Cleaner thread management, less global state.

Switch to using a ThreadPoolExecutor for handling downloads, which
gives us parallelism logic that is easier to reason about.  Also
open the door to eventually waiting until the executor is drained
to stopSelf().

Removes DownloadHandler singleton, and gives explicit path for
publishing active download speeds to notifications.

Change-Id: I1836e7742bb8a84861d1ca6bd1e59b2040bd12f8

1 files changed, 7 insertions, 8 deletions

diff --git a/src/com/android/providers/downloads/DownloadThread.java b/src/com/android/providers/downloads/DownloadThread.java
index 5bb1e9bd..bd347e42 100644
--- a/src/com/android/providers/downloads/DownloadThread.java
+++ b/src/com/android/providers/downloads/DownloadThread.java
@@ -68,10 +68,10 @@ import libcore.io.IoUtils;
 import libcore.net.http.HttpEngine;
 
 /**
- * Thread which executes a given {@link DownloadInfo}: making network requests,
+ * Task which executes a given {@link DownloadInfo}: making network requests,
  * persisting data to disk, and updating {@link DownloadProvider}.
  */
-public class DownloadThread extends Thread {
+public class DownloadThread implements Runnable {
 
     private static final int HTTP_REQUESTED_RANGE_NOT_SATISFIABLE = 416;
     private static final int HTTP_TEMP_REDIRECT = 307;
@@ -82,15 +82,17 @@ public class DownloadThread extends Thread {
     private final DownloadInfo mInfo;
     private final SystemFacade mSystemFacade;
     private final StorageManager mStorageManager;
+    private final DownloadNotifier mNotifier;
 
     private volatile boolean mPolicyDirty;
 
     public DownloadThread(Context context, SystemFacade systemFacade, DownloadInfo info,
-            StorageManager storageManager) {
+            StorageManager storageManager, DownloadNotifier notifier) {
         mContext = context;
         mSystemFacade = systemFacade;
         mInfo = info;
         mStorageManager = storageManager;
+        mNotifier = notifier;
     }
 
     /**
@@ -151,16 +153,13 @@ public class DownloadThread extends Thread {
         }
     }
 
-    /**
-     * Executes the download in a separate thread
-     */
     @Override
     public void run() {
         Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND);
         try {
             runInternal();
         } finally {
-            DownloadHandler.getInstance().dequeueDownload(mInfo.mId);
+            mNotifier.notifyDownloadSpeed(mInfo.mId, 0);
         }
     }
 
@@ -526,7 +525,7 @@ public class DownloadThread extends Thread {
             state.mSpeedSampleStart = now;
             state.mSpeedSampleBytes = state.mCurrentBytes;
 
-            DownloadHandler.getInstance().setCurrentSpeed(mInfo.mId, state.mSpeed);
+            mNotifier.notifyDownloadSpeed(mInfo.mId, state.mSpeed);
         }
 
         if (state.mCurrentBytes - state.mBytesNotified > Constants.MIN_PROGRESS_STEP &&