1# Common Events of the Resource Scheduler Subsystem 2This document lists the common system events provided by the resource scheduler subsystem to applications. Applications can use [APIs](../js-apis-commonEventManager.md) to subscribe to common system events. 3 4## COMMON_EVENT_DEVICE_IDLE_MODE_CHANGED 5Indicates that the system idle mode has changed. 6 7- Constant value: "usual.event.DEVICE_IDLE_MODE_CHANGED" 8- Required subscriber permissions: none 9 10When the user does not use the device for the specified period of time and the screen is turned off, the system delays the CPU and network access by background applications, and the event notification service is triggered to publish this event. 11 12APIs related to this event: **power**. For details, see [@ohos.power (Power Management)](../js-apis-power.md#powerisstandby10). 13 14## COMMON_EVENT_DEVICE_IDLE_EXEMPTION_LIST_UPDATED 15Indicates that the exemption list for resource usage restrictions has been updated in idle mode. 16 17- Constant value: "usual.event.DEVICE_IDLE_EXEMPTION_LIST_UPDATED" 18- Required subscriber permissions: none 19 20When the exemption list for resource usage restrictions is updated, the event notification service is triggered to publish this event. 21Resources include application network access, Timer usage, and WorkScheduler task usage. 22System applications can call JavaScript APIs to apply for removing resource usage restrictions. 23 24APIs related to this event: **deviceStandby**. For details, see [@ohos.resourceschedule.deviceStandby (Device Standby)](../js-apis-resourceschedule-deviceStandby.md#devicestandbyrequestexemptionresource). 25