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
Dependency or Precedence graph for Concurrency and Concurrent Programming:
Procedure and example
Concurrency and concurrent programming can be achieved through multi-processor, vector processor & array processor.
Dependency or precedence graph indicated which statements execute first, how one process depends on another process, and the flow of the processes.
.png)
Concurrency Condition:
S1: a = b + c;
S2: x = a * f;
S3: y = a + m;
S4: l = x + y;
Example 2:
We have code where there are three statements S1 to S3 and three semaphore variables a, b, c.
code
begin
cobegin
begin:S1;V(a);V(b) end;
begin:P(a);S2;V(c) end;
begin:P(b)P(c);S3 end;
coend
end
Here V means Up operation and P means Down operation.
Now we design a precedence graph as per the above code.
.png)
If we see the above code S1 does not depend on any statement so, S1 starts first.
S2 depends on S1 because S1 Up the semaphore variable a i.e. V(a) and until the semaphore variable a is down, S2 will not start i.e. P(a).
S3 depends on S1 because S1 Up the semaphore variable b i.e. V(b) and until the semaphore variable b is down, S3 will not start i.e. P(a).
S3 depends on S2 because S2 Up the semaphore variable c i.e. V(c) and until the semaphore variable c is down, S3 will not start i.e. P(c).
