mamaria-k / algo_virt_mem_20_10

Virtual memory

This is program for the implementation of algorithms for managing virtual memory and comparing them with each other.

The program accepts one or several files.

Description of correct format of input data:

• the file must contain the top three lines and only them
• the top line shows the number of pages in the process's address space (1 natural number)
• the second line should indicate the number of memory frames (1 natural number)
• the third line should contain a sequence of natural numbers (page references). They must be separated by spaces.

The results of the program are displayed on the screen.

Description of output:

1. The file was not in the correct format:

   • the program will fail
   • a message with error description will be displayed on the screen
   • the error description is written to the log

2. The file is in the correct format:

   • the result of each algorithm is displayed

     This is the result of the algorithm ... : [...]

     • if a free frame is replaced, then the answer is the frame number with *
     • if an already filled frame is replaced, then the answer is the frame number
     • if the page is already in memory, then the answer is +

     P.s. this output is arranged for the convenience of the user.

   • the result of the comparison is displayed

     Algorithms sorted by the number of answers of the second type: ...

3. Among the calls there are inadmissible:

   • a warning is displayed before the output of the program

     There were invalid calls in the call sequence. These calls will be ignored.

   • invalid calls are ignored

Example

$./gradlew run --args="file.txt"

File file.txt processing result:
There were invalid calls in the call sequence. These calls will be ignored.

This is the result of the algorithm FIFO: [1*, 2*, 3*, 1, +, 2, +, 3, 1]
This is the result of the algorithm LRU: [1*, 2*, 3*, 1, +, 2, +, 1, 2]
This is the result of the algorithm OPT: [1*, 2*, 3*, 2, +, 2, +, +, 1]

Algorithms sorted by the number of answers of the second type:
OPT: 6
FIFO: 7
LRU: 7

file.txt

10
3
22 4 8 7 1 1 2 7 4 10