/* * ircd-ratbox: A slightly useful ircd. * balloc.c: A block allocator. * * Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center * Copyright (C) 1996-2002 Hybrid Development Team * Copyright (C) 2002-2006 ircd-ratbox development team * * Below are the orignal headers from the old blalloc.c * * File: blalloc.c * Owner: Wohali (Joan Touzet) * * Modified 2001/11/29 for mmap() support by Aaron Sethman * * This program 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; either version 2 of the License, or * (at your option) any later version. * * This program 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 this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 * USA * * $Id: balloc.c 26100 2008-09-20 01:27:19Z androsyn $ */ /* * About the block allocator * * Basically we have three ways of getting memory off of the operating * system. Below are this list of methods and the order of preference. * * 1. mmap() anonymous pages with the MMAP_ANON flag. * 2. mmap() via the /dev/zero trick. * 3. HeapCreate/HeapAlloc (on win32) * 4. malloc() * * The advantages of 1 and 2 are this. We can munmap() the pages which will * return the pages back to the operating system, thus reducing the size * of the process as the memory is unused. malloc() on many systems just keeps * a heap of memory to itself, which never gets given back to the OS, except on * exit. This of course is bad, if say we have an event that causes us to allocate * say, 200MB of memory, while our normal memory consumption would be 15MB. In the * malloc() case, the amount of memory allocated to our process never goes down, as * malloc() has it locked up in its heap. With the mmap() method, we can munmap() * the block and return it back to the OS, thus causing our memory consumption to go * down after we no longer need it. * * * */ #include #include static uintptr_t offset_pad; /* status information for an allocated block in heap */ struct rb_heap_block { size_t alloc_size; rb_dlink_node node; unsigned long free_count; void *elems; /* Points to allocated memory */ }; typedef struct rb_heap_block rb_heap_block; /* information for the root node of the heap */ struct rb_bh { rb_dlink_node hlist; size_t elemSize; /* Size of each element to be stored */ unsigned long elemsPerBlock; /* Number of elements per block */ rb_dlink_list block_list; rb_dlink_list free_list; char *desc; }; static rb_dlink_list *heap_lists; #define rb_bh_fail(x) _rb_bh_fail(x, __FILE__, __LINE__) static void _rb_bh_fail(const char *reason, const char *file, int line) { rb_lib_log("rb_heap_blockheap failure: %s (%s:%d)", reason, file, line); abort(); } /* * void rb_init_bh(void) * * Inputs: None * Outputs: None * Side Effects: Initializes the block heap */ void rb_init_bh(void) { heap_lists = rb_malloc(sizeof(rb_dlink_list)); offset_pad = sizeof(void *); /* XXX if you get SIGBUS when trying to use a long long..here is where you need to * fix your shit */ #ifdef __sparc__ if((offset_pad % __alignof__(long long)) != 0) { offset_pad += __alignof__(long long); offset_pad &= ~(__alignof__(long long) - 1); } #endif } /* ************************************************************************ */ /* FUNCTION DOCUMENTATION: */ /* rb_bh_create */ /* Description: */ /* Creates a new blockheap from which smaller blocks can be allocated. */ /* Intended to be used instead of multiple calls to malloc() when */ /* performance is an issue. */ /* Parameters: */ /* elemsize (IN): Size of the basic element to be stored */ /* elemsperblock (IN): Number of elements to be stored in a single block */ /* of memory. When the blockheap runs out of free memory, it will */ /* allocate elemsize * elemsperblock more. */ /* Returns: */ /* Pointer to new rb_bh, or NULL if unsuccessful */ /* ************************************************************************ */ rb_bh * rb_bh_create(size_t elemsize, int elemsperblock, const char *desc) { rb_bh *bh; lrb_assert(elemsize > 0 && elemsperblock > 0); lrb_assert(elemsize >= sizeof(rb_dlink_node)); /* Catch idiotic requests up front */ if((elemsize == 0) || (elemsperblock <= 0)) { rb_bh_fail("Attempting to rb_bh_create idiotic sizes"); } if(elemsize < sizeof(rb_dlink_node)) rb_bh_fail("Attempt to rb_bh_create smaller than sizeof(rb_dlink_node)"); /* Allocate our new rb_bh */ bh = rb_malloc(sizeof(rb_bh)); bh->elemSize = elemsize; bh->elemsPerBlock = elemsperblock; if(desc != NULL) bh->desc = rb_strdup(desc); if(bh == NULL) { rb_bh_fail("bh == NULL when it shouldn't be"); } rb_dlinkAdd(bh, &bh->hlist, heap_lists); return (bh); } /* ************************************************************************ */ /* FUNCTION DOCUMENTATION: */ /* rb_bh_alloc */ /* Description: */ /* Returns a pointer to a struct within our rb_bh that's free for */ /* the taking. */ /* Parameters: */ /* bh (IN): Pointer to the Blockheap. */ /* Returns: */ /* Pointer to a structure (void *), or NULL if unsuccessful. */ /* ************************************************************************ */ void * rb_bh_alloc(rb_bh *bh) { lrb_assert(bh != NULL); if(rb_unlikely(bh == NULL)) { rb_bh_fail("Cannot allocate if bh == NULL"); } return (rb_malloc(bh->elemSize)); } /* ************************************************************************ */ /* FUNCTION DOCUMENTATION: */ /* rb_bh_free */ /* Description: */ /* Returns an element to the free pool, does not free() */ /* Parameters: */ /* bh (IN): Pointer to rb_bh containing element */ /* ptr (in): Pointer to element to be "freed" */ /* Returns: */ /* 0 if successful, 1 if element not contained within rb_bh. */ /* ************************************************************************ */ int rb_bh_free(rb_bh *bh, void *ptr) { lrb_assert(bh != NULL); lrb_assert(ptr != NULL); if(rb_unlikely(bh == NULL)) { rb_lib_log("balloc.c:rb_bhFree() bh == NULL"); return (1); } if(rb_unlikely(ptr == NULL)) { rb_lib_log("balloc.rb_bhFree() ptr == NULL"); return (1); } rb_free(ptr); return (0); } /* ************************************************************************ */ /* FUNCTION DOCUMENTATION: */ /* rb_bhDestroy */ /* Description: */ /* Completely free()s a rb_bh. Use for cleanup. */ /* Parameters: */ /* bh (IN): Pointer to the rb_bh to be destroyed. */ /* Returns: */ /* 0 if successful, 1 if bh == NULL */ /* ************************************************************************ */ int rb_bh_destroy(rb_bh *bh) { if(bh == NULL) return (1); rb_dlinkDelete(&bh->hlist, heap_lists); rb_free(bh->desc); rb_free(bh); return (0); } void rb_bh_usage(rb_bh *bh, size_t *bused, size_t *bfree, size_t *bmemusage, const char **desc) { if(bused != NULL) *bused = 0; if(bfree != NULL) *bfree = 0; if(bmemusage != NULL) *bmemusage = 0; if(desc != NULL) *desc = "no blockheap"; } void rb_bh_usage_all(rb_bh_usage_cb *cb, void *data) { rb_dlink_node *ptr; rb_bh *bh; size_t used, freem, memusage, heapalloc; static const char *unnamed = "(unnamed_heap)"; const char *desc = unnamed; if(cb == NULL) return; RB_DLINK_FOREACH(ptr, heap_lists->head) { bh = (rb_bh *)ptr->data; freem = rb_dlink_list_length(&bh->free_list); used = (rb_dlink_list_length(&bh->block_list) * bh->elemsPerBlock) - freem; memusage = used * bh->elemSize; heapalloc = (freem + used) * bh->elemSize; if(bh->desc != NULL) desc = bh->desc; cb(used, freem, memusage, heapalloc, desc, data); } return; } void rb_bh_total_usage(size_t *total_alloc, size_t *total_used) { rb_dlink_node *ptr; size_t total_memory = 0, used_memory = 0, used, freem; rb_bh *bh; RB_DLINK_FOREACH(ptr, heap_lists->head) { bh = (rb_bh *)ptr->data; freem = rb_dlink_list_length(&bh->free_list); used = (rb_dlink_list_length(&bh->block_list) * bh->elemsPerBlock) - freem; used_memory += used * bh->elemSize; total_memory += (freem + used) * bh->elemSize; } if(total_alloc != NULL) *total_alloc = total_memory; if(total_used != NULL) *total_used = used_memory; }