Overview of Concurrency in Time-Consuming Tasks

Time-consuming tasks are those that take a long time to complete. If executed in the UI main thread, they can cause application lag, frame drops, and slow response times. Typical examples include CPU intensive tasks, I/O intensive tasks, and synchronous tasks.

Typical service scenarios are as follows:

Service Scenario	Description	Is CPU Intensive Task	Is I/O Intensive Task	Is Synchronous Task
Image/Video encoding and decoding	Encoding or decoding images or videos for display.	Yes	Yes	No
Compression and decompression	Decompressing local archives or compressing local files.	Yes	Yes	No
JSON parsing	Serializing and deserializing JSON strings.	Yes	No	No
Model computation	Performing data analysis using models.	Yes	No	No
Network download	Downloading resources, images, and files via intensive network requests.	No	Yes	No
Database operations	Saving data like chat records, page layouts, or music lists to the database, or reading from the database on application restart.	No	Yes	No