SynchronousSerialExecutor.kt
/*
* Copyright 2022 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.work.testing
import androidx.annotation.GuardedBy
import androidx.work.impl.utils.taskexecutor.SerialExecutor
internal class SynchronousSerialExecutor : SerialExecutor {
private val lock = Any()
@GuardedBy("lock")
private val tasks = ArrayDeque<Runnable>()
@GuardedBy("lock")
private var isRunning = false
override fun execute(command: Runnable) {
synchronized(lock) {
tasks.add(command)
if (isRunning) return
isRunning = true
}
do {
// running potentially long task without the lock
// so other threads can grab the lock to add runnables to the queue
synchronized(lock) { tasks.removeFirstOrNull() }?.run()
// check if new tasks were added while the previous was ran.
synchronized(lock) { isRunning = tasks.isNotEmpty() }
} while (isRunning)
}
override fun hasPendingTasks(): Boolean {
return synchronized(lock) { tasks.isNotEmpty() }
}
}