add per-draw checks for lockcounts

Review URL: https://codereview.appspot.com/6943056

git-svn-id: http://skia.googlecode.com/svn/trunk@6815 2bbb7eff-a529-9590-31e7-b0007b416f81

4 files changed, 93 insertions, 0 deletions

diff --git a/src/core/SkBlitter.cpp b/src/core/SkBlitter.cpp
index 1589d51d3a..efe9d11a9d 100644
--- a/src/core/SkBlitter.cpp
+++ b/src/core/SkBlitter.cpp
@@ -22,6 +22,8 @@
 
 SkBlitter::~SkBlitter() {}
 
+bool SkBlitter::isNullBlitter() const { return false; }
+
 const SkBitmap* SkBlitter::justAnOpaqueColor(uint32_t* value) {
     return NULL;
 }
@@ -236,6 +238,8 @@ const SkBitmap* SkNullBlitter::justAnOpaqueColor(uint32_t* value) {
     return NULL;
 }
 
+bool SkNullBlitter::isNullBlitter() const { return true; }
+
 ///////////////////////////////////////////////////////////////////////////////
 
 static int compute_anti_width(const int16_t runs[]) {
diff --git a/src/core/SkBlitter.h b/src/core/SkBlitter.h
index ce74a28d0e..0a075f89ad 100644
--- a/src/core/SkBlitter.h
+++ b/src/core/SkBlitter.h
@@ -51,6 +51,13 @@ public:
     */
     virtual const SkBitmap* justAnOpaqueColor(uint32_t* value);
 
+    /**
+     *  Special method just to identify the null blitter, which is returned
+     *  from Choose() if the request cannot be fulfilled. Default impl
+     *  returns false.
+     */
+    virtual bool isNullBlitter() const;
+
     ///@name non-virtual helpers
     void blitMaskRegion(const SkMask& mask, const SkRegion& clip);
     void blitRectRegion(const SkIRect& rect, const SkRegion& clip);
@@ -92,6 +99,7 @@ public:
     virtual void blitRect(int x, int y, int width, int height) SK_OVERRIDE;
     virtual void blitMask(const SkMask&, const SkIRect& clip) SK_OVERRIDE;
     virtual const SkBitmap* justAnOpaqueColor(uint32_t* value) SK_OVERRIDE;
+    virtual bool isNullBlitter() const SK_OVERRIDE;
 };
 
 /** Wraps another (real) blitter, and ensures that the real blitter is only
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 7d25c2848c..096b42dc79 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -55,6 +55,52 @@ SK_DEFINE_INST_COUNT(SkDrawFilter)
     #define dec_canvas()
 #endif
 
+#ifdef SK_DEBUG
+#include "SkPixelRef.h"
+
+class AutoCheckLockCountBalance {
+public:
+    AutoCheckLockCountBalance(const SkBitmap& bm) : fPixelRef(bm.pixelRef()) {
+        fLockCount = fPixelRef ? fPixelRef->getLockCount() : 0;
+    }
+    ~AutoCheckLockCountBalance() {
+        const int count = fPixelRef ? fPixelRef->getLockCount() : 0;
+        SkASSERT(count == fLockCount);
+    }
+
+private:
+    const SkPixelRef* fPixelRef;
+    int               fLockCount;
+};
+
+class AutoCheckNoSetContext {
+public:
+    AutoCheckNoSetContext(const SkPaint& paint) : fPaint(paint) {
+        this->assertNoSetContext(fPaint);
+    }
+    ~AutoCheckNoSetContext() {
+        this->assertNoSetContext(fPaint);
+    }
+
+private:
+    const SkPaint& fPaint;
+
+    void assertNoSetContext(const SkPaint& paint) {
+        SkShader* s = paint.getShader();
+        if (s) {
+            SkASSERT(!s->setContextHasBeenCalled());
+        }
+    }
+};
+
+#define CHECK_LOCKCOUNT_BALANCE(bitmap)  AutoCheckLockCountBalance clcb(bitmap)
+#define CHECK_SHADER_NOSETCONTEXT(paint) AutoCheckNoSetContext     cshsc(paint)
+
+#else
+    #define CHECK_LOCKCOUNT_BALANCE(bitmap)
+    #define CHECK_SHADER_NOSETCONTEXT(paint)
+#endif
+
 typedef SkTLazy<SkPaint> SkLazyPaint;
 
 void SkCanvas::predrawNotify() {
@@ -963,6 +1009,7 @@ void SkCanvas::internalDrawDevice(SkDevice* srcDev, int x, int y,
 void SkCanvas::drawSprite(const SkBitmap& bitmap, int x, int y,
                           const SkPaint* paint) {
     SkDEBUGCODE(bitmap.validate();)
+    CHECK_LOCKCOUNT_BALANCE(bitmap);
 
     if (reject_bitmap(bitmap)) {
         return;
@@ -1422,6 +1469,8 @@ void SkCanvas::drawPaint(const SkPaint& paint) {
 }
 
 void SkCanvas::internalDrawPaint(const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     LOOPER_BEGIN(paint, SkDrawFilter::kPaint_Type)
 
     while (iter.next()) {
@@ -1437,6 +1486,8 @@ void SkCanvas::drawPoints(PointMode mode, size_t count, const SkPoint pts[],
         return;
     }
 
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     if (paint.canComputeFastBounds()) {
         SkRect r;
         // special-case 2 points (common for drawing a single line)
@@ -1463,6 +1514,8 @@ void SkCanvas::drawPoints(PointMode mode, size_t count, const SkPoint pts[],
 }
 
 void SkCanvas::drawRect(const SkRect& r, const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     if (paint.canComputeFastBounds()) {
         SkRect storage;
         if (this->quickReject(paint.computeFastBounds(r, &storage))) {
@@ -1480,6 +1533,8 @@ void SkCanvas::drawRect(const SkRect& r, const SkPaint& paint) {
 }
 
 void SkCanvas::drawOval(const SkRect& oval, const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     if (paint.canComputeFastBounds()) {
         SkRect storage;
         if (this->quickReject(paint.computeFastBounds(oval, &storage))) {
@@ -1494,6 +1549,8 @@ void SkCanvas::drawOval(const SkRect& oval, const SkPaint& paint) {
 }
 
 void SkCanvas::drawRRect(const SkRRect& rrect, const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     if (paint.canComputeFastBounds()) {
         SkRect storage;
         if (this->quickReject(paint.computeFastBounds(rrect.getBounds(), &storage))) {
@@ -1514,6 +1571,8 @@ void SkCanvas::drawRRect(const SkRRect& rrect, const SkPaint& paint) {
 
 
 void SkCanvas::drawPath(const SkPath& path, const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     if (!path.isFinite()) {
         return;
     }
@@ -1571,6 +1630,8 @@ void SkCanvas::internalDrawBitmapRect(const SkBitmap& bitmap, const SkRect* src,
         return;
     }
 
+    CHECK_LOCKCOUNT_BALANCE(bitmap);
+
     if (NULL == paint || paint->canComputeFastBounds()) {
         SkRect storage;
         const SkRect* bounds = &dst;
@@ -1611,6 +1672,7 @@ void SkCanvas::drawBitmapMatrix(const SkBitmap& bitmap, const SkMatrix& matrix,
 void SkCanvas::commonDrawBitmap(const SkBitmap& bitmap, const SkIRect* srcRect,
                                 const SkMatrix& matrix, const SkPaint& paint) {
     SkDEBUGCODE(bitmap.validate();)
+    CHECK_LOCKCOUNT_BALANCE(bitmap);
 
     LOOPER_BEGIN(paint, SkDrawFilter::kBitmap_Type)
 
@@ -1790,6 +1852,8 @@ void SkCanvas::DrawTextDecorations(const SkDraw& draw, const SkPaint& paint,
 
 void SkCanvas::drawText(const void* text, size_t byteLength,
                         SkScalar x, SkScalar y, const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     LOOPER_BEGIN(paint, SkDrawFilter::kText_Type)
 
     while (iter.next()) {
@@ -1804,6 +1868,8 @@ void SkCanvas::drawText(const void* text, size_t byteLength,
 
 void SkCanvas::drawPosText(const void* text, size_t byteLength,
                            const SkPoint pos[], const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     LOOPER_BEGIN(paint, SkDrawFilter::kText_Type)
 
     while (iter.next()) {
@@ -1818,6 +1884,8 @@ void SkCanvas::drawPosText(const void* text, size_t byteLength,
 void SkCanvas::drawPosTextH(const void* text, size_t byteLength,
                             const SkScalar xpos[], SkScalar constY,
                             const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     LOOPER_BEGIN(paint, SkDrawFilter::kText_Type)
 
     while (iter.next()) {
@@ -1832,6 +1900,8 @@ void SkCanvas::drawPosTextH(const void* text, size_t byteLength,
 void SkCanvas::drawTextOnPath(const void* text, size_t byteLength,
                               const SkPath& path, const SkMatrix* matrix,
                               const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     LOOPER_BEGIN(paint, SkDrawFilter::kText_Type)
 
     while (iter.next()) {
@@ -1846,6 +1916,8 @@ void SkCanvas::drawTextOnPath(const void* text, size_t byteLength,
 void SkCanvas::drawPosTextOnPath(const void* text, size_t byteLength,
                                  const SkPoint pos[], const SkPaint& paint,
                                  const SkPath& path, const SkMatrix* matrix) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     LOOPER_BEGIN(paint, SkDrawFilter::kText_Type)
 
     while (iter.next()) {
@@ -1862,6 +1934,8 @@ void SkCanvas::drawVertices(VertexMode vmode, int vertexCount,
                             const SkColor colors[], SkXfermode* xmode,
                             const uint16_t indices[], int indexCount,
                             const SkPaint& paint) {
+    CHECK_SHADER_NOSETCONTEXT(paint);
+
     LOOPER_BEGIN(paint, SkDrawFilter::kPath_Type)
 
     while (iter.next()) {
diff --git a/src/core/SkDraw.cpp b/src/core/SkDraw.cpp
index 2f748d9930..b6eb6825d6 100644
--- a/src/core/SkDraw.cpp
+++ b/src/core/SkDraw.cpp
@@ -2424,6 +2424,13 @@ void SkDraw::drawVertices(SkCanvas::VertexMode vmode, int count,
     }
 
     SkAutoBlitterChoose blitter(*fBitmap, *fMatrix, p);
+    // important that we abort early, as below we may manipulate the shader
+    // and that is only valid if the shader returned true from setContext.
+    // If it returned false, then our blitter will be the NullBlitter.
+    if (blitter->isNullBlitter()) {
+        return;
+    }
+
     // setup our state and function pointer for iterating triangles
     VertState       state(count, indices, indexCount);
     VertState::Proc vertProc = state.chooseProc(vmode);