10. When a process is reading/writing a memory location (e.g. a variable), can other processes read...
10. When a process is reading/writing a memory location (e.g. a variable), can other processes read or modify the same memory location?
Homework Answers
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Most of the modern operating systems use virtual memory. In virtual memory, each process gets its own virtual address space. The virtual address space is divided into two different areas namely
1.The user space and
2.The system (or Kernel) space.
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The system space is the same for all processes. However, it is not writeable from user mode and most of the addresses are not readable or executable from user mode.
The user mode address space is unique for each process. Address 3000 in one process is usually not the same as address 3000 in another process.
It is usually possible to create shared memory areas that can be accessed by multiple processes.
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When you are reading or writing an address values written by one process and when other processes try to access them , the addresses are not accessible and they start crashing. By inaccessible, those addresses have not yet been created in the process's virtual address space. Even if they were created, they would not be the same memory as in your other processes.
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