upload android base code part3

android/bionic/linker/linker_allocator.h

@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef __LINKER_ALLOCATOR_H
+#define __LINKER_ALLOCATOR_H
+
+#include <stdlib.h>
+#include <sys/cdefs.h>
+#include <sys/mman.h>
+#include <stddef.h>
+#include <unistd.h>
+
+#include <vector>
+
+#include <async_safe/log.h>
+
+#include "private/bionic_prctl.h"
+
+const uint32_t kSmallObjectMaxSizeLog2 = 10;
+const uint32_t kSmallObjectMinSizeLog2 = 4;
+const uint32_t kSmallObjectAllocatorsCount = kSmallObjectMaxSizeLog2 - kSmallObjectMinSizeLog2 + 1;
+
+class LinkerSmallObjectAllocator;
+
+// This structure is placed at the beginning of each addressable page
+// and has all information we need to find the corresponding memory allocator.
+struct page_info {
+  char signature[4];
+  uint32_t type;
+  union {
+    // we use allocated_size for large objects allocator
+    size_t allocated_size;
+    // and allocator_addr for small ones.
+    LinkerSmallObjectAllocator* allocator_addr;
+  };
+} __attribute__((aligned(16)));
+
+struct small_object_page_record {
+  void* page_addr;
+  size_t free_blocks_cnt;
+  size_t allocated_blocks_cnt;
+};
+
+// for lower_bound...
+bool operator<(const small_object_page_record& one, const small_object_page_record& two);
+
+struct small_object_block_record {
+  small_object_block_record* next;
+  size_t free_blocks_cnt;
+};
+
+// This is implementation for std::vector allocator
+template <typename T>
+class linker_vector_allocator {
+ public:
+  typedef T value_type;
+  typedef T* pointer;
+  typedef const T* const_pointer;
+  typedef T& reference;
+  typedef const T& const_reference;
+  typedef size_t size_type;
+  typedef ptrdiff_t difference_type;
+
+  T* allocate(size_t n, const T* hint = nullptr) {
+    size_t size = n * sizeof(T);
+    void* ptr = mmap(const_cast<T*>(hint), size,
+        PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);
+    if (ptr == MAP_FAILED) {
+      // Spec says we need to throw std::bad_alloc here but because our
+      // code does not support exception handling anyways - we are going to abort.
+      async_safe_fatal("mmap failed");
+    }
+
+    prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, ptr, size, "linker_alloc_vector");
+
+    return reinterpret_cast<T*>(ptr);
+  }
+
+  void deallocate(T* ptr, size_t n) {
+    munmap(ptr, n * sizeof(T));
+  }
+};
+
+typedef
+    std::vector<small_object_page_record, linker_vector_allocator<small_object_page_record>>
+    linker_vector_t;
+
+
+class LinkerSmallObjectAllocator {
+ public:
+  LinkerSmallObjectAllocator(uint32_t type, size_t block_size);
+  void* alloc();
+  void free(void* ptr);
+
+  size_t get_block_size() const { return block_size_; }
+ private:
+  void alloc_page();
+  void free_page(linker_vector_t::iterator page_record);
+  linker_vector_t::iterator find_page_record(void* ptr);
+  void create_page_record(void* page_addr, size_t free_blocks_cnt);
+
+  uint32_t type_;
+  size_t block_size_;
+
+  size_t free_pages_cnt_;
+  small_object_block_record* free_blocks_list_;
+
+  // sorted vector of page records
+  linker_vector_t page_records_;
+};
+
+class LinkerMemoryAllocator {
+ public:
+  constexpr LinkerMemoryAllocator() : allocators_(nullptr), allocators_buf_() {}
+  void* alloc(size_t size);
+
+  // Note that this implementation of realloc never shrinks allocation
+  void* realloc(void* ptr, size_t size);
+  void free(void* ptr);
+ private:
+  void* alloc_mmap(size_t size);
+  page_info* get_page_info(void* ptr);
+  LinkerSmallObjectAllocator* get_small_object_allocator(uint32_t type);
+  void initialize_allocators();
+
+  LinkerSmallObjectAllocator* allocators_;
+  uint8_t allocators_buf_[sizeof(LinkerSmallObjectAllocator)*kSmallObjectAllocatorsCount];
+};
+
+
+#endif  /* __LINKER_ALLOCATOR_H */