DO NOT MERGE ANYWHERE: ImageReader: Add discardFreeBuffers method
This method (currently @hide) discards all cached buffers for
the ImageReader, which can be useful to free up memory at the
cost of reallocation time if more buffers are needed later.
It has no effect on acquired Images, filled Images waiting to be
acquired, or buffers being actively used by the source rendering to the
Surface.
Bug: 28695173
Change-Id: I427a8ba4ad73a267083f843dbf228bfc53a730d9
(cherry picked from commit e175aa82b58d70cc75ee683d65ee6ba041b9fe43)
diff --git a/media/java/android/media/ImageReader.java b/media/java/android/media/ImageReader.java
index ec2d4bc..ea51d4c 100644
--- a/media/java/android/media/ImageReader.java
+++ b/media/java/android/media/ImageReader.java
@@ -520,6 +520,31 @@
}
}
+ /**
+ * Discard any free buffers owned by this ImageReader.
+ *
+ * <p>
+ * Generally, the ImageReader caches buffers for reuse once they have been
+ * allocated, for best performance. However, sometimes it may be important to
+ * release all the cached, unused buffers to save on memory.
+ * </p>
+ * <p>
+ * Calling this method will discard all free cached buffers. This does not include any buffers
+ * associated with Images acquired from the ImageReader, any filled buffers waiting to be
+ * acquired, and any buffers currently in use by the source rendering buffers into the
+ * ImageReader's Surface.
+ * <p>
+ * The ImageReader continues to be usable after this call, but may need to reallocate buffers
+ * when more buffers are needed for rendering.
+ * </p>
+ * @hide
+ */
+ public void discardFreeBuffers() {
+ synchronized (mCloseLock) {
+ nativeDiscardFreeBuffers();
+ }
+ }
+
@Override
protected void finalize() throws Throwable {
try {
@@ -872,6 +897,7 @@
private synchronized native void nativeReleaseImage(Image i);
private synchronized native Surface nativeGetSurface();
private synchronized native int nativeDetachImage(Image i);
+ private synchronized native void nativeDiscardFreeBuffers();
/**
* @return A return code {@code ACQUIRE_*}
diff --git a/media/jni/android_media_ImageReader.cpp b/media/jni/android_media_ImageReader.cpp
index c3993ae..724fc02 100644
--- a/media/jni/android_media_ImageReader.cpp
+++ b/media/jni/android_media_ImageReader.cpp
@@ -611,6 +611,23 @@
return OK;
}
+static void ImageReader_discardFreeBuffers(JNIEnv* env, jobject thiz) {
+ ALOGV("%s:", __FUNCTION__);
+ JNIImageReaderContext* ctx = ImageReader_getContext(env, thiz);
+ if (ctx == NULL) {
+ jniThrowException(env, "java/lang/IllegalStateException", "ImageReader was already closed");
+ return;
+ }
+
+ BufferItemConsumer* bufferConsumer = ctx->getBufferConsumer();
+ status_t res = bufferConsumer->discardFreeBuffers();
+ if (res != OK) {
+ ALOGE("Buffer discard failed: %s (%d)", strerror(-res), res);
+ jniThrowRuntimeException(env,
+ "nativeDicardFreebuffers failed");
+ }
+}
+
static jobject ImageReader_getSurface(JNIEnv* env, jobject thiz)
{
ALOGV("%s: ", __FUNCTION__);
@@ -773,6 +790,7 @@
{"nativeImageSetup", "(Landroid/media/Image;)I", (void*)ImageReader_imageSetup },
{"nativeGetSurface", "()Landroid/view/Surface;", (void*)ImageReader_getSurface },
{"nativeDetachImage", "(Landroid/media/Image;)I", (void*)ImageReader_detachImage },
+ {"nativeDiscardFreeBuffers", "()V", (void*)ImageReader_discardFreeBuffers }
};
static const JNINativeMethod gImageMethods[] = {
