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      1 /*
      2  * region-allocator.h -- region based memory allocator.
      3  *
      4  * Copyright (c) 2001-2006, NLnet Labs. All rights reserved.
      5  *
      6  * See LICENSE for the license.
      7  *
      8  */
      9 
     10 #ifndef REGION_ALLOCATOR_H
     11 #define REGION_ALLOCATOR_H
     12 
     13 #include <stdio.h>
     14 
     15 typedef struct region region_type;
     16 
     17 #define DEFAULT_CHUNK_SIZE         4096
     18 #define DEFAULT_LARGE_OBJECT_SIZE  (DEFAULT_CHUNK_SIZE / 8)
     19 #define DEFAULT_INITIAL_CLEANUP_SIZE 16
     20 
     21 
     22 /*
     23  * mmap allocator constants
     24  *
     25  */
     26 #ifdef USE_MMAP_ALLOC
     27 
     28 /* header starts with size_t containing allocated size info and has at least 16 bytes to align the returned memory */
     29 #define MMAP_ALLOC_HEADER_SIZE (sizeof(size_t) >= 16 ? (sizeof(size_t)) : 16)
     30 
     31 /* mmap allocator uses chunks of 32 4kB pages */
     32 #define MMAP_ALLOC_CHUNK_SIZE		((32 * 4096) - MMAP_ALLOC_HEADER_SIZE)
     33 #define MMAP_ALLOC_LARGE_OBJECT_SIZE	(MMAP_ALLOC_CHUNK_SIZE / 8)
     34 #define MMAP_ALLOC_INITIAL_CLEANUP_SIZE	16
     35 
     36 #endif /* USE_MMAP_ALLOC */
     37 
     38 /*
     39  * Create a new region.
     40  */
     41 region_type *region_create(void *(*allocator)(size_t),
     42 			   void (*deallocator)(void *));
     43 
     44 
     45 /*
     46  * Create a new region, with chunk size and large object size.
     47  * Note that large_object_size must be <= chunk_size.
     48  * Anything larger than the large object size is individually alloced.
     49  * large_object_size = chunk_size/8 is reasonable;
     50  * initial_cleanup_size is the number of preallocated ptrs for cleanups.
     51  * The cleanups are in a growing array, and it must start larger than zero.
     52  * If recycle is true, environmentally friendly memory recycling is be enabled.
     53  */
     54 region_type *region_create_custom(void *(*allocator)(size_t),
     55 				  void (*deallocator)(void *),
     56 				  size_t chunk_size,
     57 				  size_t large_object_size,
     58 				  size_t initial_cleanup_size,
     59 				  int recycle);
     60 
     61 
     62 /*
     63  * Destroy REGION.  All memory associated with REGION is freed as if
     64  * region_free_all was called.
     65  */
     66 void region_destroy(region_type *region);
     67 
     68 
     69 /*
     70  * Add a cleanup to REGION.  ACTION will be called with DATA as
     71  * parameter when the region is freed or destroyed.
     72  *
     73  * Returns 0 on failure.
     74  */
     75 size_t region_add_cleanup(region_type *region,
     76 			  void (*action)(void *),
     77 			  void *data);
     78 
     79 /*
     80  * Remove cleanup, both action and data must match exactly.
     81  */
     82 void region_remove_cleanup(region_type *region,
     83         void (*action)(void *), void *data);
     84 
     85 /*
     86  * Allocate SIZE bytes of memory inside REGION.  The memory is
     87  * deallocated when region_free_all is called for this region.
     88  */
     89 void *region_alloc(region_type *region, size_t size);
     90 
     91 /** Allocate array with integer overflow checks, in region */
     92 void *region_alloc_array(region_type *region, size_t num, size_t size);
     93 
     94 /*
     95  * Allocate SIZE bytes of memory inside REGION and copy INIT into it.
     96  * The memory is deallocated when region_free_all is called for this
     97  * region.
     98  */
     99 void *region_alloc_init(region_type *region, const void *init, size_t size);
    100 
    101 /**
    102  * Allocate array (with integer overflow check on sizes), and init with
    103  * the given array copied into it.  Allocated in the region
    104  */
    105 void *region_alloc_array_init(region_type *region, const void *init,
    106 	size_t num, size_t size);
    107 
    108 /*
    109  * Allocate SIZE bytes of memory inside REGION that are initialized to
    110  * 0.  The memory is deallocated when region_free_all is called for
    111  * this region.
    112  */
    113 void *region_alloc_zero(region_type *region, size_t size);
    114 
    115 /**
    116  * Allocate array (with integer overflow check on sizes), and zero it.
    117  * Allocated in the region.
    118  */
    119 void *region_alloc_array_zero(region_type *region, size_t num, size_t size);
    120 
    121 /*
    122  * Run the cleanup actions and free all memory associated with REGION.
    123  */
    124 void region_free_all(region_type *region);
    125 
    126 
    127 /*
    128  * Duplicate STRING and allocate the result in REGION.
    129  */
    130 char *region_strdup(region_type *region, const char *string);
    131 
    132 /*
    133  * Replace a string on the to_replace location, if string is different
    134  */
    135 void region_str_replace(region_type* region, char **to_replace,
    136 		const char *string);
    137 /*
    138  * Recycle an allocated memory block. Pass size used to alloc it.
    139  * Does nothing if recycling is not enabled for the region.
    140  */
    141 void region_recycle(region_type *region, void *block, size_t size);
    142 
    143 /*
    144  * Print some REGION statistics to OUT.
    145  */
    146 void region_dump_stats(region_type *region, FILE *out);
    147 
    148 /* get size of recyclebin */
    149 size_t region_get_recycle_size(region_type* region);
    150 /* get size of region memory in use */
    151 size_t region_get_mem(region_type* region);
    152 /* get size of region memory unused */
    153 size_t region_get_mem_unused(region_type* region);
    154 
    155 /* Debug print REGION statistics to LOG. */
    156 void region_log_stats(region_type *region);
    157 
    158 #endif /* REGION_ALLOCATOR_H */
    159