Projects Valhalla, Loom and GraalVM at JCon 2020

Editor's Notes

• #6: JDK 16 Mercuriual to Git to GitHub would be similar to a C struct, which the JVM does not support. Two obvious examples of candidates for this are Optional and LocalDateTime - both have the properties that would be expected of value types. This is related to the fact that the Java type system lacks a top type - there is no type that is the supertype of both Object and int. Another way of saying this is that the Java type system is not single-rooted
• #7: would be similar to a C struct, which the JVM does not support. Two obvious examples of candidates for this are Optional and LocalDateTime - both have the properties that would be expected of value types. This is related to the fact that the Java type system lacks a top type - there is no type that is the supertype of both Object and int. Another way of saying this is that the Java type system is not single-rooted
• #8: Перезагрузите расположение данных в памяти
• #9: Много ядерные
• #10: Ядро, оперативная память Inter-socket connection меж сокетная окоммуникация Mesi protocol производительность aus Performanzgründen auf die ganzen Cache-Lines (normalerweise 64 Bytes groß), wo sich mehrere Cache-Einträge befinden.
• #11: Задержка, латенция оперативная память, процессор
• #12: оперативная память
• #13: For a small object such as Integer, the overhead for an object (such as a boxed Integer object) can match or even surpass the size of the data itself (a primitive int requires 32 bits in Java). Идентичность подлинность, полиморфизм сборщик мусора
• #14: Eric Evans Domai Driven Design Value Type Entity. What classes to implement in JDK : LocalDateTime Optional Состояние статус
• #15: Have the same characteristics as primitives Выравнивать, сглаживать
• #17: Использования памяти Уменьшенная косвенность и локальностьУвеличенная местность/локальность Reduced memory usage: No additional memory is used to store object metadata, such as flags facilitating synchronization, identity, and garbage collection. Treat value classes like restricted objects. (made object primitve devide worse,+ boxing), painful migration, specailization and array (covariants) Indirection: Since objects are stored as reference types in Java, each time an object is accessed it must first be dereferenced, causing additional instructions to be executed. The flattened data associated with value types are immediately present in the location in which they are needed and therefore, require no dereferencing. Locality: Flattened value objects remove indirection which increases the likelihood that values are adjacently stored in memory–especially for arrays or other contiguous memory structures such as classes (i.e. if a class contains value type fields). (which increases locality and, consequently, the chance of cache hits).
• #18: Reduced memory usage: No additional memory is used to store object metadata, such as flags facilitating synchronization, identity, and garbage collection. Treat value classes like restricted objects. (made object primitve devide worse,+ boxing), painful migration, specailization and array (covariants)
• #19: Flatenning= Выравнивать или разглаживание? Indirection: Since objects are stored as reference types in Java, each time an object is accessed it must first be dereferenced, causing additional instructions to be executed. The flattened data associated with value types are immediately present in the location in which they are needed and therefore, require no dereferencing. classes (i.e. if a class contains value type fields). (which increases locality and, consequently, the chance of cache hits).
• #20: Locality: Flattened value objects remove indirection which increases the likelihood that values are adjacently stored in memory–especially for arrays or other contiguous memory structures such as classes (i.e. if a class contains value type fields). (which increases locality and, consequently, the chance of cache hits).
• #22: Not point in cloning them, no identity Enum has identity and can mutable. Longer answer: While the basic enum type doesn't contain mutators (and so it is immutable), your own Enum can. The problem with this is that Java enums are always singletons. If you add mutators to your enum you should keep this in mind since mutating your enum in a multithreaded application can have unforeseen
• #23: Don‘t want flattening because of recursive structures, JVM won‘t flatten container with ? Arrays are covariant
• #24: Don‘t want flattening because of recursive structures, JVM won‘t flatten container with ? Arrays are covariant. Primitive arrays don‘t subclass object arrays Массив ковариантность
• #25: Memory layout opt- value types are flattened, object headers and indiractions eliminated Compiler opt – value class methods are monomorphic because no polymorpysms of value classes allowed, so on dynamic dispatching by calling, that‘s why inlined. Value type fields are paassed in registers between compiled methods
• #26: Non-Nullability is sensible default, what what about migrating existing classes to value object, which can be null. Extra nullable Inline type inline class Point? 2 values are equals if they have the same type and all fields are equal (recurisve). But fields cann be objects that contains objects refs and value types
• #27: Don‘t want flattening because of recursive structures, JVM won‘t flatten container with ? Arrays are covariant. Primitive arrays don‘t subclass object arrays
• #28: Облегченный поток Продолжение?возобновление Parallel Universe which ... The author of Quasar, Ron Pressler Co-Routines in Oracle, Go
• #29: would be similar to a C struct, which the JVM does not support. Two obvious examples of candidates for this are Optional and LocalDateTime - both have the properties that would be expected of value types. This is related to the fact that the Java type system lacks a top type - there is no type that is the supertype of both Object and int. Another way of saying this is that the Java type system is not single-rooted
• #30: Поток. Неконтролируем главный поток A Oracle 64 bit JVM will default to 1M stack size per thread. For each gigabyte of memory you would get 1024 threads using the defaults (https://stackoverflow.com/questions/7726871/maximum-number-of-threads-in-a-jvm) ADBA is Asynchronous Database Access, a non-blocking database access api that Oracle is proposing as a Java standard. AoJ: ADBA over JDBC
• #31: Parallel Universe which ... The author of Quasar, Ron Pressler (Co-Routines in Kotlin, Go-Green Threads)
• #32: Scheduled планируется, стартуется Облегченный поток
• #33: возобновление
• #38: Pipe NIO Channel and Pipes Strand
• #39: Pipe NIO Channel and Pipes Strand
• #40: Executor now implements AutoClosable Interface and possible with try with ressources Trio library, Python Nursery concept Nesting- отвлетвения Структурированный параллелизм
• #41: Nesting
• #42: Nesting
• #43: Nesting
• #44: Pipe NIO Channel and Pipes
• #45: Java Flight Recorder (JFR) is a tool for collecting diagnostic, monitoring and profiling data about a running Java application. It is integrated into the Java Virtual Machine (JVM) and causes almost no performance overhead, so it can be used even in heavily loaded production environments.
• #46: Monitor with using directly Object.wait, Object.notify, reimplement your code with java.util.concurrent library Yield паузировать, останавливаться
• #48: GraalVM: The one to rule them all Speaker: Виктор Полищук
• #49: Shared Tools : Profiling und Debugger Производительность языковая совместимость
• #50: Throughput производительность C2 server compiler c++
• #51: Версия 20.1 Oracle Cloud
• #52: Truffle is an Open Source library for building programming language implementations as interpreters for self-modifying Abstract Syntax Trees (AST). Truffle - a toolkit and API for building language interpreters. Truffle. programming languages that can be transformed to LLVM bitcode on Graal VM. LLVM is collection of modular and reusable compiler and toolchain technologies. Sulong : LLVM compiles into the same LLVM bitcode instead of native machine code of the platform. Then GraalVM interpret this bit code and run it on JVM Interpretor for Ruby, R, JS must exist. TruffleRuby, Graal.js, FastR Not ScriptEngine and JSR 223 Nashorn JS API.
• #54: Native mashine code without interpreter, ahead-of-time compiler (all the classes to be used should be known at compile time)…optionally include dynamic compiler, no dynamic class loading, because of Ahead-of-Time-Compiler, to know in advance, what classes you need ELF- Linux Executable and Linking Format Closed-world-assumption
• #55: Native mashine code without interpreter, ahead-of-time compiler…optionally include dynamic compiler, no dynamic class loading, because of Ahead-of-Time-Compiler, to know in advance, what classes you need. Dynamic runtime : Gargbage Collector and ThreadSchedular and Memory Management modular aufgebaut
• #65: Complete CPU access during boost, Lambda hast fraction of CPU proportional to chosen RAM settings
• #67: -High throughput (network bandwidth): limited bandwidth (an order of magnitude lower than a single modern SSD) that is shared between all functions packed on the same VM -Communication: functions not directly network accessible, they must communicate via an intermediary service writing state out to slow storage and reading it back in again on subsequent calls
• #69: Максим Говорищев Quarkus
• #70: Native mashine code without interpreter, ahead-of-time compiler…optionally include dynamic compiler, no dynamic class loading, because of Ahead-of-Time-Compiler, to know in advance, what classes you need. Dynamic runtime : Gargbage Collector and ThreadSchedular and Memory Management modular aufgebaut
• #71: пропускная способность Native mashine code without interpreter, ahead-of-time compiler…optionally include dynamic compiler, no dynamic class loading, because of Ahead-of-Time-Compiler, to know in advance, what classes you need. Dynamic runtime : Gargbage Collector and ThreadSchedular and Memory Management modular aufgebaut
• #72: Максим Говорищев Quarkus
• #73: Native mashine code without interpreter, ahead-of-time compiler…optionally include dynamic compiler, no dynamic class loading, because of Ahead-of-Time-Compiler, to know in advance, what classes you need. Dynamic runtime : Gargbage Collector and ThreadSchedular and Memory Management modular aufgebaut
• #76: FinDev approach per per use/invocation proce models