/* * 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 #ifndef NOBALLOC #ifdef HAVE_MMAP /* We've got mmap() that is good */ #include /* HP-UX sucks */ #ifdef MAP_ANONYMOUS #ifndef MAP_ANON #define MAP_ANON MAP_ANONYMOUS #endif #endif #endif #endif 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; }; #ifndef NOBALLOC static int newblock(rb_bh *bh); static void rb_bh_gc_event(void *unused); #endif /* !NOBALLOC */ static rb_dlink_list *heap_lists; #if defined(WIN32) static HANDLE block_heap; #endif #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(); } #ifndef NOBALLOC /* * static inline void free_block(void *ptr, size_t size) * * Inputs: The block and its size * Output: None * Side Effects: Returns memory for the block back to the OS */ static inline void free_block(void *ptr, size_t size) { #ifdef HAVE_MMAP munmap(ptr, size); #else #ifdef _WIN32 HeapFree(block_heap, 0, ptr); #else free(ptr); #endif #endif } #endif /* !NOBALLOC */ /* * 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 #ifndef NOBALLOC #ifdef _WIN32 block_heap = HeapCreate(HEAP_NO_SERIALIZE, 0, 0); #endif rb_event_addish("rb_bh_gc_event", rb_bh_gc_event, NULL, 300); #endif /* !NOBALLOC */ } #ifndef NOBALLOC /* * static inline void *get_block(size_t size) * * Input: Size of block to allocate * Output: Pointer to new block * Side Effects: None */ static inline void * get_block(size_t size) { void *ptr; #ifdef HAVE_MMAP #ifdef MAP_ANON ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); #else int zero_fd; zero_fd = open("/dev/zero", O_RDWR); if(zero_fd < 0) rb_bh_fail("Failed opening /dev/zero"); ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, zero_fd, 0); close(zero_fd); #endif /* MAP_ANON */ if(ptr == MAP_FAILED) ptr = NULL; #else #ifdef _WIN32 ptr = HeapAlloc(block_heap, 0, size); #else ptr = malloc(size); #endif #endif return (ptr); } static void rb_bh_gc_event(void *unused) { rb_dlink_node *ptr; RB_DLINK_FOREACH(ptr, heap_lists->head) { rb_bh_gc(ptr->data); } } /* ************************************************************************ */ /* FUNCTION DOCUMENTATION: */ /* newblock */ /* Description: */ /* Allocates a new block for addition to a blockheap */ /* Parameters: */ /* bh (IN): Pointer to parent blockheap. */ /* Returns: */ /* 0 if successful, 1 if not */ /* ************************************************************************ */ static int newblock(rb_bh *bh) { rb_heap_block *b; unsigned long i; uintptr_t offset; rb_dlink_node *node; /* Setup the initial data structure. */ b = rb_malloc(sizeof(rb_heap_block)); b->alloc_size = bh->elemsPerBlock * bh->elemSize; b->elems = get_block(b->alloc_size); if(rb_unlikely(b->elems == NULL)) { return (1); } offset = (uintptr_t)b->elems; /* Setup our blocks now */ for(i = 0; i < bh->elemsPerBlock; i++, offset += bh->elemSize) { *((void **)offset) = b; node = (void *)(offset + offset_pad); rb_dlinkAdd((void *)offset, node, &bh->free_list); } rb_dlinkAdd(b, &b->node, &bh->block_list); b->free_count = bh->elemsPerBlock; return (0); } #endif /* !NOBALLOC */ /* ************************************************************************ */ /* 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)); #ifndef NOBALLOC elemsize += offset_pad; if((elemsize % sizeof(void *)) != 0) { /* Pad to even pointer boundary */ elemsize += sizeof(void *); elemsize &= ~(sizeof(void *) - 1); } #endif bh->elemSize = elemsize; bh->elemsPerBlock = elemsperblock; if(desc != NULL) bh->desc = rb_strdup(desc); #ifndef NOBALLOC /* Be sure our malloc was successful */ if(newblock(bh)) { if(bh != NULL) free(bh); rb_lib_log("newblock() failed"); rb_outofmemory(); /* die.. out of memory */ } #endif /* !NOBALLOC */ 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) { #ifndef NOBALLOC rb_dlink_node *new_node; rb_heap_block **block; void *ptr; #endif lrb_assert(bh != NULL); if(rb_unlikely(bh == NULL)) { rb_bh_fail("Cannot allocate if bh == NULL"); } #ifdef NOBALLOC return (rb_malloc(bh->elemSize)); #else if(bh->free_list.head == NULL) { /* Allocate new block and assign */ /* newblock returns 1 if unsuccessful, 0 if not */ if(rb_unlikely(newblock(bh))) { rb_lib_log("newblock() failed"); rb_outofmemory(); /* Well that didn't work either...bail */ } if(bh->free_list.head == NULL) { rb_lib_log("out of memory after newblock()..."); rb_outofmemory(); } } new_node = bh->free_list.head; block = (rb_heap_block **) new_node->data; ptr = (void *)((uintptr_t)new_node->data + (uintptr_t)offset_pad); rb_dlinkDelete(new_node, &bh->free_list); (*block)->free_count--; memset(ptr, 0, bh->elemSize - offset_pad); return (ptr); #endif } /* ************************************************************************ */ /* 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) { #ifndef NOBALLOC rb_heap_block *block; void *data; #endif 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); } #ifdef NOBALLOC rb_free(ptr); #else data = (void *)((uintptr_t)ptr - (uintptr_t)offset_pad); block = *(rb_heap_block **) data; /* XXX */ if(rb_unlikely (!((uintptr_t)ptr >= (uintptr_t)block->elems && (uintptr_t)ptr < (uintptr_t)block->elems + (uintptr_t)block->alloc_size))) { rb_bh_fail("rb_bh_free() bogus pointer"); } block->free_count++; rb_dlinkAdd(data, (rb_dlink_node *)ptr, &bh->free_list); #endif /* !NOBALLOC */ 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) { #ifndef NOBALLOC rb_dlink_node *ptr, *next; rb_heap_block *b; #endif if(bh == NULL) return (1); #ifndef NOBALLOC RB_DLINK_FOREACH_SAFE(ptr, next, bh->block_list.head) { b = ptr->data; free_block(b->elems, b->alloc_size); rb_free(b); } #endif /* !NOBALLOC */ 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) { #ifndef NOBALLOC size_t used, freem, memusage; if(bh == NULL) { return; } freem = rb_dlink_list_length(&bh->free_list); used = (rb_dlink_list_length(&bh->block_list) * bh->elemsPerBlock) - freem; memusage = used * bh->elemSize; if(bused != NULL) *bused = used; if(bfree != NULL) *bfree = freem; if(bmemusage != NULL) *bmemusage = memusage; if(desc != NULL) *desc = bh->desc; #else if(bused != NULL) *bused = 0; if(bfree != NULL) *bfree = 0; if(bmemusage != NULL) *bmemusage = 0; if(desc != NULL) *desc = "no blockheap"; #endif } 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; } #ifndef NOBALLOC int rb_bh_gc(rb_bh *bh) { rb_heap_block *b; rb_dlink_node *ptr, *next; unsigned long i; uintptr_t offset; if(bh == NULL) { /* somebody is smoking some craq..(probably lee, but don't tell him that) */ return (1); } if((rb_dlink_list_length(&bh->free_list) < bh->elemsPerBlock) || rb_dlink_list_length(&bh->block_list) == 1) { /* There couldn't possibly be an entire free block. Return. */ return (0); } RB_DLINK_FOREACH_SAFE(ptr, next, bh->block_list.head) { b = ptr->data; if(rb_dlink_list_length(&bh->block_list) == 1) return (0); if(b->free_count == bh->elemsPerBlock) { /* i'm seriously going to hell for this.. */ offset = (uintptr_t)b->elems; for(i = 0; i < bh->elemsPerBlock; i++, offset += (uintptr_t)bh->elemSize) { rb_dlinkDelete((rb_dlink_node *)(offset + offset_pad), &bh->free_list); } rb_dlinkDelete(&b->node, &bh->block_list); free_block(b->elems, b->alloc_size); rb_free(b); } } return (0); } #endif /* !NOBALLOC */