SEARCH KEYWORD -- Memory model


  Using MemoryMappedBuffer to handle large file in Java

When handling large files, it will largely affect the process speed while using traditional FileInputStream, FileOutputStream or RandomAccessFile since they trigger lots of read and write operations. In Java NIO, a new way of handling large file is introduced which is to use MmeoryMappedBuffer to create memory mapped file. Memory-mapped I/O uses the filesystem to establish a virtual memory mapping from user space directly to the applicable filesystem pages. With a memory-mapped file, you can pre...

   JAVA,IO,NIO     2015-11-13 01:58:08

  Are you ready for Facebook's phone?

According  to Sina Tech, Facebook will announce its own phone today in US. They will also release its new Android application. The Facebook phone is manufactured by HTC, the model will be HTC First. This will be a deeply customized Facebook phone, some IT professionals think this phone's name is very similar to HTC's flag model HTC One. This phone may provide a home screen application named Facebook Home. Facebook Home adopts the minimization design, it can display photos in full screen. T...

   Facebook phone,HTC,Facebook Home     2013-04-04 07:01:12

  GoLang Interview Questions

Below lists some frequently asked GoLang interview questions and their corresponding answers based on the author's experience. The list is updated frequently with new understandings. Stay tuned. What is the GMP model of GoLang? GoLang uses goroutine to achieve concurrency and it is famous for high concurrency support as the language defines its own goroutine dispatching and processing system which is well known as GMP model. How it works is that M is normally defined as the OS thread being spawn...

   MEMORY,CONCURRENCY,INTERVIEW QUESTION,GOLANG     2024-05-25 03:08:18

  HeartBleed: Should C be blamed for the HeartBleed bug?

There is a discussion about the security of applications written in C on Hacker News recently after the report of HeartBleed bug in OpenSSL. In this discussion, some people are saying that the applications written in C are unsafe. It seems all or most of the faults should be laid on C. I think this is biased. The language itself should not be blamed.Safety is a relative term for programming languages. No language is absolutely safe. We claim some languages like Java and C# are safer than C/C++ b...

   C,HeartBleed,Analysis,Code review     2014-04-14 03:52:55

  new expression vs operator new in C++

In C++, there is a new mechanism for memory allocation and management. When we want to initialize an object, we can use new expression to get enough memory for storing an object and also initialize the object. When we want to create a new object, we can use new expression, for example: Obj *obj=new Obj; Basically, what the new expression does is to allocate enough memory for storing the obj object, in addition, it will initialize the object with some intial values. Also, there is an operator new...

   C++, new expression, operator new     2012-08-12 11:42:39

  new() and make() in GoLang

GoLang is a modern, statically typed, compiled programming language designed for building scalable, concurrent, and efficient software. It provides various built-in functions and features that help developers write concise and efficient code. Among them are the new() and make() functions, which may appear similar at first glance but serve different purposes in GoLang and are crucial for memory allocation and data initialization. In this blog article, we will explore the differences between the n...

   NEW,MAKE,GOLANG     2023-11-18 13:43:25

  Output control functions in PHP

The Output Control functions in PHP allow you to control when output is sent from the script. This can be useful in several different situations, especially if you need to send headers to the browser after your script has began outputting data. The Output Control functions do not affect headers sent using header() or setcookie(), only functions such as echo and data between blocks of PHP code. These output control functions include ob_start(0, ob_clean(),ob_get_contents(), etc. To be honest, I a...

   PHP,output buffer,relationship,ob     2012-06-15 10:11:58

  Hadoop or Spark: Which One is Better?

What is Hadoop? Hadoop is one of the widely used Apache-based frameworks for big data analysis. It allows distributed processing of large data set over the computer clusters. Its scalable feature leverages the power of one to thousands of system for computing and storage purpose. A complete Hadoop framework comprised of various modules such as: Hadoop Yet Another Resource Negotiator (YARN MapReduce (Distributed processing engine) Hadoop Distributed File System (HDFS) Hadoop Common Thes...

   COMPARISON,HADOOP,SPARK     2018-11-22 07:08:57

  Simple explanation about process and thread

Process and thread are two basic concepts of operating system, but they are a bit abstract which cannot be  mastered easily. There is an analogy which explains these concepts very well. 1. The kernel of the computer is CPU, it handles all the computing tasks, it's like a factory and will run all the time. 2. Assume there is power limitation for the factory, it can only supply to one unit once,i.e, when one unit is working, other units must stop and wait. The meaning behind this is that eac...

   Process,Thread,CPU,Operating system     2013-04-24 11:33:10

  Memory related exception analysis in Java

Java Virtual Machine Specification divides the memory of JVM into several areas : Heap, Stack, The Program Counter register and Method area etc. In HotSpot JVM, heap is composed of Young, Tenured and Perm. There are different OutOfMemory error can happen in different memory area. Next is an overview of some of these OOM errors. StackOverflowError The JVM will allow only a specified number of stacks created nested. An JVM option -Xss can be set to determine the maximum stack size. If the num...

   Java, Memory model, Memory exception, OOM     2015-01-19 06:54:27

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