a compilation means unnecessary pauses and low CPU utilizations.
-optimize slows down linking because it instructs the linker to produce smaller SWFs. Note that -optimize=true|false doesn't have any effect on building SWCs because SWCs are libraries and have to be unoptimized.
I rarely mess with JVM settings because JVM knows its jobs well and tunes itself quite well at runtime. Most people make matter worse by setting various GC tuning parameters. That said, there are 3 settings most people understand and set correctly for their usage:
-Xmx (max heap size)
-server or -client (HotSpot Server or Client VM)
-XX:+UseSerialGC or -XX:+UseParallelGC (or other non-serial GC)
-server consistently outperforms -client by about 30% when running the Flex compiler.
-XX:+UseParallelGC turns on the parallel garbage collector. ideal for multicore computer and when the computer still has CPU cycles to spare.
You may also want to check out HellFire Compiler Daemon (http://bytecode-workshop.com/). It uses multiple processor cores to compile multiple Flex applications at the same time. You can also run the compiler on a second machine via sockets (assuming that your second machine has faster CPUs and more memory).
In my opinion, use more modules than libraries and use HFCD.
Hope this helps.
-Clement
There's no need to use mxmlc on the command line just to be able to add compiler flags. Right click your project in the Flex Navigator, select Properties and then Flex Compiler in the dialog that appears. There you can add any extra compiler flags.
Not sure that there's very much to do though, more code means more compile time, that's just the way it is. If you're not doing a release build (or whatever it's called in Flex Builder) it's unlikely that your compiler settings include optimize to begin with. Better choices to try would be -incremental (which only recompiles the parts that have changed) and -keep-generated-actionscript (which stops the compiler from deleting the ActionScript files it has generated from your application's MXML files).
I very much prefer using mxmlc on the command line (by way of Ant) compared to Flex Builder. Although I don't think that the latter compiles any slower, it feels more sluggish in every way. Using Ant also makes it possible to do more than just compilation when building, and conditional compilation (only compile a SWF or SWC if the source code has actually changed). Check out a blog post of mine for more info on that.
What you could try is the Flex Compiler Shell, another command line tool that can speed things up. Basically it tries to keep as much as possible in memory between builds, so no need to wait for things like the JVM starting up (the Flex compiler is a Java application). On the other hand this is sort of what Flex Builder does anyway.
In addition to the suggestions already mentioned, close any projects that you have open that you are not using.
Rich click on the Project in the Navigator view and select "Close Unrelated Projects".
Depending on how many projects you have open, this can lead to a significant improvements in compile time, as well as all around performance.
mike chambers
mesh#adobe.com
Slow compile time is most often caused by having large numbers of embedded resources ([Embed] or #Embed).
Option 2 on this article might help you: [http://www.rogue-development.com/blog2/2007/11/slow-flex-builder-compile-and-refresh-solution-modules/]
I created RAM Disk with workspace and it gives up to 10% of better compilation time. Not much, but something.
You want at least 4 gigs on your computer if possible, and make sure to override the default memory settings that eclipse/flexbuilder gives to the application.
If you're not sure how to do this, you can find the flexbuilder app in /Applications, right click and choose "Show Package Contents". Then go into the contents file and edit the eclipse.ini file. Edit that file have memory settings of at least:
-vmargs -Xms768m -Xmx768m -XX:PermSize=128m -XX:MaxPermSize=128m
It's also worthwhile to go into the eclipse/flexbuilder preferences and to check the "Show heap status" box under Windows->Preferences->General (This is in eclipse with the FB plugin, I'm assuming it's also there for standalone FB).
This shows the current memory in the lower right of the window and has a little trash icon so you can force garbage collection.
I'd also suggest turning off automatic building of the project when your files change (you can force a build with cmd-B).
We had a huge project with quite a few modules files and performance in FlexBuilder 3 was decent with these steps.
Go to Project->Properties->Flex Applications. All of the applications listed are compiled each time (even though you have a default set). If you remove everything but the default (don't worry, it won't delete the actual files), it only compiles the default app. This resulted in a significant speed up for me. If you change your default app, it ADDs it to the Flex Applications list - adding to your compile time. You will need to maintain this list to get the quickest compile.
I always disable "automatic compile" for Flex. It compiles too much, takes too long, and so interrupts my work.
If you have many different project files and all of those needs to be recompiled, but you also have other projects open and don't want to close them always you're doing a build, you can also use Eclipse Working Sets.
Unfortunately, the default Flex Navigator does not support working sets. But you can open the Package Explorer with Window / Show View / .... Click on the little white downward arrow to the topright and select Top Level Elements: Working Sets. You can then add Working Sets (aka groups of projects). Each project needs to be in at least one working set ("Other Projects" being the default), but can be in several.
Now with Project / Build Working Set / ... you can instruct Eclipse to build all the projects in this working set, but none of the others. This is especially useful if you suspect your project references to be sometimes broken - otherwise building the 'topmost' project should trigger subsequent builds automatically.
As Clement said, use the HellFire Compiler Daemon. If you have multiple modules and more CPU cores on your machine it can compile them in parallel. Another option is to use IntelliJ (the commercial version) which offers the same feature.
The SDK 4.x.x introduced silly bug (see Adobe bugsystem, issue FB-27440), which causes projects with SVN or CVS meta data compile much slower than with SDK 3.x.x. On how it can be fixed, see here.
You may want to explore the command-line compiler found in the Flex SDK, mxmlc. As I recall, Flex Builder 3 seems to hide all the compiler details, but perhaps there are arguments you can append that will help you speed up the compilation.
For example, you may want to set optimize=false which will skip the step of optimizing the bytecode (perhaps reducing compilation time)? This of course comes at the price of performance and file size of the actual application.
More documentation on mxmlc can be found at: http://livedocs.adobe.com/flex/3/html/compilers_13.html.
Good luck!
I don't use Flex Builder, but I use the Flex SDK compiler everyday and I was wasting tons of time waiting for the MXMLC compiler to do its job until I found Flex Compiler SHell:
http://blog.zarate.tv/2008/12/07/theres-something-called-flex-compiler-shell/
Although in theory Flex Builder already uses this optimizations, might be worth checking.
You can use WORKING SETS to compile just a set of your components that are part of the application that you are changing and not the whole project
http://livedocs.adobe.com/flex/3/html/help.html?content=build_6.html
Usually the first build takes the longest, and then it's pretty quick after that. That's using Vista x64 w/ core 2 duo.
Otherwise, I am nearly certain a Intel Core i7 Extreme Edition 965 3.2GHz upgrade processor would speed your Flex building up nicely .. :) :) :)