The main difference between threads and processes is: threads (in the same process) run in a shared memory space, while processes run in different memory spaces; threads use wait(), notify(), notifyAll(), etc. Methods communicate directly with other threads (same process), while processes need to use "IPC" to communicate with other processes.
What is a process?
A running application, usually called a process. Each process has its own independent address space (memory space). Whenever a user starts a process, the operating system will allocate an independent memory space to the process and allow the application to run in this independent memory space.
What is a thread?
A thread is a lightweight sub-process, the smallest processing unit; it is a separate execution path. It can be said: a thread is a subset (part) of a process.
Threads are independent. If an exception occurs in one thread, it does not affect other threads. It uses shared memory area.
The relationship between processes and threads:
As shown in the figure above, the operating system can have multiple A process can have multiple threads in a process, and the threads are executed within the process.
The difference between processes and threads:
1. It is easy to create new threads. However, creating a new process requires duplication of the parent process.
2. Threads can control other threads in the same process. A process cannot control sibling processes, only its child processes.
3. The process has its own memory space. Threads use the memory space of the process and share this space with other threads of the process; instead of allocating a separate space to each thread in the process.
4. Threads (in the same process) run in shared memory space, while processes run in different memory spaces.
5. Threads can use wait(), notify(), notifyAll() and other methods to communicate directly with other threads (the same process); however, processes need to use "inter-process communication" (IPC) to communicate with operations Communicate with other processes in the system.
Explanation:
IPC, that is, inter-process communication, specifically refers to a type of communication provided by the operating system that allows processes to manage shared data mechanism.
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