C figure 1045 basic constants and macros for

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Unformatted text preview: equests, denoted by Í , is given by Í ÑÜ À È The objective of the allocator then is to maximize the peak utilization ÍÒ ½ over the entire sequence. As we will see, there is a tension between maximizing throughput and utilization. In particular, it is easy to write an allocator that maximizes throughput at the expense of heap utilization. One of the interesting challenges in any allocator design is finding an appropriate balance between the two goals. Aside: Relaxing the monotonicity assumption. We could relax the monotonically nondecreasing assumption in our definition of Í and allow the heap to grow up and down by letting À be the highwater mark over the first requests. End Aside. 10.9.4 Fragmentation The primary cause of poor heap utilization is a phenomenon known as fragmentation, which occurs when otherwise unused memory is not available to satisfy allocate requests. There are two forms of fragmentation: internal fragmentation and external fragmentation. Internal fragmentation occurs when an allocated...
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This note was uploaded on 09/02/2010 for the course ELECTRICAL 360 taught by Professor Schultz during the Spring '10 term at BYU.

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