Tejas Networks Interview Questions, Process, and Tips

Code for producer-consumer problem using mutex

• Create a shared buffer between producer and consumer

• Use mutex to lock the buffer while accessing it

• Producer adds data to buffer and signals consumer

• Consumer waits for signal and consumes data from buffer

• Repeat until all data is produced and consumed

Mutex is used for mutual exclusion while Semaphore is used for signaling and synchronization.

• Mutex is used to protect a shared resource from simultaneous access by multiple threads.

• Semaphore is used to signal between threads or to limit the number of threads accessing a shared resource.

• Mutex can only be locked and unlocked by the thread that locked it.

• Semaphore can be signaled and waited on by different threads.

• Mutex i...read more

Mutex and Semaphores serve different purposes in managing concurrent access to shared resources.

• Mutex is used to provide exclusive access to a shared resource, while Semaphores can be used to control access to a shared resource by multiple threads.

• Mutex is binary in nature, meaning it can only be in two states - locked or unlocked, while Semaphores can have multiple states.

• Mutex is typically used for protecting critica...read more

Deadlock is a situation where two or more processes are unable to proceed because they are waiting for each other to release resources.

• Occurs in multi-threaded or multi-process environments

• Can lead to system freeze or crash

• Prevention techniques include resource ordering and timeouts

• Example: Process A holds resource X and waits for resource Y, while Process B holds resource Y and waits for resource X

Deadlock can be prevented by using techniques like resource allocation, avoidance, and detection.

• Use a resource allocation algorithm to ensure resources are allocated in a safe manner.

• Avoidance can be achieved by ensuring that resources are only requested when they are available.

• Detection involves periodically checking for deadlock and taking action to resolve it if it is detected.

• Implementing timeouts can also help pr...read more

Virtual addressing is a memory management technique that allows a program to use more memory than physically available.

• Virtual addresses are mapped to physical addresses by the operating system.

• Virtual addresses are allocated to a program during its execution.

• Virtual addressing allows for efficient use of memory resources.

• Virtual addressing enables the use of shared memory and memory protection.

• Examples of virtual addr

Linker links object files and libraries to create an executable file. Loader loads the executable file into memory and executes it.

• Linker resolves external references and generates an executable file

• Loader loads the executable file into memory and performs relocation

• Linker and loader are part of the toolchain used to build and run programs

• Example: gcc uses linker and loader to compile and run C programs

Test_and_Set program is used to ensure mutual exclusion in concurrent systems.

• Test_and_Set is a hardware instruction that sets a memory location to a value and returns its old value.

• The program uses a loop to repeatedly execute the Test_and_Set instruction until it returns 0.

• The program then enters the critical section and sets the memory location back to 0 when done.

• Example code: while(Test_and_Set(&lock)); //critica

Program to merge two sorted linked lists in sorted order

• Create a new linked list to store the merged result

• Compare the first nodes of both lists and add the smaller one to the result list

• Move the pointer of the list with the smaller node to the next node

• Repeat until one of the lists is empty, then add the remaining nodes of the other list to the result

• Return the merged list

Program to find the duplicate in an array using binary tree or hash table

• Create a binary tree or hash table

• Iterate through the array and insert each element into the tree or table

• If an element already exists, it is a duplicate

Virtual memory is still necessary even with large physical memory. Paging helps manage memory usage.

• Virtual memory allows for efficient use of physical memory by swapping data between RAM and storage devices.

• Paging helps manage memory usage by dividing memory into smaller chunks called pages, which can be swapped in and out of physical memory as needed.

• Even with large physical memory, virtual memory can still be useful...read more

Time complexity of building a heap using linked list and arrays

• Building a heap using a linked list takes O(nlogn) time complexity

• Building a heap using an array takes O(n) time complexity

• Linked list implementation is slower than array implementation

• Arrays are better for random access while linked lists are better for insertion and deletion

To find the middle of a linked list, use two pointers - one moving at twice the speed of the other.

• Initialize two pointers - slow and fast

• Move the slow pointer one step at a time and the fast pointer two steps at a time

• When the fast pointer reaches the end of the list, the slow pointer will be at the middle

• If the list has even number of nodes, there will be two middle nodes. In that case, return the second middle node