From 93dacf53b5f30c3af566358d6411619a3386b90b Mon Sep 17 00:00:00 2001
From: Jeff Gilbert <jgilbert@mozilla.com>
Date: Wed, 20 Dec 2017 16:31:58 -0800
Subject: [PATCH] Bug 1425488 - Reset last fenceId on write to buffers. -
 r=lenzak

MozReview-Commit-ID: HwPpGWKNA9W
---
 dom/canvas/WebGL2ContextBuffers.cpp | 16 +++++++++-------
 dom/canvas/WebGLBuffer.cpp          | 10 ++++++++++
 dom/canvas/WebGLBuffer.h            |  4 +++-
 dom/canvas/WebGLContextDraw.cpp     |  4 ++++
 dom/canvas/WebGLContextGL.cpp       |  2 ++
 5 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/dom/canvas/WebGL2ContextBuffers.cpp b/dom/canvas/WebGL2ContextBuffers.cpp
index 7ee14b5e4319..0c83644e3695 100644
--- a/dom/canvas/WebGL2ContextBuffers.cpp
+++ b/dom/canvas/WebGL2ContextBuffers.cpp
@@ -86,6 +86,8 @@ WebGL2Context::CopyBufferSubData(GLenum readTarget, GLenum writeTarget,
     const ScopedLazyBind readBind(gl, readTarget, readBuffer);
     const ScopedLazyBind writeBind(gl, writeTarget, writeBuffer);
     gl->fCopyBufferSubData(readTarget, writeTarget, readOffset, writeOffset, size);
+
+    writeBuffer->ResetLastUpdateFenceId();
 }
 
 void
@@ -132,16 +134,16 @@ WebGL2Context::GetBufferSubData(GLenum target, GLintptr srcByteOffset,
     case LOCAL_GL_STREAM_READ:
     case LOCAL_GL_DYNAMIC_READ:
         if (mCompletedFenceId < buffer->mLastUpdateFenceId) {
-            GeneratePerfWarning("%s: Reading from a buffer without checking for previous"
-                                " command completion likely causes pipeline stalls."
-                                " Please use FenceSync.",
-                                funcName);
+            GenerateWarning("%s: Reading from a buffer without checking for previous"
+                            " command completion likely causes pipeline stalls."
+                            " Please use FenceSync.",
+                            funcName);
         }
         break;
     default:
-        GeneratePerfWarning("%s: Reading from a buffer with usage other than *_READ"
-                            " causes pipeline stalls. Copy through a STREAM_READ buffer.",
-                            funcName);
+        GenerateWarning("%s: Reading from a buffer with usage other than *_READ"
+                        " causes pipeline stalls. Copy through a STREAM_READ buffer.",
+                        funcName);
         break;
     }
 
diff --git a/dom/canvas/WebGLBuffer.cpp b/dom/canvas/WebGLBuffer.cpp
index ae8dce16f22e..2086eab1e22d 100644
--- a/dom/canvas/WebGLBuffer.cpp
+++ b/dom/canvas/WebGLBuffer.cpp
@@ -166,6 +166,8 @@ WebGLBuffer::BufferData(GLenum target, size_t size, const void* data, GLenum usa
             mIndexRanges.clear();
         }
     }
+
+    ResetLastUpdateFenceId();
 }
 
 void
@@ -197,6 +199,8 @@ WebGLBuffer::BufferSubData(GLenum target, size_t dstByteOffset, size_t dataLen,
     const ScopedLazyBind lazyBind(gl, target, this);
 
     gl->fBufferSubData(target, dstByteOffset, dataLen, uploadData);
+
+    ResetLastUpdateFenceId();
 }
 
 bool
@@ -409,6 +413,12 @@ WebGLBuffer::ValidateCanBindToTarget(const char* funcName, GLenum target)
     return false;
 }
 
+void
+WebGLBuffer::ResetLastUpdateFenceId() const
+{
+    mLastUpdateFenceId = mContext->mNextFenceId;
+}
+
 JSObject*
 WebGLBuffer::WrapObject(JSContext* cx, JS::Handle<JSObject*> givenProto)
 {
diff --git a/dom/canvas/WebGLBuffer.h b/dom/canvas/WebGLBuffer.h
index 1e5be35cc4f4..db4bf7344aef 100644
--- a/dom/canvas/WebGLBuffer.h
+++ b/dom/canvas/WebGLBuffer.h
@@ -105,7 +105,7 @@ protected:
     size_t mByteLength;
     size_t mTFBindCount;
     size_t mNonTFBindCount;
-    uint64_t mLastUpdateFenceId = 0;
+    mutable uint64_t mLastUpdateFenceId = 0;
 
     struct IndexRange final {
         GLenum type;
@@ -128,6 +128,8 @@ protected:
 
 public:
     CacheMapInvalidator mFetchInvalidator;
+
+    void ResetLastUpdateFenceId() const;
 };
 
 } // namespace mozilla
diff --git a/dom/canvas/WebGLContextDraw.cpp b/dom/canvas/WebGLContextDraw.cpp
index 22e114bfb5a5..410dc60e41ab 100644
--- a/dom/canvas/WebGLContextDraw.cpp
+++ b/dom/canvas/WebGLContextDraw.cpp
@@ -337,6 +337,10 @@ public:
                     *out_error = true;
                     return;
                 }
+
+                // Technically we don't know that this will be updated yet, but we can
+                // speculatively mark it.
+                buffer->ResetLastUpdateFenceId();
             }
         }
 
diff --git a/dom/canvas/WebGLContextGL.cpp b/dom/canvas/WebGLContextGL.cpp
index 3de322654f62..73251ba8462b 100644
--- a/dom/canvas/WebGLContextGL.cpp
+++ b/dom/canvas/WebGLContextGL.cpp
@@ -1423,6 +1423,8 @@ WebGLContext::ReadPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum
     const ScopedLazyBind lazyBind(gl, LOCAL_GL_PIXEL_PACK_BUFFER, buffer);
 
     ReadPixelsImpl(x, y, width, height, format, type, (void*)offset, bytesAfterOffset);
+
+    buffer->ResetLastUpdateFenceId();
 }
 
 static webgl::PackingInfo