armboot-s3c4510.tar.gz_4510_armboot_armboot-1.1.6_s3c4510_s3c451

/* * Legal stuff (C) Copyright 2002 Sysgo Real-Time Solutions, GmbH <www.elinos.com> Marius Groeger <mgroeger@sysgo.de> See file CREDITS for list of people who contributed to this project. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA A version of malloc/free/realloc written by Doug Lea and released to the public domain. Send questions/comments/complaints/performance data to dl@cs.oswego.edu * VERSION 2.6.6 Sun Mar 5 19:10:03 2000 Doug Lea (dl at gee) Note: There may be an updated version of this malloc obtainable at ftp://g.oswego.edu/pub/misc/malloc.c Check before installing! * Why use this malloc? This is not the fastest, most space-conserving, most portable, or most tunable malloc ever written. However it is among the fastest while also being among the most space-conserving, portable and tunable. Consistent balance across these factors results in a good general-purpose allocator. For a high-level description, see http://g.oswego.edu/dl/html/malloc.html * Synopsis of public routines (Much fuller descriptions are contained in the program documentation below.) malloc(size_t n); Return a pointer to a newly allocated chunk of at least n bytes, or null if no space is available. free(Void_t* p); Release the chunk of memory pointed to by p, or no effect if p is null. realloc(Void_t* p, size_t n); Return a pointer to a chunk of size n that contains the same data as does chunk p up to the minimum of (n, p's size) bytes, or null if no space is available. The returned pointer may or may not be the same as p. If p is null, equivalent to malloc. Unless the #define REALLOC_ZERO_BYTES_FREES below is set, realloc with a size argument of zero (re)allocates a minimum-sized chunk. memalign(size_t alignment, size_t n); Return a pointer to a newly allocated chunk of n bytes, aligned in accord with the alignment argument, which must be a power of two. valloc(size_t n); Equivalent to memalign(pagesize, n), where pagesize is the page size of the system (or as near to this as can be figured out from all the includes/defines below.) pvalloc(size_t n); Equivalent to valloc(minimum-page-that-holds(n)), that is, round up n to nearest pagesize. calloc(size_t unit, size_t quantity); Returns a pointer to quantity * unit bytes, with all locations set to zero. cfree(Void_t* p); Equivalent to free(p). malloc_trim(size_t pad); Release all but pad bytes of freed top-most memory back to the system. Return 1 if successful, else 0. malloc_usable_size(Void_t* p); Report the number usable allocated bytes associated with allocated chunk p. This may or may not report more bytes than were requested, due to alignment and minimum size constraints. malloc_stats(); Prints brief summary statistics. mallinfo() Returns (by copy) a struct containing various summary statistics. mallopt(int parameter_number, int parameter_value) Changes one of the tunable parameters described below. Returns 1 if successful in changing the parameter, else 0. * Vital statistics: Alignment: 8-byte 8 byte alignment is currently hardwired into the design. This seems to suffice for all current machines and C compilers. Assumed pointer representation: 4 or 8 bytes Code for 8-byte pointers is untested by me but has worked reliably by Wolfram Gloger, who contributed most of the changes supporting this. Assumed size_t representation: 4 or 8 bytes Note that size_t is allowed to be 4 bytes even if pointers are 8. Minimum overhead per allocated chunk: 4 or 8 bytes Each malloced chunk has a hidden overhead of 4 bytes holding size and status information. Minimum allocated size: 4-byte ptrs: 16 bytes (including 4 overhead) 8-byte ptrs: 24/32 bytes (including, 4/8 overhead) When a chunk is freed, 12 (for 4byte ptrs) or 20 (for 8 byte ptrs but 4 byte size) or 24 (for 8/8) additional bytes are needed; 4 (8) for a trailing size field and 8 (16) bytes for free list pointers. Thus, the minimum allocatable size is 16/24/32 bytes. Even a request for zero bytes (i.e., malloc(0)) returns a pointer to something of the minimum allocatable size. Maximum allocated size: 4-byte size_t: 2^31 - 8 bytes 8-byte size_t: 2^63 - 16 bytes It is assumed that (possibly signed) size_t bit values suffice to represent chunk sizes. `Possibly signed' is due to the fact that `size_t' may be defined on a system as either a signed or an unsigned type. To be conservative, values that would appear as negative numbers are avoided. Requests for sizes with a negative sign bit when the request size is treaded as a long will return null. Maximum overhead wastage per allocated chunk: normally 15 bytes Alignnment demands, plus the minimum allocatable size restriction make the normal worst-case wastage 15 bytes (i.e., up to 15 more bytes will be allocated than were requested in malloc), with two exceptions: 1. Because requests for zero bytes allocate non-zero space, the worst case wastage for a request of zero bytes is 24 bytes. 2. For requests >= mmap_threshold that are serviced via mmap(), the worst case wastage is 8 bytes plus the remainder from a system page (the minimal mmap unit); typically 4096 bytes. * Limitations Here are some features that are NOT currently supported * No user-definable hooks for callbacks and the like. * No automated mechanism for fully checking that all accesses to malloced memory stay within their bounds. * No support for compaction. * Synopsis of compile-time options: People have reported using previous versions of this malloc on all versions of Unix, sometimes by tweaking some of the defines below. It has been tested most extensively on Solaris and Linux. It is also reported to work on WIN32 platforms. People have also reported adapting this malloc for use in stand-alone embedded systems. The implementation is in straight, hand-tuned ANSI C. Among other consequences, it uses a lot of macros. Because of this, to be at all usable, this code should be compiled using an optimizing compiler (for example gcc -O2) that can simplify expressions and control paths. __STD_C (default: derived from C compiler defines) Nonzero if using ANSI-standard C compiler, a C++ compiler, or a C compiler sufficiently close to ANSI to get away with it. DEBUG (default: NOT defined) Define to enable debugging. Adds fairly extensive assertion-based checking to help track down memory errors, but noticeably slows down execution. REALLOC_ZERO_BYTES_FREES (default: NOT defined) Define this if you think that realloc(p, 0) should be equivalent to free(p). Otherwise, since malloc returns a unique pointer for malloc(0), so does realloc(p, 0). HAVE_MEMCPY (default: def