3 2 points What is dual mode operation how can it be achieve

3. (2 points) What is dual mode operation, how can it be achieved?

4. (2 points) Describe any benefits of using shared memory over message passing communication.

Solution

Dual Mode Operation:

1. Sharing system resoruces requires operating system to ensure that if a program is incorrect it should be ensure that other program to execute incorrectly.

2. They are two modes:

User Mode: Execution will be done on behalf of user.

Monitor Mode: Execution done on behalf of OS.

3. To indicate a current mode, mode bit is added to coumputer hardware as User (1) or monitor (0).

4. When a falut or interupt occurs hardware automatically switches to monitor mode.

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Benefits of Shared memory:

1. In shared memory programming, tasks share a common address space where in message passing uses send and receive.
2. In shared memory, communication synchronize using load/store but in message passing thery will be only communication+synchronzation.
3. Shared memory will support message passing and message will support shared memory.
4. In shared memory system call are required to establish shared memory regions.
5. It has maximum speed and convenience of communication.