From 3cea37c9c2d1bf12eca916e0f9af1cf7ec2e8171 Mon Sep 17 00:00:00 2001
From: Nicolas Silva <nsilva@mozilla.com>
Date: Fri, 10 Aug 2018 17:14:57 +0200
Subject: [PATCH] Bug 1469496 - Handle video memory purge with WebRender.
 r=sotaro

---
 gfx/layers/ipc/CompositorBridgeParent.cpp      |  8 ++++++++
 gfx/layers/ipc/CompositorBridgeParent.h        |  1 +
 gfx/webrender_bindings/RendererOGL.cpp         | 18 ++++++++++++++++++
 gfx/webrender_bindings/WebRenderAPI.cpp        |  6 ++++++
 gfx/webrender_bindings/WebRenderAPI.h          |  2 ++
 gfx/webrender_bindings/src/bindings.rs         |  6 ++++++
 .../webrender_ffi_generated.h                  |  4 ++++
 7 files changed, 45 insertions(+)

diff --git a/gfx/layers/ipc/CompositorBridgeParent.cpp b/gfx/layers/ipc/CompositorBridgeParent.cpp
index 536e9b4c6d45..bf90584b6ba1 100644
--- a/gfx/layers/ipc/CompositorBridgeParent.cpp
+++ b/gfx/layers/ipc/CompositorBridgeParent.cpp
@@ -2354,6 +2354,14 @@ CompositorBridgeParent::NotifyWebRenderError(wr::WebRenderError aError)
   Unused << SendNotifyWebRenderError(aError);
 }
 
+void
+CompositorBridgeParent::NotifyWebRenderContextPurge()
+{
+  MOZ_ASSERT(CompositorLoop() == MessageLoop::current());
+  RefPtr<wr::WebRenderAPI> api = mWrBridge->GetWebRenderAPI();
+  api->ClearAllCaches();
+}
+
 #if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
 //#define PLUGINS_LOG(...) printf_stderr("CP [%s]: ", __FUNCTION__);
 //                         printf_stderr(__VA_ARGS__);
diff --git a/gfx/layers/ipc/CompositorBridgeParent.h b/gfx/layers/ipc/CompositorBridgeParent.h
index 996f6e948088..ab758d472d4c 100644
--- a/gfx/layers/ipc/CompositorBridgeParent.h
+++ b/gfx/layers/ipc/CompositorBridgeParent.h
@@ -274,6 +274,7 @@ public:
   bool IsSameProcess() const override;
 
   void NotifyWebRenderError(wr::WebRenderError aError);
+  void NotifyWebRenderContextPurge();
   void NotifyPipelineRendered(const wr::PipelineId& aPipelineId,
                               const wr::Epoch& aEpoch,
                               TimeStamp& aCompositeStart,
diff --git a/gfx/webrender_bindings/RendererOGL.cpp b/gfx/webrender_bindings/RendererOGL.cpp
index a0a6634888de..7beba4fe1af0 100644
--- a/gfx/webrender_bindings/RendererOGL.cpp
+++ b/gfx/webrender_bindings/RendererOGL.cpp
@@ -95,6 +95,12 @@ RendererOGL::Update()
   }
 }
 
+static void
+DoNotifyWebRenderContextPurge(layers::CompositorBridgeParent* aBridge)
+{
+  aBridge->NotifyWebRenderContextPurge();
+}
+
 bool
 RendererOGL::UpdateAndRender(bool aReadback)
 {
@@ -150,6 +156,18 @@ RendererOGL::UpdateAndRender(bool aReadback)
   mFrameStartTime = TimeStamp();
 #endif
 
+  gl::GLContext* gl = mCompositor->gl();
+  if (gl->IsSupported(gl::GLFeature::robustness)) {
+    GLenum resetStatus = gl->fGetGraphicsResetStatus();
+    if (resetStatus == LOCAL_GL_PURGED_CONTEXT_RESET_NV) {
+      layers::CompositorThreadHolder::Loop()->PostTask(NewRunnableFunction(
+        "DoNotifyWebRenderContextPurgeRunnable",
+        &DoNotifyWebRenderContextPurge,
+        mBridge
+      ));
+    }
+  }
+
   // TODO: Flush pending actions such as texture deletions/unlocks and
   //       textureHosts recycling.
 
diff --git a/gfx/webrender_bindings/WebRenderAPI.cpp b/gfx/webrender_bindings/WebRenderAPI.cpp
index eed72056f25c..74b33f070f8c 100644
--- a/gfx/webrender_bindings/WebRenderAPI.cpp
+++ b/gfx/webrender_bindings/WebRenderAPI.cpp
@@ -422,6 +422,12 @@ WebRenderAPI::Readback(const TimeStamp& aStartTime,
     task.Wait();
 }
 
+void
+WebRenderAPI::ClearAllCaches()
+{
+  wr_api_clear_all_caches(mDocHandle);
+}
+
 void
 WebRenderAPI::Pause()
 {
diff --git a/gfx/webrender_bindings/WebRenderAPI.h b/gfx/webrender_bindings/WebRenderAPI.h
index b33b40139035..b768abb6dd5e 100644
--- a/gfx/webrender_bindings/WebRenderAPI.h
+++ b/gfx/webrender_bindings/WebRenderAPI.h
@@ -198,6 +198,8 @@ public:
 
   void Readback(const TimeStamp& aStartTime, gfx::IntSize aSize, uint8_t *aBuffer, uint32_t aBufferSize);
 
+  void ClearAllCaches();
+
   void Pause();
   bool Resume();
 
diff --git a/gfx/webrender_bindings/src/bindings.rs b/gfx/webrender_bindings/src/bindings.rs
index 2b37489659a9..9d7a8df4d76d 100644
--- a/gfx/webrender_bindings/src/bindings.rs
+++ b/gfx/webrender_bindings/src/bindings.rs
@@ -1029,6 +1029,12 @@ pub unsafe extern "C" fn wr_api_shut_down(dh: &mut DocumentHandle) {
     dh.api.shut_down();
 }
 
+/// cbindgen:postfix=WR_DESTRUCTOR_SAFE_FUNC
+#[no_mangle]
+pub unsafe extern "C" fn wr_api_clear_all_caches(dh: &mut DocumentHandle) {
+    dh.api.send_debug_cmd(DebugCommand::ClearCaches(ClearCache::all()));
+}
+
 fn make_transaction(do_async: bool) -> Transaction {
     let mut transaction = Transaction::new();
     // Ensure that we either use async scene building or not based on the
diff --git a/gfx/webrender_bindings/webrender_ffi_generated.h b/gfx/webrender_bindings/webrender_ffi_generated.h
index 032c7f4f3bf0..2291c25ef712 100644
--- a/gfx/webrender_bindings/webrender_ffi_generated.h
+++ b/gfx/webrender_bindings/webrender_ffi_generated.h
@@ -1050,6 +1050,10 @@ void wr_api_capture(DocumentHandle *aDh,
                     uint32_t aBitsRaw)
 WR_FUNC;
 
+WR_INLINE
+void wr_api_clear_all_caches(DocumentHandle *aDh)
+WR_DESTRUCTOR_SAFE_FUNC;
+
 WR_INLINE
 void wr_api_clone(DocumentHandle *aDh,
                   DocumentHandle **aOutHandle)