Causes of Memory Leaks in C
- When dynamically allocated memory is not freed up by calling free then it leads to memory leaks. Always make ensure that for every dynamic memory allocation using malloc or calloc, there is a corresponding free call.
- When track of pointers that references to the allocated memory is lost then it may happen that memory is not freed up. Hence keep the track of all pointers and make ensure that memory is freed.
- When the program terminates abruptly and the allocated memory is not freed or if any part of code prevents the call of free then memory leaks may happen.
What is Memory Leak? How can we avoid?
A memory leak occurs when programmers create a memory in a heap and forget to delete it.
The consequence of the memory leak is that it reduces the performance of the computer by reducing the amount of available memory. Eventually, in the worst case, too much of the available memory may become allocated, all or part of the system or device stops working correctly, the application fails, or the system slows down vastly.
Memory leaks are particularly serious issues for programs like daemons and servers which by definition never terminate.
Example of Memory Leak
The below example shows the memory leak concept.
C
/* Function with memory leak */#include <stdlib.h>void f(){ int* ptr = (int*)malloc(sizeof(int)); /* Do some work */ /* Return without freeing ptr*/ return;} |