600 lines
16 KiB
C
600 lines
16 KiB
C
/*
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* ircd-ratbox: A slightly useful ircd.
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* balloc.c: A block allocator.
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*
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* Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
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* Copyright (C) 1996-2002 Hybrid Development Team
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* Copyright (C) 2002-2006 ircd-ratbox development team
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*
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* Below are the orignal headers from the old blalloc.c
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*
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* File: blalloc.c
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* Owner: Wohali (Joan Touzet)
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*
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* Modified 2001/11/29 for mmap() support by Aaron Sethman <androsyn@ratbox.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
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* USA
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*
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* $Id: balloc.c 26100 2008-09-20 01:27:19Z androsyn $
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*/
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/*
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* About the block allocator
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*
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* Basically we have three ways of getting memory off of the operating
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* system. Below are this list of methods and the order of preference.
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*
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* 1. mmap() anonymous pages with the MMAP_ANON flag.
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* 2. mmap() via the /dev/zero trick.
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* 3. HeapCreate/HeapAlloc (on win32)
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* 4. malloc()
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*
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* The advantages of 1 and 2 are this. We can munmap() the pages which will
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* return the pages back to the operating system, thus reducing the size
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* of the process as the memory is unused. malloc() on many systems just keeps
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* a heap of memory to itself, which never gets given back to the OS, except on
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* exit. This of course is bad, if say we have an event that causes us to allocate
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* say, 200MB of memory, while our normal memory consumption would be 15MB. In the
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* malloc() case, the amount of memory allocated to our process never goes down, as
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* malloc() has it locked up in its heap. With the mmap() method, we can munmap()
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* the block and return it back to the OS, thus causing our memory consumption to go
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* down after we no longer need it.
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*
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*
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*
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*/
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#include <libratbox_config.h>
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#include <ratbox_lib.h>
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#ifndef NOBALLOC
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#ifdef HAVE_MMAP /* We've got mmap() that is good */
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#include <sys/mman.h>
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/* HP-UX sucks */
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#ifdef MAP_ANONYMOUS
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#ifndef MAP_ANON
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#define MAP_ANON MAP_ANONYMOUS
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#endif
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#endif
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#endif
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#endif
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static uintptr_t offset_pad;
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/* status information for an allocated block in heap */
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struct rb_heap_block
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{
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size_t alloc_size;
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rb_dlink_node node;
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unsigned long free_count;
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void *elems; /* Points to allocated memory */
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};
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typedef struct rb_heap_block rb_heap_block;
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/* information for the root node of the heap */
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struct rb_bh
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{
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rb_dlink_node hlist;
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size_t elemSize; /* Size of each element to be stored */
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unsigned long elemsPerBlock; /* Number of elements per block */
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rb_dlink_list block_list;
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rb_dlink_list free_list;
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char *desc;
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};
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#ifndef NOBALLOC
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static int newblock(rb_bh *bh);
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static void rb_bh_gc_event(void *unused);
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#endif /* !NOBALLOC */
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static rb_dlink_list *heap_lists;
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#if defined(WIN32)
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static HANDLE block_heap;
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#endif
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#define rb_bh_fail(x) _rb_bh_fail(x, __FILE__, __LINE__)
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static void
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_rb_bh_fail(const char *reason, const char *file, int line)
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{
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rb_lib_log("rb_heap_blockheap failure: %s (%s:%d)", reason, file, line);
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abort();
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}
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#ifndef NOBALLOC
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/*
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* static inline void free_block(void *ptr, size_t size)
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*
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* Inputs: The block and its size
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* Output: None
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* Side Effects: Returns memory for the block back to the OS
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*/
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static inline void
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free_block(void *ptr, size_t size)
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{
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#ifdef HAVE_MMAP
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munmap(ptr, size);
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#else
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#ifdef _WIN32
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HeapFree(block_heap, 0, ptr);
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#else
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free(ptr);
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#endif
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#endif
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}
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#endif /* !NOBALLOC */
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/*
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* void rb_init_bh(void)
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*
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* Inputs: None
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* Outputs: None
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* Side Effects: Initializes the block heap
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*/
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void
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rb_init_bh(void)
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{
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heap_lists = rb_malloc(sizeof(rb_dlink_list));
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offset_pad = sizeof(void *);
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/* XXX if you get SIGBUS when trying to use a long long..here is where you need to
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* fix your shit
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*/
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#ifdef __sparc__
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if((offset_pad % __alignof__(long long)) != 0)
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{
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offset_pad += __alignof__(long long);
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offset_pad &= ~(__alignof__(long long) - 1);
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}
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#endif
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#ifndef NOBALLOC
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#ifdef _WIN32
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block_heap = HeapCreate(HEAP_NO_SERIALIZE, 0, 0);
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#endif
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rb_event_addish("rb_bh_gc_event", rb_bh_gc_event, NULL, 300);
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#endif /* !NOBALLOC */
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}
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#ifndef NOBALLOC
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/*
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* static inline void *get_block(size_t size)
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*
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* Input: Size of block to allocate
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* Output: Pointer to new block
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* Side Effects: None
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*/
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static inline void *
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get_block(size_t size)
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{
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void *ptr;
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#ifdef HAVE_MMAP
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#ifdef MAP_ANON
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ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
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#else
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int zero_fd;
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zero_fd = open("/dev/zero", O_RDWR);
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if(zero_fd < 0)
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rb_bh_fail("Failed opening /dev/zero");
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ptr = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, zero_fd, 0);
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close(zero_fd);
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#endif /* MAP_ANON */
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if(ptr == MAP_FAILED)
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ptr = NULL;
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#else
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#ifdef _WIN32
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ptr = HeapAlloc(block_heap, 0, size);
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#else
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ptr = malloc(size);
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#endif
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#endif
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return (ptr);
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}
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static void
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rb_bh_gc_event(void *unused)
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{
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rb_dlink_node *ptr;
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RB_DLINK_FOREACH(ptr, heap_lists->head)
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{
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rb_bh_gc(ptr->data);
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}
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}
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/* ************************************************************************ */
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/* FUNCTION DOCUMENTATION: */
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/* newblock */
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/* Description: */
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/* Allocates a new block for addition to a blockheap */
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/* Parameters: */
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/* bh (IN): Pointer to parent blockheap. */
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/* Returns: */
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/* 0 if successful, 1 if not */
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/* ************************************************************************ */
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static int
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newblock(rb_bh *bh)
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{
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rb_heap_block *b;
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unsigned long i;
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uintptr_t offset;
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rb_dlink_node *node;
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/* Setup the initial data structure. */
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b = rb_malloc(sizeof(rb_heap_block));
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b->alloc_size = bh->elemsPerBlock * bh->elemSize;
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b->elems = get_block(b->alloc_size);
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if(rb_unlikely(b->elems == NULL))
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{
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return (1);
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}
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offset = (uintptr_t)b->elems;
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/* Setup our blocks now */
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for(i = 0; i < bh->elemsPerBlock; i++, offset += bh->elemSize)
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{
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*((void **)offset) = b;
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node = (void *)(offset + offset_pad);
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rb_dlinkAdd((void *)offset, node, &bh->free_list);
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}
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rb_dlinkAdd(b, &b->node, &bh->block_list);
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b->free_count = bh->elemsPerBlock;
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return (0);
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}
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#endif /* !NOBALLOC */
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/* ************************************************************************ */
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/* FUNCTION DOCUMENTATION: */
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/* rb_bh_create */
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/* Description: */
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/* Creates a new blockheap from which smaller blocks can be allocated. */
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/* Intended to be used instead of multiple calls to malloc() when */
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/* performance is an issue. */
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/* Parameters: */
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/* elemsize (IN): Size of the basic element to be stored */
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/* elemsperblock (IN): Number of elements to be stored in a single block */
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/* of memory. When the blockheap runs out of free memory, it will */
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/* allocate elemsize * elemsperblock more. */
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/* Returns: */
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/* Pointer to new rb_bh, or NULL if unsuccessful */
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/* ************************************************************************ */
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rb_bh *
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rb_bh_create(size_t elemsize, int elemsperblock, const char *desc)
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{
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rb_bh *bh;
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lrb_assert(elemsize > 0 && elemsperblock > 0);
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lrb_assert(elemsize >= sizeof(rb_dlink_node));
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/* Catch idiotic requests up front */
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if((elemsize == 0) || (elemsperblock <= 0))
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{
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rb_bh_fail("Attempting to rb_bh_create idiotic sizes");
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}
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if(elemsize < sizeof(rb_dlink_node))
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rb_bh_fail("Attempt to rb_bh_create smaller than sizeof(rb_dlink_node)");
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/* Allocate our new rb_bh */
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bh = rb_malloc(sizeof(rb_bh));
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#ifndef NOBALLOC
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elemsize += offset_pad;
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if((elemsize % sizeof(void *)) != 0)
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{
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/* Pad to even pointer boundary */
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elemsize += sizeof(void *);
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elemsize &= ~(sizeof(void *) - 1);
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}
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#endif
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bh->elemSize = elemsize;
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bh->elemsPerBlock = elemsperblock;
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if(desc != NULL)
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bh->desc = rb_strdup(desc);
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#ifndef NOBALLOC
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/* Be sure our malloc was successful */
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if(newblock(bh))
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{
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if(bh != NULL)
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free(bh);
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rb_lib_log("newblock() failed");
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rb_outofmemory(); /* die.. out of memory */
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}
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#endif /* !NOBALLOC */
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if(bh == NULL)
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{
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rb_bh_fail("bh == NULL when it shouldn't be");
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}
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rb_dlinkAdd(bh, &bh->hlist, heap_lists);
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return (bh);
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}
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/* ************************************************************************ */
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/* FUNCTION DOCUMENTATION: */
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/* rb_bh_alloc */
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/* Description: */
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/* Returns a pointer to a struct within our rb_bh that's free for */
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/* the taking. */
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/* Parameters: */
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/* bh (IN): Pointer to the Blockheap. */
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/* Returns: */
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/* Pointer to a structure (void *), or NULL if unsuccessful. */
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/* ************************************************************************ */
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void *
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rb_bh_alloc(rb_bh *bh)
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{
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#ifndef NOBALLOC
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rb_dlink_node *new_node;
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rb_heap_block **block;
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void *ptr;
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#endif
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lrb_assert(bh != NULL);
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if(rb_unlikely(bh == NULL))
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{
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rb_bh_fail("Cannot allocate if bh == NULL");
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}
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#ifdef NOBALLOC
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return (rb_malloc(bh->elemSize));
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#else
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if(bh->free_list.head == NULL)
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{
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/* Allocate new block and assign */
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/* newblock returns 1 if unsuccessful, 0 if not */
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if(rb_unlikely(newblock(bh)))
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{
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rb_lib_log("newblock() failed");
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rb_outofmemory(); /* Well that didn't work either...bail */
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}
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if(bh->free_list.head == NULL)
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{
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rb_lib_log("out of memory after newblock()...");
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rb_outofmemory();
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}
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}
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new_node = bh->free_list.head;
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block = (rb_heap_block **) new_node->data;
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ptr = (void *)((uintptr_t)new_node->data + (uintptr_t)offset_pad);
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rb_dlinkDelete(new_node, &bh->free_list);
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(*block)->free_count--;
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memset(ptr, 0, bh->elemSize - offset_pad);
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return (ptr);
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#endif
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}
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/* ************************************************************************ */
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/* FUNCTION DOCUMENTATION: */
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/* rb_bh_free */
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/* Description: */
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/* Returns an element to the free pool, does not free() */
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/* Parameters: */
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/* bh (IN): Pointer to rb_bh containing element */
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/* ptr (in): Pointer to element to be "freed" */
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/* Returns: */
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/* 0 if successful, 1 if element not contained within rb_bh. */
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/* ************************************************************************ */
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int
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rb_bh_free(rb_bh *bh, void *ptr)
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{
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#ifndef NOBALLOC
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rb_heap_block *block;
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void *data;
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#endif
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lrb_assert(bh != NULL);
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lrb_assert(ptr != NULL);
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if(rb_unlikely(bh == NULL))
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{
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rb_lib_log("balloc.c:rb_bhFree() bh == NULL");
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return (1);
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}
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if(rb_unlikely(ptr == NULL))
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{
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rb_lib_log("balloc.rb_bhFree() ptr == NULL");
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return (1);
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}
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#ifdef NOBALLOC
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rb_free(ptr);
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#else
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data = (void *)((uintptr_t)ptr - (uintptr_t)offset_pad);
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block = *(rb_heap_block **) data;
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/* XXX */
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if(rb_unlikely
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(!((uintptr_t)ptr >= (uintptr_t)block->elems
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&& (uintptr_t)ptr < (uintptr_t)block->elems + (uintptr_t)block->alloc_size)))
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{
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rb_bh_fail("rb_bh_free() bogus pointer");
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}
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block->free_count++;
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rb_dlinkAdd(data, (rb_dlink_node *)ptr, &bh->free_list);
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#endif /* !NOBALLOC */
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return (0);
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}
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/* ************************************************************************ */
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/* FUNCTION DOCUMENTATION: */
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/* rb_bhDestroy */
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/* Description: */
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/* Completely free()s a rb_bh. Use for cleanup. */
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/* Parameters: */
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/* bh (IN): Pointer to the rb_bh to be destroyed. */
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/* Returns: */
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/* 0 if successful, 1 if bh == NULL */
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/* ************************************************************************ */
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int
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rb_bh_destroy(rb_bh *bh)
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{
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#ifndef NOBALLOC
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rb_dlink_node *ptr, *next;
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rb_heap_block *b;
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#endif
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if(bh == NULL)
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return (1);
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#ifndef NOBALLOC
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RB_DLINK_FOREACH_SAFE(ptr, next, bh->block_list.head)
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{
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b = ptr->data;
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free_block(b->elems, b->alloc_size);
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rb_free(b);
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}
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#endif /* !NOBALLOC */
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rb_dlinkDelete(&bh->hlist, heap_lists);
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rb_free(bh->desc);
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rb_free(bh);
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return (0);
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}
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void
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rb_bh_usage(rb_bh *bh, size_t *bused, size_t *bfree, size_t *bmemusage, const char **desc)
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{
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#ifndef NOBALLOC
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size_t used, freem, memusage;
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if(bh == NULL)
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{
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return;
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}
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freem = rb_dlink_list_length(&bh->free_list);
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used = (rb_dlink_list_length(&bh->block_list) * bh->elemsPerBlock) - freem;
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memusage = used * bh->elemSize;
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if(bused != NULL)
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*bused = used;
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if(bfree != NULL)
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*bfree = freem;
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if(bmemusage != NULL)
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*bmemusage = memusage;
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if(desc != NULL)
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*desc = bh->desc;
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#else
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if(bused != NULL)
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*bused = 0;
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if(bfree != NULL)
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*bfree = 0;
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if(bmemusage != NULL)
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*bmemusage = 0;
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if(desc != NULL)
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*desc = "no blockheap";
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#endif
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}
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void
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rb_bh_usage_all(rb_bh_usage_cb *cb, void *data)
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{
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rb_dlink_node *ptr;
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rb_bh *bh;
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size_t used, freem, memusage, heapalloc;
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static const char *unnamed = "(unnamed_heap)";
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const char *desc = unnamed;
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if(cb == NULL)
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return;
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RB_DLINK_FOREACH(ptr, heap_lists->head)
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{
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bh = (rb_bh *)ptr->data;
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freem = rb_dlink_list_length(&bh->free_list);
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used = (rb_dlink_list_length(&bh->block_list) * bh->elemsPerBlock) - freem;
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memusage = used * bh->elemSize;
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heapalloc = (freem + used) * bh->elemSize;
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if(bh->desc != NULL)
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desc = bh->desc;
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cb(used, freem, memusage, heapalloc, desc, data);
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}
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return;
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}
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void
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rb_bh_total_usage(size_t *total_alloc, size_t *total_used)
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{
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rb_dlink_node *ptr;
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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 */
|