分享
 
 
 

JAVA的动态编译和静态编译

王朝java/jsp·作者佚名  2008-05-31
窄屏简体版  字體: |||超大  

Two popular approaches for compiling Java programs are Just-In-Time (JIT) compilation (e.g. Sun Hotspot [29], Cacao [18], OpenJIT [24], shuJIT [28], vanilla Jalapeno [1]) and static compilation (e.g. BulletTrain [22], Excelsior JET [10], GCJ [32], IBM VisualAge for Java [14], JOVE [15]). It would be wrong to say one approach is definitely better than the other, since they are suited for different situations [7]. In fact, current research on ``quasi-static compilation'' [27] shows that combining these two may yield Excellent results.

In practice, static Java compilers are sometimes desirable over JIT compilers because they have many advantages [3,5,7]:

Static compilation yields more robust deployed applications. On the one hand, a deployment JIT may be different from the development JIT, which can cause problems due to even slight differences in the virtual machine or library code. With static compilation, programs are compiled into native code allowing the developer to test exactly what is deployed. On the other hand, compilers have bugs. Crashes caused by static compiler bugs sometimes happen at compile time (unless the bug is the kind that generates bad code silently), while bugs in the JIT may cause crashes at program execution time, and some of them may only surface after a portion of the program has been executed many times. Moreover, if the program crashes due to a bug in either the compiler or the program itself, statically compiled code is mUCh easier to debug because the run-time trace is more predictable.

Static compilation provides better intellectual property protection. Native code is much harder to reverse-engineer than Java bytecode.

Static Java compilers can perform resource intensive optimization before the execution of the program. In contrast, JIT compilers must perform analysis at execution time, thus are limited to simple optimizations that can be done without a large impact on the combined compile and execute time.

Static compilation achieves greatly reduced start-up cost, reduced memory usage, automatic sharing of code by the OS between applications, and easier linking with native code.

Last but not least, static compilation is better suited for code certification than JIT compilation. It is significantly easier to achieve higher safety assurance by removing the compiler from the trusted computing base. There has been a lot of work done in this area [23,21,19] which mostly focuses on static compilation.

Regardless of the above advantages, there is an ongoing debate in the Java community on whether statically compiled implementations can meet the Java specification on dynamic features such as binary compatibility. Our paper presents a scheme that accommodates the seemingly contradictory goal of full Java compliance and static compilation, thus showing that binary compatibility can indeed be supported using static compilers. Following the inspiration of ``quasi-static compilation'' [27], this technique in practice can also be used together with other JIT compilation techniques to achieve an optimal balance point between static and dynamic compilation. Thus we believe this result is of interest to the general audience in the JVM community.

 
 
 
免责声明:本文为网络用户发布,其观点仅代表作者个人观点,与本站无关,本站仅提供信息存储服务。文中陈述内容未经本站证实,其真实性、完整性、及时性本站不作任何保证或承诺,请读者仅作参考,并请自行核实相关内容。
2023年上半年GDP全球前十五强
 百态   2023-10-24
美众议院议长启动对拜登的弹劾调查
 百态   2023-09-13
上海、济南、武汉等多地出现不明坠落物
 探索   2023-09-06
印度或要将国名改为“巴拉特”
 百态   2023-09-06
男子为女友送行,买票不登机被捕
 百态   2023-08-20
手机地震预警功能怎么开?
 干货   2023-08-06
女子4年卖2套房花700多万做美容:不但没变美脸,面部还出现变形
 百态   2023-08-04
住户一楼被水淹 还冲来8头猪
 百态   2023-07-31
女子体内爬出大量瓜子状活虫
 百态   2023-07-25
地球连续35年收到神秘规律性信号,网友:不要回答!
 探索   2023-07-21
全球镓价格本周大涨27%
 探索   2023-07-09
钱都流向了那些不缺钱的人,苦都留给了能吃苦的人
 探索   2023-07-02
倩女手游刀客魅者强控制(强混乱强眩晕强睡眠)和对应控制抗性的关系
 百态   2020-08-20
美国5月9日最新疫情:美国确诊人数突破131万
 百态   2020-05-09
荷兰政府宣布将集体辞职
 干货   2020-04-30
倩女幽魂手游师徒任务情义春秋猜成语答案逍遥观:鹏程万里
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案神机营:射石饮羽
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案昆仑山:拔刀相助
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案天工阁:鬼斧神工
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案丝路古道:单枪匹马
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案镇郊荒野:与虎谋皮
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案镇郊荒野:李代桃僵
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案镇郊荒野:指鹿为马
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案金陵:小鸟依人
 干货   2019-11-12
倩女幽魂手游师徒任务情义春秋猜成语答案金陵:千金买邻
 干货   2019-11-12
 
推荐阅读
 
 
 
>>返回首頁<<
 
靜靜地坐在廢墟上,四周的荒凉一望無際,忽然覺得,淒涼也很美
© 2005- 王朝網路 版權所有