Refactor linker allocator
Makes it reusable for different fixed sized and not very
big structures (<PAGE_SIZE).
Change-Id: Id5ec13fc6541b1935ef7fe3671c22b98685abbae
diff --git a/linker/linker_allocator.h b/linker/linker_allocator.h
new file mode 100644
index 0000000..e5b63c5
--- /dev/null
+++ b/linker/linker_allocator.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __LINKER_ALLOCATOR_H
+#define __LINKER_ALLOCATOR_H
+
+#include <stdlib.h>
+#include <limits.h>
+#include "private/bionic_macros.h"
+
+struct LinkerAllocatorPage;
+
+/*
+ * This class is a non-template version of the LinkerAllocator
+ * It keeps code inside .cpp file by keeping the interface
+ * template-free.
+ *
+ * Please use LinkerAllocator<type> where possible (everywhere).
+ */
+class LinkerBlockAllocator {
+ public:
+ LinkerBlockAllocator();
+
+ void init(size_t block_size);
+ void* alloc();
+ void free(void* block);
+ void protect_page(void* block, int prot);
+ void protect_all(int prot);
+
+ private:
+ void create_new_page();
+ LinkerAllocatorPage* find_page(void* block);
+
+ size_t block_size_;
+ LinkerAllocatorPage* page_list_;
+ void* free_block_list_;
+
+ DISALLOW_COPY_AND_ASSIGN(LinkerBlockAllocator);
+};
+
+/*
+ * A simple allocator for the dynamic linker. An allocator allocates instances
+ * of a single fixed-size type. Allocations are backed by page-sized private
+ * anonymous mmaps.
+ */
+template<typename T>
+class LinkerAllocator {
+ public:
+ LinkerAllocator() : block_allocator_() {}
+ void init() { block_allocator_.init(sizeof(T)); }
+ T* alloc() { return reinterpret_cast<T*>(block_allocator_.alloc()); }
+ void free(T* t) { block_allocator_.free(t); }
+ void protect_page(T* t, int prot) { block_allocator_.protect_page(t, prot); }
+ void protect_all(int prot) { block_allocator_.protect_all(prot); }
+ private:
+ LinkerBlockAllocator block_allocator_;
+ DISALLOW_COPY_AND_ASSIGN(LinkerAllocator);
+};
+#endif // __LINKER_ALLOCATOR_H