July 2020 - armedbear-devel - mailman3.common-lisp.net

Setting different class loader
by Steven Nunez 06 Feb '23

06 Feb '23

Greetings all, I have what I think is a problem with the ABCL class loader. I am working with a 'big data' library, Spark, but run into an issue on line 2 of the programming guide example. I am able to load the JARs from Maven with the ASDF system definition: (asdf:defsystem #:spark :description "Wrapper for Spark 3.0" :serial t :defsystem-depends-on (abcl-asdf) :depends-on (#:jss #:javaparser) :components ((:mvn "org.apache.spark/spark-core_2.12" :version "3.0.0") (:file "package") (:file "spark"))) and can create a SparkConf object: (defvar *spark-conf* #1"new SparkConf() .setAppName("abcl-app") .setMaster("local")" ) But when I try to create a 'context' (defvar *sc* (new 'JavaSparkContext *spark-conf*)) I get an error in the initialisation: Java exception 'java.lang.NoClassDefFoundError: Could not initialize class org.apache.spark.package$'. There isn't much on this except from the Jenkins guys, who have attempted to put Spark and Spark applications into a CI system. They seem to think that it's related to a call to get a properties file in the package class and on a StackOverflow discussion suggested that "you should make sure that you set the classloader that Spark was loaded through using the Thread.currentThread().setContextClassLoader(myCustomLoader) call". I've verified with (java:dump-classpath) that the JAR is on the ABCL classpath, and the JAR file does contain the spark-version-info.properties file. I've also tried getting the file myself with: (defvar rs #1"Thread.currentThread() .getContextClassLoader() .getResourceAsStream("spark-version-info.properties")" ) which returns nil, so their theory may be correct. Messing around with class loaders is a bit beyond my 20 year old Java knowledge so I thought I'd ask here if anyone has any ideas on how I can load Spark in way to use the default Java class loader. Alternatively it occurs to me to ask why the ABCL class loader isn't able to find the properties file if the JAR is on the classpath and then to correct whatever that problem is. Cheers, Steve

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run-program issues with OpenJDK 11
by Eric Timmons 30 Jul '20

30 Jul '20

It appears that java.lang.UNIXProcess was removed in OpenJDK 9 or thereabouts, assuming I'm interpreting https://github.com/openjdk/jdk/commit/aa6b19f38ee4dc69cac664d1211bff0e69b31… correctly (/definitely/ not a Java developer here...). This seems to make run-program unusable when using prebuilt jars on recent JREs. Using the prebuilt 1.7.0 release and OpenJDK 11, I get the errors shown in prebuilt-openjdk11.txt (attached). If compiling using OpenJDK 11, run-program seems usable, but any attempt to get the PID of a process gives the error in from-source-openjdk11.txt (attached). -Eric VM settings: Max. Heap Size (Estimated): 7.79G Using VM: OpenJDK 64-Bit Server VM Armed Bear Common Lisp 1.7.0 Java 11.0.7 Oracle Corporation OpenJDK 64-Bit Server VM Low-level initialization completed in 0.198 seconds. Startup completed in 1.107 seconds. Type ":help" for a list of available commands. CL-USER(1): (sys:run-program "ls" nil) Error loading jar:file:/home/abcl/work/abcl/dist/abcl.jar!/org/armedbear/lisp/run-program.abcl at line 278 (offset 19142) #<THREAD "interpreter" {5C1AE0C4}>: Debugger invoked on condition of type ERROR Class not found: java.lang.UNIXProcess Restarts: 0: TOP-LEVEL Return to top level. [1] SYS(2): 0 java.lang.ExceptionInInitializerError at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490) at java.base/java.lang.Class.newInstance(Class.java:584) at org.armedbear.lisp.FaslClassLoader.loadFunction(FaslClassLoader.java:130) at org.armedbear.lisp.FaslClassLoader$pf_get_fasl_function.execute(FaslClassLoader.java:165) at org.armedbear.lisp.LispThread.execute(LispThread.java:832) at org.armedbear.lisp.Lisp.evalCall(Lisp.java:582) at org.armedbear.lisp.Lisp.eval(Lisp.java:540) at org.armedbear.lisp.Lisp.evalCall(Lisp.java:577) at org.armedbear.lisp.Lisp.eval(Lisp.java:540) at org.armedbear.lisp.Lisp.progn(Lisp.java:709) at org.armedbear.lisp.SpecialOperators$sf_progn.execute(SpecialOperators.java:273) at org.armedbear.lisp.Lisp.eval(Lisp.java:530) at org.armedbear.lisp.Load.faslLoadStream(Load.java:667) at org.armedbear.lisp.Load$init_fasl.execute(Load.java:457) at org.armedbear.lisp.LispThread.execute(LispThread.java:832) at org.armedbear.lisp.Lisp.evalCall(Lisp.java:582) at org.armedbear.lisp.Lisp.eval(Lisp.java:540) at org.armedbear.lisp.Load.loadStream(Load.java:629) at org.armedbear.lisp.Load.loadFileFromStream(Load.java:597) at org.armedbear.lisp.Load.loadFileFromStream(Load.java:477) at org.armedbear.lisp.Load.loadSystemFile(Load.java:375) at org.armedbear.lisp.Load.loadSystemFile(Load.java:255) at org.armedbear.lisp.Autoload.effectiveLoad(Autoload.java:110) at org.armedbear.lisp.Autoload.load(Autoload.java:147) at org.armedbear.lisp.Lisp.eval(Lisp.java:537) at org.armedbear.lisp.Primitives$pf__eval.execute(Primitives.java:345) at org.armedbear.lisp.LispThread.execute(LispThread.java:814) at org.armedbear.lisp.Lisp.evalCall(Lisp.java:575) at org.armedbear.lisp.Lisp.eval(Lisp.java:540) at org.armedbear.lisp.Lisp.progn(Lisp.java:709) at org.armedbear.lisp.Primitives$sf_block.execute(Primitives.java:3743) at org.armedbear.lisp.Lisp.eval(Lisp.java:530) at org.armedbear.lisp.Lisp.progn(Lisp.java:709) at org.armedbear.lisp.Closure.execute(Closure.java:220) at org.armedbear.lisp.Closure.execute(Closure.java:148) at org.armedbear.lisp.LispThread.execute(LispThread.java:814) at org.armedbear.lisp.Lisp$1.execute(Lisp.java:285) at org.armedbear.lisp.Symbol.execute(Symbol.java:803) at org.armedbear.lisp.LispThread.execute(LispThread.java:814) at org.armedbear.lisp.top_level_47.execute(top-level.lisp:407) at org.armedbear.lisp.CompiledClosure.execute(CompiledClosure.java:89) at org.armedbear.lisp.Symbol.execute(Symbol.java:793) at org.armedbear.lisp.LispThread.execute(LispThread.java:798) at org.armedbear.lisp.top_level_48.execute(top-level.lisp:415) at org.armedbear.lisp.LispThread.execute(LispThread.java:798) at org.armedbear.lisp.Interpreter.run(Interpreter.java:361) at org.armedbear.lisp.Main$1.run(Main.java:48) at java.base/java.lang.Thread.run(Thread.java:834) Caused by: org.armedbear.lisp.Go Error loading jar:file:/home/abcl/work/abcl/dist/abcl.jar!/org/armedbear/lisp/run-program.abcl at line 278 (offset 19142) #<THREAD "interpreter" {5C1AE0C4}>: Debugger invoked on condition of type ERROR Compiled function can't be loaded: org.armedbear.lisp.run_program_60 from org.armedbear.lisp.Pathname@49bd2fd0 Restarts: 0: TOP-LEVEL Return to top level. [1] SYS(3): 0 CL-USER(4): (exit) VM settings: Max. Heap Size (Estimated): 7.79G Using VM: OpenJDK 64-Bit Server VM Armed Bear Common Lisp 1.7.1-dev Java 11.0.7 Oracle Corporation OpenJDK 64-Bit Server VM Low-level initialization completed in 0.205 seconds. Startup completed in 1.224 seconds. Type ":help" for a list of available commands. CL-USER(1): (sys:run-program "ls" nil :wait nil) #S(SYSTEM:PROCESS :JPROCESS #<java.lang.ProcessImpl Process[pid=125, exitValue=0] {1E464845}> :%INPUT #S(SYSTEM::SYSTEM-STREAM) :%OUTPUT #S(SYSTEM::SYSTEM-STREAM) :%ERROR #S(SYSTEM::SYSTEM-STREAM)) CL-USER(2): (sys:process-pid *) #<THREAD "interpreter" {7278E1D6}>: Debugger invoked on condition of type ERROR Class not found: java.lang.UNIXProcess Restarts: 0: TOP-LEVEL Return to top level. [1] CL-USER(3): 0 CL-USER(4): (exit)

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java:jinterface-implementation: multiple interfaces?
by Steven Nunez 30 Jul '20

30 Jul '20

Is there a way to implement multiple interfaces on a single Java proxy? This code almost works: (java:jinterface-implementation "org.apache.spark.api.java.function.Function" "call" (lambda (s) (length s))) except that the proxy also needs to implement Serializable. The jproxy code in java.lisp seems to suggest that multiple implementations are allowed: (defgeneric jmake-proxy (interface implementation &optional lisp-this) (:documentation "Returns a proxy Java object implementing the provided interface(s)... but I can't see adding multiple implementations in the code. I see there's a few jmake-proxy methods in there though: are there any documentation or examples for their usage? Lsw2 doesn't use this at all and I can't find any other good examples of using ABCL. Multiple interfaces from the jinterface-implementation function would be ideal, as the above code could then be wrapped with a macro to produce a 'spark-lambda' and be used nearly like the regular ABCL lambda.

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JDK8 Style Lambda Functions and ABCL
by Steven Nunez 30 Jul '20

30 Jul '20

Greetings all, I'm trying to convert the following Java code in the "Basics" section of the Spark Programming Guide to ABCL: JavaRDD<Integer> lineLengths = lines.map(s -> s.length()); I know that "s -> s.length" is a JDK8 style lambda function with one parameter, returning the result of calling length() on 's'. What I'd like to be able to do is write: (let ((line-lengths (#"map" *lines* (lambda (s) (#"length" s))))) but this isn't getting me anywhere, with Java saying there is no applicable method 'map' on *lines* (an instance of JavaRDD). There is such a method (if it matters, it is inherited by JavaRDD from interface JavaRDDLike). Investigating that map method a bit further, it seems to want an org.apache.spark.api.java.function. Here's a clip from the Spark description: Spark’s API relies heavily on passing functions in the driver program to run on the cluster. In Java, functions are represented by classes implementing the interfaces in the org.apache.spark.api.java.function package. There are two ways to create such functions: - Implement the Function interfaces in your own class, either as an anonymous inner class or a named one, and pass an instance of it to Spark. - Use lambda expressions to concisely define an implementation. I think what I'm getting from the ABCL lambda expression is a java.util.function: SPARK> (describe (lambda (s) #"length" s))#<FUNCTION #<FUNCTION (LAMBDA (S)) {70B82AD0}> {70B82AD0}> is an object of type FUNCTION.The function's lambda list is: (S) I do wonder though how the Java lambda "s -> s.length()" manages to produce the correct result, so this theory may not be correct. The Spark guide goes on to say: While much of this guide uses lambda syntax for conciseness, it is easy to use all the same APIs in long-form. For example, we could have written our code above as follows: JavaRDD<String> lines = sc.textFile("data.txt"); JavaRDD<Integer> lineLengths = lines.map(new Function<String, Integer>() { public Integer call(String s) { return s.length(); } }); int totalLength = lineLengths.reduce(new Function2<Integer, Integer, Integer>() { public Integer call(Integer a, Integer b) { return a + b; } }); Or, if writing the functions inline is unwieldy: class GetLength implements Function<String, Integer> { public Integer call(String s) { return s.length(); } } class Sum implements Function2<Integer, Integer, Integer> { public Integer call(Integer a, Integer b) { return a + b; } } JavaRDD<String> lines = sc.textFile("data.txt"); JavaRDD<Integer> lineLengths = lines.map(new GetLength()); int totalLength = lineLengths.reduce(new Sum()); To me, both of those examples look unwieldy. There was a stack overflow discussion on creating Java classes with ABCL from 9 years ago, and I've read the java interface examples on abcl.org, but both of those techniques look like they will produce code just as unwieldy as the Java syntax above. Is there any way to use a lisp-style lambda syntax to produce a function that will satisfy Spark's requirement to implement the org.apache.spark.api.java.function interface? If not, the obvious route would be some macrology to create a defsparkfun, defsparkfun2, etc. that wrap the ABCL function I want to use with something that implements 'call' in the org.apache.spark.api.java.function interface. I'm hoping there's a better way.

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Third Brick Wall
by Steven Nunez 27 Jul '20

27 Jul '20

OK, I'm on lines 4 and 5 of 'hello world' and ran into yet another brick wall. Trying to convert the following two lines into ABCL: List<Integer> data = Arrays.asList(1, 2, 3, 4, 5); JavaRDD<Integer> distData = sc.parallelize(data); it looks like it should be easy. Heck, I can do that in one line: (#"parallelize" *sc* '(1 2 3 4 5)) ; *sc* defined yesterday and known to be correct But no, it claims "no applicable method named parallelize found on JavaSparkContext" (but there is!). Reading through section 3.1.1 of the documentation, it appears that this is probably because '(1 2 3...) is a LispObject and not a Java object (why no automatic conversion?). Let's try to convert it: (#"parallelize" *sc* (#"copytoArray" '(1 2 3 4 5))) No instance method named copytoArray found for type org.armedbear.lisp.Cons' And the same with using an array, e.g. (#"parallelize" *sc* (#"copytoArray" #(1 2 3 4 5))) Sigh It's been a week and my intention was to have a working prototype by now and present ABCL as a viable alternative to use in a project. I haven't got past line 5 in 'hello world'. This doesn't bode well. I've been reading about ABCL for years, and it's impressive. Full MOP, extensible sequences, nearly 100% ANSI compliance, and the ability to deploy on the JVM are major achievements. However, as a not-inexperienced Lisp programmer, I find the barrier to entry remarkably high and the documentation and examples sparse and insufficient to surmount the hurdles I encountered. Please take these comments in the way they are intended: constructive feedback from someone who is a fan of the project and would love to be able to use it. It's nearly impossible to get Lisp introduced into enterprise environments, and ABCL provides a wedge into those types of projects, ticking the boxes on deployment and ability to work with legacy Java code. Perhaps it makes more sense to someone approaching Lisp from the Java side, but coming from the Lisp side to Java, there's a high barrier to entry. I know that no volunteer wants to write documentation, but more and clearer docs are sorely needed here. This is probably not news, but sometimes it helps to be reminded of the obvious. I hate giving up, so this will be a personal background project in the hopes that at the next opportunity things will have improved to the point where we can consider introducing ABCL, so if anyone has any pointers, generally (though I think I would have found any docs or examples (lsw2) by now) and explaining this problem in particular, it would be greatly appreciated. @easye, you mentioned your ember project. If you're going to continue with that, please message me. A Spark wrapper would be useful, serve as a good exemplar for using ABCL to wrap a large library and, with a companion tutorial, help others overcome the kind of obstacles I've encountered. I'd be happy to contribute.

4 9

Create instance of generic class at runtime, supplying specializer?
by Alan Ruttenberg 21 Jul '20

21 Jul '20

For instance in http://owlcs.github.io/owlapi/apidocs_4/org/semanticweb/owlapi/util/Inferre… It says: Type Parameters:A - the axiom type Question is: how do I supply the axiom type when creating an instance. Thanks ALan

3 5

abcl-1.7.1 released
by Mark Evenson 18 Jul '20

18 Jul '20

With gentle prodding, we have released ABCL 1.7.1, a decidedly minor release correcting a few bugs resulting from the overhaul of arrays specialized on unsigned byte types. The brief list of CHANGES is a available for your perusal. <https://abcl.org/releases/1.7.1/> <https://abcl.org/svn/tags/1.7.1/CHANGES>. "A screaming comes across the sky. It has happened before but there is nothing to compare to it now."

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