513 lines
12 KiB
C
513 lines
12 KiB
C
#include <stdlib.h>
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#include <string.h>
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#include "hurdmalloc.h" /* XXX see that file */
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#include <mach.h>
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#define vm_allocate __vm_allocate
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#define vm_page_size __vm_page_size
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/*
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* Mach Operating System
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* Copyright (c) 1991,1990,1989 Carnegie Mellon University
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* All Rights Reserved.
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*
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* Permission to use, copy, modify and distribute this software and its
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* documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
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* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie Mellon
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* the rights to redistribute these changes.
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*/
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/*
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* HISTORY
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* $Log$
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* Revision 1.15 2001/09/19 03:04:09 drepper
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* (bcopy): Removed.
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* (realloc): Replace bcopy with memcpy.
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*
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* Revision 1.14 2001/04/01 05:03:14 roland
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* 2001-03-11 Roland McGrath <roland@frob.com>
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*
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* * mach/mach_error.h: Fix ancient #endif syntax.
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* * hurd/hurdmalloc.c: Likewise.
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*
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* Revision 1.13 1996/12/20 01:32:01 drepper
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* Update from main archive 961219
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*
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* Revision 1.12 1996/11/15 19:44:13 thomas
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* Tue Nov 12 16:58:41 1996 Thomas Bushnell, n/BSG <thomas@gnu.ai.mit.edu>
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*
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* * mach/msg-destroy.c (mach_msg_destroy_port,
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* mach_msg_destroy_memory): Use prototype syntax.
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* * hurd/hurdmalloc.c (more_memory, malloc_fork_prepare,
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* malloc_fork_parent, malloc_fork_child): Likewise.
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*
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* Revision 1.11 1996/06/06 15:13:47 miles
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* Changes to bring in line with the hurd libthreads/malloc.c:
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* (more_memory): Use assert_perror instead of MACH_CALL.
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* "cthread_internals.h": Include removed.
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* (realloc): Use LOG2_MIN_SIZE.
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* (LOG2_MIN_SIZE): New macro.
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* (realloc): Don't bother allocating a new block if the
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* new size request fits in the old one and doesn't waste any space.
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* Only free the old block if we successfully got a new one.
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* [MCHECK] (struct header): New type.
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* (union header): Only define if !MCHECK.
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* (HEADER_SIZE, HEADER_NEXT, HEADER_FREE, HEADER_CHECK): New macros.
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* [MCHECK] (MIN_SIZE): Add correct definition for this case.
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* (more_memory, malloc, free, realloc): Use above macros, and add
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* appropriate checks & frobs in MCHECK case.
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*
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* Revision 1.6 1996/03/07 21:13:08 miles
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* (realloc):
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* Use LOG2_MIN_SIZE.
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* Don't bother allocating a new block if the new size request fits in the old
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* one and doesn't waste any space.
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* Only free the old block if we successfully got a new one.
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* (LOG2_MIN_SIZE): New macro.
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*
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* Revision 1.5 1996/03/06 23:51:04 miles
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* [MCHECK] (struct header): New type.
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* (union header): Only define if !MCHECK.
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* (HEADER_SIZE, HEADER_NEXT, HEADER_FREE, HEADER_CHECK): New macros.
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* [MCHECK] (MIN_SIZE): Add correct definition for this case.
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* (more_memory, malloc, free, realloc):
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* Use above macros, and add appropriate checks & frobs in MCHECK case.
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*
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* Revision 1.4 1994/05/05 11:21:42 roland
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* entered into RCS
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*
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* Revision 2.7 91/05/14 17:57:34 mrt
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* Correcting copyright
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*
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* Revision 2.6 91/02/14 14:20:26 mrt
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* Added new Mach copyright
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* [91/02/13 12:41:21 mrt]
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*
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* Revision 2.5 90/11/05 14:37:33 rpd
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* Added malloc_fork* code.
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* [90/11/02 rwd]
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*
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* Add spin_lock_t.
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* [90/10/31 rwd]
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*
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* Revision 2.4 90/08/07 14:31:28 rpd
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* Removed RCS keyword nonsense.
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*
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* Revision 2.3 90/06/02 15:14:00 rpd
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* Converted to new IPC.
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* [90/03/20 20:56:57 rpd]
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*
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* Revision 2.2 89/12/08 19:53:59 rwd
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* Removed conditionals.
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* [89/10/23 rwd]
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*
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* Revision 2.1 89/08/03 17:09:46 rwd
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* Created.
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*
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*
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* 13-Sep-88 Eric Cooper (ecc) at Carnegie Mellon University
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* Changed realloc() to copy min(old size, new size) bytes.
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* Bug found by Mike Kupfer at Olivetti.
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*/
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/*
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* File: malloc.c
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* Author: Eric Cooper, Carnegie Mellon University
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* Date: July, 1988
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*
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* Memory allocator for use with multiple threads.
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*/
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#include <assert.h>
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#include <cthreads.h>
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#define MCHECK
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/*
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* Structure of memory block header.
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* When free, next points to next block on free list.
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* When allocated, fl points to free list.
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* Size of header is 4 bytes, so minimum usable block size is 8 bytes.
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*/
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#define CHECK_BUSY 0x8a3c743e
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#define CHECK_FREE 0x66688b92
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#ifdef MCHECK
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typedef struct header {
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long check;
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union {
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struct header *next;
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struct free_list *fl;
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} u;
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} *header_t;
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#define HEADER_SIZE sizeof (struct header)
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#define HEADER_NEXT(h) ((h)->u.next)
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#define HEADER_FREE(h) ((h)->u.fl)
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#define HEADER_CHECK(h) ((h)->check)
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#define MIN_SIZE 16
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#define LOG2_MIN_SIZE 4
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#else /* ! MCHECK */
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typedef union header {
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union header *next;
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struct free_list *fl;
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} *header_t;
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#define HEADER_SIZE sizeof (union header)
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#define HEADER_NEXT(h) ((h)->next)
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#define HEADER_FREE(h) ((h)->fl)
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#define MIN_SIZE 8 /* minimum block size */
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#define LOG2_MIN_SIZE 3
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#endif /* MCHECK */
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typedef struct free_list {
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spin_lock_t lock; /* spin lock for mutual exclusion */
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header_t head; /* head of free list for this size */
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#ifdef DEBUG
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int in_use; /* # mallocs - # frees */
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#endif /* DEBUG */
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} *free_list_t;
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/*
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* Free list with index i contains blocks of size 2 ^ (i + LOG2_MIN_SIZE)
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* including header. Smallest block size is MIN_SIZE, with MIN_SIZE -
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* HEADER_SIZE bytes available to user. Size argument to malloc is a signed
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* integer for sanity checking, so largest block size is 2^31.
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*/
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#define NBUCKETS 29
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static struct free_list malloc_free_list[NBUCKETS];
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/* Initialization just sets everything to zero, but might be necessary on a
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machine where spin_lock_init does otherwise, and is necessary when
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running an executable that was written by something like Emacs's unexec.
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It preserves the values of data variables like malloc_free_list, but
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does not save the vm_allocate'd space allocated by this malloc. */
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static void
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malloc_init (void)
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{
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int i;
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for (i = 0; i < NBUCKETS; ++i)
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{
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spin_lock_init (&malloc_free_list[i].lock);
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malloc_free_list[i].head = NULL;
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#ifdef DEBUG
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malloc_free_list[i].in_use = 0;
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#endif
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}
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/* This not only suppresses a `defined but not used' warning,
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but it is ABSOLUTELY NECESSARY to avoid the hyperclever
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compiler from "optimizing out" the entire function! */
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(void) &malloc_init;
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}
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static void
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more_memory(int size, free_list_t fl)
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{
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register int amount;
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register int n;
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vm_address_t where;
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register header_t h;
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kern_return_t r;
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if (size <= vm_page_size) {
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amount = vm_page_size;
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n = vm_page_size / size;
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/* We lose vm_page_size - n*size bytes here. */
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} else {
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amount = size;
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n = 1;
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}
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r = vm_allocate(mach_task_self(), &where, (vm_size_t) amount, TRUE);
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assert_perror (r);
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h = (header_t) where;
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do {
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HEADER_NEXT (h) = fl->head;
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#ifdef MCHECK
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HEADER_CHECK (h) = CHECK_FREE;
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#endif
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fl->head = h;
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h = (header_t) ((char *) h + size);
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} while (--n != 0);
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}
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/* Declaration changed to standard one for GNU. */
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void *
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malloc(size)
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register size_t size;
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{
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register int i, n;
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register free_list_t fl;
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register header_t h;
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if ((int) size < 0) /* sanity check */
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return 0;
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size += HEADER_SIZE;
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/*
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* Find smallest power-of-two block size
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* big enough to hold requested size plus header.
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*/
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i = 0;
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n = MIN_SIZE;
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while (n < size) {
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i += 1;
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n <<= 1;
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}
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ASSERT(i < NBUCKETS);
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fl = &malloc_free_list[i];
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spin_lock(&fl->lock);
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h = fl->head;
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if (h == 0) {
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/*
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* Free list is empty;
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* allocate more blocks.
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*/
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more_memory(n, fl);
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h = fl->head;
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if (h == 0) {
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/*
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* Allocation failed.
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*/
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spin_unlock(&fl->lock);
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return 0;
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}
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}
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/*
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* Pop block from free list.
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*/
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fl->head = HEADER_NEXT (h);
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#ifdef MCHECK
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assert (HEADER_CHECK (h) == CHECK_FREE);
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HEADER_CHECK (h) = CHECK_BUSY;
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#endif
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#ifdef DEBUG
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fl->in_use += 1;
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#endif /* DEBUG */
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spin_unlock(&fl->lock);
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/*
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* Store free list pointer in block header
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* so we can figure out where it goes
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* at free() time.
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*/
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HEADER_FREE (h) = fl;
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/*
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* Return pointer past the block header.
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*/
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return ((char *) h) + HEADER_SIZE;
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}
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/* Declaration changed to standard one for GNU. */
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void
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free(base)
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void *base;
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{
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register header_t h;
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register free_list_t fl;
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register int i;
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if (base == 0)
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return;
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/*
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* Find free list for block.
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*/
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h = (header_t) (base - HEADER_SIZE);
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#ifdef MCHECK
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assert (HEADER_CHECK (h) == CHECK_BUSY);
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#endif
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fl = HEADER_FREE (h);
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i = fl - malloc_free_list;
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/*
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* Sanity checks.
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*/
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if (i < 0 || i >= NBUCKETS) {
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ASSERT(0 <= i && i < NBUCKETS);
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return;
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}
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if (fl != &malloc_free_list[i]) {
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ASSERT(fl == &malloc_free_list[i]);
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return;
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}
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/*
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* Push block on free list.
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*/
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spin_lock(&fl->lock);
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HEADER_NEXT (h) = fl->head;
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#ifdef MCHECK
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HEADER_CHECK (h) = CHECK_FREE;
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#endif
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fl->head = h;
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#ifdef DEBUG
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fl->in_use -= 1;
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#endif /* DEBUG */
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spin_unlock(&fl->lock);
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return;
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}
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/* Declaration changed to standard one for GNU. */
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void *
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realloc(old_base, new_size)
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void *old_base;
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size_t new_size;
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{
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register header_t h;
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register free_list_t fl;
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register int i;
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unsigned int old_size;
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char *new_base;
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if (old_base == 0)
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return malloc (new_size);
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/*
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* Find size of old block.
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*/
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h = (header_t) (old_base - HEADER_SIZE);
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#ifdef MCHECK
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assert (HEADER_CHECK (h) == CHECK_BUSY);
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#endif
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fl = HEADER_FREE (h);
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i = fl - malloc_free_list;
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/*
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* Sanity checks.
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*/
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if (i < 0 || i >= NBUCKETS) {
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ASSERT(0 <= i && i < NBUCKETS);
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return 0;
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}
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if (fl != &malloc_free_list[i]) {
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ASSERT(fl == &malloc_free_list[i]);
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return 0;
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}
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/*
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* Free list with index i contains blocks of size
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* 2 ^ (i + * LOG2_MIN_SIZE) including header.
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*/
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old_size = (1 << (i + LOG2_MIN_SIZE)) - HEADER_SIZE;
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if (new_size <= old_size
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&& new_size > (((old_size + HEADER_SIZE) >> 1) - HEADER_SIZE))
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/* The new size still fits in the same block, and wouldn't fit in
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the next smaller block! */
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return old_base;
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/*
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* Allocate new block, copy old bytes, and free old block.
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*/
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new_base = malloc(new_size);
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if (new_base)
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memcpy (new_base, old_base,
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(int) (old_size < new_size ? old_size : new_size));
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if (new_base || new_size == 0)
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/* Free OLD_BASE, but only if the malloc didn't fail. */
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free (old_base);
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return new_base;
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}
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#ifdef DEBUG
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void
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print_malloc_free_list()
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{
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register int i, size;
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register free_list_t fl;
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register int n;
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register header_t h;
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int total_used = 0;
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int total_free = 0;
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fprintf(stderr, " Size In Use Free Total\n");
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for (i = 0, size = MIN_SIZE, fl = malloc_free_list;
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i < NBUCKETS;
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i += 1, size <<= 1, fl += 1) {
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spin_lock(&fl->lock);
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if (fl->in_use != 0 || fl->head != 0) {
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total_used += fl->in_use * size;
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for (n = 0, h = fl->head; h != 0; h = HEADER_NEXT (h), n += 1)
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;
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total_free += n * size;
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fprintf(stderr, "%10d %10d %10d %10d\n",
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size, fl->in_use, n, fl->in_use + n);
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}
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spin_unlock(&fl->lock);
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}
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fprintf(stderr, " all sizes %10d %10d %10d\n",
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total_used, total_free, total_used + total_free);
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}
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#endif /* DEBUG */
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static void
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malloc_fork_prepare(void)
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/*
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* Prepare the malloc module for a fork by insuring that no thread is in a
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* malloc critical section.
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*/
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{
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register int i;
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for (i = 0; i < NBUCKETS; i++) {
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spin_lock(&malloc_free_list[i].lock);
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}
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}
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static void
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malloc_fork_parent(void)
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/*
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* Called in the parent process after a fork() to resume normal operation.
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*/
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{
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register int i;
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for (i = NBUCKETS-1; i >= 0; i--) {
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spin_unlock(&malloc_free_list[i].lock);
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}
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}
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static void
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malloc_fork_child(void)
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/*
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* Called in the child process after a fork() to resume normal operation.
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*/
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{
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register int i;
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for (i = NBUCKETS-1; i >= 0; i--) {
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spin_unlock(&malloc_free_list[i].lock);
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}
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}
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text_set_element (_hurd_fork_prepare_hook, malloc_fork_prepare);
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text_set_element (_hurd_fork_parent_hook, malloc_fork_parent);
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text_set_element (_hurd_fork_child_hook, malloc_fork_child);
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text_set_element (_hurd_preinit_hook, malloc_init);
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