Android -使用BitmapRegionDecoder时的内存泄漏

Question

我正在尝试写一个小部件来显示来自SD卡的图像，具有平移/缩放功能。在意识到大多数图像不能作为完全采样的位图放入内存后，我尝试了一些更复杂的方法-我将使用整个图像的下采样位图进行快速平移和缩放，以及在视口上可见的图像的高分辨率裁剪部分，这将在背景中计算并在完成后绘制在低分辨率上(单独的线程)。

在分配搜索之后，我终于找到了一个非常棒的BitmapRegionDecoder，它可以为我加载图像的一部分，在这个过程中没有内存异常。

哇哦，对吧？

只是..。当在多个图像之间切换时-我发现BitmapRegionDecoder在调用recycle()之后并没有真正释放它正在使用的内存……堆不断增长，直到我遇到令人沮丧的内存不足……

下面是一个演示问题的小循环：

new AsyncTask<String, Integer, Void>() {
    BitmapRegionDecoder decoder;

    @Override
    protected Void doInBackground(String... params) {

        for (int i=0; i<30;i++){
            try {
                // get a decoder instance
                decoder = BitmapRegionDecoder.newInstance(params[0], false);

                // (I'm not even doing anything with it!)

                // recycle, null-it, g-collect it, just die already:
                decoder.recycle();
                decoder=null;
                System.gc();
            } catch (IOException e) {
                e.printStackTrace();
                return null;
            }

            //print the memory usage after each step:
            onProgressUpdate(i);
        }

        return null;
    }

    @Override
    protected void onProgressUpdate(Integer... values) {
        super.onProgressUpdate(values);

        //just print the heap sizes
        Double allocated = Double.valueOf(Debug.getNativeHeapAllocatedSize())/Double.valueOf((1048576));
        Double available = Double.valueOf(Debug.getNativeHeapSize())/1048576.0;
        Double free = Double.valueOf(Debug.getNativeHeapFreeSize())/1048576.0;
        DecimalFormat df = new DecimalFormat();
        df.setMaximumFractionDigits(2);
        df.setMinimumFractionDigits(2);

        Log.d("MEM", Integer.toString(values[0]) + " - alloc " + df.format(allocated) + "MB of " + df.format(available) + "MB (" + df.format(free) + "MB free)");

    }

}.execute(SOME_LARGE_IMAGE_PATH);

SOME_LARGE_IMAGE_PATH是一个3000x3000的PNG文件(离相机拍摄的图像不远)。

在使用API-10的仿真器上运行。

下面是LogCat，只针对MEM标记进行了过滤：

 0 - alloc 11.44MB of 18.95MB (0.09MB free)
 1 - alloc 18.40MB of 25.98MB (0.10MB free)
 2 - alloc 25.38MB of 32.96MB (0.10MB free)
 3 - alloc 32.36MB of 39.94MB (0.10MB free)
 4 - alloc 39.35MB of 46.92MB (0.10MB free)
 5 - alloc 46.33MB of 53.90MB (0.10MB free)
 6 - alloc 53.31MB of 60.88MB (0.10MB free)
 7 - alloc 60.30MB of 67.87MB (0.10MB free)
 8 - alloc 67.28MB of 74.85MB (0.09MB free)
 9 - alloc 74.26MB of 81.83MB (0.09MB free)
 10 - alloc 81.24MB of 88.81MB (0.09MB free)
 11 - alloc 88.23MB of 95.79MB (0.09MB free)
 12 - alloc 95.21MB of 102.78MB (0.09MB free)
 13 - alloc 102.19MB of 109.76MB (0.09MB free)
 14 - alloc 109.17MB of 116.74MB (0.09MB free)
 15 - alloc 116.16MB of 123.72MB (0.09MB free)
 16 - alloc 123.14MB of 130.70MB (0.09MB free)
 17 - alloc 130.12MB of 137.69MB (0.09MB free)
 18 - alloc 137.11MB of 144.67MB (0.09MB free)
 19 - alloc 144.09MB of 151.65MB (0.09MB free)
 20 - alloc 151.07MB of 158.63MB (0.09MB free)
 21 - alloc 158.05MB of 165.61MB (0.10MB free)
 22 - alloc 165.04MB of 172.61MB (0.09MB free)
 23 - alloc 172.02MB of 179.59MB (0.09MB free)
 24 - alloc 179.00MB of 186.57MB (0.09MB free)
 25 - alloc 185.45MB of 193.55MB (0.16MB free)
 26 - alloc 192.44MB of 200.07MB (0.16MB free)

然后它崩溃了..。

和完整的LogCat：

 0 - alloc 11.44MB of 18.95MB (0.09MB free)
 GC_EXPLICIT freed 37K, 51% free 2644K/5379K, external 2043K/2137K, paused 47ms
 1 - alloc 18.40MB of 25.98MB (0.10MB free)
 GC_EXPLICIT freed 41K, 51% free 2637K/5379K, external 2043K/2137K, paused 55ms
 2 - alloc 25.38MB of 32.96MB (0.10MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 46ms
 3 - alloc 32.36MB of 39.94MB (0.10MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 54ms
 4 - alloc 39.35MB of 46.92MB (0.10MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 48ms
 5 - alloc 46.33MB of 53.90MB (0.10MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 59ms
 6 - alloc 53.31MB of 60.88MB (0.10MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 47ms
 7 - alloc 60.30MB of 67.87MB (0.10MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 54ms
 8 - alloc 67.28MB of 74.85MB (0.09MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 66ms
 9 - alloc 74.26MB of 81.83MB (0.09MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 91ms
 10 - alloc 81.24MB of 88.81MB (0.09MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 75ms
 11 - alloc 88.23MB of 95.79MB (0.09MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 56ms
 12 - alloc 95.21MB of 102.78MB (0.09MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 46ms
 13 - alloc 102.19MB of 109.76MB (0.09MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 53ms
 14 - alloc 109.17MB of 116.74MB (0.09MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 57ms
 15 - alloc 116.16MB of 123.72MB (0.09MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 61ms
 16 - alloc 123.14MB of 130.70MB (0.09MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 47ms
 17 - alloc 130.12MB of 137.69MB (0.09MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 56ms
 18 - alloc 137.11MB of 144.67MB (0.09MB free)
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 56ms
 19 - alloc 144.09MB of 151.65MB (0.09MB free)
 Process com.android.settings (pid 166) has died.
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 58ms
 20 - alloc 151.07MB of 158.63MB (0.09MB free)
 Process com.android.deskclock (pid 262) has died.
 Process com.android.music (pid 204) has died.
 Process com.yakstudio.moody (pid 287) has died.
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 52ms
 21 - alloc 158.05MB of 165.61MB (0.10MB free)
 Process com.android.email (pid 275) has died.
 Process android.process.media (pid 231) has died.
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 55ms
 22 - alloc 165.04MB of 172.61MB (0.09MB free)
 Process com.android.defcontainer (pid 427) has died.
 Process com.svox.pico (pid 440) has died.
 Process com.android.quicksearchbox (pid 218) has died.
 Low Memory: No more background processes.
 purging 38K from font cache [5 entries]
 GC_EXPLICIT freed 125K, 51% free 2771K/5639K, external 2168K/2674K, paused 107ms
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 46ms
 23 - alloc 172.02MB of 179.59MB (0.09MB free)
 Process com.android.launcher (pid 150) has died.
 Low Memory: No more background processes.
 WIN DEATH: Window{40735be0 com.android.launcher/com.android.launcher2.Launcher paused=false}
 purging 6K from font cache [1 entries]
 GC_EXPLICIT freed 183K, 50% free 2925K/5767K, external 1625K/2137K, paused 113ms
 GC_EXPLICIT freed 33K, 51% free 2637K/5379K, external 2043K/2137K, paused 60ms
 24 - alloc 179.00MB of 186.57MB (0.09MB free)
 purging 67K from font cache [6 entries]
 GC_EXPLICIT freed 1K, 51% free 2669K/5379K, external 2043K/2137K, paused 83ms
 purging 141K from font cache [14 entries]
 GC_EXPLICIT freed 230K, 49% free 4217K/8263K, external 3125K/3903K, paused 190ms
 GC_EXPLICIT freed 69K, 52% free 2600K/5379K, external 1645K/2137K, paused 67ms
 25 - alloc 185.45MB of 193.55MB (0.16MB free)
 Process jp.co.omronsoft.openwnn (pid 124) has died.
 Scheduling restart of crashed service jp.co.omronsoft.openwnn/.OpenWnnJAJP in 5000ms
 Low Memory: No more background processes.
 Session failed to close due to remote exception
 android.os.DeadObjectException
    at android.os.BinderProxy.transact(Native Method)
    at com.android.internal.view.IInputMethodSession$Stub$Proxy.finishSession(IInputMethodSession.java:346)
    at com.android.server.InputMethodManagerService.finishSession(InputMethodManagerService.java:896)
    at com.android.server.InputMethodManagerService.clearCurMethodLocked(InputMethodManagerService.java:907)
    at com.android.server.InputMethodManagerService.onServiceDisconnected(InputMethodManagerService.java:924)
    at android.app.LoadedApk$ServiceDispatcher.doDeath(LoadedApk.java:1069)
    at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:1083)
    at android.os.Handler.handleCallback(Handler.java:587)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:123)
    at com.android.server.ServerThread.run(SystemServer.java:540)
 Session failed to close due to remote exception
 android.os.DeadObjectException
    at android.os.BinderProxy.transact(Native Method)
    at com.android.internal.view.IInputMethodSession$Stub$Proxy.finishSession(IInputMethodSession.java:346)
    at com.android.server.InputMethodManagerService.finishSession(InputMethodManagerService.java:896)
    at com.android.server.InputMethodManagerService.clearCurMethodLocked(InputMethodManagerService.java:911)
    at com.android.server.InputMethodManagerService.onServiceDisconnected(InputMethodManagerService.java:924)
    at android.app.LoadedApk$ServiceDispatcher.doDeath(LoadedApk.java:1069)
    at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:1083)
    at android.os.Handler.handleCallback(Handler.java:587)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:123)
    at com.android.server.ServerThread.run(SystemServer.java:540)
 Start proc jp.co.omronsoft.openwnn for service jp.co.omronsoft.openwnn/.OpenWnnJAJP: pid=723 uid=10004 gids={}
 GC_EXPLICIT freed 10K, 53% free 2538K/5379K, external 1625K/2137K, paused 201ms
 GC_EXPLICIT freed <1K, 53% free 2538K/5379K, external 1625K/2137K, paused 228ms
 GC_EXPLICIT freed <1K, 53% free 2538K/5379K, external 1625K/2137K, paused 158ms
 No JNI_OnLoad found in /system/lib/libwnndict.so 0x40515658, skipping init
 GC_CONCURRENT freed 1052K, 55% free 3079K/6727K, external 1625K/2137K, paused 9ms+8ms
 Ignoring onBind: cur seq=12, given seq=15
 GC_EXPLICIT freed 34K, 52% free 2600K/5379K, external 1645K/2137K, paused 92ms
 26 - alloc 192.44MB of 200.07MB (0.16MB free)
 Process jp.co.omronsoft.openwnn (pid 723) has died.
 Scheduling restart of crashed service jp.co.omronsoft.openwnn/.OpenWnnJAJP in 20000ms
 Low Memory: No more background processes.
 Session failed to close due to remote exception
 android.os.DeadObjectException
    at android.os.BinderProxy.transact(Native Method)
    at com.android.internal.view.IInputMethodSession$Stub$Proxy.finishSession(IInputMethodSession.java:346)
    at com.android.server.InputMethodManagerService.finishSession(InputMethodManagerService.java:896)
    at com.android.server.InputMethodManagerService.clearCurMethodLocked(InputMethodManagerService.java:907)
    at com.android.server.InputMethodManagerService.onServiceDisconnected(InputMethodManagerService.java:924)
    at android.app.LoadedApk$ServiceDispatcher.doDeath(LoadedApk.java:1069)
    at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:1083)
    at android.os.Handler.handleCallback(Handler.java:587)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:123)
    at com.android.server.ServerThread.run(SystemServer.java:540)
 Session failed to close due to remote exception
 android.os.DeadObjectException
    at android.os.BinderProxy.transact(Native Method)
    at com.android.internal.view.IInputMethodSession$Stub$Proxy.finishSession(IInputMethodSession.java:346)
    at com.android.server.InputMethodManagerService.finishSession(InputMethodManagerService.java:896)
    at com.android.server.InputMethodManagerService.clearCurMethodLocked(InputMethodManagerService.java:911)
    at com.android.server.InputMethodManagerService.onServiceDisconnected(InputMethodManagerService.java:924)
    at android.app.LoadedApk$ServiceDispatcher.doDeath(LoadedApk.java:1069)
    at android.app.LoadedApk$ServiceDispatcher$RunConnection.run(LoadedApk.java:1083)
    at android.os.Handler.handleCallback(Handler.java:587)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:123)
    at com.android.server.ServerThread.run(SystemServer.java:540)
 Process com.ykstudio.ykLibDemo (pid 626) has died.
 WIN DEATH: Window{4069b908 com.ykstudio.ykLibDemo/com.ykstudio.ykLibDemo.MainActivity paused=false}
 channel '406fd480 com.ykstudio.ykLibDemo/com.ykstudio.ykLibDemo.SuperImageViewActivity (server)' ~ Consumer closed input channel or an error occurred.  events=0x8
 channel '406fd480 com.ykstudio.ykLibDemo/com.ykstudio.ykLibDemo.SuperImageViewActivity (server)' ~ Channel is unrecoverably broken and will be disposed!
 WIN DEATH: Window{406fd480 com.ykstudio.ykLibDemo/com.ykstudio.ykLibDemo.SuperImageViewActivity paused=false}
 Start proc com.ykstudio.ykLibDemo for activity com.ykstudio.ykLibDemo/.MainActivity: pid=734 uid=10035 gids={}
 Low Memory: No more background processes.
 Got RemoteException sending setActive(false) notification to pid 626 uid 10035
 Displayed com.ykstudio.ykLibDemo/.MainActivity: +1s306ms

帮助!有什么想法吗？...

Answer 1

如果我对文档的理解是正确的，那么您可以重用BitmapRegionDecoder，而无需在每次使用它时重新实例化它。你有没有试着重复使用它？

我必须同意:每个人都写BitmapRegionDecoder应该用于这个场景(显示大的位图而不会遇到OOM)，但是没有人确切地知道如何正确地使用它:(