Questions

It is a useful, memory-saving technique for multiprogrammed timesharing systems. A Reentrant Procedure is one in which multiple users can share a single copy of a program during the same period. Reentrancy has 2 key aspects: The program code cannot modify itself, and the local data for each user process must be stored separately. Thus, the permanent part is the code, and the temporary part is the pointer back to the calling program and local variables used by that program. Each execution instance is called activation. It executes the code in the permanent part, but has its own copy of local variables/parameters. The temporary part associated with each activation is the activation record. Generally, the activation record is kept on the stack.

Note: A reentrant procedure can be interrupted and called by an interrupting program, and still execute correctly on returning to the procedure.

MAU is Multistation Access Unit

Joseph F. Glidden - Father of Barbed Wire.

• Glidden was born in New York in 1812. He invented Barbed Wire in 1873 and was granted the patent on Nov. 24, 1874. After a three year battle over the patent, which he eventually won received a patent for the modern invention in 1874 after he made his own modifications to previous versions.

Polo