Property:Summary
From COMP15212 Wiki
Text A summary of the page.
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For many years the magnetic disk has been the choice for backing store - i.e. ‘memory’ which is not directly addressable by a processor. This is typically, but not always exclusively, for files. Sometimes other technologies are (inaccurately) called “disks” too! +
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Fragmentation is when something - such as a file - which would be nice to have as one big item has been split into several smaller parts. +
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Gaining access to files by <i>making them appear</i> as arrays in the address space. +
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How files are organised. +
How files may be written and read. +
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In Unix, a set of “signals” allow system-level inter-process communication. For example, this allows one process to destroy another (permissions permitting). A target process can intercept and handle most signals in its own way. +
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In this context, means of connecting a file <i>tree</i> structure into a directed <i>graph</i>. +
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Increasing security by limiting access to various memory areas. This includes preventing one process from corrupting any others' spaces. +
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Information about Unix command-line interfaces. +
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Issues connected with memory made visible to more than one process. +
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Memory is the fundamental element in conventional contemporary computers, (apparently) containing all the code and data of executing programs. Its management as a resource is a fundamental task. +
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Methods by which the software can communicate with the I/O devices. +
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Mutual exclusion means “one at a time”. In this case it is largely about only allowing one of many possible threads to change some structure or I/O device. +
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Not restricted to OS code, pointers are used in all computer programming. They are used extensively in (and around) an OS and a thorough understanding is important. +
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OS provided calls that provide privileged, protected services using trusted code. Used to provide access to I/O devices, system variables etc. +
