How does the system determine which process to terminate?

The system uses an Out-of-memory killer (OOM killer) algorithm to terminate processes in order to free resources. Each process has a priority based on its state and components:

• Foreground process: Activity with which the user interacts. Highest priority.
• Visible process: Activity visible on the screen but not in the foreground (e.g., a dialog box). High priority.
• Service process: A running service (e.g., playing music in the background). Priority lower than visible processes.
• Cached process: A process that has no active components and can be restarted. Lowest priority.

The OOM killer first attempts to terminate processes with the lowest priority (Cached process), then moves on to Service processes, and so on, until enough free memory is available.

It also considers:

• Time since last activity: Older processes with lower priority are terminated first.
• Amount of memory used: Processes consuming a lot of memory may be terminated earlier, even if their priority is higher than others using fewer resources.

The system aims to maintain responsiveness and stability by terminating processes in the least disruptive way for the user.