李盈賢

 Start a process with a specific priority class  Methods: 1)Cmd: start /’priority’ ‘filename’ 2)Create a shortcut

 To enter the real-time range, Increase scheduling priority privilege is necessary

 Many kernel-mode system threads run in the real-time priority range, so if threads spend excessive time running in this range, they might block critical system functions

 Threads normally run at IRQL 0 or 1  User-mode threads always run at IRQL 0.  Kernel-mode APCs execute at IRQL 1  Threads running in kernel mode can raise IRQL to higher levels

1. Ready 2. Standby 3. Running 4. Waiting 5. Transition 6. Terminated 7. Initialized 8. (Win2003)Deferred Ready

 while a thread is being created

 Wait to be executed.  The dispatcher considers only the pool of threads in the ready state.

 Only on Windows Server 2003  for threads that have been selected to run on a specific processor but have not yet been scheduled  the kernel can minimize the amount of time the systemwide lock on the scheduling database is held

 It has been selected to run next on a particular processor.  a thread can be preempted out of the standby state before it ever executes  In multiprocessor system, only one thread can be in the standby state for each processor.

 Via context switching of the dispatcher  Until its quantum ends, preempted by a higher priority thread, terminates, yields execution, or it voluntarily enters the wait state.

 A thread can enter the wait state in several ways, e.g. voluntarily wait for an object to synchronize its execution, I/O operation, or an environment subsystem can direct the thread to suspend itself  When the thread’s wait ends, depending on the priority, the thread either begins running immediately or is moved back to the ready state.

 Ready for execution but its kernel stack is paged out of memory.  Once its kernel stack is brought back into memory, the thread enters the ready state.

 When a thread finishes executing, it enters the terminated state.  Once the thread is terminated, the executive thread block might or might not be deallocated. (The object manager sets policy regarding when to delete the object.)

 A set of kernel data structures.  To make thread-scheduling decisions  Keeps track of which threads are waiting to execute and which processors are executing which threads

On uniprocessor systems, the dispatcher database is synchronized by raising IRQL to DPC/dispatch level and SYNCH_LEVEL (both of which are defined as level 2). On multiprocessor systems, more is required than raising IRQL because each processor can, at the same time, raise to the same IRQL and attempt to operate on the dispatcher database