Dynamic Memory Allocation

1. Introduction

From JavaScript Garbage Collection to C Manual Memory Management

In JavaScript, memory management is automatic - the garbage collector frees unused memory. In C, you must manually allocate and deallocate memory using functions like malloc(), calloc(), realloc(), and free().

💡 Key Concept: C's manual memory management gives you precise control but requires careful attention to prevent memory leaks and undefined behavior.

2. Basic Memory Allocation

3. Advanced Memory Functions

4. Memory Leaks and Prevention

5. Common Pitfalls

• Memory leaks: Forgetting to call free()
• Double free: Calling free() on already freed memory
• Dangling pointers: Using pointers after freeing memory
• Buffer overflows: Writing beyond allocated memory
• NULL pointer dereference: Not checking if malloc() returned NULL

6. Exercises

1. Write a function that allocates memory for a string, copies a given string into it, and returns the pointer. Don't forget to free it later.
2. Create a function that dynamically allocates a 2D array and initializes it with values.
3. Write a program that demonstrates memory leak detection by tracking allocations and deallocations.

7. Performance Analysis

• Manual memory management can be more efficient than garbage collection
• Memory fragmentation can occur with frequent allocations/deallocations
• Memory pools can improve performance for small, frequent allocations
• Proper memory management is crucial for long-running applications

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Summary: C's manual memory management provides control and performance but requires discipline. Always pair malloc() with free(), check for allocation failures, and use tools like Valgrind to detect memory leaks.