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