Bug 638549 - WebGL about:memory - part 1: initial implementation accounting for WebGLContexts and WebGLTextures - r=jrmuizel

content/canvas/src/WebGLContext.cpp

@@ -73,6 +73,54 @@ using namespace mozilla;
 using namespace mozilla::gl;
 using namespace mozilla::layers;
 
+WebGLMemoryReporter* WebGLMemoryReporter::sUniqueInstance = nsnull;
+
+NS_MEMORY_REPORTER_IMPLEMENT(WebGLTextureMemoryUsed,
+                             "webgl-texture-memory",
+                             KIND_OTHER,
+                             UNITS_BYTES,
+                             WebGLMemoryReporter::GetTextureMemoryUsed,
+                             "Memory used by WebGL textures. The OpenGL implementation is free to store these textures in either video memory or main memory.")
+
+NS_MEMORY_REPORTER_IMPLEMENT(WebGLTextureCount,
+                             "webgl-texture-count",
+                             KIND_OTHER,
+                             UNITS_COUNT,
+                             WebGLMemoryReporter::GetTextureCount,
+                             "Number of WebGL textures.")
+
+NS_MEMORY_REPORTER_IMPLEMENT(WebGLContextCount,
+                             "webgl-context-count",
+                             KIND_OTHER,
+                             UNITS_COUNT,
+                             WebGLMemoryReporter::GetContextCount,
+                             "Number of WebGL contexts.")
+
+WebGLMemoryReporter* WebGLMemoryReporter::UniqueInstance()
+{
+    if (!sUniqueInstance) {
+        sUniqueInstance = new WebGLMemoryReporter;
+    }
+    return sUniqueInstance;
+}
+
+WebGLMemoryReporter::WebGLMemoryReporter()
+    : mTextureMemoryUsageReporter(new NS_MEMORY_REPORTER_NAME(WebGLTextureMemoryUsed))
+    , mTextureCountReporter(new NS_MEMORY_REPORTER_NAME(WebGLTextureCount))
+    , mContextCountReporter(new NS_MEMORY_REPORTER_NAME(WebGLContextCount))
+{
+    NS_RegisterMemoryReporter(mTextureMemoryUsageReporter);
+    NS_RegisterMemoryReporter(mTextureCountReporter);
+    NS_RegisterMemoryReporter(mContextCountReporter);
+}
+
+WebGLMemoryReporter::~WebGLMemoryReporter()
+{
+    NS_UnregisterMemoryReporter(mTextureMemoryUsageReporter);
+    NS_UnregisterMemoryReporter(mTextureCountReporter);
+    NS_UnregisterMemoryReporter(mContextCountReporter);
+}
+
 nsresult NS_NewCanvasRenderingContextWebGL(nsIDOMWebGLRenderingContext** aResult);
 
 nsresult
@@ -165,11 +213,14 @@ WebGLContext::WebGLContext()
     // See OpenGL ES 2.0.25 spec, 6.2 State Tables, table 6.13
     mPixelStorePackAlignment = 4;
     mPixelStoreUnpackAlignment = 4;
+    
+    WebGLMemoryReporter::AddWebGLContext(this);
 }
 
 WebGLContext::~WebGLContext()
 {
     DestroyResourcesAndContext();
+    WebGLMemoryReporter::RemoveWebGLContext(this);
 }
 
 static PLDHashOperator

content/canvas/src/WebGLContext.h

@@ -56,6 +56,7 @@
 #include "nsWeakReference.h"
 #include "nsIDOMHTMLElement.h"
 #include "nsIJSNativeInitializer.h"
+#include "nsIMemoryReporter.h"
 
 #include "GLContextProvider.h"
 #include "Layers.h"
@@ -320,6 +321,8 @@ class WebGLContext :
     public nsICanvasRenderingContextInternal,
     public nsSupportsWeakReference
 {
+    friend class WebGLMemoryReporter;
+
 public:
     WebGLContext();
     virtual ~WebGLContext();
@@ -469,6 +472,8 @@ protected:
     PRBool ValidateAttribIndex(WebGLuint index, const char *info);
     PRBool ValidateStencilParamsForDrawCall();
     
+    static PRUint32 GetTexelSize(WebGLenum format, WebGLenum type);
+
     void Invalidate();
     void DestroyResourcesAndContext();
 
@@ -909,6 +914,12 @@ protected:
             return is_pot_assuming_nonnegative(mWidth) &&
                    is_pot_assuming_nonnegative(mHeight); // negative sizes should never happen (caught in texImage2D...)
         }
+        PRInt64 MemoryUsage() const {
+            if (!mIsDefined)
+                return 0;
+            PRInt64 texelSize = WebGLContext::GetTexelSize(mFormat, mType);
+            return PRInt64(mWidth) * PRInt64(mHeight) * texelSize;
+        }
         WebGLsizei mWidth, mHeight;
         WebGLenum mFormat, mType;
         PRBool mIsDefined;
@@ -939,6 +950,22 @@ public:
         return target == LOCAL_GL_TEXTURE_2D ? 0 : target - LOCAL_GL_TEXTURE_CUBE_MAP_POSITIVE_X;
     }
 
+    PRInt64 MemoryUsage() const {
+        PRInt64 result = 0;
+        for(size_t face = 0; face < mFacesCount; face++) {
+            if (mHaveGeneratedMipmap) {
+                // Each mipmap level is 1/4 the size of the previous level
+                // 1 + x + x^2 + ... = 1/(1-x)
+                // for x = 1/4, we get 1/(1-1/4) = 4/3
+                result += ImageInfoAt(0, face).MemoryUsage() * 4 / 3;
+            } else {
+                for(size_t level = 0; level <= mMaxLevelWithCustomImages; level++)
+                    result += ImageInfoAt(level, face).MemoryUsage();
+            }
+        }
+        return result;
+    }
+
 protected:
 
     WebGLenum mTarget;
@@ -2066,6 +2093,72 @@ WebGLContext::CanGetConcreteObject(const char *info,
     return GetConcreteObject(info, aInterface, &aConcreteObject, isNull, isDeleted, PR_FALSE);
 }
 
+class WebGLMemoryReporter
+{
+    WebGLMemoryReporter();
+    ~WebGLMemoryReporter();
+    static WebGLMemoryReporter* sUniqueInstance;
+
+    // here we store plain pointers, not RefPtrs: we don't want the WebGLMemoryReporter unique instance to keep alive all
+    // WebGLContexts ever created.
+    typedef nsTArray<const WebGLContext*> ContextsArrayType;
+    ContextsArrayType mContexts;
+    
+    nsIMemoryReporter *mTextureMemoryUsageReporter;
+    nsIMemoryReporter *mTextureCountReporter;
+    nsIMemoryReporter *mContextCountReporter;
+
+    static WebGLMemoryReporter* UniqueInstance();
+
+    static ContextsArrayType & Contexts() { return UniqueInstance()->mContexts; }
+
+  public:
+
+    static void AddWebGLContext(const WebGLContext* c) {
+        Contexts().AppendElement(c);
+    }
+
+    static void RemoveWebGLContext(const WebGLContext* c) {
+        ContextsArrayType & contexts = Contexts();
+        contexts.RemoveElement(c);
+        if (contexts.IsEmpty()) {
+            delete sUniqueInstance;
+            sUniqueInstance = nsnull;
+        }
+    }
+
+    static PLDHashOperator TextureMemoryUsageFunction(const PRUint32&, WebGLTexture *aValue, void *aData)
+    {
+        PRInt64 *result = (PRInt64*) aData;
+        *result += aValue->MemoryUsage();
+        return PL_DHASH_NEXT;
+    }
+
+    static PRInt64 GetTextureMemoryUsed() {
+        const ContextsArrayType & contexts = Contexts();
+        PRInt64 result = 0;
+        for(size_t i = 0; i < contexts.Length(); ++i) {
+            PRInt64 textureMemoryUsageForThisContext = 0;
+            contexts[i]->mMapTextures.EnumerateRead(TextureMemoryUsageFunction, &textureMemoryUsageForThisContext);
+            result += textureMemoryUsageForThisContext;
+        }
+        return result;
+    }
+    
+    static PRInt64 GetTextureCount() {
+        const ContextsArrayType & contexts = Contexts();
+        PRInt64 result = 0;
+        for(size_t i = 0; i < contexts.Length(); ++i) {
+            result += contexts[i]->mMapTextures.Count();
+        }
+        return result;
+    }
+    
+    static PRInt64 GetContextCount() {
+        return Contexts().Length();
+    }
+};
+
 }
 
 #endif

content/canvas/src/WebGLContextValidate.cpp

@@ -328,6 +328,34 @@ PRBool WebGLContext::ValidateDrawModeEnum(WebGLenum mode, const char *info)
     }
 }
 
+PRUint32 WebGLContext::GetTexelSize(WebGLenum format, WebGLenum type)
+{
+    if (type == LOCAL_GL_UNSIGNED_BYTE || type == LOCAL_GL_FLOAT) {
+        int multiplier = type == LOCAL_GL_FLOAT ? 4 : 1;
+        switch (format) {
+            case LOCAL_GL_ALPHA:
+            case LOCAL_GL_LUMINANCE:
+                return 1 * multiplier;
+            case LOCAL_GL_LUMINANCE_ALPHA:
+                return 2 * multiplier;
+            case LOCAL_GL_RGB:
+                return 3 * multiplier;
+            case LOCAL_GL_RGBA:
+                return 4 * multiplier;
+            default:
+                break;
+        }
+    } else if (type == LOCAL_GL_UNSIGNED_SHORT_4_4_4_4 ||
+               type == LOCAL_GL_UNSIGNED_SHORT_5_5_5_1 ||
+               type == LOCAL_GL_UNSIGNED_SHORT_5_6_5)
+    {
+        return 2;
+    }
+
+    NS_ABORT();
+    return 0;
+}
+
 PRBool WebGLContext::ValidateTexFormatAndType(WebGLenum format, WebGLenum type, int jsArrayType,
                                               PRUint32 *texelSize, const char *info)
 {