Change Atlas recycling to track current flush count and recycle if Atlas not used in current flush.

src/gpu/GrTextStrike.cpp

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrAtlas.h"
 #include "GrGpu.h"
 #include "GrRectanizer.h"
@@ skipping 68 matching lines @@
         GrTextStrike* strikeToPurge = strike;
         strike = strikeToPurge->fPrev;
         if (purge) {
             // keep purging if we won't free up any atlases with this strike.
             purge = (NULL == strikeToPurge->fAtlas);
             int index = fCache.slowFindIndex(strikeToPurge);
             GrAssert(index >= 0);
             fCache.removeAt(index, strikeToPurge->fFontScalerKey->getHash());
             this->detachStrikeFromList(strikeToPurge);
             delete strikeToPurge;
-        } else {
-            // for the remaining strikes, we just mark them unused
-            GrAtlas::MarkAllUnused(strikeToPurge->fAtlas);
         }
     }
 #if FONT_CACHE_STATS
     ++g_PurgeCount;
 #endif
 }
 
-void GrFontCache::freeAtlasExceptFor(GrTextStrike* preserveStrike) {
+void GrFontCache::freeAtlasExceptFor(GrTextStrike* preserveStrike, uint64_t currentFlushCount) {
     GrTextStrike* strike = fTail;
     while (strike) {
         if (strike == preserveStrike) {
             strike = strike->fPrev;
             continue;
         }
         GrTextStrike* strikeToPurge = strike;
         strike = strikeToPurge->fPrev;
-        if (strikeToPurge->removeUnusedAtlases()) {
+        if (strikeToPurge->removeUnusedAtlases(currentFlushCount)) {
             if (NULL == strikeToPurge->fAtlas) {
                 int index = fCache.slowFindIndex(strikeToPurge);
                 GrAssert(index >= 0);
                 fCache.removeAt(index, strikeToPurge->fFontScalerKey->getHash());
                 this->detachStrikeFromList(strikeToPurge);
                 delete strikeToPurge;
             }
             break;
         }
     }
@@ skipping 58 matching lines @@
 #if GR_DEBUG
 //    GrPrintf(" GrTextStrike %p %d\n", this, gCounter);
     gCounter += 1;
 #endif
 }
 
 // these signatures are needed because they're used with
 // SkTDArray::visitAll() (see destructor & removeUnusedAtlases())
 static void free_glyph(GrGlyph*& glyph) { glyph->free(); }
 
+static uint64_t gCurrentFlushCount = 0;

[bsalomon, 2013/08/13 21:18:28]

wha? There can be multiple GrContexts

[jvanverth1, 2013/08/14 13:24:32]

A bit of a hack to get around the fact that visitAll() only takes one argument.
But I agree it's not thread-safe (and a hack). Changed to something cleaner,
below.

+
 static void invalidate_glyph(GrGlyph*& glyph) {
-    if (glyph->fAtlas && !glyph->fAtlas->used()) {
+    if (glyph->fAtlas && glyph->fAtlas->lastFlush() < gCurrentFlushCount) {
         glyph->fAtlas = NULL;
     }
 }
 
 GrTextStrike::~GrTextStrike() {
     GrAtlas::FreeLList(fAtlas);
     fFontScalerKey->unref();
     fCache.getArray().visitAll(free_glyph);
 
 #if GR_DEBUG
     gCounter -= 1;
 //    GrPrintf("~GrTextStrike %p %d\n", this, gCounter);
 #endif
 }
 
 GrGlyph* GrTextStrike::generateGlyph(GrGlyph::PackedID packed,
                                      GrFontScaler* scaler) {
     SkIRect bounds;
     if (!scaler->getPackedGlyphBounds(packed, &bounds)) {
         return NULL;
     }
 
     GrGlyph* glyph = fPool.alloc();
     glyph->init(packed, bounds);
     fCache.insert(packed, glyph);
     return glyph;
 }
 
-bool GrTextStrike::removeUnusedAtlases() {
+bool GrTextStrike::removeUnusedAtlases(uint64_t currentFlushCount) {
+    gCurrentFlushCount = currentFlushCount;
     fCache.getArray().visitAll(invalidate_glyph);
-    return GrAtlas::RemoveUnusedAtlases(fAtlasMgr, &fAtlas);
+    return GrAtlas::RemoveUnusedAtlases(fAtlasMgr, &fAtlas, currentFlushCount);
 
     return false;
 }
 
-bool GrTextStrike::getGlyphAtlas(GrGlyph* glyph, GrFontScaler* scaler) {
+bool GrTextStrike::getGlyphAtlas(GrGlyph* glyph, GrFontScaler* scaler, uint64_t currentFlushCount) {
 #if 0   // testing hack to force us to flush our cache often
     static int gCounter;
     if ((++gCounter % 10) == 0) return false;
 #endif
 
     GrAssert(glyph);
     GrAssert(scaler);
     GrAssert(fCache.contains(glyph));
     if (glyph->fAtlas) {
-        glyph->fAtlas->setUsed(true);
+        glyph->fAtlas->setLastFlush(currentFlushCount);
         return true;
     }
 
     GrAutoRef ar(scaler);
 
     int bytesPerPixel = GrMaskFormatBytesPerPixel(fMaskFormat);
     size_t size = glyph->fBounds.area() * bytesPerPixel;
     SkAutoSMalloc<1024> storage(size);
     if (!scaler->getPackedGlyphImage(glyph->fPackedID, glyph->width(),
                                      glyph->height(),
                                      glyph->width() * bytesPerPixel,
                                      storage.get())) {
         return false;
     }
 
     GrAtlas* atlas = fAtlasMgr->addToAtlas(&fAtlas, glyph->width(),
                                            glyph->height(), storage.get(),
                                            fMaskFormat,
                                            &glyph->fAtlasLocation);
     if (NULL == atlas) {
         return false;
     }
 
     glyph->fAtlas = atlas;
-    atlas->setUsed(true);
+    atlas->setLastFlush(currentFlushCount);
     return true;
 }