"Internet Exam Series-1" process with thread

I. Characteristics of the process

1. Structural Features: Program section, related data segment and PCB (Process Control block-)

2, Dynamic: The essence of the process is the process of the entity's implementation process, process entities have a certain period of life. The program is static.

3. Concurrency: Multiple process Entities are stored in memory and can be run concurrently over a period of time.

4. Independence: The process entity is a basic unit which can run independently, allocate resources independently and accept the dispatch independently.

5. Asynchrony: Processes move forward at their own, unpredictable speed.

Ii. definition of the process

Process is the process entity running process, is a system for resource allocation and scheduling of an independent unit.

Iii. three basic states of the process

1. Ready state: Multiple queued-ready queues.

2. State of execution.

3, blocking state.

4. Suspend state.

Iv. Process Control:

1. Process diagram: The child process can inherit the resources owned by the parent process, and the child process will return the resources obtained from the parent process to the parent process when it is revoked. All child processes must be revoked when the parent process is revoked.

2, Process creation: Allocate memory space to know the size of the memory required by the process. An address space that can share an existing memory.

V. Inter-process communication:

Advanced communication mechanism: Shared memory system, message delivery system, Pipeline communication system (shared pipe file).

Six, thread

1, scheduling: The thread as the basic unit of dispatch and dispatch, basically do not have resources.

2. Resources: The resources of the process are shared by almost no resources and other threads of the unified process.

3. A process in a multithreaded OS is not an executable entity.

4. Synchronization and communication between threads: Mutex, condition variable, semaphore mechanism.

"Internet Exam Series-1" process with thread