Western Digital Firmware Engineer Interview Questions and Answers for Experienced

Dynamic polymorphism is the ability of an object to take on multiple forms during runtime.

• It allows objects of different classes to be treated as if they are of the same class.

• It is achieved through virtual functions and inheritance.

• Examples include function overriding and templates in C++.

C++ has four types of casts: static_cast, dynamic_cast, const_cast, and reinterpret_cast.

• static_cast is used for implicit conversions between related types

• dynamic_cast is used for runtime type checking and casting of polymorphic types

• const_cast is used to remove const or volatile qualifiers from a variable

• reinterpret_cast is used for low-level casting between unrelated types

• Examples: static_cast(3.14), dynamic_castread more

IPC mechanisms in Linux are used for inter-process communication between processes running on the same system.

• IPC mechanisms include pipes, message queues, shared memory, and semaphores.

• Pipes are used for one-way communication between two processes.

• Message queues allow for asynchronous communication between processes.

• Shared memory allows multiple processes to access the same memory space.

• Semaphores are used for synchro...read more

map and unordered_map are associative containers while vector and list are sequence containers.

• map and unordered_map are used to store key-value pairs while vector and list are used to store sequences of elements.

• map and unordered_map provide faster search and insertion of elements while vector and list provide faster insertion and deletion of elements.

• map and unordered_map use red-black trees and hash tables respectiv...read more

Functors are objects that can be treated as functions in C++. They are used for generic programming and can be passed as arguments.

• Functors are often used in algorithms that require a function object as a parameter.

• They can be used to implement callbacks and event handlers.

• Functors can be used to create custom comparators for sorting algorithms.

• They can also be used to implement function objects for mathematical operat...read more

Move constructors enable efficient resource transfer from rvalues, avoiding unnecessary copies and improving performance.

• A move constructor takes an rvalue reference as a parameter, e.g., `MyClass(MyClass&& other)`. This allows transferring resources.

• Using `std::move`, you can cast an lvalue to an rvalue, enabling move semantics, e.g., `std::vector<int> v2 = std::move(v1);`.

• Move constructors should 'steal...read more

Synchronizing thread blocks is important for efficient and correct execution of parallel programs.

• Thread blocks must be synchronized to avoid race conditions and ensure correct program output.

• Synchronization can be achieved using locks, semaphores, or barriers.

• Examples of synchronization include ensuring that shared resources are accessed by only one thread at a time, or that threads wait for each other before proceedi...read more