SkGlyphCache_Globals: SkMutex -> SkSpinlock

src/core/SkGlyphCache.cpp

Index: src/core/SkGlyphCache.cpp
diff --git a/src/core/SkGlyphCache.cpp b/src/core/SkGlyphCache.cpp
index 6ae17b10741bc00204000daf1974137e3e5db967..f935dffbbbe79767bef07146dbbe5b709546ad75 100755
--- a/src/core/SkGlyphCache.cpp
+++ b/src/core/SkGlyphCache.cpp
@@ -21,7 +21,7 @@
 namespace {
 
 SkGlyphCache_Globals* create_globals() {
-    return SkNEW_ARGS(SkGlyphCache_Globals, (SkGlyphCache_Globals::kYes_UseMutex));
+    return SkNEW(SkGlyphCache_Globals);
 }
 
 }  // namespace
@@ -35,8 +35,7 @@ static SkGlyphCache_Globals& getSharedGlobals() {
 
 // Returns the TLS globals (if set), or the shared globals
 static SkGlyphCache_Globals& getGlobals() {

[mtklein_C, 2015/07/09 16:46:22]

seems like we can merge getGlobals() and getSharedGlobals() now?

(If we do merge them, Skia style wants this  static functionto be named
get_globals())

[herb_g, 2015/07/09 18:21:15]

Done.

-    SkGlyphCache_Globals* tls = SkGlyphCache_Globals::FindTLS();
-    return tls ? *tls : getSharedGlobals();
+    return getSharedGlobals();
 }
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -418,13 +417,22 @@ void SkGlyphCache::invokeAndRemoveAuxProcs() {
 ///////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////
 
+
+class AutoAcquire {
+public:
+    AutoAcquire(SkSpinlock& lock) : fLock(lock) { fLock.acquire(); }
+    ~AutoAcquire() { fLock.release(); }
+private:
+    SkSpinlock& fLock;
+};
+
 size_t SkGlyphCache_Globals::setCacheSizeLimit(size_t newLimit) {
     static const size_t minLimit = 256 * 1024;
     if (newLimit < minLimit) {
         newLimit = minLimit;
     }
 
-    SkAutoMutexAcquire    ac(fMutex);
+    AutoAcquire ac(fLock);
 
     size_t prevLimit = fCacheSizeLimit;
     fCacheSizeLimit = newLimit;
@@ -437,7 +445,7 @@ int SkGlyphCache_Globals::setCacheCountLimit(int newCount) {
         newCount = 0;
     }
 
-    SkAutoMutexAcquire    ac(fMutex);
+    AutoAcquire ac(fLock);
 
     int prevCount = fCacheCountLimit;
     fCacheCountLimit = newCount;
@@ -446,7 +454,7 @@ int SkGlyphCache_Globals::setCacheCountLimit(int newCount) {
 }
 
 void SkGlyphCache_Globals::purgeAll() {
-    SkAutoMutexAcquire    ac(fMutex);
+    AutoAcquire ac(fLock);
     this->internalPurge(fTotalMemoryUsed);
 }
 
@@ -466,25 +474,25 @@ SkGlyphCache* SkGlyphCache::VisitCache(SkTypeface* typeface,
     SkASSERT(desc);
 
     SkGlyphCache_Globals& globals = getGlobals();
-    SkAutoMutexAcquire    ac(globals.fMutex);
     SkGlyphCache*         cache;
-    bool                  insideMutex = true;
-
-    globals.validate();
 
-    for (cache = globals.internalGetHead(); cache != NULL; cache = cache->fNext) {
-        if (cache->fDesc->equals(*desc)) {
-            globals.internalDetachCache(cache);
-            goto FOUND_IT;
+    {
+        AutoAcquire ac(globals.fLock);
+
+        globals.validate();
+
+        for (cache = globals.internalGetHead(); cache != NULL; cache = cache->fNext) {
+            if (cache->fDesc->equals(*desc)) {
+                globals.internalDetachCache(cache);
+                if (!proc(cache, context)) {
+                    globals.internalAttachCacheToHead(cache);

[mtklein_C, 2015/07/09 16:46:22]

Thanks, I find this code a lot easier to follow than the old code.

[herb_g, 2015/07/09 18:21:15]

Acknowledged.

+                    cache = NULL;
+                }
+                return cache;
+            }
         }
     }
 
-    /* Release the mutex now, before we create a new entry (which might have
-        side-effects like trying to access the cache/mutex (yikes!)
-    */
-    ac.release();           // release the mutex now
-    insideMutex = false;    // can't use globals anymore
-
     // Check if we can create a scaler-context before creating the glyphcache.
     // If not, we may have exhausted OS/font resources, so try purging the
     // cache once and try again.
@@ -500,16 +508,10 @@ SkGlyphCache* SkGlyphCache::VisitCache(SkTypeface* typeface,
         cache = SkNEW_ARGS(SkGlyphCache, (typeface, desc, ctx));
     }
 
-FOUND_IT:
-
     AutoValidate av(cache);
 
     if (!proc(cache, context)) {   // need to reattach
-        if (insideMutex) {
-            globals.internalAttachCacheToHead(cache);
-        } else {
-            globals.attachCacheToHead(cache);
-        }
+        globals.attachCacheToHead(cache);
         cache = NULL;
     }
     return cache;
@@ -524,7 +526,7 @@ void SkGlyphCache::AttachCache(SkGlyphCache* cache) {
 
 void SkGlyphCache::Dump() {
     SkGlyphCache_Globals& globals = getGlobals();
-    SkAutoMutexAcquire    ac(globals.fMutex);
+    AutoAcquire           ac(globals.fLock);
     SkGlyphCache*         cache;
 
     globals.validate();
@@ -552,7 +554,7 @@ void SkGlyphCache::Dump() {
 ///////////////////////////////////////////////////////////////////////////////
 
 void SkGlyphCache_Globals::attachCacheToHead(SkGlyphCache* cache) {
-    SkAutoMutexAcquire    ac(fMutex);
+    AutoAcquire ac(fLock);
 
     this->validate();
     cache->validate();
@@ -681,8 +683,10 @@ void SkGlyphCache_Globals::validate() const {
         head = head->fNext;
     }
 
-    SkASSERT(fTotalMemoryUsed == computedBytes);
-    SkASSERT(fCacheCount == computedCount);
+    SkASSERTF(fCacheCount == computedCount, "fCacheCount: %d, computedCount: %d", fCacheCount,
+              computedCount);
+    SkASSERTF(fTotalMemoryUsed == computedBytes, "fTotalMemoryUsed: %d, computedBytes: %d",
+              fTotalMemoryUsed, computedBytes);
 }
 
 #endif
@@ -722,14 +726,8 @@ void SkGraphics::PurgeFontCache() {
 }
 
 size_t SkGraphics::GetTLSFontCacheLimit() {

[mtklein_C, 2015/07/09 16:46:22]

TODO(mtklein): clean up TLS apis ?

[herb_g, 2015/07/09 18:21:15]

Done.

-    const SkGlyphCache_Globals* tls = SkGlyphCache_Globals::FindTLS();
-    return tls ? tls->getCacheSizeLimit() : 0;
+    return 0;
 }
 
 void SkGraphics::SetTLSFontCacheLimit(size_t bytes) {
-    if (0 == bytes) {
-        SkGlyphCache_Globals::DeleteTLS();
-    } else {
-        SkGlyphCache_Globals::GetTLS().setCacheSizeLimit(bytes);
-    }
 }