Smartphone Operating System (779883), страница 68

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. .concepts 141–3, 146–54physical/logical addressing, memorymanagement 141–3, 146–54, 156–59,177–78, 216pipes 82platforms, operating systems 39–3PLCB (partition-label control block) 179plug-and-play concepts 6, 42, 51, 227PNG files 168polling 203–4POP (Post Office Protocol) 268, 275–6, 280portability needs, operating systems 7ports 202POSIX standards, Unix 76, 84Post Office Protocol (POP) 268, 275–6, 280power management 10, 15, 16pre-emptive/non-pre-emptive concepts,process scheduling 90–106, 133–4predictions, execution times 105–6printers 198, 206–7see also I/Opriorities, interrupts 55–6, 98, 104–6priority inheritance 128priority inversion concepts 104priority queues, process scheduling 101,104–6, 127–28priority strategy, process scheduling 98–1,103, 105–6, 128privileged-mode operations, operating systems35–6, 42–3, 48–9, 54, 55–6, 76–7process control blocks (PCBs), concepts64–7, 74, 76–84, 99–100, 104–5,145–7, 295process schedulingaging concepts 100–1basics 25, 49, 64–6, 76–7, 90–4concepts 25, 49, 64–6, 76–7, 89–108,216CPU 89–108330INDEXprocess scheduling (continued )criteria 92–4deadlines 102, 105–6dispatchers 91–4first-come-first-served strategy (FCFS)94–6, 98, 116microkernels 93–4, 104–6multiple-queuing strategy 101, 106pre-emptive/non-pre-emptive concepts90–106, 133–4predicted execution-times 105–6priority strategy 98–1, 103, 105–6, 128real-time strategy 101–6response times 93–106round-robin strategy 97–98shortest-job-first strategy (SJF) 96–98starvation issues 100–1, 113–16, 122,134static monotonic scheduling 102, 105–6strategies 93–103Symbian OS 105–6system types 93–4turnaround times 92–103waiting times 93–103, 113processessee also threadsaccess permissions 32, 33–38, 192clones 72, 79–4, 124–6concepts 13–16, 25, 32, 37–38, 48–9,55–6, 61–88, 89–108, 138–1, 219–2concurrently-shared resources 34–5, 42,69, 109–36, 236–7context-switches 25, 37–38, 40–1,49–50, 55, 74, 76, 82, 91–102, 138,145–6, 156, 160–1conventional programming model 79–2deadlocks 120–3, 133–4definition 25, 61–2distributed systems 13–14, 219–2file structures 171–2forking issues 72, 79–2, 124–6identification 32, 64, 66–7, 74, 113–16,287–88implementation concepts 66–7interleaving processes 111–12, 207IPC 128–2life cycle 138–1Linux 74–6, 79–1, 84, 91, 103–4multitasking 25, 37–38, 40–3, 50–1,61–88overview 62–79parent–child relationships 64–5, 66–7,74–5, 81–3, 279programming 79–7programs 62–3queues 66, 75–6, 79–2, 90–106, 127–28rollback approaches 134shared data 82, 91–4, 109–36signals 72, 117–18source code 138–1states 63–7, 72, 74–5, 90–4, 133–4,145, 236–7Symbian OS 73–4, 76–79, 83–7, 105–6types 32, 62zombie processes 67, 74–5producer–consumer problem,concurrently-shared resources 122–3program counter 62–4, 67, 74program stack 62–3, 68–9, 76–7, 156, 306programmingconcurrent processes 120conventional model 79–2historical background 8–11MTM 276–7processes 79–7Symbian OS 83–7, 276–7threads 82–7programs, processes 62–3protection issuessee also security .

. .definition 285file systems 189–4hardware 33–38, 48–9, 189–4memory 36–38, 40–1, 153–4, 162–3,216messaging 277–78modes 35–6, 48–9, 54, 76–7INDEXoperating systems 33–38, 40–1, 42–3,48–4, 76–7, 82, 153–4, 190–4,277–78, 285–97, 301–2software 34–38, 40–1, 48–9, 285–97virtual machines 301–2protocols 39, 42, 57, 105, 218–19, 226,227, 232–5, 238–4, 282concepts 39, 200, 218–19, 227, 240–2encapsulation concepts 218–19PRT modules 239, 241–2Psion Computerssee also Symbian OShistorical background 9–10, 247PSTN (public-switched-telephone network)248, 260–1Pthreads standard 76public-switched-telephone network (PSTN)248, 260–1pull model, messaging 267punched cards 12push model, messaging 267, 269, 272PVM 220queuesdevices 66FIFO queues 90process scheduling 66, 75–6, 79–2,90–106, 127–28radio connectivity 3–5, 9, 217RAID 185–6RAM 137–65, 221–2, 231see also memoryrandom (direct) access, files 174–5, 205RBusLogicalChannel 240RCall 253–4, 257–60read 244read locks 118–20read operations, files 173, 178, 192, 205,209read-only memory (ROM) 25, 223, 305reader–writer problem, concurrently-sharedresources 122331ready queues, process scheduling 66, 75–6,79–2, 90–106ready state, processes 63–4, 66, 79–2,90–106real-time OS (RTOS), concepts 56–7real-time systemsconcepts 16, 27, 56–7, 93–4, 101–6deadlines 102, 105–6performance considerations 102process scheduling 101–6Symbian OS 16, 56, 105–6types 16, 101–2record-keeping needs, operating systems 28recursive problems, new operating systems301–2registersconcepts 29–2, 37, 62–4, 68–9, 74, 91,137, 159–60, 202–4definition 30I/O 202–4polling 203–4relocation registers 142–3relay servers, messaging 266–69reliability property, socket streams 131relocatable binding 140–1relocation registers, MMUs 142–3remote file systems 187–88remote procedure calls (RPCs)see also phone modelIPC 130, 132removable storage media 212–13replication benefits, files 224reposition operations, files 173reserved-page frames 162–3resource modelsconcepts 2, 4–9, 33–38operating systems 2–9, 33–38response times, concepts 51, 93–106RFCOMM 234RFile 42see also file serversrich text data 278–9ring networks 218–19ringtones 271332INDEXRitchie, Dennis 8RLine 253–60RMessage2 132robustness needs, operating systems 6–7rollback approaches, deadlocked processes134ROM (read-only memory) 25, 223, 305roots, files 171, 180, 190, 279‘rose-tinted glasses’ 1, 167round-robin strategy, process scheduling97–98routers, networks 218–19RPCs (remote procedure calls), IPC 130, 132RPhone 253–59RS230 port 240RSemaphore 127RTelServer 251–4RTOS (real-time OS), concepts 56–7RunL 84–6, 259running state, processes 63–4, 66, 90–103,105–6, 145scalability needs, operating systems 6scheduling 25, 49, 64–6, 76–7, 89–108,216see also process schedulingjobs 12, 40–1nanokernel 49threads 71–2screenssee also displaysLCD management 210–11SCSI (Small Computer Systems Interface) bus200–1SDs (secure-digital cards) 31, 154, 212–13secondary storagesee also disk .

. . ; flash . . .concepts 30–1, 137, 146–7, 167–68,176–7definition 31sectors, disks 177, 181secure-digital cards (SDs) 31, 154, 212–13security issues 7, 33–38, 40–1, 42–3,48–4, 76–7, 82, 153–4, 189–4, 223–4,277–78, 285–97see also protection . . .authentication concepts 54, 192–4,288–6authorization concepts 287–88, 293–4buffer overflows 286, 292capabilities 54, 192–4, 254–5, 295–6concepts 33–38, 40–1, 42–3, 48–4,189–4, 223–4, 285–97data caging 296definition 285difficulties 286–7failures 190–2, 286file systems 189–4finger example 286, 292gatekeeper security model 294–6human level 286–7, 292levels 286–7Linux 287Microsoft Windows 288networks 223–4, 286–7, 293operating systems 7, 33–38, 40–1, 42–3,48–4, 76–7, 82, 153–4, 190–4,277–78, 285–97passwords 288–6personal information 290–1physical level 286–7, 290–1signed applications 294–6smartphones 193–4, 293–6Symbian OS 193–4, 293–6threat types 292–4Unix 286, 288–90, 292–3virtual machines 301–2security needs, operating systems 7segmentation, memory management156–59, 161, 162–3select 245semaphores 49, 50, 77–78, 116–36see also synchronization operationsbinary semaphores 118–20, 126–7concepts 116–20definition 126–7INDEXlocks 118–20monitors 119–20Unix example 123–6Send 85–6send-as messaging interface, MTM 276–81senders, message characteristics 264–71,273–5SendItem 85–6sequential access, files 174–5, 205serial connectivity 9, 85–6, 210serializability goal, concurrently-sharedresources 112–13serially-shared network resources 33–5Server Message Block (SMB) 187, 189, 225serverssee also file .

. .; socketsclient–server architecture 11, 14, 93,130–1, 221, 231–2, 235, 237–42,245, 265–68, 275–81concepts 10–11, 14, 18, 20–2, 39, 42,43, 48–9, 53, 57, 93, 130–1, 132,178, 187–88, 190–4, 211–12, 221,231–2, 251–60, 265–68ETel 247, 249, 251–60kernel 20–2, 43, 47–59, 132messaging functions 42–3, 275–81passive kernel components 53relay servers 266–69roles 49, 132, 231–2Session Initiation Protocol (SIP) 261–2SetActive 84–6shared data, processes 82, 91–4, 109–36shared memory 137–65, 221–4see also memory . . .shared resources 33–4, 61–88, 90–4,109–36, 137–65, 205, 216–28see also concurrently-shared . .

. ; memorymanagement; networksshell access, Unix 288shortest-job-first strategy (SJF), processscheduling 96–98SIBO 9–10, 42signal 117–18, 119–20, 122–7see also synchronization333signals, processes 72, 117–18signed applications 294–6SIMD (single instruction, multiple data)distributed systems 221Simple Mail Transfer Protocol (SMTP) 268,275single instruction, multiple data (SIMD)distributed systems 221SIP (Session Initiation Protocol) 261–2sizesapplications 155directories 179files 170–1, 181–3SJF (shortest-job-first strategy) 96–98sleeping state, nanothreads 77–78Small Computer Systems Interface (SCSI) bus200–1smartphones 9–11, 20–2, 42–3, 47–58,93–4, 154–6, 177, 229–30, 247–62,285–97see also mobile phones; Symbian OScommunications models 229–30constraints 154–6, 231file systems 188–9, 193–4flash storage 2, 31, 52, 146, 154, 167–68,177, 188–9historical background 9–11, 42–3, 247memory management 154–6, 159–2microkernels 20–2, 43, 47–58, 93–4,104–6, 132, 249, 277networks 218, 226–7platform uniqueness 56security issues 193–4, 293–6storage media 177, 211–12telephony 247–62SMB (Server Message Block) 187, 189, 225SMS 53, 242, 263, 267, 268–1, 276, 280see also messagingSMTP (Simple Mail Transfer Protocol) 268,275socketssee also servers; TCP/IPconcepts 39, 49, 130–2, 225–7, 235,243–5, 261334INDEXsockets (continued )connected sockets 131IPC 130–2, 235network communications 225–7, 243–5,261streams 131SOCK_STREAM 243–5soft real-time systemssee also real-time .

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