commit 8429c793029135827ca336dee01de7179c683cb4
author Chris Dalton <csmartdalton@google.com> Tue Oct 23 15:56:22 2018 -0600
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Tue Oct 23 22:31:21 2018 +0000
tree ff1fec957dc56071958d2d6d00e7c42c6c388641
parent c96740729a6a524ec4c768af84b876dcac1dbd7f

ccpr: Don't use the GrContext id for the path cache id

Currently this is probably safe, but somebody could easily make a
change in the future that adds another path cache to the context and
accidentally introduces tricky bugs.

TBR=brianosman@google.com

Bug: chromium:897510
Bug: chromium:897413
Bug: chromium:897245
Bug: chromium:897507
Change-Id: I6bc40ac671058f78eb290dd775612d99008d32e7
Reviewed-on: https://skia-review.googlesource.com/c/164700
Reviewed-by: Chris Dalton <csmartdalton@google.com>
Commit-Queue: Chris Dalton <csmartdalton@google.com>

src/gpu/ccpr/GrCCPathCache.cpp

diff --git a/src/gpu/ccpr/GrCCPathCache.cpp b/src/gpu/ccpr/GrCCPathCache.cpp
index db85641..6d37b4f 100644
--- a/src/gpu/ccpr/GrCCPathCache.cpp
+++ b/src/gpu/ccpr/GrCCPathCache.cpp
@@ -12,6 +12,16 @@
 
 DECLARE_SKMESSAGEBUS_MESSAGE(sk_sp<GrCCPathCacheEntry>);
 
+static inline uint32_t next_path_cache_id() {
+    static std::atomic<uint32_t> gNextID(1);
+    for (;;) {
+        uint32_t id = gNextID.fetch_add(+1, std::memory_order_acquire);
+        if (SK_InvalidUniqueID != id) {
+            return id;
+        }
+    }
+}
+
 static inline bool SkShouldPostMessageToBus(
         const sk_sp<GrCCPathCacheEntry>& entry, uint32_t msgBusUniqueID) {
     return entry->pathCacheUniqueID() == msgBusUniqueID;
@@ -20,6 +30,7 @@
 // The maximum number of cache entries we allow in our own cache.
 static constexpr int kMaxCacheCount = 1 << 16;
 
+
 GrCCPathCache::MaskTransform::MaskTransform(const SkMatrix& m, SkIVector* shift)
         : fMatrix2x2{m.getScaleX(), m.getSkewX(), m.getSkewY(), m.getScaleY()} {
     SkASSERT(!m.hasPerspective());
@@ -128,6 +139,11 @@
     return GrResourceKeyHash(&key.fData[1], key.fData[0]);
 }
 
+
+GrCCPathCache::GrCCPathCache()
+    : fInvalidatedEntriesInbox(next_path_cache_id()) {
+}
+
 #ifdef SK_DEBUG
 GrCCPathCache::~GrCCPathCache() {
     // Ensure the hash table and LRU list are still coherent.
@@ -248,9 +264,8 @@
             fCachedAtlasInfo->fNumInvalidatedPathPixels >= fCachedAtlasInfo->fNumPathPixels / 2) {
             // Too many invalidated pixels: purge the atlas texture from the resource cache.
             // The GrContext and CCPR path cache both share the same unique ID.
-            uint32_t contextUniqueID = fPathCacheUniqueID;
             SkMessageBus<GrUniqueKeyInvalidatedMessage>::Post(
-                    GrUniqueKeyInvalidatedMessage(fAtlasKey, contextUniqueID));
+                    GrUniqueKeyInvalidatedMessage(fAtlasKey, fCachedAtlasInfo->fContextUniqueID));
             fCachedAtlasInfo->fIsPurgedFromResourceCache = true;
         }
     }