Memory optimizations for libhwui

Bug #5566149

Lazily initialize font renderers
Keep 60% of the texture cache when an app goes to the background
Delete least used font renderer when going to the background
Delete all font renderers on full memory trim

Change-Id: I3c2454d46dc1107ec0f0f72a9ce69cbbcc8825e7

6 files changed, 127 insertions, 27 deletions

diff --git a/libs/hwui/Caches.cpp b/libs/hwui/Caches.cpp
index 24ec4e8..75b07de 100644
--- a/libs/hwui/Caches.cpp
+++ b/libs/hwui/Caches.cpp
@@ -170,8 +170,11 @@ void Caches::flush(FlushMode mode) {
             patchCache.clear();
             dropShadowCache.clear();
             gradientCache.clear();
+            fontRenderer.clear();
             // fall through
         case kFlushMode_Moderate:
+            fontRenderer.flush();
+            textureCache.flush();
             pathCache.clear();
             roundRectShapeCache.clear();
             circleShapeCache.clear();
diff --git a/libs/hwui/GammaFontRenderer.cpp b/libs/hwui/GammaFontRenderer.cpp
index e8362dc..eb863e9 100644
--- a/libs/hwui/GammaFontRenderer.cpp
+++ b/libs/hwui/GammaFontRenderer.cpp
@@ -67,20 +67,63 @@ GammaFontRenderer::GammaFontRenderer() {
     const float whiteGamma = 1.0f / gamma;
 
     for (uint32_t i = 0; i <= 255; i++) {
-        mDefault[i] = i;
+        mGammaTable[i] = i;
 
         const float v = i / 255.0f;
         const float black = pow(v, blackGamma);
         const float white = pow(v, whiteGamma);
 
-        mBlackGamma[i] = uint8_t((float)::floor(black * 255.0f + 0.5f));
-        mWhiteGamma[i] = uint8_t((float)::floor(white * 255.0f + 0.5f));
+        mGammaTable[256 + i] = uint8_t((float)::floor(black * 255.0f + 0.5f));
+        mGammaTable[512 + i] = uint8_t((float)::floor(white * 255.0f + 0.5f));
     }
 
-    // Configure the font renderers
-    mDefaultRenderer.setGammaTable(&mDefault[0]);
-    mBlackGammaRenderer.setGammaTable(&mBlackGamma[0]);
-    mWhiteGammaRenderer.setGammaTable(&mWhiteGamma[0]);
+    memset(mRenderers, 0, sizeof(FontRenderer*) * kGammaCount);
+    memset(mRenderersUsageCount, 0, sizeof(uint32_t) * kGammaCount);
+}
+
+GammaFontRenderer::~GammaFontRenderer() {
+    for (int i = 0; i < kGammaCount; i++) {
+        delete mRenderers[i];
+    }
+}
+
+void GammaFontRenderer::clear() {
+    for (int i = 0; i < kGammaCount; i++) {
+        delete mRenderers[i];
+        mRenderers[i] = NULL;
+    }
+}
+
+void GammaFontRenderer::flush() {
+    int count = 0;
+    int min = -1;
+    uint32_t minCount = UINT_MAX;
+
+    for (int i = 0; i < kGammaCount; i++) {
+        if (mRenderers[i]) {
+            count++;
+            if (mRenderersUsageCount[i] < minCount) {
+                minCount = mRenderersUsageCount[i];
+                min = i;
+            }
+        }
+    }
+
+    if (count <= 1 || min < 0) return;
+
+    delete mRenderers[min];
+    mRenderers[min] = NULL;
+}
+
+FontRenderer* GammaFontRenderer::getRenderer(Gamma gamma) {
+    FontRenderer* renderer = mRenderers[gamma];
+    if (!renderer) {
+        renderer = new FontRenderer();
+        mRenderers[gamma] = renderer;
+        renderer->setGammaTable(&mGammaTable[gamma * 256]);
+    }
+    mRenderersUsageCount[gamma]++;
+    return renderer;
 }
 
 FontRenderer& GammaFontRenderer::getFontRenderer(const SkPaint* paint) {
@@ -92,12 +135,12 @@ FontRenderer& GammaFontRenderer::getFontRenderer(const SkPaint* paint) {
         const int luminance = (r * 2 + g * 5 + b) >> 3;
 
         if (luminance <= mBlackThreshold) {
-            return mBlackGammaRenderer;
+            return *getRenderer(kGammaBlack);
         } else if (luminance >= mWhiteThreshold) {
-            return mWhiteGammaRenderer;
+            return *getRenderer(kGammaWhite);
         }
     }
-    return mDefaultRenderer;
+    return *getRenderer(kGammaDefault);
 }
 
 }; // namespace uirenderer
diff --git a/libs/hwui/GammaFontRenderer.h b/libs/hwui/GammaFontRenderer.h
index 96d960c..54c208e 100644
--- a/libs/hwui/GammaFontRenderer.h
+++ b/libs/hwui/GammaFontRenderer.h
@@ -26,36 +26,43 @@ namespace uirenderer {
 
 struct GammaFontRenderer {
     GammaFontRenderer();
+    ~GammaFontRenderer();
+
+    enum Gamma {
+        kGammaDefault = 0,
+        kGammaBlack = 1,
+        kGammaWhite = 2,
+        kGammaCount = 3
+    };
+
+    void clear();
+    void flush();
 
     FontRenderer& getFontRenderer(const SkPaint* paint);
 
     uint32_t getFontRendererCount() const {
-        return 3;
+        return kGammaCount;
     }
 
     uint32_t getFontRendererSize(uint32_t fontRenderer) const {
-        switch (fontRenderer) {
-            case 0:
-                return mDefaultRenderer.getCacheHeight() * mDefaultRenderer.getCacheWidth();
-            case 1:
-                return mBlackGammaRenderer.getCacheHeight() * mBlackGammaRenderer.getCacheWidth();
-            case 2:
-                return mWhiteGammaRenderer.getCacheHeight() * mWhiteGammaRenderer.getCacheWidth();
-        }
-        return 0;
+        if (fontRenderer >= kGammaCount) return 0;
+
+        FontRenderer* renderer = mRenderers[fontRenderer];
+        if (!renderer) return 0;
+
+        return renderer->getCacheHeight() * renderer->getCacheWidth();
     }
 
 private:
-    FontRenderer mDefaultRenderer;
-    FontRenderer mBlackGammaRenderer;
-    FontRenderer mWhiteGammaRenderer;
+    FontRenderer* getRenderer(Gamma gamma);
+
+    uint32_t mRenderersUsageCount[kGammaCount];
+    FontRenderer* mRenderers[kGammaCount];
 
     int mBlackThreshold;
     int mWhiteThreshold;
 
-    uint8_t mDefault[256];
-    uint8_t mBlackGamma[256];
-    uint8_t mWhiteGamma[256];
+    uint8_t mGammaTable[256 * kGammaCount];
 };
 
 }; // namespace uirenderer
diff --git a/libs/hwui/Properties.h b/libs/hwui/Properties.h
index 5bd0d4f..8c01e3a 100644
--- a/libs/hwui/Properties.h
+++ b/libs/hwui/Properties.h
@@ -61,6 +61,9 @@ enum DebugLevel {
 #define PROPERTY_DROP_SHADOW_CACHE_SIZE "ro.hwui.drop_shadow_cache_size"
 #define PROPERTY_FBO_CACHE_SIZE "ro.hwui.fbo_cache_size"
 
+// These properties are defined in percentage (range 0..1)
+#define PROPERTY_TEXTURE_CACHE_FLUSH_RATE "ro.hwui.texture_cache_flush_rate"
+
 // These properties are defined in pixels
 #define PROPERTY_TEXT_CACHE_WIDTH "ro.hwui.text_cache_width"
 #define PROPERTY_TEXT_CACHE_HEIGHT "ro.hwui.text_cache_height"
@@ -82,6 +85,8 @@ enum DebugLevel {
 #define DEFAULT_DROP_SHADOW_CACHE_SIZE 2.0f
 #define DEFAULT_FBO_CACHE_SIZE 16
 
+#define DEFAULT_TEXTURE_CACHE_FLUSH_RATE 0.6f
+
 #define DEFAULT_TEXT_GAMMA 1.4f
 #define DEFAULT_TEXT_BLACK_GAMMA_THRESHOLD 64
 #define DEFAULT_TEXT_WHITE_GAMMA_THRESHOLD 192
diff --git a/libs/hwui/TextureCache.cpp b/libs/hwui/TextureCache.cpp
index fbdbf92..018ce3e 100644
--- a/libs/hwui/TextureCache.cpp
+++ b/libs/hwui/TextureCache.cpp
@@ -34,7 +34,8 @@ namespace uirenderer {
 
 TextureCache::TextureCache():
         mCache(GenerationCache<SkBitmap*, Texture*>::kUnlimitedCapacity),
-        mSize(0), mMaxSize(MB(DEFAULT_TEXTURE_CACHE_SIZE)) {
+        mSize(0), mMaxSize(MB(DEFAULT_TEXTURE_CACHE_SIZE)),
+        mFlushRate(DEFAULT_TEXTURE_CACHE_FLUSH_RATE) {
     char property[PROPERTY_VALUE_MAX];
     if (property_get(PROPERTY_TEXTURE_CACHE_SIZE, property, NULL) > 0) {
         INIT_LOGD("  Setting texture cache size to %sMB", property);
@@ -43,6 +44,15 @@ TextureCache::TextureCache():
         INIT_LOGD("  Using default texture cache size of %.2fMB", DEFAULT_TEXTURE_CACHE_SIZE);
     }
 
+    if (property_get(PROPERTY_TEXTURE_CACHE_FLUSH_RATE, property, NULL) > 0) {
+        float flushRate = atof(property);
+        INIT_LOGD("  Setting texture cache flush rate to %.2f%%", flushRate * 100.0f);
+        setFlushRate(flushRate);
+    } else {
+        INIT_LOGD("  Using default texture cache flush rate of %.2f%%",
+                DEFAULT_TEXTURE_CACHE_FLUSH_RATE * 100.0f);
+    }
+
     init();
 }
 
@@ -84,6 +94,10 @@ void TextureCache::setMaxSize(uint32_t maxSize) {
     }
 }
 
+void TextureCache::setFlushRate(float flushRate) {
+    mFlushRate = fmaxf(0.0f, fminf(1.0f, flushRate));
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // Callbacks
 ///////////////////////////////////////////////////////////////////////////////
@@ -168,6 +182,21 @@ void TextureCache::clear() {
     TEXTURE_LOGD("TextureCache:clear(), mSize = %d", mSize);
 }
 
+void TextureCache::flush() {
+    if (mFlushRate >= 1.0f || mCache.size() == 0) return;
+    if (mFlushRate <= 0.0f) {
+        clear();
+        return;
+    }
+
+    uint32_t targetSize = uint32_t(mSize * mFlushRate);
+    TEXTURE_LOGD("TextureCache::flush: target size: %d", targetSize);
+
+    while (mSize > targetSize) {
+        mCache.removeOldest();
+    }
+}
+
 void TextureCache::generateTexture(SkBitmap* bitmap, Texture* texture, bool regenerate) {
     SkAutoLockPixels alp(*bitmap);
 
diff --git a/libs/hwui/TextureCache.h b/libs/hwui/TextureCache.h
index f7707f7..ce924b4 100644
--- a/libs/hwui/TextureCache.h
+++ b/libs/hwui/TextureCache.h
@@ -98,6 +98,17 @@ public:
      */
     uint32_t getSize();
 
+    /**
+     * Partially flushes the cache. The amount of memory freed by a flush
+     * is defined by the flush rate.
+     */
+    void flush();
+    /**
+     * Indicates the percentage of the cache to retain when a
+     * memory trim is requested (see Caches::flush).
+     */
+    void setFlushRate(float flushRate);
+
 private:
     /**
      * Generates the texture from a bitmap into the specified texture structure.
@@ -119,6 +130,8 @@ private:
     uint32_t mMaxSize;
     GLint mMaxTextureSize;
 
+    float mFlushRate;
+
     bool mDebugEnabled;
 
     Vector<SkBitmap*> mGarbage;