Make GrTextureStripAtlas flush pending IO on newly acquired texture

tests/GrTextureStripAtlasTest.cpp

Index: tests/GrTextureStripAtlasTest.cpp
diff --git a/tests/GrTextureStripAtlasTest.cpp b/tests/GrTextureStripAtlasTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..5bdef4f8bb2cb60e2cb1ab211c662b58d808d8e1
--- /dev/null
+++ b/tests/GrTextureStripAtlasTest.cpp
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "Test.h"
+#if SK_SUPPORT_GPU
+
+#include "GrContext.h"
+#include "GrGpu.h"
+#include "GrTextureStripAtlas.h"
+#include "GrTypes.h"
+#include "SkGpuDevice.h"
+
+// This tests that GrTextureStripAtlas flushes pending IO on the texture it acquires.
+DEF_GPUTEST_FOR_RENDERING_CONTEXTS(GrTextureStripAtlasFlush, reporter, ctxInfo) {
+    GrContext* context = ctxInfo.grContext();
+    GrSurfaceDesc desc;
+    desc.fWidth = 32;
+    desc.fHeight = 32;
+    desc.fConfig = kRGBA_8888_GrPixelConfig;
+    GrTexture* texture = context->textureProvider()->createTexture(desc, SkBudgeted::kYes, nullptr, 0);

[bsalomon, 2016/08/24 13:31:10]

nit, we wrap lines at 100 cols.

[ajuma, 2016/08/24 14:56:09]

Fixed.

+
+    GrSurfaceDesc targetDesc = desc;
+    targetDesc.fFlags = kRenderTarget_GrSurfaceFlag;
+    GrTexture* target = context->textureProvider()->createTexture(targetDesc, SkBudgeted::kYes, nullptr, 0);
+
+    SkAutoTMalloc<uint32_t> pixels(desc.fWidth * desc.fHeight);
+    memset(pixels.get(), 0xFF, sizeof(uint32_t) * desc.fWidth * desc.fHeight);
+    texture->writePixels(0, 0, desc.fWidth, desc.fHeight, kRGBA_8888_GrPixelConfig, pixels.get());
+
+    // Add a pending read to the texture, and then make it available for reuse.
+    context->copySurface(target, texture);
+    texture->unref();
+
+    // Create an atlas with parameters that allow it to reuse the texture.
+    GrTextureStripAtlas::Desc atlasDesc;
+    atlasDesc.fContext = context;
+    atlasDesc.fConfig = desc.fConfig;
+    atlasDesc.fWidth = desc.fWidth;
+    atlasDesc.fHeight = desc.fHeight;
+    atlasDesc.fRowHeight = 1;
+    GrTextureStripAtlas* atlas = GrTextureStripAtlas::GetAtlas(atlasDesc);

[bsalomon, 2016/08/24 13:31:10]

Can we check that the atlas's texture is the same as 'texture' above?

[ajuma, 2016/08/24 14:56:09]

Added a check that the texture is the same when we're not in
preferVRAMUseOverFlushes mode.

+
+    // Write to the atlas' texture.
+    SkImageInfo info = SkImageInfo::MakeN32(desc.fWidth, desc.fHeight, kPremul_SkAlphaType);
+    size_t rowBytes = desc.fWidth * GrBytesPerPixel(desc.fConfig);
+    SkBitmap bitmap;
+    bitmap.allocPixels(info, rowBytes);
+    memset(bitmap.getPixels(), 1, rowBytes * desc.fHeight);
+    atlas->lockRow(bitmap);
+
+    // The atlas' use of its texture shouldn't change which pixels got copied to the target.
+    SkAutoTMalloc<uint32_t> actualPixels(desc.fWidth * desc.fHeight);
+    bool success = target->readPixels(0, 0, desc.fWidth, desc.fHeight, kRGBA_8888_GrPixelConfig, actualPixels.get());
+    REPORTER_ASSERT(reporter, success);
+    REPORTER_ASSERT(reporter,
+                    !memcmp(pixels.get(), actualPixels.get(), sizeof(uint32_t) * desc.fWidth * desc.fHeight));
+    target->unref();
+}
+
+#endif