Merge "Fix race from DisplayRepository.getDisplay" into main (dd822a5d) · Commits · e / os / android_frameworks_libs_systemui

displaylib/src/com/android/app/displaylib/DisplayRepository.kt

+37 −2

Original line number	Diff line number	Diff line
		@@ -86,11 +86,28 @@ interface DisplayRepository {
		/**
		* Given a display ID int, return the corresponding Display object, or null if none exist.
		*
		* This method is guaranteed to not result in any binder call.
		* This method will not result in a binder call in most cases. The only exception is if there is
		* an existing binder call ongoing to get the [Display] instance already. In that case, this
		* will wait for the end of the binder call.
		*/
		fun getDisplay(displayId: Int): Display? =
		fun getDisplay(displayId: Int): Display?

		/**
		* As [getDisplay], but it's always guaranteed to not block on any binder call.
		*
		* This might return null if the display id was not mapped to a [Display] object yet.
		*/
		fun getCachedDisplay(displayId: Int): Display? =
		displays.value.firstOrNull { it.displayId == displayId }

		/**
		* Returns whether the given displayId is in the set of enabled displays.
		*
		* This is guaranteed to not cause a binder call. Use this instead of [getDisplay] (see its docs
		* for why)
		*/
		fun containsDisplay(displayId: Int): Boolean = displayIds.value.contains(displayId)

		/** Represents a connected display that has not been enabled yet. */
		interface PendingDisplay {
		/** Id of the pending display. */
		@@ -375,6 +392,24 @@ constructor(
		.map { defaultDisplay.state == Display.STATE_OFF }
		.distinctUntilChanged()

		override fun getDisplay(displayId: Int): Display? {
		val cachedDisplay = getCachedDisplay(displayId)
		if (cachedDisplay != null) return cachedDisplay
		// cachedDisplay could be null for 2 reasons:
		// 1. the displayId is being mapped to a display in the background, but the binder call is
		// not done
		// 2. the display is not there
		// In case of option one, let's get it synchronously from display manager to make sure for
		// this to be consistent.
		return if (displayIds.value.contains(displayId)) {
		traceSection("$TAG#getDisplayFallbackToDisplayManager") {
		getDisplayFromDisplayManager(displayId)
		}
		} else {
		null
		}
		}

		private fun <T> Flow<T>.debugLog(flowName: String): Flow<T> {
		return if (DEBUG) {
		traceEach(flowName, logcat = true, traceEmissionCount = true)

displaylib/src/com/android/app/displaylib/PerDisplayRepository.kt

+1 −1

Original line number	Diff line number	Diff line
		@@ -192,7 +192,7 @@ constructor(
		}

		override fun get(displayId: Int): T? {
		if (displayRepository.getDisplay(displayId) == null) {
		if (!displayRepository.containsDisplay(displayId)) {
		Log.e(TAG, "<$debugName: Display with id $displayId doesn't exist.")
		return null
		}