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   // Content processes should have gotten a call to SetValuesForInitialize,
  51   // which will have set gGfxVarInitUpdates.
  52   MOZ_ASSERT_IF(XRE_IsContentProcess(), gGfxVarInitUpdates);
  53
  54   if (gGfxVarInitUpdates) {
  55     // Apply any updates from gGfxVarInitUpdates.
  56     for (const auto& varUpdate : *gGfxVarInitUpdates) {
  57       ApplyUpdate(varUpdate);
  58     }
  59     gGfxVarInitUpdates = nullptr;
  60   }
  61 }
  62
  63 gfxVars::gfxVars() = default;
  64
  65 void gfxVars::Shutdown() {
  66   sInstance = nullptr;
  67   sVarList = nullptr;
  68   gGfxVarInitUpdates = nullptr;
  69 }
  70
  71 /* static */
  72 void gfxVars::ApplyUpdate(const GfxVarUpdate& aUpdate) {
  73   // Only subprocesses receive updates and apply them locally.
  74   MOZ_ASSERT(!XRE_IsParentProcess());
  75   MOZ_DIAGNOSTIC_ASSERT(sVarList || gGfxVarInitUpdates);
  76   if (sVarList) {
  77     sVarList->ElementAt(aUpdate.index())->SetValue(aUpdate.value());
  78   } else if (gGfxVarInitUpdates) {
  79     // Too early, we haven't been initialized, so just add to
  80     // the array waiting for the initialization...
  81     gGfxVarInitUpdates->AppendElement(aUpdate);
  82   }
  83 }
  84
  85 /* static */
  86 void gfxVars::AddReceiver(gfxVarReceiver* aReceiver) {
  87   MOZ_ASSERT(NS_IsMainThread());
  88
  89   // Don't double-add receivers, in case a broken content process sends two
  90   // init messages.
  91   if (!sInstance->mReceivers.Contains(aReceiver)) {
  92     sInstance->mReceivers.AppendElement(aReceiver);
  93   }
  94 }
  95
  96 /* static */
  97 void gfxVars::RemoveReceiver(gfxVarReceiver* aReceiver) {
  98   MOZ_ASSERT(NS_IsMainThread());
  99
 100   if (sInstance) {
 101     sInstance->mReceivers.RemoveElement(aReceiver);
 102   }
 103 }
 104
 105 /* static */
 106 nsTArray<GfxVarUpdate> gfxVars::FetchNonDefaultVars() {
 107   MOZ_ASSERT(NS_IsMainThread());
 108   MOZ_ASSERT(sVarList);
 109
 110   nsTArray<GfxVarUpdate> updates;
 111   for (size_t i = 0; i < sVarList->Length(); i++) {
 112     VarBase* var = sVarList->ElementAt(i);
 113     if (var->HasDefaultValue()) {
 114       continue;
 115     }
 116
 117     GfxVarValue value;
 118     var->GetValue(&value);
 119
 120     updates.AppendElement(GfxVarUpdate(i, value));
 121   }
 122
 123   return updates;
 124 }
 125
 126 gfxVars::VarBase::VarBase() {
 127   mIndex = gfxVars::sVarList->Length();
 128   gfxVars::sVarList->AppendElement(this);
 129 }
 130
 131 void gfxVars::NotifyReceivers(VarBase* aVar) {
 132   MOZ_ASSERT(NS_IsMainThread());
 133
 134   GfxVarValue value;
 135   aVar->GetValue(&value);
 136
 137   GfxVarUpdate update(aVar->Index(), value);
 138   for (auto& receiver : mReceivers) {
 139     receiver->OnVarChanged(update);
 140   }
 141 }
 142
 143 }  // namespace gfx
 144 }  // namespace mozilla