Implementation perspective of Simple List Of Blocks

Understanding Malloc

This issue is continuation of previous instalment, i.e. on Simple List Of Blocks. In previous section we saw the logical perspective of SLOB, In this section we would look into the implementation perspective of SLOB.

Data Structure. To start with, lets first derive data structure necessary to make the implementation work.Usually, the correct selection of data structure is the key to designing a good algorithm. To design for SLOB we primarily need two data structures, one is the list holding the chunks of same size and other to hold the chunk frame itself.

The List. Each element in the list needs to be a collection holding at least two elements, namely a variable holding the size of the chunks and other holding the head of the chunk frames. The list we are intending to design could be of two kinds; contiguous and disjoint. Both has its own advantages and disadvantages; the list being contiguous saves space of holding reference to the next element, but at the same time prevents the list from further expansion. In this implementation we would design blocks as disjoint linked list and list as contiguous. This approach imitates the implementation of many real libraries.

Semantic version of Simple List Of Blocks

Understanding Malloc

The previous section helped us understand two major syscalls namely brk and sbrk. I also implemented a basic malloc technique using these syscalls and addressed the problem on direct accessing these syscalls, i.e. The order of Free should be exact reverse of malloc, else would lead to segmentation violation.

A series of articles that tries to provide understanding on Dynamic allocation and related algorithms

Understanding Malloc

The Word Dynamism in memory has always been a fascinating area to understand. For many beginner level programmers, the allocation of dynamic memory using library calls like malloc have been a magic like complex implementation.

A Study On Memory Management - Scan Rate Policy

Understanding Memory Management Watermarks in Unix

Determining Watermark in Linux