android - Webview 导致 ANR

Question

我编写了一个应用程序，它在 Webviews 中显示 html 页面，这些页面在 ViewPager 中进行管理。一切正常，但从一页滑动到另一页时我遇到了一些 ANR。 ANR 数据转储显示主线程已通过 ThreadedRenderer.nSyncAndDrawFrame() 进行调用，它调用了一个 native 方法，显然与渲染器线程通信，并等待该线程完成绘制 View 。由于这两个都在执行 native 代码，因此很难弄清楚发生了什么，但渲染器线程似乎从未向主线程发出恢复信号，因此导致了 ANR。 ANR 报告之前的 logcat 中没有任何问题。

有没有人对如何解决这个问题有建议？我假设对 ThreadedRenderer.nSyncAndDrawFrame() 的调用与 Webview 相关联，但我实际上没有任何东西可以证实这一点。

问题是不可重复的，因为如果我重新启动应用程序并导航到发生 ANR 时显示的同一页面，它就不会再次发生。设备是运行 Android 5.1 的 Nexus 7。

主线程和渲染器线程的 ANR 堆栈跟踪:

"main" prio=5 tid=1 Native
| group="main" sCount=1 dsCount=0 obj=0x73547000 self=0xb4827800
| sysTid=1248 nice=-6 cgrp=default sched=0/0 handle=0xb6fd6bec
| state=S schedstat=( 0 0 0 ) utm=6035 stm=1406 core=0 HZ=100
| stack=0xbe5a6000-0xbe5a8000 stackSize=8MB
| held mutexes=
kernel: (couldn't read /proc/self/task/1248/stack)
native: #00 pc 000133b8 /system/lib/libc.so (syscall+28)
native: #01 pc 00016a81 /system/lib/libc.so (__pthread_cond_timedwait_relative(pthread_cond_t*, pthread_mutex_t*, timespec const*)+56)
native: #02 pc 0003c73b /system/lib/libhwui.so (???)
native: #03 pc 0003c771 /system/lib/libhwui.so (???)
native: #04 pc 0083fd83 /data/dalvik-cache/arm/system@framework@boot.oat (Java_android_view_ThreadedRenderer_nSyncAndDrawFrame__JJJF+134)
at android.view.ThreadedRenderer.nSyncAndDrawFrame(Native method)
at android.view.ThreadedRenderer.draw(ThreadedRenderer.java:340)
at android.view.ViewRootImpl.draw(ViewRootImpl.java:2530)
at android.view.ViewRootImpl.performDraw(ViewRootImpl.java:2352)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1982)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1061)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5885)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
at android.view.Choreographer.doCallbacks(Choreographer.java:580)
at android.view.Choreographer.doFrame(Choreographer.java:550)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5254)
at java.lang.reflect.Method.invoke!(Native method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

"RenderThread" prio=5 tid=26 Native
| group="main" sCount=1 dsCount=0 obj=0x12c07820 self=0xa1c30800
| sysTid=1303 nice=-4 cgrp=default sched=0/0 handle=0xa1c44c00
| state=S schedstat=( 0 0 0 ) utm=8314 stm=1817 core=0 HZ=100
| stack=0xa0cc2000-0xa0cc4000 stackSize=1012KB
| held mutexes=
kernel: (couldn't read /proc/self/task/1303/stack)
native: #00 pc 000133b8 /system/lib/libc.so (syscall+28)
native: #01 pc 0001741b /system/lib/libc.so (__futex_wait_ex+42)
native: #02 pc 00017761 /system/lib/libc.so (pthread_mutex_lock+230)
native: #03 pc 0001d767 /system/vendor/lib/libgsl.so (os_mutex_lock+6)
native: #04 pc 0001ea88 /system/vendor/lib/egl/libEGL_adreno.so (egliDoDestroyEGLImage+180)
native: #05 pc 0008698d /system/vendor/lib/egl/libGLESv2_adreno.so (rb_image_try_release+32)
native: #06 pc 00086acf /system/vendor/lib/egl/libGLESv2_adreno.so (rb_destroy_resource_updates_pure+136)
native: #07 pc 00085491 /system/vendor/lib/egl/libGLESv2_adreno.so (rb_perform_resolve+276)
native: #08 pc 00085761 /system/vendor/lib/egl/libGLESv2_adreno.so (rb_resolve+464)
native: #09 pc 0008a891 /system/vendor/lib/egl/libGLESv2_adreno.so (rb_surface_swap+228)
native: #10 pc 0006af89 /system/vendor/lib/egl/libGLESv2_adreno.so (gl2_surface_swap+76)
native: #11 pc 0005d12b /system/vendor/lib/egl/libGLESv2_adreno.so (oglSwapBuffer+194)
native: #12 pc 00013ddc /system/vendor/lib/egl/libEGL_adreno.so (qeglDrvAPI_eglSwapBuffers+1776)
native: #13 pc 00007b60 /system/vendor/lib/egl/libEGL_adreno.so (eglSwapBuffers+16)
native: #14 pc 0001237f /system/lib/libEGL.so (eglSwapBuffers+290)
native: #15 pc 0003d291 /system/lib/libhwui.so (???)
native: #16 pc 0003bd05 /system/lib/libhwui.so (???)
native: #17 pc 0003beb5 /system/lib/libhwui.so (???)
native: #18 pc 0003caed /system/lib/libhwui.so (???)
native: #19 pc 0003e743 /system/lib/libhwui.so (android::uirenderer::renderthread::RenderThread::threadLoop()+66)
native: #20 pc 000104d5 /system/lib/libutils.so (android::Thread::_threadLoop(void*)+112)
native: #21 pc 0005f839 /system/lib/libandroid_runtime.so (android::AndroidRuntime::javaThreadShell(void*)+72)
native: #22 pc 00010045 /system/lib/libutils.so (???)
native: #23 pc 00016baf /system/lib/libc.so (__pthread_start(void*)+30)
native: #24 pc 00014af3 /system/lib/libc.so (__start_thread+6)

Answer 1

可能是Android 7.0 WebView的bug，可以通过以下两种方式修复:

1、webView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);

2、android:hardwareAccelerated="false"