Adds extra debugging to SkPathRef that can optionally be turned on in a release build.

This is pretty hacky but hopefully will be quite short-lived.
Review URL: https://codereview.appspot.com/6584074

git-svn-id: http://skia.googlecode.com/svn/trunk@5793 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 74 insertions, 13 deletions

diff --git a/src/core/SkPathRef.h b/src/core/SkPathRef.h
index 339166340e..80ca50cabc 100644
--- a/src/core/SkPathRef.h
+++ b/src/core/SkPathRef.h
@@ -32,13 +32,29 @@
  * verb array use ref.verbs()[~i] (because verbs() returns a pointer just beyond the first
  * logical verb or the last verb in memory).
  */
+
+class SkPathRef;
+SkPathRef* gEmptyPathRef; // This path ref should never be deleted once it is created.
+
+// Temporary hackery to try to nail down http://code.google.com/p/chromium/issues/detail?id=148637
+#if SK_DEBUG_PATH_REF
+    #define PR_CONTAINER SkPath::PathRefDebugRef
+    #define SkDEBUGCODE_X(code) code
+    #define SkASSERT_X(cond) SK_DEBUGBREAK(cond)
+    SK_DECLARE_STATIC_MUTEX(gOwnersMutex);
+#else
+    #define PR_CONTAINER SkAutoTUnref<SkPathRef>
+    #define SkDEBUGCODE_X(code) SkDEBUGCODE(code)
+    #define SkASSERT_X(cond) SkASSERT(cond)
+#endif
+
 class SkPathRef : public ::SkRefCnt {
 public:
     SK_DECLARE_INST_COUNT(SkPathRef);
 
     class Editor {
     public:
-        Editor(SkAutoTUnref<SkPathRef>* pathRef,
+        Editor(PR_CONTAINER* pathRef,
                int incReserveVerbs = 0,
                int incReservePoints = 0) {
             if (pathRef->get()->getRefCnt() > 1) {
@@ -50,10 +66,10 @@ public:
             }
             fPathRef = pathRef->get();
             fPathRef->fGenerationID = 0;
-            SkDEBUGCODE(sk_atomic_inc(&fPathRef->fEditorsAttached);)
+            SkDEBUGCODE_X(sk_atomic_inc(&fPathRef->fEditorsAttached);)
         }
 
-        ~Editor() { SkDEBUGCODE(sk_atomic_dec(&fPathRef->fEditorsAttached);) }
+        ~Editor() { SkDEBUGCODE_X(sk_atomic_dec(&fPathRef->fEditorsAttached);) }
 
         /**
          * Returns the array of points.
@@ -112,28 +128,56 @@ public:
     };
 
 public:
+#if SK_DEBUG_PATH_REF
+    void addOwner(SkPath* owner) {
+        gOwnersMutex.acquire();
+        for (int i = 0; i < fOwners.count(); ++i) {
+            SkASSERT_X(fOwners[i] != owner);
+        }
+        *fOwners.append() = owner;
+        SkASSERT_X((this->getRefCnt() == fOwners.count()) ||
+                   (this == gEmptyPathRef && this->getRefCnt() == fOwners.count() + 1));
+        gOwnersMutex.release();
+    }
+
+    void removeOwner(SkPath* owner) {
+        gOwnersMutex.acquire();
+        SkASSERT_X((this->getRefCnt() == fOwners.count()) ||
+                   (this == gEmptyPathRef && this->getRefCnt() == fOwners.count() + 1));
+        bool found = false;
+        for (int i = 0; !found && i < fOwners.count(); ++i) {
+            found = (owner == fOwners[i]);
+            if (found) {
+                fOwners.remove(i);
+            }
+        }
+        SkASSERT_X(found);
+        gOwnersMutex.release();
+    }
+#endif
 
     /**
      * Gets a path ref with no verbs or points.
      */
     static SkPathRef* CreateEmpty() {
-        static SkAutoTUnref<SkPathRef> gEmptyPathRef(SkNEW(SkPathRef));
-        gEmptyPathRef.get()->ref();
-        return gEmptyPathRef.get();
+        if (!gEmptyPathRef) {
+            gEmptyPathRef = SkNEW(SkPathRef); // leak!
+        }
+        return SkRef(gEmptyPathRef);
     }
 
     /**
      * Transforms a path ref by a matrix, allocating a new one only if necessary.
      */
-    static void CreateTransformedCopy(SkAutoTUnref<SkPathRef>* dst,
+    static void CreateTransformedCopy(PR_CONTAINER* dst,
                                       const SkPathRef& src,
                                       const SkMatrix& matrix) {
         src.validate();
         if (matrix.isIdentity()) {
             if (dst->get() != &src) {
+                src.ref();
                 dst->reset(const_cast<SkPathRef*>(&src));
                 (*dst)->validate();
-                src.ref();
             }
             return;
         }
@@ -184,7 +228,7 @@ public:
      * repopulated with approximately the same number of verbs and points. A new path ref is created
      * only if necessary.
      */
-    static void Rewind(SkAutoTUnref<SkPathRef>* pathRef) {
+    static void Rewind(PR_CONTAINER* pathRef) {
         if (1 == (*pathRef)->getRefCnt()) {
             (*pathRef)->validate();
             (*pathRef)->fVerbCnt = 0;
@@ -201,8 +245,21 @@ public:
     }
 
     virtual ~SkPathRef() {
+        SkASSERT_X(this != gEmptyPathRef);
+#if SK_DEBUG_PATH_REF
+        SkASSERT_X(!fOwners.count());
+#endif
+
         this->validate();
         sk_free(fPoints);
+
+        SkDEBUGCODE_X(fPoints = NULL;)
+        SkDEBUGCODE_X(fVerbs = NULL;)
+        SkDEBUGCODE_X(fVerbCnt = 0x9999999;)
+        SkDEBUGCODE_X(fPointCnt = 0xAAAAAAA;)
+        SkDEBUGCODE_X(fPointCnt = 0xBBBBBBB;)
+        SkDEBUGCODE_X(fGenerationID = 0xEEEEEEEE;)
+        SkDEBUGCODE_X(fEditorsAttached = 0x7777777;)
     }
 
     int countPoints() const { this->validate(); return fPointCnt; }
@@ -282,7 +339,7 @@ public:
 #if NEW_PICTURE_FORMAT
     void writeToBuffer(SkWBuffer* buffer) {
         this->validate();
-        SkDEBUGCODE(size_t beforePos = buffer->pos();)
+        SkDEBUGCODE_X(size_t beforePos = buffer->pos();)
 
         // TODO: write gen ID here. Problem: We don't know if we're cross process or not from
         // SkWBuffer. Until this is fixed we write 0.
@@ -319,7 +376,7 @@ private:
         fPoints = NULL;
         fFreeSpace = 0;
         fGenerationID = kEmptyGenID;
-        SkDEBUGCODE(fEditorsAttached = 0;)
+        SkDEBUGCODE_X(fEditorsAttached = 0;)
         this->validate();
     }
 
@@ -480,7 +537,7 @@ private:
      * for the path ref.
      */
     int32_t genID() const {
-        SkDEBUGCODE(SkASSERT(!fEditorsAttached));
+        SkASSERT_X(!fEditorsAttached);
         if (!fGenerationID) {
             if (0 == fPointCnt && 0 == fVerbCnt) {
                 fGenerationID = kEmptyGenID;
@@ -521,7 +578,11 @@ private:
         kEmptyGenID = 1, // GenID reserved for path ref with zero points and zero verbs.
     };
     mutable int32_t     fGenerationID;
-    SkDEBUGCODE(int32_t fEditorsAttached;) // assert that only one editor in use at any time.
+    SkDEBUGCODE_X(int32_t fEditorsAttached;) // assert that only one editor in use at any time.
+
+#if SK_DEBUG_PATH_REF
+    SkTDArray<SkPath*> fOwners;
+#endif
 
     typedef SkRefCnt INHERITED;
 };