斗 长 Reentrant and AsynchronousOperation ￥斗 ★★ o Windowskemel is fully reentrant Kemel functions can be invoked by multiple threads simultaneously No serializationof userthreads when perfomingsys calls yo systemworksfully asynchronously Asynchronous I/O improves application'sthroughput Synchronous functions provide ease-of-progamming
16 Reentrant and Asynchronous Operation Windows kernel is fully reentrant – Kernel functions can be invoked by multiple threads simultaneously – No serialization of user threads when performing sys calls I/O system works fully asynchronously – Asynchronous I/O improves application’s throughput – Synchronous wrapper functions provide ease-of-programming
斗 长 Key windows System Files ￥斗 ★★ o Core OSoomponents: NTOSKRNL. EXEX*. Exeative and kemel HAL.DLL: Hardware abstraction layer NTDLL DLL: Intemal support functions and system service dispatch stubs to exective functions 9 Core systemprocesses SMSSEXE: Session manager process WINLOGON. EXE: Logon process SERVICES. EXE: Service controller process LSASS EXE Local Security Authority Subsystem
17 Key Windows System Files Core OS components: – NTOSKRNL.EXE**: Executive and kernel – HAL.DLL: Hardware abstraction layer – NTDLL.DLL: Internal support functions and system service dispatch stubs toexecutive functions Core system processes: – SMSS.EXE: Session manager process – WINLOGON.EXE: Logon process – SERVICES.EXE: Service controller process – LSASS.EXE : Local Security Authority Subsystem
斗 长 Key windows System Files ￥斗 ★★ o Windowingsubsystem CSRSSEXE*: Windows subsystemprocess WIN32K SYS: in 32 and GDI kemel-mode components KERNEL32/USER32/ GDI32. DLL: Win32 subsystem DLLS
18 Key Windows System Files Windowing subsystem: – CSRSS.EXE*: Windows subsystem process – WIN32K.SYS: in32 and GDI kernel-mode components – KERNEL32/USER32/GDI32.DLL: Win32 subsystem DLLs
斗 长 Key system Components ￥斗 ★★ Environment Subsystems System User service Application POSX Processes Subsystem DLL os2」 Windows User Windows Mode Kemel Mo Executive Windows Device Drivers Kemel User/GDI Hardware Abstraction Layer ( HAL) Device Driver
19 Key System Components OS/2 Windows POSIX Environment Subsystems User Application Subsystem DLL Windows User/GDI Device Driver Executive Device Drivers Kernel Hardware Abstraction Layer (HAL) User Mode Kernel Mode System & Service Processes Windows
斗 长 Multiple os Personalities ￥斗 ★★ o NT wasdesigned to supportmultiplepersonalities', called environment subsystems Progamming interface File systemsyntax Process semantics
20 Multiple OS Personalities NT was designed to support multiple “personalities”, called environment subsystems – Programming interface – File system syntax – Process semantics