Linked List-based Malloc
How it works
This is a simple implementation of malloc() and free(). It uses a first
fit approach, backed by a linked list. That is, whenever free() is called,
it stores the newly freed memory fragments in a linked list sorted by memory
address and merges fragments which are adjacent in memory. Then when
malloc() is called, it first scans this list for an available memory
fragment. If none is found, it issues a request to the kernel to allocate
another piece of memory for it.
Building and running
The static object (.so) library can be built simply by running
make
There are no external dependencies. Running make produces libmalloc.so,
which can be used in another process by executing e.g.
env LD_PRELOAD="./libmalloc.so" ls
Replace ls with the command you want to run. Alternately, you can use your
libmalloc.so for everything by executing
export LD_PRELOAD="/path/to/libmalloc.so"
To switch back to the standard library, issue
export LD_PRELOAD=""
Testing
A test script, test.sh, has been provided. This script simply runs a unit
test with the custom malloc library preloaded, as well as ls --color=auto.
The script can be easily modified to test other commands.