Merge branch 'cpp-11' into jgrpp

projects/openttd_vs100.vcxproj

@@ -694,6 +694,7 @@
     <ClCompile Include="..\src\core\bitmath_func.cpp" />
     <ClInclude Include="..\src\core\bitmath_func.hpp" />
     <ClInclude Include="..\src\core\container_func.hpp" />
+    <ClInclude Include="..\src\core\dyn_arena_alloc.hpp" />
     <ClInclude Include="..\src\core\endian_func.hpp" />
     <ClInclude Include="..\src\core\endian_type.hpp" />
     <ClInclude Include="..\src\core\enum_type.hpp" />

projects/openttd_vs100.vcxproj.filters

@@ -1314,6 +1314,9 @@
     <ClInclude Include="..\src\core\container_func.hpp">
       <Filter>Core Source Code</Filter>
     </ClInclude>
+    <ClInclude Include="..\src\core\dyn_arena_alloc.hpp">
+      <Filter>Core Source Code</Filter>
+    </ClInclude>
     <ClInclude Include="..\src\core\endian_func.hpp">
       <Filter>Core Source Code</Filter>
     </ClInclude>

projects/openttd_vs140.vcxproj

@@ -711,6 +711,7 @@
     <ClCompile Include="..\src\core\bitmath_func.cpp" />
     <ClInclude Include="..\src\core\bitmath_func.hpp" />
     <ClInclude Include="..\src\core\container_func.hpp" />
+    <ClInclude Include="..\src\core\dyn_arena_alloc.hpp" />
     <ClInclude Include="..\src\core\endian_func.hpp" />
     <ClInclude Include="..\src\core\endian_type.hpp" />
     <ClInclude Include="..\src\core\enum_type.hpp" />

projects/openttd_vs140.vcxproj.filters

@@ -1314,6 +1314,9 @@
     <ClInclude Include="..\src\core\container_func.hpp">
       <Filter>Core Source Code</Filter>
     </ClInclude>
+    <ClInclude Include="..\src\core\dyn_arena_alloc.hpp">
+      <Filter>Core Source Code</Filter>
+    </ClInclude>
     <ClInclude Include="..\src\core\endian_func.hpp">
       <Filter>Core Source Code</Filter>
     </ClInclude>

projects/openttd_vs80.vcproj

@@ -2054,6 +2054,10 @@
 				RelativePath=".\..\src\core\container_func.hpp"
 				>
 			</File>
+			<File
+				RelativePath=".\..\src\core\dyn_arena_alloc.hpp"
+				>
+			</File>
 			<File
 				RelativePath=".\..\src\core\endian_func.hpp"
 				>

projects/openttd_vs90.vcproj

@@ -2051,6 +2051,10 @@
 				RelativePath=".\..\src\core\container_func.hpp"
 				>
 			</File>
+			<File
+				RelativePath=".\..\src\core\dyn_arena_alloc.hpp"
+				>
+			</File>
 			<File
 				RelativePath=".\..\src\core\endian_func.hpp"
 				>

source.list

@@ -451,6 +451,7 @@ core/backup_type.hpp
 core/bitmath_func.cpp
 core/bitmath_func.hpp
 core/container_func.hpp
+core/dyn_arena_alloc.hpp
 core/endian_func.hpp
 core/endian_type.hpp
 core/enum_type.hpp

src/core/dyn_arena_alloc.hpp

@@ -0,0 +1,97 @@
+/* $Id$ */
+
+/*
+ * This file is part of OpenTTD.
+ * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
+ * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/** @file dyn_arena_alloc.hpp Dynamic chunk-size arena allocator. */
+
+#include <vector>
+
+/**
+ * Custom arena allocator for uniform-size allocations of a variable size.
+ * The allocation and chunk sizes may only be changed when the arena is empty.
+ */
+class DynUniformArenaAllocator {
+	std::vector<void *> used_blocks;
+
+	void *current_block = nullptr;
+	void *last_freed = nullptr;
+	size_t next_position = 0;
+
+	size_t item_size = 0;
+	size_t items_per_chunk = 0;
+
+	void NewBlock()
+	{
+		current_block = malloc(item_size * items_per_chunk);
+		assert(current_block != nullptr);
+		next_position = 0;
+		used_blocks.push_back(current_block);
+	}
+
+	public:
+	DynUniformArenaAllocator() = default;
+	DynUniformArenaAllocator(const DynUniformArenaAllocator &other) = delete;
+	DynUniformArenaAllocator& operator=(const DynUniformArenaAllocator &other) = delete;
+
+	~DynUniformArenaAllocator()
+	{
+		EmptyArena();
+	}
+
+	void EmptyArena()
+	{
+		current_block = nullptr;
+		last_freed = nullptr;
+		next_position = 0;
+		for (void *block : used_blocks) {
+			free(block);
+		}
+		used_blocks.clear();
+	}
+
+	void ResetArena()
+	{
+		EmptyArena();
+		item_size = 0;
+		items_per_chunk = 0;
+	}
+
+	void *Allocate() {
+		assert(item_size != 0);
+		if (last_freed) {
+			void *ptr = last_freed;
+			last_freed = *reinterpret_cast<void**>(ptr);
+			return ptr;
+		} else {
+			if (current_block == nullptr || next_position == items_per_chunk) {
+				NewBlock();
+			}
+			void *out = reinterpret_cast<char *>(current_block) + (item_size * next_position);
+			next_position++;
+			return out;
+		}
+	}
+
+	void Free(void *ptr) {
+		if (!ptr) return;
+		assert(current_block != nullptr);
+
+		*reinterpret_cast<void**>(ptr) = last_freed;
+		last_freed = ptr;
+	}
+
+	void SetParameters(size_t item_size, size_t items_per_chunk)
+	{
+		if (item_size < sizeof(void *)) item_size = sizeof(void *);
+		if (this->item_size == item_size && this->items_per_chunk == items_per_chunk) return;
+
+		assert(current_block == nullptr);
+		this->item_size = item_size;
+		this->items_per_chunk = items_per_chunk;
+	}
+};