Semispace, Operating System

Semispace works by maintaining two disjoint areas from which memory can be allocated. These areas are called the from-space and the to-space. At ?rst, the algorithm allocates memory only from the from-space, without ever worrying about garbage collection. Allocation then is typically performed using simple pointer bumping, which simpli?es the whole process a lot. When we ?nally run out of space in the from-space, we sweep through all allocated objects that can be somehow reached; those are the ones that are still live. We then move each of these live objects to the to-space, taking care to update all pointers to the live objects to point to its new location in the to-space. Hence semispace is called a copying collector. After having done all this moving, only live objects are in the to-space. From this moment on, we can start using the to-space to perform allocation. The process is repeated again when the to-space eventually runs out of space. Thismethod has as advantages the fact that it might "compact" objects in the memory, thus increasing locality and minimizing fragmentation. Also, when performing allocation from one of the spaces, it can use simple pointer bumping, which is very fast. However, this approach doubles the memory requirements.

Posted Date: 3/13/2013 2:57:31 AM | Location : United States







Related Discussions:- Semispace, Assignment Help, Ask Question on Semispace, Get Answer, Expert's Help, Semispace Discussions

Write discussion on Semispace
Your posts are moderated
Related Questions
what are the factors influencing the choice of a mode of transportation?

Define what an assembler is An assembler is machine dependant.

Q. State three merits of placing functionality in a device controller rather than in the kernel and State three disadvantages. Answer: Three advantages: Bugs are less probabl

Q. Why do some systems stay track of the type of a file while others leave it to the user or simply don't implement multiple file types? Which system is "better?" Answer: A f

One reason to learn C and C++ is simply that so much software is written in these languages. A related, butmore fundamental reason, is that C and C++ are relatively low-level, allo

Explain the various methods for handling deadlocks.      A set of processes is deadlocked if every process in the set is waiting for an event that only a process in the

What are overlays? To enable a process to be larger than the amount of memory allocated to it, overlays are used. The idea of overlays is to keep in memory only those instructi

Vyvtvtn8

Describe the technique of packing. The physical record size will not accurately match the length of the desired logical record and the Logical records may even differ in length

List the Coffman's conditions that lead to a deadlock. Mutual Exclusion : Only one process might be use a critical resource at a time. Hold & Wait: A process may be alloc