[2661] Fix BroadcastReceiver ANR at ScreenOffTrigger

leakcanary/leakcanary-android-release/src/main/java/leakcanary/ScreenOffTrigger.kt

@@ -8,7 +8,10 @@ import android.content.Intent.ACTION_SCREEN_OFF
 import android.content.Intent.ACTION_SCREEN_ON
 import android.content.IntentFilter
 import android.os.Build
+import android.os.Handler
+import android.os.Looper
 import java.util.concurrent.Executor
+import java.util.concurrent.atomic.AtomicReference
 import leakcanary.internal.friendly.checkMainThread
 import shark.SharkLog
 
@@ -32,30 +35,39 @@ class ScreenOffTrigger(
   private val analysisCallback: (HeapAnalysisJob.Result) -> Unit = { result ->
     SharkLog.d { "$result" }
   },
+
+  /**
+   * Initial delay to wait for analysisExecutor to start analysis
+   *
+   * If not specified, the initial delay is 500 ms
+   */
+  private val analysisExecutorDelayMillis: Long = INITIAL_EXECUTOR_DELAY_MILLIS
 ) {
 
-  @Volatile
-  private var currentJob: HeapAnalysisJob? = null
+  private val currentJob = AtomicReference<HeapAnalysisJob?>()
+  private val analysisHandler = Handler(Looper.getMainLooper())
+  private var analysisRunnable: Runnable? = null
 
   private val screenReceiver = object : BroadcastReceiver() {
     override fun onReceive(
       context: Context,
       intent: Intent
     ) {
-      if (intent.action == ACTION_SCREEN_OFF) {
-        if (currentJob == null) {
-          val job =
-            analysisClient.newJob(JobContext(ScreenOffTrigger::class))
-          currentJob = job
-          analysisExecutor.execute {
+      if (intent.shouldStartAnalysis()) {
+        val job =
+          analysisClient.newJob(JobContext(ScreenOffTrigger::class))
+        if (currentJob.compareAndSet(null, job)) {
+          schedule {
             val result = job.execute()
-            currentJob = null
             analysisCallback(result)
           }
         }
       } else {
-        currentJob?.cancel("screen on again")
-        currentJob = null
+        cancelScheduledAction()
+        currentJob.getAndUpdate { job ->
+          job?.cancel("screen on again")
+          null
+        }
       }
     }
   }
@@ -78,4 +90,22 @@ class ScreenOffTrigger(
     checkMainThread()
     application.unregisterReceiver(screenReceiver)
   }
+
+  private fun Intent.shouldStartAnalysis(): Boolean {
+    return this.action == ACTION_SCREEN_OFF && currentJob.get() == null
+  }
+
+  private fun schedule(action: Runnable) {
+    analysisRunnable = Runnable {
+      analysisExecutor.execute(action)
+    }.also { analysisHandler.postDelayed(it, analysisExecutorDelayMillis) }
+  }
+
+  private fun cancelScheduledAction() {
+    analysisRunnable?.let { analysisHandler.removeCallbacks(it) }
+  }
+
+  companion object {
+    private const val INITIAL_EXECUTOR_DELAY_MILLIS = 500L
+  }
 }