ui/gl/gl_fence.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ui/gl/gl_fence.h"
   6
   7 #include "base/compiler_specific.h"
   8 #include "ui/gl/gl_bindings.h"
   9 #include "ui/gl/gl_context.h"
  10
  11 namespace {
  12
  13 class GLFenceNVFence: public gfx::GLFence {
  14  public:
  15   GLFenceNVFence() {
  16     // What if either of these GL calls fails? TestFenceNV will return true.
  17     // See spec:
  18     // http://www.opengl.org/registry/specs/NV/fence.txt
  19     //
  20     // What should happen if TestFenceNV is called for a name before SetFenceNV
  21     // is called?
  22     //     We generate an INVALID_OPERATION error, and return TRUE.
  23     //     This follows the semantics for texture object names before
  24     //     they are bound, in that they acquire their state upon binding.
  25     //     We will arbitrarily return TRUE for consistency.
  26     glGenFencesNV(1, &fence_);
  27     glSetFenceNV(fence_, GL_ALL_COMPLETED_NV);
  28     glFlush();
  29   }
  30
  31   virtual bool HasCompleted() OVERRIDE {
  32     return !!glTestFenceNV(fence_);
  33   }
  34
  35   virtual void ClientWait() OVERRIDE {
  36     glFinishFenceNV(fence_);
  37   }
  38
  39  private:
  40   virtual ~GLFenceNVFence() {
  41     glDeleteFencesNV(1, &fence_);
  42   }
  43
  44   GLuint fence_;
  45 };
  46
  47 class GLFenceARBSync: public gfx::GLFence {
  48  public:
  49   GLFenceARBSync() {
  50     sync_ = glFenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
  51     glFlush();
  52   }
  53
  54   virtual bool HasCompleted() OVERRIDE {
  55     // Handle the case where FenceSync failed.
  56     if (!sync_)
  57       return true;
  58
  59     // We could potentially use glGetSynciv here, but it doesn't work
  60     // on OSX 10.7 (always says the fence is not signaled yet).
  61     // glClientWaitSync works better, so let's use that instead.
  62     return  glClientWaitSync(sync_, 0, 0) != GL_TIMEOUT_EXPIRED;
  63   }
  64
  65   virtual void ClientWait() OVERRIDE {
  66     glClientWaitSync(sync_, GL_SYNC_FLUSH_COMMANDS_BIT, GL_TIMEOUT_IGNORED);
  67   }
  68
  69  private:
  70   virtual ~GLFenceARBSync() {
  71     glDeleteSync(sync_);
  72   }
  73
  74   GLsync sync_;
  75 };
  76
  77 #if !defined(OS_MACOSX)
  78 class EGLFenceSync : public gfx::GLFence {
  79  public:
  80   EGLFenceSync() {
  81     display_ = eglGetCurrentDisplay();
  82     sync_ = eglCreateSyncKHR(display_, EGL_SYNC_FENCE_KHR, NULL);
  83     glFlush();
  84   }
  85
  86   virtual bool HasCompleted() OVERRIDE {
  87     EGLint value = 0;
  88     eglGetSyncAttribKHR(display_, sync_, EGL_SYNC_STATUS_KHR, &value);
  89     DCHECK(value == EGL_SIGNALED_KHR || value == EGL_UNSIGNALED_KHR);
  90     return !value || value == EGL_SIGNALED_KHR;
  91   }
  92
  93   virtual void ClientWait() OVERRIDE {
  94     EGLint flags = 0;
  95     EGLTimeKHR time = EGL_FOREVER_KHR;
  96     eglClientWaitSyncKHR(display_, sync_, flags, time);
  97   }
  98
  99  private:
 100   virtual ~EGLFenceSync() {
 101     eglDestroySyncKHR(display_, sync_);
 102   }
 103
 104   EGLSyncKHR sync_;
 105   EGLDisplay display_;
 106 };
 107 #endif // !OS_MACOSX
 108
 109 }  // namespace
 110
 111 namespace gfx {
 112
 113 GLFence::GLFence() {
 114 }
 115
 116 GLFence::~GLFence() {
 117 }
 118
 119 // static
 120 GLFence* GLFence::Create() {
 121 #if !defined(OS_MACOSX)
 122   if (gfx::g_driver_egl.ext.b_EGL_KHR_fence_sync)
 123     return new EGLFenceSync();
 124 #endif
 125   if (gfx::g_driver_gl.ext.b_GL_NV_fence)
 126     return new GLFenceNVFence();
 127   if (gfx::g_driver_gl.ext.b_GL_ARB_sync)
 128     return new GLFenceARBSync();
 129   return NULL;
 130 }
 131
 132 }  // namespace gfx