Parallel cache - preliminary

src/core/SkGlyphCache.h

Index: src/core/SkGlyphCache.h
diff --git a/src/core/SkGlyphCache.h b/src/core/SkGlyphCache.h
index 1c985bf6715070bd1ff520535919aec3786429d2..029d598f8017a0904189b28505ac5a72b4e55248 100644
--- a/src/core/SkGlyphCache.h
+++ b/src/core/SkGlyphCache.h
@@ -7,12 +7,16 @@
 #ifndef SkGlyphCache_DEFINED
 #define SkGlyphCache_DEFINED
 
+#include <SkSpinlock.h>

[mtklein_C, 2015/08/14 15:31:37]

kill?

 #include "SkBitmap.h"
 #include "SkChunkAlloc.h"
 #include "SkDescriptor.h"
 #include "SkGlyph.h"
+#include "SkMutex.h"
 #include "SkTHash.h"
 #include "SkScalerContext.h"
+#include "SkSharedMutex.h"
+#include "SkSpinlock.h"
 #include "SkTemplates.h"
 #include "SkTDArray.h"
 
@@ -112,12 +116,23 @@ public:
 
     SkScalerContext* getScalerContext() const { return fScalerContext; }
 
+    struct GlyphAndCache {
+        SkGlyphCache* cache;
+        const SkGlyph* glyph;
+    };
+
+    static void onceFillInImage(GlyphAndCache gc);
+
+    static void onceFillInPath(GlyphAndCache gc);
+
+    typedef bool (*VisitProc)(const SkGlyphCache*, void*);
+
     /** Find a matching cache entry, and call proc() with it. If none is found create a new one.
         If the proc() returns true, detach the cache and return it, otherwise leave it and return
         NULL.
     */
     static SkGlyphCache* VisitCache(SkTypeface*, const SkDescriptor* desc,
-                                    bool (*proc)(const SkGlyphCache*, void*),
+                                    VisitProc proc,
                                     void* context);
 
     /** Given a strike that was returned by either VisitCache() or DetachCache() add it back into
@@ -171,18 +186,21 @@ private:
         kFull_MetricsType
     };
 
-    enum {
-        kHashBits           = 8,
-        kHashCount          = 1 << kHashBits,
-        kHashMask           = kHashCount - 1
-    };
-
     typedef uint32_t PackedGlyphID;    // glyph-index + subpixel-pos
     typedef uint32_t PackedUnicharID;  // unichar + subpixel-pos
 
     struct CharGlyphRec {
-        PackedUnicharID    fPackedUnicharID;
-        PackedGlyphID      fPackedGlyphID;
+        class HashTraits {
+        public:
+            static PackedUnicharID GetKey(const CharGlyphRec& rec) {
+                return rec.fPackedUnicharID;
+            }
+            static uint32_t Hash(PackedUnicharID unicharID) {
+                return SkChecksum::CheapMix(unicharID);
+            }
+        };
+        PackedUnicharID fPackedUnicharID;
+        PackedGlyphID fPackedGlyphID;
     };
 
     struct AuxProcRec {
@@ -195,6 +213,9 @@ private:
     SkGlyphCache(SkTypeface*, const SkDescriptor*, SkScalerContext*);
     ~SkGlyphCache();
 
+    void increaseMemoryUsed(size_t used);
+    size_t memoryUsed() const;
+
     // Return the SkGlyph* associated with MakeID. The id parameter is the
     // combined glyph/x/y id generated by MakeID. If it is just a glyph id
     // then x and y are assumed to be zero.
@@ -204,12 +225,17 @@ private:
     SkGlyph* lookupByChar(SkUnichar id, MetricsType type, SkFixed x = 0, SkFixed y = 0);
 
     // Return a new SkGlyph for the glyph ID and subpixel position id. Limit the amount
-    // of work
-    // using type.
+    // of work using type.
     SkGlyph* allocateNewGlyph(PackedGlyphID packedGlyphID, MetricsType type);
 
+    // Add the full metrics to an existing glyph.
+    void addFullMetrics(SkGlyph* glyph);
+
     static bool DetachProc(const SkGlyphCache*, void*) { return true; }
 
+    CharGlyphRec PackedUnicharIDtoCharGlyphRec(PackedUnicharID packedUnicharID);
+
+
     // The id arg is a combined id generated by MakeID.
     CharGlyphRec* getCharGlyphRec(PackedUnicharID id);
 
@@ -217,23 +243,34 @@ private:
 
     inline static SkGlyphCache* FindTail(SkGlyphCache* head);
 
+    // The following are protected by the SkGlyphCache_Globals fLock mutex.
     SkGlyphCache*          fNext;
     SkGlyphCache*          fPrev;
     SkDescriptor* const    fDesc;
-    SkScalerContext* const fScalerContext;
     SkPaint::FontMetrics   fFontMetrics;
+    int                    refCount;
 
+    // The following fields are protected by fMu.
+    mutable SkSharedMutex  fMu;
     // Map from a combined GlyphID and sub-pixel position to a SkGlyph.
     SkTHashTable<SkGlyph, PackedGlyphID, SkGlyph::HashTraits> fGlyphMap;
-
     SkChunkAlloc           fGlyphAlloc;
-
-    SkAutoTArray<CharGlyphRec> fPackedUnicharIDToPackedGlyphID;
-
+    typedef SkTHashTable<CharGlyphRec, PackedUnicharID, CharGlyphRec::HashTraits>
+            PackedUnicharIDToPackedGlyphIDMap;
+    SkAutoTDelete<PackedUnicharIDToPackedGlyphIDMap> fPackedUnicharIDToPackedGlyphID;
     // used to track (approx) how much ram is tied-up in this cache
     size_t                 fMemoryUsed;
 
+    // The FScalerMutex protects the following fields. It is mainly used to ensure single-threaded
+    // access to the font scaler, but it also protects the fAuxProcList.
+    mutable SkMutex        fScalerMutex;
+    SkScalerContext* const fScalerContext;
     AuxProcRec*            fAuxProcList;
+
+    // BEWARE: Mutex ordering
+    // If you need to hold both fMu and fScalerMutex then fMu must be held first.
+    // fLock from SkGlyphCache_Globals should not be held when you need to hold either fMu
+    // or fScalerMutex.
 };
 
 class SkAutoGlyphCacheBase {