FOR FREE MATERIALS
- Introduction: OS
- Booting Process
- Command Interpreter
- Dual mode of operation
- System Calls
- Difference between system call and library call
- Interrupt and Trap
- Introduction
- Scheduling Criteria, Terms and Concepts
- Different Type Scheduling Algorithms
- Longest Job First
- Longest Remaining Time First
- Highest Response Ratio Next (HRRN)
- Priority Scheduling
- Least Completed Next (LCN) Scheduling
- Multi-Level Queue Scheduling
- Multilevel Feedback Queue Scheduling
- Guaranteed Scheduling
- Fair Share Scheduling
- Lottery Scheduling
- Multi-Processor Scheduling
- Deadline Scheduling
- Rate-Monotonic Scheduling
- POSIX Real-Time Scheduling
- Priority Inversion
- Proportional Share Scheduling
- Comparison table of Scheduling Algorithm
- Algorithm Evaluation for Scheduling
- Important concept of MM
- Memory Representation as Address
- Memory layout for a Process
- Logical and Physical Address Space
- Necessity of Memory Management
- Introduction
- Concept of Non-contiguous memory allocation
- Basic concept of Paging
- Address Translation
- Process of Paging Method
- Calculation of Offset for paging
- Calculation of Logical Address Bit and number of Pages
- Calculation of Physical Address Bit and number of Frames
- Calculation of Page Table Size
- Organization of MMU
- Why Page size power of 2
- Paging Address Calculation: example1
- Paging Numeric Problem: Example2
- Paging Address Calculation: Example3
- Paging Address Calculation: Question1
- Some Important Question 2
- Paging Address Translation: Question3
- UGC NET Paging Question
- GATE Paging Question
- Number of information at Page Entry
- Exams Question on Page Entry Information
- Exam Question: Page Entry Information
- Calculates Page Table Entry Size
- Calculates Page Size
- Calculation of Optimal Page Size
- Question on Optimal Page Size
- Hashed Page Table with Example
- Inverted Page Table with Gate Question
- Question on Inverted Page Table
- Multi-Level Paging
- Multi-level paging: Example1
- Multi-level paging: Example2
- Allocation of Frames
- Subject Mock
Process Synchronization as a solution of Critical Section
To synchronize processes, we put extra code before Critical Section is called entry and after Critical Section(CS) is called exit. This synchronization mechanism avoids critical section problems or race conditions.
Example: Process Synchronization as a solution of critical section problem
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Note: Non- Critical Section (NCS): The portion of the program text, where the independent code of the processes will be placed.
This synchronization procedure using entry and exit code before and after Critical Section (CS) ensures that if one process is inside its Critical Section then no other processes are allowed to go inside its own Critical Section or at a time only one process is allowed to go inside the Critical Section.
So, to avoid race condition, only one process should be allowed in the Critical Section.
Synchronization mechanism:
- # Mutual exclusion ensure that there is no problem of race condition among processes
- # Process should not be allowed to access the critical section directly.
- # Process must be request permission to enter the CS.
- # Entry section must ensure the "Mutual Exclusion" principal
- # Process must notify when leaving the region.
- # Exit section informs the availability of the critical section to other waiting processes.
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