Initialize buffers before allowing access to them.

gpu/command_buffer/service/buffer_manager.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GPU_COMMAND_BUFFER_SERVICE_BUFFER_MANAGER_H_
 #define GPU_COMMAND_BUFFER_SERVICE_BUFFER_MANAGER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 60 matching lines @@
   // count is in elements of type.
   bool GetMaxValueForRange(GLuint offset, GLsizei count, GLenum type,
                            bool primitive_restart_enabled, GLuint* max_value);
 
   // Returns a pointer to shadowed data.
   const void* GetRange(GLintptr offset, GLsizeiptr size) const;
 
   // Check if an offset, size range is valid for the current buffer.
   bool CheckRange(GLintptr offset, GLsizeiptr size) const;
 
-  // Sets a range of this buffer's shadowed data. Returns false if offset/size
-  // is out of range.
-  bool SetRange(GLintptr offset, GLsizeiptr size, const GLvoid * data);
+  // Sets a range of this buffer's shadowed data.
+  void SetRange(GLintptr offset, GLsizeiptr size, const GLvoid * data);
 
   bool IsDeleted() const {
     return deleted_;
   }
 
   bool IsValid() const {
     return initial_target() && !IsDeleted();
   }
 
   bool IsClientSideArray() const {
     return is_client_side_array_;
   }
 
   void SetMappedRange(GLintptr offset, GLsizeiptr size, GLenum access,
                       void* pointer, scoped_refptr<gpu::Buffer> shm,
-                      unsigned int shm_offset) {
-    mapped_range_.reset(
-        new MappedRange(offset, size, access, pointer, shm, shm_offset));
-  }
-
-  void RemoveMappedRange() {
-    mapped_range_.reset(nullptr);
-  }
-
+                      unsigned int shm_offset);
+  void RemoveMappedRange();
   const MappedRange* GetMappedRange() const {
     return mapped_range_.get();
   }
 
  private:
   friend class BufferManager;
   friend class BufferManagerTestBase;
   friend class base::RefCounted<Buffer>;
 
   // Represents a range in a buffer.
@@ skipping 181 matching lines @@
   bool UseNonZeroSizeForClientSideArrayBuffer();
 
   void SetPrimitiveRestartFixedIndexIfNecessary(GLenum type);
 
   Buffer* GetBufferInfoForTarget(ContextState* state, GLenum target) const;
 
   // base::trace_event::MemoryDumpProvider implementation.
   bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
                     base::trace_event::ProcessMemoryDump* pmd) override;
 
+  // Validate if a buffer is bound at target, if it's unmapped, if it's
+  // large enough. Return the buffer bound to |target| if access is granted;
+  // return nullptr if a GL error is generated.
+  Buffer* RequestBufferAccess(ContextState* context_state,
+                              GLenum target,
+                              GLintptr offset,
+                              GLsizeiptr size,
+                              const char* func_name);
+  // Same as above, but assume to access the entire buffer.
+  Buffer* RequestBufferAccess(ContextState* context_state,
+                              GLenum target,
+                              const char* func_name);
+  // Same as above, but it can be any buffer rather than the buffer bound to
+  // |target|. Return true if access is granted; return false if a GL error is
+  // generated.
+  bool RequestBufferAccess(ErrorState* error_state,
+                           Buffer* buffer,
+                           const char* func_name,
+                           const char* message_tag);
+
+  uint32_t mapped_buffer_count() const {

[piman, 2016/10/24 22:47:11]

nit: I didn't see being used. Is that for a follow-up?

+    return mapped_buffer_count_;
+  }
+
  private:
   friend class Buffer;
   friend class TestHelper;  // Needs access to DoBufferData.
   friend class BufferManagerTestBase;  // Needs access to DoBufferSubData.
   friend class IndexedBufferBindingHostTest;  // Needs access to SetInfo.
 
   void StartTracking(Buffer* buffer);
   void StopTracking(Buffer* buffer);
 
   // Does a glBufferSubData and updates the appropriate accounting.
   // Assumes the values have already been validated.
   void DoBufferSubData(
-      ErrorState* error_state,
       Buffer* buffer,
       GLenum target,
       GLintptr offset,
       GLsizeiptr size,
       const GLvoid* data);
 
   // Does a glBufferData and updates the appropriate accounting.
   // Assumes the values have already been validated.
   void DoBufferData(
       ErrorState* error_state,
@@ skipping 18 matching lines @@
   bool UseShadowBuffer(GLenum target, GLenum usage);
 
   // Sets the size, usage and initial data of a buffer.
   // If data is NULL buffer will be initialized to 0 if shadowed.
   void SetInfo(Buffer* buffer,
                GLenum target,
                GLsizeiptr size,
                GLenum usage,
                bool use_shadow);
 
+  void IncreaseMappedBufferCount();
+  void DecreaseMappedBufferCount();
+
   std::unique_ptr<MemoryTypeTracker> memory_type_tracker_;
   MemoryTracker* memory_tracker_;
   scoped_refptr<FeatureInfo> feature_info_;
 
   // Info for each buffer in the system.
   typedef base::hash_map<GLuint, scoped_refptr<Buffer> > BufferMap;
   BufferMap buffers_;
 
   // The maximum size of buffers.
   GLsizeiptr max_buffer_size_;
 
   // Whether or not buffers can be bound to multiple targets.
   bool allow_buffers_on_multiple_targets_;
 
   // Whether or not allow using GL_FIXED type for vertex attribs.
   bool allow_fixed_attribs_;
 
   // Counts the number of Buffer allocated with 'this' as its manager.
   // Allows to check no Buffer will outlive this.
   unsigned int buffer_count_;
 
   GLuint primitive_restart_fixed_index_;
 
   bool lost_context_;
   bool use_client_side_arrays_for_stream_buffers_;
 
+  // Keep track of total mapped buffer count. In most use cases it should be 0,
+  // so we could bypass checking each individual buffer as an optimization.
+  uint32_t mapped_buffer_count_;
+
   DISALLOW_COPY_AND_ASSIGN(BufferManager);
 };
 
 }  // namespace gles2
 }  // namespace gpu
 
 #endif  // GPU_COMMAND_BUFFER_SERVICE_BUFFER_MANAGER_H_