| #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); |