2. WHAT IS MUTLI PROGRAMMING ?
• MULTIPROGRAMMING IN AN OPERATING SYSTEM AS THE NAME SUGGESTS MULTI
MEANS MORE THAN MULTIPROGRAMMING IN AN OPERATING SYSTEM AS THE
NAME SUGGESTS MULTI MEANS MORE THAN ONE AND PROGRAMMING MEANS
THE EXECUTION OF THE PROGRAM. WHEN MORE THAN ONE PROGRAM CAN
EXECUTE IN AN OPERATING SYSTEM THEN THIS IS TERMED A
MULTIPROGRAMMING OPERATING SYSTEM.
3. TYPES OF MULTI- PROGRAMMING
• MULTI-USER OPERATING SYSTEM
• MULTITASKING OPERATING SYSTEM
4. WHAT IS MULTI USER OPERATING SYSTEM
• IN A MULTIUSER OPERATING SYSTEM, MULTIPLE NUMBERS OF USERS CAN
ACCESS DIFFERENT RESOURCES OF A COMPUTER AT THE SAME TIME. THE
ACCESS IS PROVIDED USING A NETWORK THAT CONSISTS OF VARIOUS PERSONAL
COMPUTERS ATTACHED TO A MAINFRAME COMPUTER SYSTEM. A MULTI-USER
OPERATING SYSTEM ALLOWS THE PERMISSION OF MULTIPLE USERS FOR
ACCESSING A SINGLE MACHINE AT A TIME. THE VARIOUS PERSONAL COMPUTERS
CAN SEND AND RECEIVE INFORMATION TO THE MAINFRAME COMPUTER SYSTEM.
THUS, THE MAINFRAME COMPUTER ACTS AS THE SERVER AND OTHER PERSONAL
COMPUTERS ACT AS CLIENTS FOR THAT SERVER
5. WHAT IS MULTITASKING OPERATING SYSTEM
• MULTI TASKING OPERATING SYSTEMS ALLOW MULTIPLE USERS TO PERFORM
MULTIPLE TASKS AT THE SAME TIME. THE ALLOCATION OF SYSTEM RESOURCES
SUCH AS INPUT/OUTPUT DEVICES, CPU AND MEMORY AMONG PROCESSES CAN
BE EASILY MANAGED BY MULTI-TASKING OPERATING SYSTEM. THERE ARE
VARIOUS STATES THROUGH WHICH A PROCESSOR PASSES TO COMPLETE
PARTICULAR OR MULTIPLE EXECUTIONS. MULTITASKING IS THE ABILITY OF
AN OS TO EXECUTE MORE THAN ONE TASK SIMULTANEOUSLY
ON A CPU MACHINE
6. TYPES OF MULTITASKING OPERATING SYSTEM
• PREEMPTIVE SCHEDULING ALGORITHM: IN THE PREEMPTIVE SCHEDULING
ALGORITHM IF MORE THAN ONE PROCESS WANTS TO ENTER INTO THE CRITICAL
SECTION THEN IT WILL BE ALLOWED AND IT CAN ENTER INTO THE CRITICAL
SECTION WITHOUT ANY INTERRUPTION ONLY IF NO OTHER PROGRESS IS IN
THE CRITICAL SECTION.
• NON-PREEMPTIVE SCHEDULING ALGORITHM: IF A PROCESS GETS A CRITICAL
SECTION THEN IT WILL NOT LEAVE THE CRITICAL SECTION UNTIL OR UNLESS IT
WORKS GETS DONE.
7. FEATURES OF MULTIPROGRAMMING
• NEED SINGLE CPU FOR IMPLEMENTATION.
• CONTEXT SWITCH BETWEEN PROCESS.
• SWITCHING HAPPENS WHEN CURRENT PROCESS UNDERGOES WAITING STATE.
• CPU IDLE TIME IS REDUCED.
• HIGH RESOURCE UTILIZATION.
• HIGH PERFORMANCE.
8. ADVANTAGES OF MULTIPROGRAMMING
• IT PROVIDES LESS RESPONSE TIME.
• IT MAY HELP TO RUN VARIOUS JOBS IN A SINGLE APPLICATION
SIMULTANEOUSLY.
• IT HELPS TO OPTIMIZE THE TOTAL JOB THROUGHPUT OF THE COMPUTER.
• VARIOUS USERS MAY USE THE MULTIPROGRAMMING SYSTEM AT ONCE.
• SHORT-TIME JOBS ARE DONE QUICKLY IN COMPARISON TO LONG-TIME JOBS
10. DISADVANTAGES OF MULTIPROGRAMMING
• PRIOR KNOWLEDGE OF SCHEDULING ALGORITHMS IS REQUIRED.
• IF IT HAS A LARGE NUMBER OF JOBS, THEN LONG-TERM JOBS WILL HAVE TO
REQUIRE A LONG WAIT.
• MEMORY MANAGEMENT IS NEEDED IN THE OPERATING SYSTEM BECAUSE ALL
TYPES OF TASKS ARE STORED IN THE MAIN MEMORY.
• USING MULTIPROGRAMMING UP TO A LARGER EXTENT CAN CAUSE A HEAT-UP
ISSUE