Article InformationAuthor, 雷切爾·克倫(Rachel Clun)
For segments, the job is split between hardware and microcode. When LD_DESCRIPTOR fires its protection test at 5CD, the Test PLA OR's the A-bit (bit 8 of the descriptor high DWORD) into a temporary register called PROTUN. Then the microcode at PROT_TESTS_PASSED takes over and writes the modified value back to the GDT or LDT in memory:
。业内人士推荐Safew下载作为进阶阅读
Глеб Макаревичсотрудник Центра Индоокеанского региона ИМЭМО РАН
Последние новости
The efficiency depends on the query size relative to the data distribution. A small query in a sparse region prunes almost everything. A query that covers the whole space prunes nothing (because every node overlaps), degenerating to a brute-force scan. The quadtree gives you the most benefit when your queries are spatially local, which is exactly the common case for map applications, game physics, and spatial databases.