From 3672cb1c5e46f7e0359d9ec376679f582e128476 Mon Sep 17 00:00:00 2001
From: Jeff Gilbert <jgilbert@mozilla.com>
Date: Tue, 7 Mar 2017 14:10:09 -0800
Subject: [PATCH] Bug 1339256 - Double-check robustness. - r=daoshengmu

MozReview-Commit-ID: 20csUTf7q6e
---
 gfx/gl/GLContext.cpp | 21 ++++++++++++++++++++-
 gfx/gl/GLDefs.h      |  4 +++-
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/gfx/gl/GLContext.cpp b/gfx/gl/GLContext.cpp
index 22d85c1f514e..c0a6f5aa60fd 100644
--- a/gfx/gl/GLContext.cpp
+++ b/gfx/gl/GLContext.cpp
@@ -1009,6 +1009,11 @@ GLContext::InitWithPrefixImpl(const char* prefix, bool trygl)
 
     ////////////////
 
+    const auto err = mSymbols.fGetError();
+    MOZ_RELEASE_ASSERT(!err);
+    if (err)
+        return false;
+
     LoadMoreSymbols(prefix, trygl);
 
     ////////////////////////////////////////////////////////////////////////////
@@ -1145,6 +1150,14 @@ GLContext::LoadMoreSymbols(const char* prefix, bool trygl)
         return fnLoadForFeature(list, feature);
     };
 
+    if (IsSupported(GLFeature::robustness)) {
+        const auto resetStrategy = GetIntAs<GLuint>(LOCAL_GL_RESET_NOTIFICATION_STRATEGY);
+        if (resetStrategy != LOCAL_GL_LOSE_CONTEXT_ON_RESET) {
+            MOZ_ASSERT(resetStrategy == LOCAL_GL_NO_RESET_NOTIFICATION);
+            NS_WARNING("Robustness supported, but not active!");
+            MarkUnsupported(GLFeature::robustness);
+        }
+    }
     if (IsSupported(GLFeature::robustness)) {
         const SymLoadStruct symbols[] = {
             { (PRFuncPtr*) &mSymbols.fGetGraphicsResetStatus, { "GetGraphicsResetStatus",
@@ -1154,7 +1167,13 @@ GLContext::LoadMoreSymbols(const char* prefix, bool trygl)
                                                                 nullptr } },
             END_SYMBOLS
         };
-        fnLoadForFeature(symbols, GLFeature::sync);
+        if (fnLoadForFeature(symbols, GLFeature::robustness)) {
+            const auto status = mSymbols.fGetGraphicsResetStatus();
+            MOZ_ALWAYS_TRUE(!status);
+
+            const auto err = mSymbols.fGetError();
+            MOZ_ALWAYS_TRUE(!err);
+        }
     }
 
     if (IsSupported(GLFeature::sync)) {
diff --git a/gfx/gl/GLDefs.h b/gfx/gl/GLDefs.h
index 10b6782e192f..a46c201b78df 100644
--- a/gfx/gl/GLDefs.h
+++ b/gfx/gl/GLDefs.h
@@ -81,7 +81,9 @@
 // Others
 #define LOCAL_EGL_PRESERVED_RESOURCES                   0x3030
 #define LOCAL_EGL_CONTEXT_RESET_NOTIFICATION_STRATEGY_EXT 0x3138
-#define LOCAL_GL_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB 0x8256
+#define LOCAL_GL_RESET_NOTIFICATION_STRATEGY            0x8256
+#define LOCAL_GL_LOSE_CONTEXT_ON_RESET                  0x8252
+#define LOCAL_GL_NO_RESET_NOTIFICATION                  0x8261
 #define LOCAL_GL_CONTEXT_LOST                           0x9242
 #define LOCAL_GL_CONTEXT_FLAGS_ARB                      0x2094
 #define LOCAL_GL_CONTEXT_CORE_PROFILE_BIT_ARB           0x00000001