fix a crasher in SurfaceTexture::updateTexImage()

we now make sure to drain the buffer queue on disconnect.
this happens only when in synchrnous mode. in async mode
we clear all buffers except the head of the queue.

for extra safety we also catch the null pointer
in updateTexImage (which should  never happen) and return
an error.

Bug: 5111008

Change-Id: I5174a6ecbb0de641c6510ef56a611cbb4e9e1f59

1 files changed, 56 insertions, 25 deletions

diff --git a/libs/gui/SurfaceTexture.cpp b/libs/gui/SurfaceTexture.cpp
index 631cc1c..4afca68 100644
--- a/libs/gui/SurfaceTexture.cpp
+++ b/libs/gui/SurfaceTexture.cpp
@@ -418,7 +418,9 @@ status_t SurfaceTexture::setSynchronousMode(bool enabled) {
 
     if (!enabled) {
         // going to asynchronous mode, drain the queue
-        drainQueueLocked();
+        err = drainQueueLocked();
+        if (err != NO_ERROR)
+            return err;
     }
 
     if (mSynchronousMode != enabled) {
@@ -616,13 +618,9 @@ status_t SurfaceTexture::disconnect(int api) {
         case NATIVE_WINDOW_API_MEDIA:
         case NATIVE_WINDOW_API_CAMERA:
             if (mConnectedApi == api) {
+                drainQueueAndFreeBuffersLocked();
                 mConnectedApi = NO_CONNECTED_API;
-                if (mQueue.isEmpty()) {
-                    // if the queue is not empty, we need to wait for it
-                    // to drain before we can free all buffers. This is
-                    // done in updateTexImage().
-                    freeAllBuffersLocked();
-                }
+                mDequeueCondition.signal();
             } else {
                 LOGE("disconnect: connected to another api (cur=%d, req=%d)",
                         mConnectedApi, api);
@@ -658,7 +656,7 @@ status_t SurfaceTexture::updateTexImage() {
 
     if (mAbandoned) {
         LOGE("calling updateTexImage() on an abandoned SurfaceTexture");
-        //return NO_INIT;
+        return NO_INIT;
     }
 
     // In asynchronous mode the list is guaranteed to be one buffer
@@ -667,21 +665,14 @@ status_t SurfaceTexture::updateTexImage() {
         Fifo::iterator front(mQueue.begin());
         int buf = *front;
 
-        if (uint32_t(buf) >= NUM_BUFFER_SLOTS) {
-            LOGE("buffer index out of range (index=%d)", buf);
-            //return BAD_VALUE;
-        }
-
         // Update the GL texture object.
         EGLImageKHR image = mSlots[buf].mEglImage;
         if (image == EGL_NO_IMAGE_KHR) {
             EGLDisplay dpy = eglGetCurrentDisplay();
-
             if (mSlots[buf].mGraphicBuffer == 0) {
                 LOGE("buffer at slot %d is null", buf);
-                //return BAD_VALUE;
+                return BAD_VALUE;
             }
-
             image = createImage(dpy, mSlots[buf].mGraphicBuffer);
             mSlots[buf].mEglImage = image;
             mSlots[buf].mEglDisplay = dpy;
@@ -871,24 +862,64 @@ void SurfaceTexture::setFrameAvailableListener(
     mFrameAvailableListener = listener;
 }
 
+void SurfaceTexture::freeBufferLocked(int i) {
+    mSlots[i].mGraphicBuffer = 0;
+    mSlots[i].mBufferState = BufferSlot::FREE;
+    if (mSlots[i].mEglImage != EGL_NO_IMAGE_KHR) {
+        eglDestroyImageKHR(mSlots[i].mEglDisplay, mSlots[i].mEglImage);
+        mSlots[i].mEglImage = EGL_NO_IMAGE_KHR;
+        mSlots[i].mEglDisplay = EGL_NO_DISPLAY;
+    }
+}
+
 void SurfaceTexture::freeAllBuffersLocked() {
     LOGW_IF(!mQueue.isEmpty(),
             "freeAllBuffersLocked called but mQueue is not empty");
     for (int i = 0; i < NUM_BUFFER_SLOTS; i++) {
-        mSlots[i].mGraphicBuffer = 0;
-        mSlots[i].mBufferState = BufferSlot::FREE;
-        if (mSlots[i].mEglImage != EGL_NO_IMAGE_KHR) {
-            eglDestroyImageKHR(mSlots[i].mEglDisplay, mSlots[i].mEglImage);
-            mSlots[i].mEglImage = EGL_NO_IMAGE_KHR;
-            mSlots[i].mEglDisplay = EGL_NO_DISPLAY;
+        freeBufferLocked(i);
+    }
+}
+
+void SurfaceTexture::freeAllBuffersExceptHeadLocked() {
+    LOGW_IF(!mQueue.isEmpty(),
+            "freeAllBuffersExceptCurrentLocked called but mQueue is not empty");
+    int head = -1;
+    if (!mQueue.empty()) {
+        Fifo::iterator front(mQueue.begin());
+        head = *front;
+    }
+    for (int i = 0; i < NUM_BUFFER_SLOTS; i++) {
+        if (i != head) {
+            freeBufferLocked(i);
         }
     }
 }
 
-void SurfaceTexture::drainQueueLocked() {
+status_t SurfaceTexture::drainQueueLocked() {
     while (mSynchronousMode && !mQueue.isEmpty()) {
         mDequeueCondition.wait(mMutex);
+        if (mAbandoned) {
+            LOGE("drainQueueLocked: SurfaceTexture has been abandoned!");
+            return NO_INIT;
+        }
+        if (mConnectedApi == NO_CONNECTED_API) {
+            LOGE("drainQueueLocked: SurfaceTexture is not connected!");
+            return NO_INIT;
+        }
     }
+    return NO_ERROR;
+}
+
+status_t SurfaceTexture::drainQueueAndFreeBuffersLocked() {
+    status_t err = drainQueueLocked();
+    if (err == NO_ERROR) {
+        if (mSynchronousMode) {
+            freeAllBuffersLocked();
+        } else {
+            freeAllBuffersExceptHeadLocked();
+        }
+    }
+    return err;
 }
 
 EGLImageKHR SurfaceTexture::createImage(EGLDisplay dpy,
@@ -960,10 +991,10 @@ int SurfaceTexture::query(int what, int* outValue)
 
 void SurfaceTexture::abandon() {
     Mutex::Autolock lock(mMutex);
-    // clear the queue
-    freeAllBuffersLocked();
+    mQueue.clear();
     mAbandoned = true;
     mCurrentTextureBuf.clear();
+    freeAllBuffersLocked();
     mDequeueCondition.signal();
 }