基于Java語言的操縱體系設(shè)計與實現(xiàn)技術(shù)研討

1、基于Java語言的操縱體系設(shè)計與實現(xiàn)技術(shù)研討        【中文摘要】跟著網(wǎng)絡技術(shù)的敏捷發(fā)鋪,人們對普適盤算的需求越來越高。傳統(tǒng)的操縱體系加中間件的方式已經(jīng)不能知足普適盤算的需求。普適盤算須要既具有平臺無關(guān)性又具有高安全性的新型操縱體系。應用Java語言來開發(fā)操縱體系不僅可以實現(xiàn)平臺無關(guān)性,而且可以解決緩沖區(qū)溢出等安全題目。但是Java操縱體系為我們帶來優(yōu)勢的同時,也帶來了良多挑戰(zhàn)。本文分離針對Java操縱體系的體系構(gòu)造設(shè)計、Java對象行為規(guī)律、全體系垃圾收集算法以及Java操縱體系的實現(xiàn)技術(shù)鋪開深入研討。體系

2、構(gòu)造的設(shè)計是操縱體系技術(shù)的基本。本文結(jié)合Java語言的特色,研討了Java操縱體系的體系構(gòu)造設(shè)計技術(shù)。在新的體系構(gòu)造下,研討了以JTOC(Java Table of Contents)為基本的入程軟隔離技術(shù),通過肯定入程的“內(nèi)存邊界”和“接口邊界”來實現(xiàn)入程間的隔離。提出Java操縱體系須要將垃圾收集技術(shù)和體系的存儲管理相結(jié)合實現(xiàn)全體系的垃圾收集技術(shù),從而實現(xiàn)安全高效自動的內(nèi)存管理。Java對象性命行為規(guī)律可認為垃圾收集算法的設(shè)計提供主要依據(jù),但目前對Java運行時程序行為的剖析仍是基于10多年前的統(tǒng)計數(shù)據(jù),因為當時的軟硬件環(huán)境和現(xiàn)在差異較大,所以前人的剖析數(shù)據(jù)已經(jīng)不能知足需求。本文設(shè)計實現(xiàn)了

3、Java對象性命行為的追蹤統(tǒng)計框架和E-Merlin程序準確追蹤算法,實現(xiàn)了對象性命行為的追蹤。應用此框架對SPECjvm98中的測試程序入行追蹤后,通過對追蹤結(jié)果入行解析和統(tǒng)計發(fā)現(xiàn):1)Java對象幾乎平均分布在5個范圍之內(nèi),每類對象中,邊界對象占絕大多數(shù);2)Java對象在內(nèi)存中的組織相似一個深度很淺的大胖樹,在根下,掛了良多小的Java對象簇,而且對象聚集成簇的現(xiàn)象非常普遍。目前的垃圾收集算法都是針對應用入程設(shè)計的,如果直接作為體系的垃圾收集算法,因為不能和體系的內(nèi)存管理相配合,所以機能低下。本文在深入研討了經(jīng)典垃圾收集算法(引用計數(shù)、標志清掃、半?yún)^(qū)復制和分代算法)和新型垃圾收集算法(火

4、車算法,Mark-Copy算法)原理的基本上,基于Mark-Copy算法,應用體系內(nèi)存管理機制和Java對象的內(nèi)存行為規(guī)律,設(shè)計實現(xiàn)了全體系垃圾收集算法FSMC(Full System Mark-Copy)。經(jīng)由測試,FSMC算法相對于Mark-Copy算法節(jié)省了20%以上的時光,取得了較好的后果。本文基于X86平臺設(shè)計實現(xiàn)了Junicorn原型體系。Junicorn體系的硬件抽象層采取C和匯編語言實現(xiàn),完成體系的引導和硬件裝備的初始化并對上層提供基本的硬件控制與中止處置服務。微內(nèi)核層基于JikesRVM實現(xiàn)了動態(tài)編譯引擎,基于分代式垃圾收集算法實現(xiàn)了體系垃圾收集器,并設(shè)計了中止異常服務框架,

5、目前可以處置X86中的大多數(shù)異常(如缺頁異常,除法異常等),提供了時鐘中止和鍵盤中止處置服務。目前Junicron支持鍵盤和顯示器兩種裝備,可以在華碩EPC上運行SPECjvm98中的測試程序。');【Abstract】 With the network technology developing rapidly, people inquire more and more about ubiquitous computing. The traditional technology which combines operating system and midware together

6、can not satisfy the need of ubiquitous computing. Ubiquitous computing requires a new kind of operating system which is both platform-independent and highly-secure. Using Java language to implement this type of operating system not only can make the system platform-independent, but also can solve sa

7、fety threats such as buffer-overflow-attack. Using Java to implement an operating system will bring us a lot of advantages, also it will introduce some challenges. This thesis deeply studies the architecture design of Java operating system, behavior rules of Java objects, full system garbage collect

8、ion algorithm and the implementing technology of Java operating system.The architecture design is the basic of operating system technology. According to the features of Java language, this thesis designs the architecture of Java operating system, under the new architecture, studies the technology of

9、 software-isolation among processes which based on the JTOC (Java Table of Contents) can define the memory and inte*ce border. In order to make the system memory management secure and efficient, this thesis put forwards the idea which should integrate the garbage collection and system management tog

10、ether to implement full-system garbage collection.Life behavior rules of Java objects can provide important evidence for the design of garbage collection algorithms, but the analysis of Java program behavior using data which was gathered more than ten years ago and is not suitable for current applic

11、ations because of the differences in hardware and software. This thesis designs a new framework and implements E-Merlin tracing algorithm to trace the behavior of every Java object. After using this framework to trace programs in SPECjvm98, we discover two basic rules about Java objects. First, Java

12、 objects typically distribute equally in five categories and in each category, broader objects account for large percents. Second, the structure of Java objects in memory is just like a broad fat-tree which is flat. There are a lot of objects directly attach to the root object.All of garbage collect

13、ion algorithms are designed for processes currently, not for operating systems. To use them directly as the garbage collection algorithms of operating system will be inefficient, because they could not cooperate with the mechanism of memory management effectively. This thesis deeply studies the prin

14、ciple of four classic garbage collection algorithms (reference count, mark-sweep, semi-space and generation algorithm) and two new algorithms (train and mark-copy algorithm), and analyses the advantages and shortages of every algorithm. Using the principle of Mark-Copy algorithm and behavior rules o

15、f Java objects, this thesis designs and implements a new full system algorithm named FSMC. According to the test results, FSMC improves the performance by 20% compared with Mark-Copy, which is very efficient.This thesis implements a prototype of Java operating system named Junicorn on the X86 platfo

16、rm. The hardware abstract layer of Junicorn, which is implented in C and assemble language, accomplishes system booting and the initialization of hardware, provides basic hardware control and interrupt management service for micro-kernel. The micro-kernel of Junicorn implements the dynamic compiling engine and full system gar