kc3-lang/angle/src/libANGLE/HandleAllocator.h

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• Author : Jamie Madill
  Date : 2018-01-03 13:46:21
  Hash : fc3463da
  Message : HandleAllocator: Fix heap ordering using std::greater. The default heap ordering is to return the greatest element in the heap. Since the handle allocator expects a minimal return value on a new allocation, this caused a bug. The bug is triggered by reserving handles, allocating new handles, then freeing the handles and allocating again with the same allocator. Fix the bug by using std::greater instead of std::less, which will make the heap return the smallest value instead of largest. Also adds some logging debugging code for the handle allocators. Bug: angleproject:1458 Change-Id: Ibef5dcbed0a664ccad0e0335f081e2355162584b Reviewed-on: https://chromium-review.googlesource.com/848644 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Frank Henigman <fjhenigman@chromium.org>

• src/libANGLE/HandleAllocator.h

• //
  // Copyright (c) 2002-2011 The ANGLE Project Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  //
  
  // HandleAllocator.h: Defines the gl::HandleAllocator class, which is used to
  // allocate GL handles.
  
  #ifndef LIBANGLE_HANDLEALLOCATOR_H_
  #define LIBANGLE_HANDLEALLOCATOR_H_
  
  #include "common/angleutils.h"
  
  #include "angle_gl.h"
  
  namespace gl
  {
  
  class HandleAllocator final : angle::NonCopyable
  {
    public:
      // Maximum handle = MAX_UINT-1
      HandleAllocator();
      // Specify maximum handle value. Used for testing.
      HandleAllocator(GLuint maximumHandleValue);
  
      ~HandleAllocator();
  
      void setBaseHandle(GLuint value);
  
      GLuint allocate();
      void release(GLuint handle);
      void reserve(GLuint handle);
      void reset();
  
      void enableLogging(bool enabled);
  
    private:
      GLuint mBaseValue;
      GLuint mNextValue;
      typedef std::vector<GLuint> HandleList;
      HandleList mFreeValues;
  
      // Represents an inclusive range [begin, end]
      struct HandleRange
      {
          HandleRange(GLuint beginIn, GLuint endIn) : begin(beginIn), end(endIn) {}
  
          GLuint begin;
          GLuint end;
      };
  
      struct HandleRangeComparator;
  
      // The freelist consists of never-allocated handles, stored
      // as ranges, and handles that were previously allocated and
      // released, stored in a heap.
      std::vector<HandleRange> mUnallocatedList;
      std::vector<GLuint> mReleasedList;
  
      bool mLoggingEnabled;
  };
  
  }  // namespace gl
  
  #endif   // LIBANGLE_HANDLEALLOCATOR_H_