(1) The CPU supports the OS protection mode; The intelx86/Pentium series CPU can provide Program Code4 levels of rights;
(2) kernel (3) primitive: It is a special generalized instruction. Its function is to be completed by the system through an inseparable instruction operation. It is also called an atomic operation, the primitive is completed in the core State; Process Control Operations (creation, cancellation, and blocking) are mostly primitive operations; (4) kernel function: the kernel is the first layer of extended software on computer hardware, it is a key part of the OS. It is a management control center. The kernel runs in the same state of mind and is resident in the memory. The kernel implements "necessary and limited processing" by executing various primitive operations ", clock management and primitive operations; complete basic management functions of various resources of processes (processors), memory and devices at the same time; Worker Process Control primitive (1) Create primitive: A program can create a new process by creating the original language. The new process is its sub-process. The process is mainly to create a PCB for the new process and obtain its internal identifier; then, enter the parameters provided by the calling process, such as the external name, body segment, first data segment address, size, required resources, and priority, in the blank PCB table, set the new process to the active/static ready state, and insert the PCB into the RQ of the ready queue to enter the system for concurrent execution. (2) destroy) /termination: For a tree-structured process system, the primitive revocation policy is issued by the parent process to cancel a child process and all child processes of the child process; all resources (primary memory, I/O resources, and PCB tables) of the withdrawn process are released and returned to the system. They are removed from all queues. For example, the withdrawn process is running; the scheduler is called to distribute the processor to other processes;
