1 2 /*--------------------------------------------------------------------*/ 3 /*--- A simple pool (memory) allocator. pub_tool_poolalloc.h ---*/ 4 /*--------------------------------------------------------------------*/ 5 6 /* 7 This file is part of Valgrind, a dynamic binary instrumentation 8 framework. 9 10 Copyright (C) 2011-2013 OpenWorks LLP info (at) open-works.co.uk, 11 Philippe Waroquiers philippe.waroquiers (at) skynet.be 12 13 This program is free software; you can redistribute it and/or 14 modify it under the terms of the GNU General Public License as 15 published by the Free Software Foundation; either version 2 of the 16 License, or (at your option) any later version. 17 18 This program is distributed in the hope that it will be useful, but 19 WITHOUT ANY WARRANTY; without even the implied warranty of 20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 21 General Public License for more details. 22 23 You should have received a copy of the GNU General Public License 24 along with this program; if not, write to the Free Software 25 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 26 02111-1307, USA. 27 28 The GNU General Public License is contained in the file COPYING. 29 */ 30 31 #ifndef __PUB_TOOL_POOLALLOC_H 32 #define __PUB_TOOL_POOLALLOC_H 33 34 #include "pub_tool_basics.h" // UWord 35 36 //-------------------------------------------------------------------- 37 // PURPOSE: Provides efficient allocation and free of elements of 38 // the same size. 39 // This pool allocator manages elements alloc/free by allocating 40 // "pools" of many elements from a lower level allocator (typically 41 // pub_tool_mallocfree.h). 42 // Single elements can then be allocated and released from these pools. 43 // A pool allocator is faster and has less memory overhead than 44 // calling directly pub_tool_mallocfree.h 45 // Note: the pools of elements are not freed, even if all the 46 // single elements have been freed. The only way to free the underlying 47 // pools of elements is to delete the pool allocator. 48 //-------------------------------------------------------------------- 49 50 51 typedef struct _PoolAlloc PoolAlloc; 52 53 /* Create new PoolAlloc, using given allocation and free function, and 54 for elements of the specified size. Alloc fn must not fail (that 55 is, if it returns it must have succeeded.) */ 56 PoolAlloc* VG_(newPA) ( UWord elemSzB, 57 UWord nPerPool, 58 void* (*alloc)(const HChar*, SizeT), 59 const HChar* cc, 60 void (*free_fn)(void*) ); 61 62 63 /* Free all memory associated with a PoolAlloc. */ 64 extern void VG_(deletePA) ( PoolAlloc* pa); 65 66 /* Allocates an element from pa. */ 67 extern void* VG_(allocEltPA) ( PoolAlloc* pa); 68 69 /* Free element of pa. */ 70 extern void VG_(freeEltPA) ( PoolAlloc* pa, void* p); 71 72 /* A pool allocator can be shared between multiple data structures. 73 For example, multiple OSet* can allocate/free nodes from the same 74 pool allocator. 75 The Pool Allocator provides support to use a ref counter 76 to detect a pool allocator is not needed anymore. 77 It is the caller responsibility to call VG_(addRefPA) for 78 each new reference to a pool and VG_(releasePA) when such a reference 79 disappears. 80 VG_(releasePA) will automatically call VG_(deletePA) 81 to delete the PA when the ref counter drops to 0. */ 82 83 // VG_(addRefPA) indicates there is a new reference to pa. 84 extern void VG_(addRefPA) ( PoolAlloc* pa); 85 86 // VG_(releasePA) decrements the pa reference count and deletes the pa if that 87 // reference count has dropped to zero. Returns the new value of the reference 88 // count. 89 extern UWord VG_(releasePA) ( PoolAlloc* pa); 90 91 #endif // __PUB_TOOL_POOLALLOC_ 92 93 /*--------------------------------------------------------------------*/ 94 /*--- end pub_tool_poolalloc.h ---*/ 95 /*--------------------------------------------------------------------*/ 96
