C Dynamic Memory Allocation - Common Errors

Common Errors

The improper use of dynamic memory allocation can frequently be a source of bugs.

Most common errors are as follows:

• Not checking for allocation failures. Memory allocation is not guaranteed to succeed. If there's no check for successful allocation implemented, this usually leads to a crash of the program or the entire system.
• Memory leaks. Failure to deallocate memory using free leads to buildup of memory that is non-reusable memory, which is no longer used by the program. This wastes memory resources and can lead to allocation failures when these resources are exhausted.
• Logical errors. All allocations must follow the same pattern: allocation using malloc, usage to store data, deallocation using free. Failures to adhere to this pattern, such as memory usage after a call to free or before a call to malloc, calling free twice ("double free"), etc., usually leads to a crash of the program.