Merge "Camera2: Support early finished tasks" into nyc-mr1-dev (5fb00f4d) · Commits · e / os / android_frameworks_base

core/java/android/hardware/camera2/utils/TaskDrainer.java

+21 −8

Original line number	Diff line number	Diff line
		@@ -29,8 +29,9 @@ import static com.android.internal.util.Preconditions.*;
		* (and new ones won't begin).
		*
		* <p>The initial state is to allow all tasks to be started and finished. A task may only be started
		* once, after which it must be finished before starting again. Likewise, finishing a task
		* that hasn't been started is also not allowed.</p>
		* once, after which it must be finished before starting again. Likewise, a task may only be
		* finished once, after which it must be started before finishing again. It is okay to finish a
		* task before starting it due to different threads handling starting and finishing.</p>
		*
		* <p>When draining begins, no more new tasks can be started. This guarantees that at some
		* point when all the tasks are finished there will be no more collective new tasks,
		@@ -60,6 +61,11 @@ public class TaskDrainer<T> {

		/** Set of tasks which have been started but not yet finished with #taskFinished */
		private final Set<T> mTaskSet = new HashSet<T>();
		/**
		* Set of tasks which have been finished but not yet started with #taskStarted. This may happen
		* if taskStarted and taskFinished are called from two different threads.
		*/
		private final Set<T> mEarlyFinishedTaskSet = new HashSet<T>();
		private final Object mLock = new Object();

		private boolean mDraining = false;
		@@ -118,18 +124,21 @@ public class TaskDrainer<T> {
		throw new IllegalStateException("Can't start more tasks after draining has begun");
		}

		// Try to remove the task from the early finished set.
		if (!mEarlyFinishedTaskSet.remove(task)) {
		// The task is not finished early. Add it to the started set.
		if (!mTaskSet.add(task)) {
		throw new IllegalStateException("Task " + task + " was already started");
		}
		}
		}
		}


		/**
		* Mark an asynchronous task as having finished.
		*
		* <p>A task cannot be finished if it hasn't started. Once finished, a task
		* cannot be finished again (unless it's started again).</p>
		* <p>A task cannot be finished more than once without first having started.</p>
		*
		* @param task a key to identify a task
		*
		@@ -137,7 +146,7 @@ public class TaskDrainer<T> {
		* @see #beginDrain
		*
		* @throws IllegalStateException
		* If attempting to start a task which is already finished (and not re-started),
		* If attempting to finish a task which is already finished (and not started),
		*/
		public void taskFinished(T task) {
		synchronized (mLock) {
		@@ -145,9 +154,13 @@ public class TaskDrainer<T> {
		Log.v(TAG + "[" + mName + "]", "taskFinished " + task);
		}

		// Try to remove the task from started set.
		if (!mTaskSet.remove(task)) {
		// Task is not started yet. Add it to the early finished set.
		if (!mEarlyFinishedTaskSet.add(task)) {
		throw new IllegalStateException("Task " + task + " was already finished");
		}
		}

		// If this is the last finished task and draining has already begun, fire #onDrained
		checkIfDrainFinished();