Fixed disconnect bug in SurfaceTexture

BufferQueue's disconnect could race with updateTexImage
where invalid buffers could be released.  Additionally
fixed similar bug with setBufferCount.  Tests were added
to stress the disconnect mechanism.

Change-Id: I9afa4c64f3e025984e8a9e8d924852a71d044716

1 files changed, 15 insertions, 12 deletions

diff --git a/libs/gui/SurfaceTexture.cpp b/libs/gui/SurfaceTexture.cpp
index 18c86fa..dd96f84 100644
--- a/libs/gui/SurfaceTexture.cpp
+++ b/libs/gui/SurfaceTexture.cpp
@@ -176,6 +176,8 @@ status_t SurfaceTexture::updateTexImage() {
     ST_LOGV("updateTexImage");
     Mutex::Autolock lock(mMutex);
 
+    status_t err = NO_ERROR;
+
     if (mAbandoned) {
         ST_LOGE("updateTexImage: SurfaceTexture is abandoned!");
         return NO_INIT;
@@ -269,11 +271,17 @@ status_t SurfaceTexture::updateTexImage() {
                 mCurrentTextureBuf != NULL ? mCurrentTextureBuf->handle : 0,
                 buf, item.mGraphicBuffer != NULL ? item.mGraphicBuffer->handle : 0);
 
-        // Release the old buffer
+        // release old buffer
         if (mCurrentTexture != BufferQueue::INVALID_BUFFER_SLOT) {
-            mBufferQueue->releaseBuffer(mCurrentTexture, dpy,
-                    mEGLSlots[mCurrentTexture].mFence);
+            status_t status = mBufferQueue->releaseBuffer(mCurrentTexture, dpy, mEGLSlots[mCurrentTexture].mFence);
+
             mEGLSlots[mCurrentTexture].mFence = EGL_NO_SYNC_KHR;
+            if (status == BufferQueue::STALE_BUFFER_SLOT) {
+                freeBufferLocked(mCurrentTexture);
+            } else if (status != OK) {
+                ST_LOGE("updateTexImage: released invalid buffer");
+                err = status;
+            }
         }
 
         // Update the SurfaceTexture state.
@@ -289,7 +297,7 @@ status_t SurfaceTexture::updateTexImage() {
         glBindTexture(mTexTarget, mTexName);
     }
 
-    return OK;
+    return err;
 }
 
 status_t SurfaceTexture::detachFromContext() {
@@ -630,6 +638,9 @@ bool SurfaceTexture::isSynchronousMode() const {
 void SurfaceTexture::freeBufferLocked(int slotIndex) {
     ST_LOGV("freeBufferLocked: slotIndex=%d", slotIndex);
     mEGLSlots[slotIndex].mGraphicBuffer = 0;
+    if (slotIndex == mCurrentTexture) {
+        mCurrentTexture = BufferQueue::INVALID_BUFFER_SLOT;
+    }
     if (mEGLSlots[slotIndex].mEglImage != EGL_NO_IMAGE_KHR) {
         EGLImageKHR img = mEGLSlots[slotIndex].mEglImage;
         if (img != EGL_NO_IMAGE_KHR) {
@@ -693,12 +704,6 @@ sp<BufferQueue> SurfaceTexture::getBufferQueue() const {
 }
 
 // Used for refactoring, should not be in final interface
-status_t SurfaceTexture::setBufferCount(int bufferCount) {
-    Mutex::Autolock lock(mMutex);
-    return mBufferQueue->setBufferCount(bufferCount);
-}
-
-// Used for refactoring, should not be in final interface
 status_t SurfaceTexture::connect(int api,
                 uint32_t* outWidth, uint32_t* outHeight, uint32_t* outTransform) {
     Mutex::Autolock lock(mMutex);
@@ -737,8 +742,6 @@ void SurfaceTexture::onBuffersReleased() {
             freeBufferLocked(i);
         }
     }
-
-    mCurrentTexture = BufferQueue::INVALID_BUFFER_SLOT;
 }
 
 void SurfaceTexture::dump(String8& result) const