下面的代码片段的输出是什么?为什么? 解析:这是一道动态内存分配(Dynamic memory allocation)题.    尽管不像非嵌入式计算那么常见,嵌入式系统还是有从堆(heap)中动态分配内存的过程.面试官期望应试者能解决内存碎片.碎片收集.变量的执行时间等问题.这是一个有趣的问题.故意把0值传给了函数malloc,得到了一个合法的指针,这就是上面的代码,该代码的输出是“Got a valid pointer”.我用这个来讨论这样的一道面试例题,看看被面试者是否能想到库例程这样做是…
原文: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.87.3870&rep=rep1&type=pdf Abstract 动态内存分配器(malloc/free)在多线程环境下依靠互斥锁来保护共享数据的一致性.使用锁在性能,可用性,健壮性,程序灵活性方面有很多缺点.Lock-free的内存分配器能消除线程延迟或被杀死以及CPU的调度策略对程序的性能影响.这篇paper呈上了一个完整的无锁内存分配器.它的实现只使用被广泛支…
1. 对象的空间在括号开始就已经分配,但是构造在定义对象的时候才会实现,若跳过(譬如goto),到括号结束析构会发生错误,编译会通不过. 2.初始化 1 struct X { int i ; float f; char c;}; 2 3 - X x1 = { 1,2.2,'c'}; 4 X x2[3] = { {1,1.1,'a'},{2,2.2,'b'} }; 5 6 7 struct Y {float f; int i; Y(int a);} ; 8 9 Y y1[] = {Y(1),Y(2…
Memory management is the act of managing computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is…
  In the programs seen in previous chapters, all memory needs were determined before program execution by defining the variables needed. But there may be cases where the memory needs of a program can only be determined during runtime. For example, wh…
Generally, the use of a table/array (Static Memory) is most common in COBOL modules in an application system. When a space abend (SOC4) occurs, due to the exceeding of a dimension of an array, the developer must have to find each & every place in the…
The checking logic would be refactored into an aspect file, as follows: after(void * s) : (call($ malloc(...)) || call($ calloc(...)) || call($ realloc(...))) && result(s) { char * result = (char *)(s); if (result == NULL) { /* routine to handle t…
Learning Dynamic Memory Networks for Object Tracking  ECCV 2018Updated on 2018-08-05 16:36:30 Paper: arXiv version Code: https://github.com/skyoung/MemTrack (Tensorflow Implementation) [Note]This paper is developed based on Siamese Network and DNC(Na…
May 01, 2003  By Gianluca Insolvibile  in Embedded Software Call some useful fuctions of the GNU C library to save precious memory and to find nasty bugs. Dealing with dynamic memory traditionally has been one of the most awkward issues of C and C++…
微信搜索lxw1234bigdata | 邀请体验:数阅–数据管理.OLAP分析与可视化平台 | 赞助作者:赞助作者 Spark动态资源分配-Dynamic Resource Allocation Spark lxw1234@qq.com 4年前 (2015-12-31) 30544℃ 6评论 关键字:spark.资源分配.dynamic resource allocation Spark中,所谓资源单位一般指的是executors,和Yarn中的Containers一样,在Spark On Y…