Bug 830881 - Port layerscope GL changes to new layers. r=vlad

gfx/gl/GLContext.cpp

@@ -28,6 +28,8 @@
 #include "TextureGarbageBin.h"
 #include "gfx2DGlue.h"
 
+#include "OGLShaderProgram.h" // for ShaderProgramType
+
 #include "mozilla/DebugOnly.h"
 #include "mozilla/Preferences.h"
 
@@ -41,6 +43,7 @@
 #endif
 
 using namespace mozilla::gfx;
+using namespace mozilla::layers;
 
 namespace mozilla {
 namespace gl {
@@ -273,6 +276,11 @@ GLContext::GLContext(const SurfaceCaps& caps,
     mWorkAroundDriverBugs(true)
 {
     mOwningThread = NS_GetCurrentThread();
+
+    mReadTextureImagePrograms[0] = 0;
+    mReadTextureImagePrograms[1] = 0;
+    mReadTextureImagePrograms[2] = 0;
+    mReadTextureImagePrograms[3] = 0;
 }
 
 GLContext::~GLContext() {
@@ -1855,6 +1863,11 @@ GLContext::MarkDestroyed()
         mBlitHelper = nullptr;
         mBlitTextureImageHelper = nullptr;
 
+        fDeleteProgram(mReadTextureImagePrograms[0]);
+        fDeleteProgram(mReadTextureImagePrograms[1]);
+        fDeleteProgram(mReadTextureImagePrograms[2]);
+        fDeleteProgram(mReadTextureImagePrograms[3]);
+
         mTexGarbageBin->GLContextTeardown();
     } else {
         NS_WARNING("MakeCurrent() failed during MarkDestroyed! Skipping GL object teardown.");
@@ -1938,144 +1951,340 @@ GLContext::GetTexImage(GLuint aTexture, bool aYInvert, SurfaceFormat aFormat)
     return surf.forget();
 }
 
-already_AddRefed<gfxImageSurface>
+static float
-GLContext::ReadTextureImage(GLuint aTexture,
+gReadTextureImageVerts[4*4] = {
-                            const gfxIntSize& aSize,
+    -1.0f, -1.0f, 0.0f, 1.0f,
-                            GLenum aTextureFormat,
+     1.0f, -1.0f, 0.0f, 1.0f,
-                            bool aYInvert)
+    -1.0f,  1.0f, 0.0f, 1.0f,
+     1.0f,  1.0f, 0.0f, 1.0f
+};
+
+static float*
+ReadTextureVertexArray()
 {
-    MakeCurrent();
+    return gReadTextureImageVerts;
+}
 
-    nsRefPtr<gfxImageSurface> isurf;
+static float
+gReadTextureImageTexcoords[2*4] = {
+    0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f
+};
 
-    GLint oldrb, oldfb, oldprog, oldPackAlignment;
+static float*
-    GLint success;
+ReadTextureTexCoordArray(float aWidth, float aHeight, bool aFlip)
+{
+    const float u0 = 0.0f;
+    const float u1 = aWidth;
+    const float v0 = (aFlip) ? aHeight : 0.0f;
+    const float v1 = (aFlip) ? 0.0f : aHeight;
 
-    GLuint rb = 0, fb = 0;
+    float* uvs = gReadTextureImageTexcoords;
-    GLuint vs = 0, fs = 0, prog = 0;
+    uvs[0] = u0;
+    uvs[1] = v0;
+    uvs[2] = u1;
+    uvs[3] = v0;
+    uvs[4] = u0;
+    uvs[5] = v1;
+    uvs[6] = u1;
+    uvs[7] = v1;
 
-    const char *vShader =
+    return uvs;
-        "attribute vec4 aVertex;\n"
+}
-        "attribute vec2 aTexCoord;\n"
-        "varying vec2 vTexCoord;\n"
-        "void main() { gl_Position = aVertex; vTexCoord = aTexCoord; }";
-    const char *fShader =
-        "#ifdef GL_ES\n"
-        "precision mediump float;\n"
-        "#endif\n"
-        "varying vec2 vTexCoord;\n"
-        "uniform sampler2D uTexture;\n"
-        "void main() { gl_FragColor = texture2D(uTexture, vTexCoord); }";
 
-    float verts[4*4] = {
+static const char*
-        -1.0f, -1.0f, 0.0f, 1.0f,
+gReadTextureImageVS =
-         1.0f, -1.0f, 0.0f, 1.0f,
+    "attribute vec4 aVertex;\n"
-        -1.0f,  1.0f, 0.0f, 1.0f,
+    "attribute vec2 aTexCoord;\n"
-         1.0f,  1.0f, 0.0f, 1.0f
+    "varying vec2 vTexCoord;\n"
-    };
+    "void main() { gl_Position = aVertex; vTexCoord = aTexCoord; }";
 
-    float texcoords[2*4] = {
+static const char*
-        0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f
+gReadTextureImageFS[] = {
-    };
+    /* TEXTURE_2D */
+    "#ifdef GL_ES\n"
+    "precision mediump float;\n"
+    "#endif\n"
+    "varying vec2 vTexCoord;\n"
+    "uniform sampler2D uTexture;\n"
+    "void main() { gl_FragColor = texture2D(uTexture, vTexCoord); }"
+    ,
+    /* TEXTURE_2D with R/B swizzling */
+    "#ifdef GL_ES\n"
+    "precision mediump float;\n"
+    "#endif\n"
+    "varying vec2 vTexCoord;\n"
+    "uniform sampler2D uTexture;\n"
+    "void main() { gl_FragColor = texture2D(uTexture, vTexCoord).bgra; }"
+    ,
+    /* TEXTURE_EXTERNAL */
+    "#extension GL_OES_EGL_image_external : require\n"
+    "#ifdef GL_ES\n"
+    "precision mediump float;\n"
+    "#endif\n"
+    "varying vec2 vTexCoord;\n"
+    "uniform samplerExternalOES uTexture;\n"
+    "void main() { gl_FragColor = texture2D(uTexture, vTexCoord); }"
+    ,
+    /* TEXTURE_RECTANGLE */
+    "#extension GL_ARB_texture_rectangle\n"
+    "#ifdef GL_ES\n"
+    "precision mediump float;\n"
+    "#endif\n"
+    "varying vec2 vTexCoord;\n"
+    "uniform sampler2DRect uTexture;\n"
+    "void main() { gl_FragColor = texture2DRect(uTexture, vTexCoord).bgra; }"
+};
 
-    fGetIntegerv(LOCAL_GL_RENDERBUFFER_BINDING, &oldrb);
+GLuint
-    fGetIntegerv(LOCAL_GL_FRAMEBUFFER_BINDING, &oldfb);
+GLContext::TextureImageProgramFor(GLenum aTextureTarget, int aShader) {
-    fGetIntegerv(LOCAL_GL_CURRENT_PROGRAM, &oldprog);
+    int variant = 0;
+    if (aTextureTarget == LOCAL_GL_TEXTURE_2D &&
+        (aShader == layers::BGRALayerProgramType ||
+         aShader == layers::BGRXLayerProgramType))
+    {   // Need to swizzle R/B.
+        variant = 1;
+    } else if (aTextureTarget == LOCAL_GL_TEXTURE_EXTERNAL) {
+        variant = 2;
+    } else if (aTextureTarget == LOCAL_GL_TEXTURE_RECTANGLE) {
+        variant = 3;
+    }
+
+    /* This might be overkill, but assure that we don't access out-of-bounds */
+    MOZ_ASSERT((size_t) variant < ArrayLength(mReadTextureImagePrograms));
+    if (!mReadTextureImagePrograms[variant]) {
+        GLuint vs = fCreateShader(LOCAL_GL_VERTEX_SHADER);
+        fShaderSource(vs, 1, (const GLchar**) &gReadTextureImageVS, NULL);
+        fCompileShader(vs);
+
+        GLuint fs = fCreateShader(LOCAL_GL_FRAGMENT_SHADER);
+        fShaderSource(fs, 1, (const GLchar**) &gReadTextureImageFS[variant], NULL);
+        fCompileShader(fs);
+
+        GLuint program = fCreateProgram();
+        fAttachShader(program, vs);
+        fAttachShader(program, fs);
+        fBindAttribLocation(program, 0, "aVertex");
+        fBindAttribLocation(program, 1, "aTexCoord");
+        fLinkProgram(program);
+
+        GLint success;
+        fGetProgramiv(program, LOCAL_GL_LINK_STATUS, &success);
+
+        if (!success) {
+            fDeleteProgram(program);
+            program = 0;
+        }
+
+        fDeleteShader(vs);
+        fDeleteShader(fs);
+
+        mReadTextureImagePrograms[variant] = program;
+    }
+
+    return mReadTextureImagePrograms[variant];
+}
+
+static bool
+DidGLErrorOccur(GLContext* aGL, const char* str)
+{
+    GLenum error = aGL->fGetError();
+    if (error != LOCAL_GL_NO_ERROR) {
+        printf_stderr("GL ERROR: %s (0x%04x) %s\n",
+                      aGL->GLErrorToString(error), error, str);
+        return true;
+    }
+
+    return false;
+}
+
+bool
+GLContext::ReadBackPixelsIntoSurface(gfxImageSurface* aSurface, const gfxIntSize& aSize) {
+    GLint oldPackAlignment;
     fGetIntegerv(LOCAL_GL_PACK_ALIGNMENT, &oldPackAlignment);
 
-    PushViewportRect(nsIntRect(0, 0, aSize.width, aSize.height));
-
-    fGenRenderbuffers(1, &rb);
-    fBindRenderbuffer(LOCAL_GL_RENDERBUFFER, rb);
-    fRenderbufferStorage(LOCAL_GL_RENDERBUFFER, LOCAL_GL_RGBA,
-                         aSize.width, aSize.height);
-
-    fGenFramebuffers(1, &fb);
-    fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, fb);
-    fFramebufferRenderbuffer(LOCAL_GL_FRAMEBUFFER, LOCAL_GL_COLOR_ATTACHMENT0,
-                             LOCAL_GL_RENDERBUFFER, rb);
-
-    if (fCheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER) !=
-        LOCAL_GL_FRAMEBUFFER_COMPLETE)
-    {
-        goto cleanup;
-    }
-
-    vs = fCreateShader(LOCAL_GL_VERTEX_SHADER);
-    fs = fCreateShader(LOCAL_GL_FRAGMENT_SHADER);
-    fShaderSource(vs, 1, (const GLchar**) &vShader, nullptr);
-    fShaderSource(fs, 1, (const GLchar**) &fShader, nullptr);
-    fCompileShader(vs);
-    fCompileShader(fs);
-    prog = fCreateProgram();
-    fAttachShader(prog, vs);
-    fAttachShader(prog, fs);
-    fBindAttribLocation(prog, 0, "aVertex");
-    fBindAttribLocation(prog, 1, "aTexCoord");
-    fLinkProgram(prog);
-
-    fGetProgramiv(prog, LOCAL_GL_LINK_STATUS, &success);
-    if (!success) {
-        goto cleanup;
-    }
-
-    fUseProgram(prog);
-
-    fEnableVertexAttribArray(0);
-    fEnableVertexAttribArray(1);
-
-    fVertexAttribPointer(0, 4, LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0, verts);
-    fVertexAttribPointer(1, 2, LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0, texcoords);
-
-    fActiveTexture(LOCAL_GL_TEXTURE0);
-    fBindTexture(LOCAL_GL_TEXTURE_2D, aTexture);
-
-    fUniform1i(fGetUniformLocation(prog, "uTexture"), 0);
-
-    fDrawArrays(LOCAL_GL_TRIANGLE_STRIP, 0, 4);
-
-    fDisableVertexAttribArray(1);
-    fDisableVertexAttribArray(0);
-
-    isurf = new gfxImageSurface(aSize, gfxImageFormatARGB32);
-    if (!isurf || isurf->CairoStatus()) {
-        isurf = nullptr;
-        goto cleanup;
-    }
-
     if (oldPackAlignment != 4)
         fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, 4);
 
     fReadPixels(0, 0, aSize.width, aSize.height,
                 LOCAL_GL_RGBA, LOCAL_GL_UNSIGNED_BYTE,
-                isurf->Data());
+                aSurface->Data());
 
-    SwapRAndBComponents(isurf);
+    bool result = DidGLErrorOccur(this, "when reading pixels into surface");
 
     if (oldPackAlignment != 4)
         fPixelStorei(LOCAL_GL_PACK_ALIGNMENT, oldPackAlignment);
 
-    if (aYInvert) {
+    return result;
-      isurf = YInvertImageSurface(isurf);
+}
+
+#define CLEANUP_IF_GLERROR_OCCURRED(x)                                      \
+    if (DidGLErrorOccur(this, (x))) {                                       \
+        isurf = nullptr;                                                    \
+        break;                                                              \
     }
 
- cleanup:
+already_AddRefed<gfxImageSurface>
-    // note that deleting 0 has no effect in any of these calls
+GLContext::ReadTextureImage(GLuint aTextureId,
-    fDeleteRenderbuffers(1, &rb);
+                            GLenum aTextureTarget,
-    fDeleteFramebuffers(1, &fb);
+                            const gfxIntSize& aSize,
-    fDeleteShader(vs);
+    /* ShaderProgramType */ int aShaderProgram,
-    fDeleteShader(fs);
+                            bool aYInvert)
-    fDeleteProgram(prog);
+{
+    // Check aShaderProgram is in bounds for a layers::ShaderProgramType
+    MOZ_ASSERT(0 <= aShaderProgram && aShaderProgram < NumProgramTypes);
 
+    if (aTextureTarget != LOCAL_GL_TEXTURE_2D &&
+        aTextureTarget != LOCAL_GL_TEXTURE_EXTERNAL &&
+        aTextureTarget != LOCAL_GL_TEXTURE_RECTANGLE_ARB)
+    {
+        printf_stderr("ReadTextureImage target is not TEXTURE_2D || "
+                      "TEXTURE_EXTERNAL || TEXTURE_RECTANGLE\n");
+        return nullptr;
+    }
+
+    MakeCurrent();
+
+    /* Allocate resulting image surface */
+    nsRefPtr<gfxImageSurface> isurf;
+    isurf = new gfxImageSurface(aSize, gfxImageFormatARGB32);
+    if (!isurf || isurf->CairoStatus()) {
+        isurf = nullptr;
+        return isurf.forget();
+    }
+
+    realGLboolean oldBlend, oldScissor;
+    GLint oldrb, oldfb, oldprog, oldTexUnit, oldTex;
+    GLuint rb, fb;
+
+    do {
+        /* Save current GL state */
+        oldBlend = fIsEnabled(LOCAL_GL_BLEND);
+        oldScissor = fIsEnabled(LOCAL_GL_SCISSOR_TEST);
+
+        fGetIntegerv(LOCAL_GL_RENDERBUFFER_BINDING, &oldrb);
+        fGetIntegerv(LOCAL_GL_FRAMEBUFFER_BINDING, &oldfb);
+        fGetIntegerv(LOCAL_GL_CURRENT_PROGRAM, &oldprog);
+        fGetIntegerv(LOCAL_GL_ACTIVE_TEXTURE, &oldTexUnit);
+        fActiveTexture(LOCAL_GL_TEXTURE0);
+        switch (aTextureTarget) {
+        case LOCAL_GL_TEXTURE_2D:
+            fGetIntegerv(LOCAL_GL_TEXTURE_BINDING_2D, &oldTex);
+            break;
+        case LOCAL_GL_TEXTURE_EXTERNAL:
+            fGetIntegerv(LOCAL_GL_TEXTURE_BINDING_EXTERNAL, &oldTex);
+            break;
+        case LOCAL_GL_TEXTURE_RECTANGLE:
+            fGetIntegerv(LOCAL_GL_TEXTURE_BINDING_RECTANGLE, &oldTex);
+            break;
+        default: /* Already checked above */
+            break;
+        }
+
+        /* Set required GL state */
+        fDisable(LOCAL_GL_BLEND);
+        fDisable(LOCAL_GL_SCISSOR_TEST);
+
+        PushViewportRect(nsIntRect(0, 0, aSize.width, aSize.height));
+
+        /* Setup renderbuffer */
+        fGenRenderbuffers(1, &rb);
+        fBindRenderbuffer(LOCAL_GL_RENDERBUFFER, rb);
+
+        GLenum rbInternalFormat =
+            IsGLES2()
+                ? (IsExtensionSupported(OES_rgb8_rgba8) ? LOCAL_GL_RGBA8 : LOCAL_GL_RGBA4)
+                : LOCAL_GL_RGBA;
+        fRenderbufferStorage(LOCAL_GL_RENDERBUFFER, rbInternalFormat, aSize.width, aSize.height);
+        CLEANUP_IF_GLERROR_OCCURRED("when binding and creating renderbuffer");
+
+        /* Setup framebuffer */
+        fGenFramebuffers(1, &fb);
+        fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, fb);
+        fFramebufferRenderbuffer(LOCAL_GL_FRAMEBUFFER, LOCAL_GL_COLOR_ATTACHMENT0,
+                                 LOCAL_GL_RENDERBUFFER, rb);
+        CLEANUP_IF_GLERROR_OCCURRED("when binding and creating framebuffer");
+
+        if (fCheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER) != LOCAL_GL_FRAMEBUFFER_COMPLETE) {
+            printf_stderr("framebuffer is incomplete\n");
+            break; //goto cleanup;
+        }
+
+        /* Setup vertex and fragment shader */
+        layers::ShaderProgramType shaderProgram = (ShaderProgramType) aShaderProgram;
+        GLuint program = TextureImageProgramFor(aTextureTarget, shaderProgram);
+        if (!program) {
+            printf_stderr("failed to compile program for texture target %u and"
+                          " shader program type %d\n",
+                          aTextureTarget, aShaderProgram);
+            break; // goto cleanup;
+        }
+
+        fUseProgram(program);
+        CLEANUP_IF_GLERROR_OCCURRED("when using program");
+        fUniform1i(fGetUniformLocation(program, "uTexture"), 0);
+        CLEANUP_IF_GLERROR_OCCURRED("when setting uniform location");
+
+        /* Setup quad geometry */
+        fBindBuffer(LOCAL_GL_ARRAY_BUFFER, 0);
+        fEnableVertexAttribArray(0);
+        fEnableVertexAttribArray(1);
+
+        float w = (aTextureTarget == LOCAL_GL_TEXTURE_RECTANGLE) ? (float) aSize.width : 1.0f;
+        float h = (aTextureTarget == LOCAL_GL_TEXTURE_RECTANGLE) ? (float) aSize.height : 1.0f;
+        fVertexAttribPointer(0, 4, LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0, ReadTextureVertexArray());
+        fVertexAttribPointer(1, 2, LOCAL_GL_FLOAT, LOCAL_GL_FALSE, 0, ReadTextureTexCoordArray(w, h, aYInvert));
+
+        /* Bind the texture */
+        if (aTextureId) {
+            fBindTexture(aTextureTarget, aTextureId);
+            CLEANUP_IF_GLERROR_OCCURRED("when binding texture");
+        }
+
+        /* Draw quad */
+        fClearColor(1.0f, 0.0f, 1.0f, 1.0f);
+        fClear(LOCAL_GL_COLOR_BUFFER_BIT);
+        CLEANUP_IF_GLERROR_OCCURRED("when clearing color buffer");
+
+        fDrawArrays(LOCAL_GL_TRIANGLE_STRIP, 0, 4);
+        CLEANUP_IF_GLERROR_OCCURRED("when drawing texture");
+
+        fDisableVertexAttribArray(1);
+        fDisableVertexAttribArray(0);
+
+        /* Read-back draw results */
+        ReadBackPixelsIntoSurface(isurf, aSize);
+        CLEANUP_IF_GLERROR_OCCURRED("when reading pixels into surface");
+    } while (false);
+
+    /* Restore GL state */
+//cleanup:
     fBindRenderbuffer(LOCAL_GL_RENDERBUFFER, oldrb);
     fBindFramebuffer(LOCAL_GL_FRAMEBUFFER, oldfb);
     fUseProgram(oldprog);
 
+    // note that deleting 0 has no effect in any of these calls
+    fDeleteRenderbuffers(1, &rb);
+    fDeleteFramebuffers(1, &fb);
+
+    if (oldBlend)
+        fEnable(LOCAL_GL_BLEND);
+
+    if (oldScissor)
+        fEnable(LOCAL_GL_SCISSOR_TEST);
+
+    if (aTextureId)
+        fBindTexture(aTextureTarget, oldTex);
+
+    if (oldTexUnit != LOCAL_GL_TEXTURE0)
+        fActiveTexture(oldTexUnit);
+
     PopViewportRect();
 
     return isurf.forget();
 }
 
+#undef CLEANUP_IF_GLERROR_OCCURRED
+
 static bool
 GetActualReadFormats(GLContext* gl, GLenum destFormat, GLenum destType,
                      GLenum& readFormat, GLenum& readType)

gfx/gl/GLContext.h

@@ -2734,6 +2734,14 @@ public:
         return nullptr;
     }
 
+private:
+    /**
+     * Helpers for ReadTextureImage
+     */
+    GLuint TextureImageProgramFor(GLenum aTextureTarget, int aShader);
+    bool ReadBackPixelsIntoSurface(gfxImageSurface* aSurface, const gfxIntSize& aSize);
+
+public:
     /**
      * Read the image data contained in aTexture, and return it as an ImageSurface.
      * If GL_RGBA is given as the format, a gfxImageFormatARGB32 surface is returned.
@@ -2744,13 +2752,20 @@ public:
      * THIS IS EXPENSIVE.  It is ridiculously expensive.  Only do this
      * if you absolutely positively must, and never in any performance
      * critical path.
+     *
+     * NOTE: aShaderProgram is really mozilla::layers::ShaderProgramType. It is
+     * passed as int to eliminate including LayerManagerOGLProgram.h in this
+     * hub header.
      */
-    already_AddRefed<gfxImageSurface> ReadTextureImage(GLuint aTexture,
+    already_AddRefed<gfxImageSurface> ReadTextureImage(GLuint aTextureId,
+                                                       GLenum aTextureTarget,
                                                        const gfxIntSize& aSize,
-                                                       GLenum aTextureFormat,
+                               /* ShaderProgramType */ int aShaderProgram,
                                                        bool aYInvert = false);
 
-    already_AddRefed<gfxImageSurface> GetTexImage(GLuint aTexture, bool aYInvert, SurfaceFormat aFormat);
+    already_AddRefed<gfxImageSurface> GetTexImage(GLuint aTexture,
+                                                  bool aYInvert,
+                                                  SurfaceFormat aFormat);
 
     /**
      * Call ReadPixels into an existing gfxImageSurface.
@@ -3111,6 +3126,8 @@ public:
 protected:
     nsDataHashtable<nsPtrHashKey<void>, void*> mUserData;
 
+    GLuint mReadTextureImagePrograms[4];
+
     bool InitWithPrefix(const char *prefix, bool trygl);
 
     void InitExtensions();

gfx/gl/GLDefs.h

@@ -17,6 +17,7 @@
 
 // OES_EGL_image_external
 #define LOCAL_GL_TEXTURE_EXTERNAL                       0x8D65
+#define LOCAL_GL_TEXTURE_BINDING_EXTERNAL               0x8D67
 
 // EGL_KHR_fence_sync
 #define LOCAL_EGL_SYNC_FENCE                            0x30F9

gfx/layers/Effects.h

@@ -189,8 +189,12 @@ struct EffectSolidColor : public Effect
 
 struct EffectChain
 {
+  EffectChain() : mLayerRef(NULL) {}
+  explicit EffectChain(void* aLayerRef) : mLayerRef(aLayerRef) {}
+
   RefPtr<Effect> mPrimaryEffect;
   RefPtr<Effect> mSecondaryEffects[EFFECT_MAX_SECONDARY];
+  void* mLayerRef; //!< For LayerScope logging
 };
 
 /**

gfx/layers/LayerScope.cpp

@@ -0,0 +1,590 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* This must occur *after* layers/PLayers.h to avoid typedefs conflicts. */
+#include "LayerScope.h"
+
+#include "mozilla/Util.h"
+
+#include "Composer2D.h"
+#include "Effects.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/Preferences.h"
+#include "TexturePoolOGL.h"
+#include "mozilla/layers/TextureHostOGL.h"
+
+#include "gfxColor.h"
+#include "gfxContext.h"
+#include "gfxUtils.h"
+#include "gfxPlatform.h"
+#include "nsIWidget.h"
+
+#include "GLContext.h"
+#include "GLContextProvider.h"
+
+#include "nsIServiceManager.h"
+#include "nsIConsoleService.h"
+
+#include <memory>
+#include "mozilla/Compression.h"
+#include "mozilla/LinkedList.h"
+#include "nsThreadUtils.h"
+#include "nsISocketTransport.h"
+#include "nsIServerSocket.h"
+#include "nsNetCID.h"
+#include "nsIOutputStream.h"
+#include "nsIEventTarget.h"
+#include "nsProxyRelease.h"
+
+#ifdef __GNUC__
+#define PACKED_STRUCT __attribute__((packed))
+#else
+#define PACKED_STRUCT
+#endif
+
+namespace mozilla {
+namespace layers {
+
+using namespace mozilla::Compression;
+using namespace mozilla::gfx;
+using namespace mozilla::gl;
+using namespace mozilla;
+
+class DebugDataSender;
+
+static bool gDebugConnected = false;
+static nsCOMPtr<nsIServerSocket> gDebugServerSocket;
+static nsCOMPtr<nsIThread> gDebugSenderThread;
+static nsCOMPtr<nsISocketTransport> gDebugSenderTransport;
+static nsCOMPtr<nsIOutputStream> gDebugStream;
+static nsCOMPtr<DebugDataSender> gCurrentSender;
+
+class DebugGLData : public LinkedListElement<DebugGLData> {
+public:
+    typedef enum {
+        FrameStart,
+        FrameEnd,
+        TextureData,
+        ColorData
+    } DataType;
+
+    virtual ~DebugGLData() { }
+
+    DataType GetDataType() const { return mDataType; }
+    intptr_t GetContextAddress() const { return mContextAddress; }
+    int64_t GetValue() const { return mValue; }
+
+    DebugGLData(DataType dataType)
+        : mDataType(dataType),
+          mContextAddress(0),
+          mValue(0)
+    { }
+
+    DebugGLData(DataType dataType, GLContext* cx)
+        : mDataType(dataType),
+          mContextAddress(reinterpret_cast<intptr_t>(cx)),
+          mValue(0)
+    { }
+
+    DebugGLData(DataType dataType, GLContext* cx, int64_t value)
+        : mDataType(dataType),
+          mContextAddress(reinterpret_cast<intptr_t>(cx)),
+          mValue(value)
+    { }
+
+    virtual bool Write() {
+        if (mDataType != FrameStart &&
+            mDataType != FrameEnd)
+        {
+            NS_WARNING("Unimplemented data type!");
+            return false;
+        }
+
+        DebugGLData::BasicPacket packet;
+
+        packet.type = mDataType;
+        packet.ptr = static_cast<uint64_t>(mContextAddress);
+        packet.value = mValue;
+
+        return WriteToStream(&packet, sizeof(packet));
+    }
+
+    static bool WriteToStream(void *ptr, uint32_t size) {
+        uint32_t written = 0;
+        nsresult rv;
+        while (written < size) {
+            uint32_t cnt;
+            rv = gDebugStream->Write(reinterpret_cast<char*>(ptr) + written,
+                                     size - written, &cnt);
+            if (NS_FAILED(rv))
+                return false;
+
+            written += cnt;
+        }
+
+        return true;
+    }
+
+protected:
+    DataType mDataType;
+    intptr_t mContextAddress;
+    int64_t mValue;
+
+public:
+  // the data packet formats; all packed
+#ifdef _MSC_VER
+#pragma pack(push, 1)
+#endif
+    typedef struct {
+        uint32_t type;
+        uint64_t ptr;
+        uint64_t value;
+    } PACKED_STRUCT BasicPacket;
+
+    typedef struct {
+        uint32_t type;
+        uint64_t ptr;
+        uint64_t layerref;
+        uint32_t color;
+        uint32_t width;
+        uint32_t height;
+    } PACKED_STRUCT ColorPacket;
+
+    typedef struct {
+        uint32_t type;
+        uint64_t ptr;
+        uint64_t layerref;
+        uint32_t name;
+        uint32_t width;
+        uint32_t height;
+        uint32_t stride;
+        uint32_t format;
+        uint32_t target;
+        uint32_t dataFormat;
+        uint32_t dataSize;
+    } PACKED_STRUCT TexturePacket;
+#ifdef _MSC_VER
+#pragma pack(pop)
+#endif
+};
+
+class DebugGLTextureData : public DebugGLData {
+public:
+    DebugGLTextureData(GLContext* cx, void* layerRef, GLuint target, GLenum name, gfxImageSurface* img)
+        : DebugGLData(DebugGLData::TextureData, cx),
+          mLayerRef(layerRef),
+          mTarget(target),
+          mName(name),
+          mImage(img)
+    { }
+
+    void *GetLayerRef() const { return mLayerRef; }
+    GLuint GetName() const { return mName; }
+    gfxImageSurface* GetImage() const { return mImage; }
+    GLenum GetTextureTarget() const { return mTarget; }
+
+    virtual bool Write() {
+        DebugGLData::TexturePacket packet;
+        char* dataptr = nullptr;
+        uint32_t datasize = 0;
+        std::auto_ptr<char> compresseddata;
+
+        packet.type = mDataType;
+        packet.ptr = static_cast<uint64_t>(mContextAddress);
+        packet.layerref = reinterpret_cast<uint64_t>(mLayerRef);
+        packet.name = mName;
+        packet.format = 0;
+        packet.target = mTarget;
+        packet.dataFormat = LOCAL_GL_RGBA;
+
+        if (mImage) {
+            packet.width = mImage->Width();
+            packet.height = mImage->Height();
+            packet.stride = mImage->Stride();
+            packet.dataSize = mImage->GetDataSize();
+
+            dataptr = (char*) mImage->Data();
+            datasize = mImage->GetDataSize();
+
+            compresseddata = std::auto_ptr<char>((char*) moz_malloc(LZ4::maxCompressedSize(datasize)));
+            if (compresseddata.get()) {
+                int ndatasize = LZ4::compress(dataptr, datasize, compresseddata.get());
+                if (ndatasize > 0) {
+                    datasize = ndatasize;
+                    dataptr = compresseddata.get();
+
+                    packet.dataFormat = (1 << 16) | packet.dataFormat;
+                    packet.dataSize = datasize;
+                }
+            }
+        } else {
+            packet.width = 0;
+            packet.height = 0;
+            packet.stride = 0;
+            packet.dataSize = 0;
+        }
+
+        // write the packet header data
+        if (!WriteToStream(&packet, sizeof(packet)))
+            return false;
+
+        // then the image data
+        if (!WriteToStream(dataptr, datasize))
+            return false;
+
+        // then pad out to 4 bytes
+        if (datasize % 4 != 0) {
+            static char buf[] = { 0, 0, 0, 0 };
+            if (!WriteToStream(buf, 4 - (datasize % 4)))
+                return false;
+        }
+
+        return true;
+    }
+
+protected:
+    void* mLayerRef;
+    GLenum mTarget;
+    GLuint mName;
+    nsRefPtr<gfxImageSurface> mImage;
+};
+
+class DebugGLColorData : public DebugGLData {
+public:
+    DebugGLColorData(void* layerRef, const gfxRGBA& color, int width, int height)
+        : DebugGLData(DebugGLData::ColorData),
+          mColor(color.Packed()),
+          mSize(width, height)
+    { }
+
+    void *GetLayerRef() const { return mLayerRef; }
+    uint32_t GetColor() const { return mColor; }
+    const nsIntSize& GetSize() const { return mSize; }
+
+    virtual bool Write() {
+        DebugGLData::ColorPacket packet;
+
+        packet.type = mDataType;
+        packet.ptr = static_cast<uint64_t>(mContextAddress);
+        packet.layerref = reinterpret_cast<uintptr_t>(mLayerRef);
+        packet.color = mColor;
+        packet.width = mSize.width;
+        packet.height = mSize.height;
+
+        return WriteToStream(&packet, sizeof(packet));
+    }
+
+protected:
+    void *mLayerRef;
+    uint32_t mColor;
+    nsIntSize mSize;
+};
+
+static bool
+CheckSender()
+{
+    if (!gDebugConnected)
+        return false;
+
+    // At some point we may want to support sending
+    // data in between frames.
+#if 1
+    if (!gCurrentSender)
+        return false;
+#else
+    if (!gCurrentSender)
+        gCurrentSender = new DebugDataSender();
+#endif
+
+    return true;
+}
+
+
+class DebugListener : public nsIServerSocketListener
+{
+public:
+
+    NS_DECL_THREADSAFE_ISUPPORTS
+
+    DebugListener() { }
+    virtual ~DebugListener() { }
+
+    /* nsIServerSocketListener */
+
+    NS_IMETHODIMP OnSocketAccepted(nsIServerSocket *aServ,
+                                   nsISocketTransport *aTransport)
+    {
+        printf_stderr("*** LayerScope: Accepted connection\n");
+        gDebugConnected = true;
+        gDebugSenderTransport = aTransport;
+        aTransport->OpenOutputStream(nsITransport::OPEN_BLOCKING, 0, 0, getter_AddRefs(gDebugStream));
+        return NS_OK;
+    }
+
+    NS_IMETHODIMP OnStopListening(nsIServerSocket *aServ,
+                                  nsresult aStatus)
+    {
+        return NS_OK;
+    }
+};
+
+NS_IMPL_ISUPPORTS1(DebugListener, nsIServerSocketListener);
+
+
+class DebugDataSender : public nsIRunnable
+{
+public:
+
+    NS_DECL_THREADSAFE_ISUPPORTS
+
+    DebugDataSender() {
+        mList = new LinkedList<DebugGLData>();
+    }
+
+    virtual ~DebugDataSender() {
+        Cleanup();
+    }
+
+    void Append(DebugGLData *d) {
+        mList->insertBack(d);
+    }
+
+    void Cleanup() {
+        if (!mList)
+            return;
+
+        DebugGLData *d;
+        while ((d = mList->popFirst()) != nullptr)
+            delete d;
+        delete mList;
+
+        mList = nullptr;
+    }
+
+    /* nsIRunnable impl; send the data */
+
+    NS_IMETHODIMP Run() {
+        DebugGLData *d;
+        nsresult rv = NS_OK;
+
+        // If we got closed while trying to write some stuff earlier, just
+        // throw away everything.
+        if (!gDebugStream) {
+            Cleanup();
+            return NS_OK;
+        }
+
+        while ((d = mList->popFirst()) != nullptr) {
+            std::auto_ptr<DebugGLData> cleaner(d);
+            if (!d->Write()) {
+                rv = NS_ERROR_FAILURE;
+                break;
+            }
+        }
+
+        Cleanup();
+
+        if (NS_FAILED(rv)) {
+            gDebugSenderTransport->Close(rv);
+            gDebugConnected = false;
+            gDebugStream = nullptr;
+            gDebugServerSocket = nullptr;
+        }
+
+        return NS_OK;
+    }
+
+protected:
+    LinkedList<DebugGLData> *mList;
+};
+
+NS_IMPL_ISUPPORTS1(DebugDataSender, nsIRunnable);
+
+void
+LayerScope::CreateServerSocket()
+{
+    if (!Preferences::GetBool("gfx.layerscope.enabled", false)) {
+        return;
+    }
+
+    if (!gDebugSenderThread) {
+        NS_NewThread(getter_AddRefs(gDebugSenderThread));
+    }
+
+    if (!gDebugServerSocket) {
+        gDebugServerSocket = do_CreateInstance(NS_SERVERSOCKET_CONTRACTID);
+        int port = Preferences::GetInt("gfx.layerscope.port", 23456);
+        gDebugServerSocket->Init(port, false, -1);
+        gDebugServerSocket->AsyncListen(new DebugListener);
+    }
+}
+
+void
+LayerScope::DestroyServerSocket()
+{
+    gDebugConnected = false;
+    gDebugStream = nullptr;
+    gDebugServerSocket = nullptr;
+}
+
+void
+LayerScope::BeginFrame(GLContext* aGLContext, int64_t aFrameStamp)
+{
+    if (!gDebugConnected)
+        return;
+
+#if 0
+    // if we're sending data in between frames, flush the list down the socket,
+    // and start a new one
+    if (gCurrentSender) {
+        gDebugSenderThread->Dispatch(gCurrentSender, NS_DISPATCH_NORMAL);
+    }
+#endif
+
+    gCurrentSender = new DebugDataSender();
+    gCurrentSender->Append(new DebugGLData(DebugGLData::FrameStart, aGLContext, aFrameStamp));
+}
+
+void
+LayerScope::EndFrame(GLContext* aGLContext)
+{
+    if (!CheckSender())
+        return;
+
+    gCurrentSender->Append(new DebugGLData(DebugGLData::FrameEnd, aGLContext));
+    gDebugSenderThread->Dispatch(gCurrentSender, NS_DISPATCH_NORMAL);
+    gCurrentSender = nullptr;
+}
+
+static void
+SendColor(void* aLayerRef, const gfxRGBA& aColor, int aWidth, int aHeight)
+{
+    if (!CheckSender())
+        return;
+
+    gCurrentSender->Append(
+        new DebugGLColorData(aLayerRef, aColor, aWidth, aHeight));
+}
+
+static void
+SendTextureSource(GLContext* aGLContext,
+                  void* aLayerRef,
+                  TextureSourceOGL* aSource,
+                  bool aFlipY)
+{
+    GLenum textureTarget = aSource->GetTextureTarget();
+    int shaderProgram =
+        (int) ShaderProgramFromTargetAndFormat(textureTarget,
+                                               aSource->GetFormat());
+
+    aSource->BindTexture(LOCAL_GL_TEXTURE0);
+
+    GLuint textureId = 0;
+    // This is horrid hack. It assumes that aGLContext matches the context
+    // aSource has bound to.
+    if (textureTarget == LOCAL_GL_TEXTURE_2D) {
+        aGLContext->GetUIntegerv(LOCAL_GL_TEXTURE_BINDING_2D, &textureId);
+    } else if (textureTarget == LOCAL_GL_TEXTURE_EXTERNAL) {
+        aGLContext->GetUIntegerv(LOCAL_GL_TEXTURE_BINDING_EXTERNAL, &textureId);
+    } else if (textureTarget == LOCAL_GL_TEXTURE_RECTANGLE) {
+        aGLContext->GetUIntegerv(LOCAL_GL_TEXTURE_BINDING_RECTANGLE, &textureId);
+    }
+
+    gfx::IntSize size = aSource->GetSize();
+
+    // By sending 0 to ReadTextureImage rely upon aSource->BindTexture binding
+    // texture correctly. textureId is used for tracking in DebugGLTextureData.
+    nsRefPtr<gfxImageSurface> img =
+        aGLContext->ReadTextureImage(0, textureTarget,
+                                     gfxIntSize(size.width, size.height),
+                                     shaderProgram, aFlipY);
+
+    gCurrentSender->Append(
+        new DebugGLTextureData(aGLContext, aLayerRef, textureTarget,
+                               textureId, img));
+}
+
+static void
+SendTexturedEffect(GLContext* aGLContext,
+                   void* aLayerRef,
+                   const TexturedEffect* aEffect)
+{
+    TextureSourceOGL* source = aEffect->mTexture->AsSourceOGL();
+    if (!source)
+        return;
+
+    bool flipY = false;
+    SendTextureSource(aGLContext, aLayerRef, source, flipY);
+}
+
+static void
+SendYCbCrEffect(GLContext* aGLContext,
+                void* aLayerRef,
+                const EffectYCbCr* aEffect)
+{
+    TextureSource* sourceYCbCr = aEffect->mTexture;
+    if (!sourceYCbCr)
+        return;
+
+    const int Y = 0, Cb = 1, Cr = 2;
+    TextureSourceOGL* sourceY =  sourceYCbCr->GetSubSource(Y)->AsSourceOGL();
+    TextureSourceOGL* sourceCb = sourceYCbCr->GetSubSource(Cb)->AsSourceOGL();
+    TextureSourceOGL* sourceCr = sourceYCbCr->GetSubSource(Cr)->AsSourceOGL();
+
+    bool flipY = false;
+    SendTextureSource(aGLContext, aLayerRef, sourceY,  flipY);
+    SendTextureSource(aGLContext, aLayerRef, sourceCb, flipY);
+    SendTextureSource(aGLContext, aLayerRef, sourceCr, flipY);
+}
+
+void
+LayerScope::SendEffectChain(GLContext* aGLContext,
+                            const EffectChain& aEffectChain,
+                            int aWidth, int aHeight)
+{
+    if (!CheckSender())
+        return;
+
+    const Effect* primaryEffect = aEffectChain.mPrimaryEffect;
+    switch (primaryEffect->mType) {
+    case EFFECT_BGRX:
+    case EFFECT_RGBX:
+    case EFFECT_BGRA:
+    case EFFECT_RGBA:
+    {
+        const TexturedEffect* texturedEffect =
+            static_cast<const TexturedEffect*>(primaryEffect);
+        SendTexturedEffect(aGLContext, aEffectChain.mLayerRef, texturedEffect);
+    }
+    break;
+    case EFFECT_YCBCR:
+    {
+        const EffectYCbCr* yCbCrEffect =
+            static_cast<const EffectYCbCr*>(primaryEffect);
+        SendYCbCrEffect(aGLContext, aEffectChain.mLayerRef, yCbCrEffect);
+    }
+    case EFFECT_SOLID_COLOR:
+    {
+        const EffectSolidColor* solidColorEffect =
+            static_cast<const EffectSolidColor*>(primaryEffect);
+        gfxRGBA color(solidColorEffect->mColor.r,
+                      solidColorEffect->mColor.g,
+                      solidColorEffect->mColor.b,
+                      solidColorEffect->mColor.a);
+        SendColor(aEffectChain.mLayerRef, color, aWidth, aHeight);
+    }
+    break;
+    case EFFECT_COMPONENT_ALPHA:
+    case EFFECT_RENDER_TARGET:
+    default:
+        break;
+    }
+
+    //const Effect* secondaryEffect = aEffectChain.mSecondaryEffects[EFFECT_MASK];
+    // TODO:
+}
+
+} /* layers */
+} /* mozilla */

gfx/layers/LayerScope.h

@@ -0,0 +1,35 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef GFX_LAYERSCOPE_H
+#define GFX_LAYERSCOPE_H
+
+#include <stdint.h>
+
+struct nsIntSize;
+
+namespace mozilla {
+
+namespace gl { class GLContext; }
+
+namespace layers {
+
+struct EffectChain;
+
+class LayerScope {
+public:
+    static void CreateServerSocket();
+    static void DestroyServerSocket();
+    static void BeginFrame(gl::GLContext* aGLContext, int64_t aFrameStamp);
+    static void EndFrame(gl::GLContext* aGLContext);
+    static void SendEffectChain(gl::GLContext* aGLContext,
+                                const EffectChain& aEffectChain,
+                                int aWidth, int aHeight);
+};
+
+} /* layers */
+} /* mozilla */
+
+#endif /* GFX_LAYERSCOPE_H */

gfx/layers/composite/CanvasLayerComposite.cpp

@@ -93,7 +93,8 @@ CanvasLayerComposite::RenderLayer(const nsIntRect& aClipRect)
   }
 #endif
 
-  EffectChain effectChain;
+  EffectChain effectChain(this);
+
   LayerManagerComposite::AutoAddMaskEffect autoMaskEffect(mMaskLayer, effectChain);
   gfx::Matrix4x4 transform;
   ToMatrix4x4(GetEffectiveTransform(), transform);

gfx/layers/moz.build

@@ -28,6 +28,7 @@ EXPORTS += [
     'ipc/CompositorParent.h',
     'ipc/ShadowLayersManager.h',
     'Layers.h',
+    'LayerScope.h',
     'LayersLogging.h',
     'LayerSorter.h',
     'LayerTreeInvalidation.h',
@@ -251,6 +252,7 @@ UNIFIED_SOURCES += [
     'ipc/SharedRGBImage.cpp',
     'ipc/TaskThrottler.cpp',
     'Layers.cpp',
+    'LayerScope.cpp',
     'LayersLogging.cpp',
     'LayerSorter.cpp',
     'LayerTreeInvalidation.cpp',

gfx/layers/opengl/CompositorOGL.cpp

@@ -11,6 +11,7 @@
 #include "GLContextProvider.h"          // for GLContextProvider
 #include "GLContext.h"                  // for GLContext
 #include "Layers.h"                     // for WriteSnapshotToDumpFile
+#include "LayerScope.h"                 // for LayerScope
 #include "gfx2DGlue.h"                  // for ThebesFilter
 #include "gfx3DMatrix.h"                // for gfx3DMatrix
 #include "gfxASurface.h"                // for gfxASurface, etc
@@ -50,7 +51,7 @@
 #endif
 
 #define BUFFER_OFFSET(i) ((char *)nullptr + (i))
- 
+
 namespace mozilla {
 
 using namespace gfx;
@@ -767,6 +768,8 @@ CompositorOGL::BeginFrame(const nsIntRegion& aInvalidRegion,
   PROFILER_LABEL("CompositorOGL", "BeginFrame");
   MOZ_ASSERT(!mFrameInProgress, "frame still in progress (should have called EndFrame or AbortFrame");
 
+  LayerScope::BeginFrame(mGLContext, PR_Now());
+
   mVBOs.Reset();
 
   mFrameInProgress = true;
@@ -1014,6 +1017,9 @@ CompositorOGL::DrawQuad(const Rect& aRect,
   mGLContext->PushScissorRect(nsIntRect(intClipRect.x, intClipRect.y,
                                         intClipRect.width, intClipRect.height));
 
+  LayerScope::SendEffectChain(mGLContext, aEffectChain,
+                              aRect.width, aRect.height);
+
   MaskType maskType;
   EffectMask* effectMask;
   TextureSourceOGL* sourceMask = nullptr;
@@ -1308,6 +1314,8 @@ CompositorOGL::EndFrame()
 
   mFrameInProgress = false;
 
+  LayerScope::EndFrame(mGLContext);
+
   if (mTarget) {
     CopyToTarget(mTarget, mCurrentRenderTarget->GetTransform());
     mGLContext->fBindBuffer(LOCAL_GL_ARRAY_BUFFER, 0);

modules/libpref/src/init/all.js

@@ -308,6 +308,10 @@ pref("apz.axis_lock_mode", 0);
 pref("gfx.hidpi.enabled", 2);
 #endif
 
+// Whether to enable LayerScope tool and default listening port
+pref("gfx.layerscope.enabled", false);
+pref("gfx.layerscope.port", 23456);
+
 // 0 = Off, 1 = Full, 2 = Tagged Images Only. 
 // See eCMSMode in gfx/thebes/gfxPlatform.h
 pref("gfx.color_management.mode", 2);

widget/xpwidgets/nsBaseWidget.cpp

@@ -41,6 +41,7 @@
 #include "mozilla/gfx/2D.h"
 #include "mozilla/MouseEvents.h"
 #include "GLConsts.h"
+#include "LayerScope.h"
 
 #ifdef ACCESSIBILITY
 #include "nsAccessibilityService.h"
@@ -161,6 +162,8 @@ static void DeferredDestroyCompositor(CompositorParent* aCompositorParent,
 
 void nsBaseWidget::DestroyCompositor()
 {
+  LayerScope::DestroyServerSocket();
+
   if (mCompositorChild) {
     mCompositorChild->SendWillStop();
     mCompositorChild->Destroy();
@@ -749,7 +752,7 @@ NS_IMETHODIMP nsBaseWidget::MakeFullScreen(bool aFullScreen)
     if (!mOriginalBounds)
       mOriginalBounds = new nsIntRect();
     GetScreenBounds(*mOriginalBounds);
-    // convert dev pix to display pix for window manipulation 
+    // convert dev pix to display pix for window manipulation
     CSSToLayoutDeviceScale scale = GetDefaultScale();
     mOriginalBounds->x = NSToIntRound(mOriginalBounds->x / scale.scale);
     mOriginalBounds->y = NSToIntRound(mOriginalBounds->y / scale.scale);
@@ -950,6 +953,9 @@ void nsBaseWidget::CreateCompositor(int aWidth, int aHeight)
     return;
   }
 
+  // The server socket has to be created on the main thread.
+  LayerScope::CreateServerSocket();
+
   mCompositorParent = NewCompositorParent(aWidth, aHeight);
   MessageChannel *parentChannel = mCompositorParent->GetIPCChannel();
   ClientLayerManager* lm = new ClientLayerManager(this);