1. 计算机系 信息处理实验室 Lecture 8 Processes, Threads, and Jobs (2) xlanchen@04/08/2005

2. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 2 Contents The internal structures of process How to create a process The internal structures of thread How to create a thread Thread Scheduling Job Objects

3. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 3 Thread structures a Windows 2000 thread is represented by ETHREAD block in the system address space except TEB How is the thread related to Csrss and Win32k.sys

4. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 4 Fibers vs. Threads Fibers "lightweight" threads implemented in user mode in Kernel32.dll allow an App. to schedule its own "threads" outside the priority-based scheduling mechanism of 2K ConvertThreadToFiber, win32 function CreateFiber SwitchToFiber

5. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 5 Structure of the kernel thread block

6. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 6 EXPERIMENT Displaying ETHREAD and KTHREAD Structures

7. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 7 Fields of the TEB

8. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 8 EXPERIMENT Examining the TEB

9. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 9 Related Kernel Variables PspCreateThreadNotifyRoutine PspCreateThreadNotifyRoutineCount PspCreateProcessNotifyRoutine PspCreateProcessNotifyRoutineCount PspCidTable

10. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 10 Related Performance Counters Process: Priority Base Thread: % Privileged Time % Processor Time % User Time Context Switches/Sec Elapsed Time ID Process ID Thread Priority Base Priority Current Start Address Thread State Thread Wait Reason

11. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 11 Win32 Thread Functions CreateThread CreateRemoteThread ExitThread TerminateThread GetExitCodeThread GetThreadTimes Get/SetThreadContext GetThreadSelectorEntry

12. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 12 EXPERIMENT Using the Kernel Debugger !thread Command

13. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 13 EXPERIMENT Viewing Thread Information

14. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 14 Create a thread CreateThread to create a Win32 thread In Kernel32.dll 1.Creates a user-mode stack 2.Initializes the thread's hardware context 3.Calles NtCreateThread to create the executive thread object in the suspended state 4.Notifies the Win32 subsystem about the new thread 5.Return the thread handle and its ID to the caller

15. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 15 the thread starts running KiThreadStartup PspUserThreadStartup LdrInitializeThunk (in Ntdll.dll)

16. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 16 Flow of CreateThread

17. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 17 2K Scheduling priority-driven, preemptive the highest-priority runnable (ready) thread always runs, processor affinity quantum the length of time a thread is allowed to run before Windows 2000 interrupts the thread to find out whether another thread at the same priority level or higher is waiting to run or whether the thread's priority needs to be reduced

18. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 18 EXPERIMENT Viewing Ready Threads

19. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 19 EXPERIMENT Thread-Scheduling State Changes

20. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 20 Thread priority levels

21. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 21 Kernel priorities Win32 vs. Windows 2000

22. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 22 kernel's dispatcher dispatching occurs at DPC/dispatch level and is triggered by any of the following events A thread becomes ready to execute A thread leaves the running state because its time quantum ends, it terminates, or it enters a wait state A thread's priority changes The processor affinity of a running thread changes.

23. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 23 Win32 Scheduling APIs Suspend/ResumeThread Suspends or resumes a paused thread from execution. Get/SetPriorityClass Returns or sets a process's priority class (base priority). Get/SetThreadPriority Returns or sets a thread's priority (relative to its process base priority).

24. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 24 Get/SetProcessAffinityMask Returns or sets a process's affinity mask. SetThreadAffinityMask Sets a thread's affinity mask (must be a subset of the process's affinity mask) for a particular set of processors, restricting it to running on those processors.

25. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 25 Get/SetThreadPriorityBoost Returns or sets the ability for Windows 2000 to boost the priority of a thread temporarily (applies only to threads in the dynamic range). SetThreadIdealProcessor Establishes a preferred processor for a particular thread but doesn't restrict the thread to that processor. Get/SetProcessPriorityBoost Returns or sets the default priority boost control state of the current process. (This function is used to set the thread priority boost control state when a thread is created.)

26. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 26 SwitchToThread Yields execution for one or more quantums. Sleep Puts the current thread into a wait state for a specified time interval (figured in milliseconds [msec]). A zero value relinquishes the rest of the thread's quantum. SleepEx Causes the current thread to go into a wait state until either an I/O completion callback is completed, an APC is queued to the thread, or the specified time interval ends.

27. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 27 EXPERIMENT Examining and Specifying Process and Thread Priorities

28. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 28 Real-Time Priorities Increase scheduling priority privilege 2K is not a true real-time operating system

29. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 29 Interrupt Levels vs. Priority Levels

30. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 30 Thread states

31. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 31 Quantum Quantum Accounting Default: 6 Per clock interrupt: -3 ??? The clock interval is determined by hardware platform Controlling the Quantum

32. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 32 EXPERIMENT Determining the Clock Interval Frequency

33. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 33 Scheduling Data Structures

34. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 34 Scheduling Scenarios Voluntary Switch Preemption Quantum End Termination

35. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 35 Voluntary switching

36. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 36 Preemptive thread scheduling

37. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 37 Quantum End

38. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 38 Context Switching A thread's context and the procedure for context switching vary depending on the processor's architecture A typical context switch requires saving and reloading the following data: Program counter Processor status register Other register contents User and kernel stack pointers A pointer to the address space in which the thread runs (the process's page table directory)

39. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 39 Idle Thread Dispatched when no runnable thread exists on a CPU Each CPU is allotted one idle thread the basic flow Enables and disables interrupts (allowing any pending interrupts to be delivered). Checks whether any DPCs are pending on the processor. If DPCs are pending, clears the pending software interrupt and delivers them. Checks whether a thread has been selected to run next on the processor, and if so, dispatches that thread. Calls the HAL processor idle routine (in case any power management functions need to be performed).

40. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 40 Priority Boosts In five cases, Windows 2000 can boost (increase) the current priority value of threads On completion of I/O operations After waiting on executive events or semaphores After threads in the foreground process complete a wait operation When GUI threads wake up because of windowing activity When a thread that's ready to run hasn't been running for some time (CPU starvation)

41. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 41 Priority boosting and decay

42. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 42 EXPERIMENT Watching Foreground Priority Boosts and Decays

43. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 43 EXPERIMENT Watching Priority Boosts on GUI Threads

44. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 44 EXPERIMENT Watching Priority Boosts for CPU Starvation

45. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 45 Scheduling on SMP Systems Affinity Ideal and Last Processor Choosing a Processor for a Ready Thread Selecting a Thread to Run on a Specific CPU When the Highest-Priority Ready Threads Are Not Running ?

46. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 46 Job Objects A job object is a nameable, securable, shareable kernel object that allows control of one or more processes as a group. basic function to allow groups of processes to be managed and manipulated as a unit

47. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 47 A process can be a member of only one job object Win32 API Functions for Jobs CreateJobObject OpenJobObject AssignProcessToJobObject TerminateJobObject SetInformationJobObject QueryInformationJobObject

48. 计算机系 信息处理实验室 xlanchen@04/08/2005Understanding the Inside of Windows2000 48 EXPERIMENT Viewing the Job Object