ui/gl/gl_fence_nv.cc

   1 // Copyright 2014 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_nv.h"
   6
   7 #include "ui/gl/gl_bindings.h"
   8 #include "ui/gl/gl_context.h"
   9
  10 namespace gfx {
  11
  12 GLFenceNV::GLFenceNV(bool flush) {
  13   // What if either of these GL calls fails? TestFenceNV will return true.
  14   // See spec:
  15   // http://www.opengl.org/registry/specs/NV/fence.txt
  16   //
  17   // What should happen if TestFenceNV is called for a name before SetFenceNV
  18   // is called?
  19   //     We generate an INVALID_OPERATION error, and return TRUE.
  20   //     This follows the semantics for texture object names before
  21   //     they are bound, in that they acquire their state upon binding.
  22   //     We will arbitrarily return TRUE for consistency.
  23   glGenFencesNV(1, &fence_);
  24   glSetFenceNV(fence_, GL_ALL_COMPLETED_NV);
  25   DCHECK(glIsFenceNV(fence_));
  26   if (flush) {
  27     glFlush();
  28   } else {
  29     flush_event_ = GLContext::GetCurrent()->SignalFlush();
  30   }
  31 }
  32
  33 bool GLFenceNV::HasCompleted() {
  34   DCHECK(glIsFenceNV(fence_));
  35   return !!glTestFenceNV(fence_);
  36 }
  37
  38 void GLFenceNV::ClientWait() {
  39   DCHECK(glIsFenceNV(fence_));
  40   if (!flush_event_.get() || flush_event_->IsSignaled()) {
  41     glFinishFenceNV(fence_);
  42   } else {
  43     LOG(ERROR) << "Trying to wait for uncommitted fence. Skipping...";
  44   }
  45 }
  46
  47 void GLFenceNV::ServerWait() {
  48   DCHECK(glIsFenceNV(fence_));
  49   ClientWait();
  50 }
  51
  52 GLFenceNV::~GLFenceNV() {
  53   DCHECK(glIsFenceNV(fence_));
  54   glDeleteFencesNV(1, &fence_);
  55 }
  56
  57 }  // namespace gfx