Bug 1621762: Part 5 - Change PWebGL alloc+constructor to Initialize message r=jgilbert,jld

We need to separate WebGL actor construction and initialization since IpdlQueue initialization needs the actor to already exist.

Differential Revision: https://phabricator.services.mozilla.com/D68262

dom/canvas/ClientWebGLContext.cpp

@@ -750,15 +750,17 @@ bool ClientWebGLContext::CreateHostContext(const uvec2& requestedSize) {
     auto sink = MakeUnique<HostWebGLCommandSinkP>(commandPcq->TakeConsumer(),
                                                   responsePcq->TakeProducer());
 
-    // Use the error/warning and command queues to construct a
-    // ClientWebGLContext in this process and a HostWebGLContext
-    // in the host process.
-    outOfProcess.mWebGLChild = new dom::WebGLChild(*this);
-    if (!cbc->SendPWebGLConstructor(outOfProcess.mWebGLChild.get(), initDesc,
-                                    &notLost.info)) {
+    outOfProcess.mWebGLChild = new WebGLChild(*this);
+    outOfProcess.mWebGLChild = static_cast<dom::WebGLChild*>(
+        cbc->SendPWebGLConstructor(outOfProcess.mWebGLChild));
+    if (!outOfProcess.mWebGLChild) {
       return Err("SendPWebGLConstructor failed");
     }
 
+    if (!outOfProcess.mWebGLChild->SendInitialize(initDesc, &notLost.info)) {
+      return Err("WebGL actor Initialize failed");
+    }
+
     notLost.outOfProcess = Some(std::move(outOfProcess));
     return Ok();
   }();

dom/canvas/PWebGL.ipdl

@@ -11,6 +11,8 @@ include protocol PLayerTransaction;
 using mozilla::layers::CompositableHandle from "mozilla/layers/LayersTypes.h";
 using mozilla::webgl::ContextLossReason from "mozilla/dom/WebGLIpdl.h";
 using std::string from "ipc/IPCMessageUtils.h";
+using mozilla::webgl::InitContextDesc from "mozilla/dom/WebGLIpdl.h";
+using mozilla::webgl::InitContextResult from "mozilla/dom/WebGLIpdl.h";
 
 namespace mozilla {
 namespace dom {
@@ -25,6 +27,9 @@ sync refcounted protocol PWebGL
   manager PCompositorBridge;
 
 parent:
+  sync Initialize(InitContextDesc desc)
+    returns (InitContextResult res);
+
   async __delete__();
 
   // DLP: TODO: Does this need to be sync?

dom/canvas/WebGLParent.cpp

@@ -14,30 +14,28 @@ namespace mozilla {
 
 namespace dom {
 
-/* static */
-RefPtr<WebGLParent> WebGLParent::Create(const webgl::InitContextDesc& desc,
-                                        webgl::InitContextResult* const out) {
-  RefPtr<WebGLParent> parent = new WebGLParent;
+mozilla::ipc::IPCResult WebGLParent::RecvInitialize(
+    const webgl::InitContextDesc& desc, webgl::InitContextResult* const out) {
   auto remotingData = Some(HostWebGLContext::RemotingData{
-      *parent, {},  // std::move(commandSink),
+      *this, {},  // std::move(commandSink),
   });
 
-  parent->mHost = HostWebGLContext::Create(
+  mHost = HostWebGLContext::Create(
       {
           {},
           std::move(remotingData),
       },
       desc, out);
 
-  if (!parent->mHost) {
-    WEBGL_BRIDGE_LOGE("Failed to create HostWebGLContext");
-    return nullptr;
+  if (!mHost) {
+    return IPC_FAIL(this, "Failed to create HostWebGLContext");
   }
-  if (!parent->BeginCommandQueueDrain()) {
-    WEBGL_BRIDGE_LOGE("Failed to start WebGL command queue drain");
-    return nullptr;
+
+  if (!BeginCommandQueueDrain()) {
+    return IPC_FAIL(this, "Failed to start WebGL command queue drain");
   }
-  return parent;
+
+  return IPC_OK();
 }
 
 WebGLParent::WebGLParent() = default;

dom/canvas/WebGLParent.h

@@ -28,13 +28,15 @@ class WebGLParent final : public PWebGLParent,
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(WebGLParent, override);
   MOZ_DECLARE_WEAKREFERENCE_TYPENAME(WebGLParent)
 
-  static RefPtr<WebGLParent> Create(const webgl::InitContextDesc&,
-                                    webgl::InitContextResult* out);
+  mozilla::ipc::IPCResult RecvInitialize(const webgl::InitContextDesc&,
+                                         webgl::InitContextResult* out);
 
   RefPtr<layers::SharedSurfaceTextureClient> GetVRFrame(webgl::ObjectId);
 
- private:
+  // For IPDL:
   WebGLParent();
+
+ private:
   ~WebGLParent();
 
   bool BeginCommandQueueDrain();

gfx/layers/ipc/CompositorBridgeChild.cpp

@@ -12,7 +12,6 @@
 #include "base/message_loop.h"   // for MessageLoop
 #include "base/task.h"           // for NewRunnableMethod, etc
 #include "mozilla/StaticPrefs_layers.h"
-#include "mozilla/dom/WebGLChild.h"
 #include "mozilla/layers/CompositorManagerChild.h"
 #include "mozilla/layers/ImageBridgeChild.h"
 #include "mozilla/layers/APZChild.h"

gfx/layers/ipc/CompositorBridgeParent.h

@@ -302,8 +302,7 @@ class CompositorBridgeParentBase : public PCompositorBridgeParent,
     return IPC_FAIL_NO_REASON(this);
   }
 
-  virtual already_AddRefed<PWebGLParent> AllocPWebGLParent(
-      const webgl::InitContextDesc&, webgl::InitContextResult* out) = 0;
+  virtual already_AddRefed<PWebGLParent> AllocPWebGLParent() = 0;
 
   bool mCanSend;
 
@@ -693,8 +692,7 @@ class CompositorBridgeParent final : public CompositorBridgeParentBase,
   WebRenderBridgeParent* GetWrBridge() { return mWrBridge; }
   webgpu::WebGPUParent* GetWebGPUBridge() { return mWebGPUBridge; }
 
-  already_AddRefed<PWebGLParent> AllocPWebGLParent(
-      const webgl::InitContextDesc&, webgl::InitContextResult*) override {
+  already_AddRefed<PWebGLParent> AllocPWebGLParent() override {
     MOZ_ASSERT_UNREACHABLE(
         "This message is CrossProcessCompositorBridgeParent only");
     return nullptr;

gfx/layers/ipc/ContentCompositorBridgeParent.cpp

@@ -766,11 +766,9 @@ mozilla::ipc::IPCResult ContentCompositorBridgeParent::RecvPreferredDXGIAdapter(
 }
 
 already_AddRefed<dom::PWebGLParent>
-ContentCompositorBridgeParent::AllocPWebGLParent(
-    const webgl::InitContextDesc& aInitDesc,
-    webgl::InitContextResult* const out) {
-  RefPtr<dom::PWebGLParent> ret = dom::WebGLParent::Create(aInitDesc, out);
-  return ret.forget();
+ContentCompositorBridgeParent::AllocPWebGLParent() {
+  RefPtr<dom::PWebGLParent> parent = new dom::WebGLParent();
+  return parent.forget();
 }
 
 }  // namespace layers

gfx/layers/ipc/ContentCompositorBridgeParent.h

@@ -161,8 +161,7 @@ class ContentCompositorBridgeParent final : public CompositorBridgeParentBase {
     return IPC_FAIL_NO_REASON(this);
   }
 
-  already_AddRefed<dom::PWebGLParent> AllocPWebGLParent(
-      const webgl::InitContextDesc&, webgl::InitContextResult* out) override;
+  already_AddRefed<dom::PWebGLParent> AllocPWebGLParent() override;
 
   // Use DidCompositeLocked if you already hold a lock on
   // sIndirectLayerTreesLock; Otherwise use DidComposite, which would request

gfx/layers/ipc/PCompositorBridge.ipdl

@@ -48,8 +48,6 @@ using mozilla::wr::MaybeExternalImageId from "mozilla/webrender/WebRenderTypes.h
 using mozilla::layers::LayersObserverEpoch from "mozilla/layers/LayersTypes.h";
 using mozilla::layers::TransactionId from "mozilla/layers/LayersTypes.h";
 using struct DxgiAdapterDesc from "mozilla/D3DMessageUtils.h";
-using mozilla::webgl::InitContextDesc from "mozilla/dom/WebGLIpdl.h";
-using mozilla::webgl::InitContextResult from "mozilla/dom/WebGLIpdl.h";
 
 namespace mozilla {
 namespace layers {
@@ -300,9 +298,7 @@ parent:
   async RequestFxrOutput();
 
   // Actor that represents one WebGL context.
-  // (modeled after `sync PBackgroundLSSnapshot`)
-  sync PWebGL(InitContextDesc desc)
-    returns (InitContextResult res);
+  async PWebGL();
 
 child:
   // Send back Compositor Frame Metrics from APZCs so tiled layers can

ipc/ipdl/sync-messages.ini

@@ -1213,8 +1213,8 @@ description = Synchronous ping allowing worker thread to confirm actor is create
 description = Synchronous launch of a child process that in turn launches and sandboxes another process. Called on a dedicated thread and targets a dedicated process, so this shouldn't block anything.
 [PWebGL::UpdateCompositableHandle]
 description = Compositing WebGL is synchronous by spec. Updates to WebGL canvas contents must be updated in lockstep with other DOM updates.
-[PCompositorBridge::PWebGL]
-description = Creation of WebGL contexts is synchronous by spec.
+[PWebGL::Initialize]
+description = Initialization of WebGL contexts is synchronous by spec.
 [PSocketProcess::GetTLSClientCert]
 description = Synchronously get client certificate and key from parent process. Once bug 696976 has been fixed, this can be removed.