1. Virtual Memory
1.1. pages table TP
1.1.1. inside real memory
1.1.2. VM pages memory position
1.1.3. validity indicators
1.1.3.1. limit virtual space
1.2. aux table TA
1.2.1. VM pages HDD position
1.2.2. Upon page defect...
1.2.2.1. indicates HDD page/file
1.3. Hyper pages
1.3.1. 2+ levels
1.4. TLB
1.4.1. access speed optimizers
1.5. Virtual space (122)
1.5.1. each program
1.5.2. SHARING
1.5.2.1. 1+ pages -> 1 real page
1.6. REAL MEMORY
1.6.1. controlled by system
1.6.1.1. - thrashing
1.6.2. replacement algorithms
1.6.2.1. FIFO
1.6.2.2. LRU
1.6.2.3. Ref. bit
1.6.2.4. Optimal
1.6.3. work space
1.6.3.1. intersection - defects quantity
2. Server concurrence
2.1. Iterative
2.1.1. Simple
2.1.2. No context changes
2.1.3. Idle process = idle CPU
2.1.4. Only 1 CPU
2.2. Concurrent
2.2.1. + 1+ CPU's
2.2.2. + CPU free for use
2.2.3. - Time for
2.2.3.1. context change
2.2.3.2. units creation
2.2.4. - No control: concurrence units
2.2.5. - No charge balance
2.2.6. TYPES
2.2.6.1. Connection thread
2.2.6.2. Request thread
2.2.6.3. Thread pool
2.2.6.3.1. + dynamic creation
2.2.6.3.2. + resources control
2.2.6.3.3. + NO time thread creation
2.2.6.3.4. + charge balance (long queues)
2.2.6.3.5. - context change
2.2.6.3.6. - queue handling
2.2.6.3.7. - NO request priorities
3. Async Programming
3.1. interruptions
3.1.1. temporal pause
3.1.2. additional tasks
3.1.3. COULD
3.1.3.1. mask
3.1.3.2. patch
3.2. elements
3.2.1. DMA
3.2.1.1. memory controller
3.2.2. Driver
3.2.2.1. DMA controller program
3.2.3. Port
3.2.3.1. Logical, physic
3.2.4. BIOS
3.2.4.1. drivers group
3.2.5. Buffer
3.2.5.1. speed buffer