gfx/config/gfxVars.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "gfxVars.h"
   8 #include "gfxVarReceiver.h"
   9 #include "mozilla/dom/ContentChild.h"
  10
  11 namespace mozilla {
  12 namespace gfx {
  13
  14 StaticAutoPtr<gfxVars> gfxVars::sInstance;
  15 StaticAutoPtr<nsTArray<gfxVars::VarBase*>> gfxVars::sVarList;
  16
  17 StaticAutoPtr<nsTArray<GfxVarUpdate>> gGfxVarInitUpdates;
  18
  19 void gfxVars::SetValuesForInitialize(
  20     const nsTArray<GfxVarUpdate>& aInitUpdates) {
  21   // This should only be called once
  22   MOZ_RELEASE_ASSERT(!gGfxVarInitUpdates);
  23
  24   // We expect aInitUpdates to be provided before any other gfxVars operation,
  25   // and for sInstance to be null here, but handle the alternative.
  26   if (sInstance) {
  27     // Apply the updates, the object has been created already
  28     for (const auto& varUpdate : aInitUpdates) {
  29       ApplyUpdate(varUpdate);
  30     }
  31   } else {
  32     // Save the values for Initialize call
  33     gGfxVarInitUpdates = new nsTArray<GfxVarUpdate>(aInitUpdates.Clone());
  34   }
  35 }
  36
  37 void gfxVars::Initialize() {
  38   if (sInstance) {
  39     MOZ_RELEASE_ASSERT(
  40         !gGfxVarInitUpdates,
  41         "Initial updates should not be present after any gfxVars operation");
  42     return;
  43   }
  44
  45   // sVarList must be initialized first since it's used in the constructor for
  46   // sInstance.
  47   sVarList = new nsTArray<gfxVars::VarBase*>();
  48   sInstance = new gfxVars;
  49
  50   // Note the GPU process is not handled here - it cannot send sync
  51   // messages, so instead the initial data is pushed down.
  52   if (XRE_IsContentProcess()) {
  53     MOZ_ASSERT(gGfxVarInitUpdates,
  54                "Initial updates should be provided in content process");
  55     if (!gGfxVarInitUpdates) {
  56       // No provided initial updates, sync-request them from parent.
  57       nsTArray<GfxVarUpdate> initUpdates;
  58       dom::ContentChild::GetSingleton()->SendGetGfxVars(&initUpdates);
  59       gGfxVarInitUpdates = new nsTArray<GfxVarUpdate>(std::move(initUpdates));
  60     }
  61     for (const auto& varUpdate : *gGfxVarInitUpdates) {
  62       ApplyUpdate(varUpdate);
  63     }
  64     gGfxVarInitUpdates = nullptr;
  65   }
  66 }
  67
  68 gfxVars::gfxVars() = default;
  69
  70 void gfxVars::Shutdown() {
  71   sInstance = nullptr;
  72   sVarList = nullptr;
  73   gGfxVarInitUpdates = nullptr;
  74 }
  75
  76 /* static */
  77 void gfxVars::ApplyUpdate(const GfxVarUpdate& aUpdate) {
  78   // Only subprocesses receive updates and apply them locally.
  79   MOZ_ASSERT(!XRE_IsParentProcess());
  80   MOZ_DIAGNOSTIC_ASSERT(sVarList || gGfxVarInitUpdates);
  81   if (sVarList) {
  82     sVarList->ElementAt(aUpdate.index())->SetValue(aUpdate.value());
  83   } else if (gGfxVarInitUpdates) {
  84     // Too early, we haven't been initialized, so just add to
  85     // the array waiting for the initialization...
  86     gGfxVarInitUpdates->AppendElement(aUpdate);
  87   }
  88 }
  89
  90 /* static */
  91 void gfxVars::AddReceiver(gfxVarReceiver* aReceiver) {
  92   MOZ_ASSERT(NS_IsMainThread());
  93
  94   // Don't double-add receivers, in case a broken content process sends two
  95   // init messages.
  96   if (!sInstance->mReceivers.Contains(aReceiver)) {
  97     sInstance->mReceivers.AppendElement(aReceiver);
  98   }
  99 }
 100
 101 /* static */
 102 void gfxVars::RemoveReceiver(gfxVarReceiver* aReceiver) {
 103   MOZ_ASSERT(NS_IsMainThread());
 104
 105   if (sInstance) {
 106     sInstance->mReceivers.RemoveElement(aReceiver);
 107   }
 108 }
 109
 110 /* static */
 111 nsTArray<GfxVarUpdate> gfxVars::FetchNonDefaultVars() {
 112   MOZ_ASSERT(NS_IsMainThread());
 113   MOZ_ASSERT(sVarList);
 114
 115   nsTArray<GfxVarUpdate> updates;
 116   for (size_t i = 0; i < sVarList->Length(); i++) {
 117     VarBase* var = sVarList->ElementAt(i);
 118     if (var->HasDefaultValue()) {
 119       continue;
 120     }
 121
 122     GfxVarValue value;
 123     var->GetValue(&value);
 124
 125     updates.AppendElement(GfxVarUpdate(i, value));
 126   }
 127
 128   return updates;
 129 }
 130
 131 gfxVars::VarBase::VarBase() {
 132   mIndex = gfxVars::sVarList->Length();
 133   gfxVars::sVarList->AppendElement(this);
 134 }
 135
 136 void gfxVars::NotifyReceivers(VarBase* aVar) {
 137   MOZ_ASSERT(NS_IsMainThread());
 138
 139   GfxVarValue value;
 140   aVar->GetValue(&value);
 141
 142   GfxVarUpdate update(aVar->Index(), value);
 143   for (auto& receiver : mReceivers) {
 144     receiver->OnVarChanged(update);
 145   }
 146 }
 147
 148 }  // namespace gfx
 149 }  // namespace mozilla