From 2e2aaf6e0497302bc03c218949d29b01f469316e Mon Sep 17 00:00:00 2001 From: Eino-Ville Talvala Date: Thu, 21 Jul 2016 17:04:19 -0700 Subject: [PATCH] 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 reallocationt 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 --- media/java/android/media/ImageReader.java | 26 ++++++++++++++++++++++++++ media/jni/android_media_ImageReader.cpp | 18 ++++++++++++++++++ 2 files changed, 44 insertions(+) diff --git a/media/java/android/media/ImageReader.java b/media/java/android/media/ImageReader.java index 682512c91708..2cbeb3a260be 100644 --- a/media/java/android/media/ImageReader.java +++ b/media/java/android/media/ImageReader.java @@ -520,6 +520,31 @@ public class ImageReader implements AutoCloseable { } } + /** + * Discard any free buffers owned by this ImageReader. + * + *

+ * 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. + *

+ *

+ * 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. + *

+ * The ImageReader continues to be usable after this call, but may need to reallocate buffers + * when more buffers are needed for rendering. + *

+ * @hide + */ + public void discardFreeBuffers() { + synchronized (mCloseLock) { + nativeDiscardFreeBuffers(); + } + } + @Override protected void finalize() throws Throwable { try { @@ -872,6 +897,7 @@ public class ImageReader implements AutoCloseable { 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 c3993ae20183..724fc02271e3 100644 --- a/media/jni/android_media_ImageReader.cpp +++ b/media/jni/android_media_ImageReader.cpp @@ -611,6 +611,23 @@ static jint ImageReader_detachImage(JNIEnv* env, jobject thiz, jobject image) { 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 @@ static const JNINativeMethod gImageReaderMethods[] = { {"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[] = { -- 2.11.0