Add some basic Pool-allocation infrastructure. This adds a Recycler class,

for handling bookkeeping for deleted objects, as well as the alist class
template, for keeping lists of objects allocated from Recyclers, and some
related utilities.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53210 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 60 insertions, 0 deletions

diff --git a/include/llvm/Support/RecyclingAllocator.h b/include/llvm/Support/RecyclingAllocator.h
new file mode 100644
index 0000000000..a338c0eb63
--- /dev/null
+++ b/include/llvm/Support/RecyclingAllocator.h
@@ -0,0 +1,60 @@
+//==- llvm/Support/RecyclingAllocator.h - Recycling Allocator ----*- C++ -*-==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the RecyclingAllocator class.  See the doxygen comment for
+// RecyclingAllocator for more details on the implementation.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SUPPORT_RECYCLINGALLOCATOR_H
+#define LLVM_SUPPORT_RECYCLINGALLOCATOR_H
+
+#include <cassert>
+#include "llvm/Support/Recycler.h"
+#include "llvm/ADT/STLExtras.h"
+
+namespace llvm {
+
+/// RecyclingAllocator - This class wraps an Allocator, adding the
+/// functionality of recycling deleted objects.
+///
+template<class AllocatorType, class T, class LargestT = T>
+class RecyclingAllocator {
+private:
+  /// Base - Implementation details.
+  ///
+  Recycler<T, LargestT> Base;
+
+  /// Allocator - The wrapped allocator.
+  ///
+  AllocatorType Allocator;
+
+public:
+  ~RecyclingAllocator() { Base.clear(Allocator); }
+
+  /// Allocate - Return a pointer to storage for an object of type
+  /// SubClass. The storage may be either newly allocated or recycled.
+  ///
+  template<class SubClass>
+  SubClass *Allocate() { return Base.Allocate<SubClass>(Allocator); }
+
+  T *Allocate() { return Base.Allocate(Allocator); }
+
+  /// Deallocate - Release storage for the pointed-to object. The
+  /// storage will be kept track of and may be recycled.
+  ///
+  template<class SubClass>
+  void Deallocate(SubClass* E) { return Base.Deallocate(Allocator, E); }
+
+  void PrintStats() { Base.PrintStats(); }
+};
+
+}
+
+#endif