Return-Path: X-Original-To: archive-asf-public-internal@cust-asf2.ponee.io Delivered-To: archive-asf-public-internal@cust-asf2.ponee.io Received: from cust-asf.ponee.io (cust-asf.ponee.io [163.172.22.183]) by cust-asf2.ponee.io (Postfix) with ESMTP id C6F83200CDD for ; Sun, 23 Jul 2017 20:39:13 +0200 (CEST) Received: by cust-asf.ponee.io (Postfix) id C5650163474; Sun, 23 Jul 2017 18:39:13 +0000 (UTC) Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by cust-asf.ponee.io (Postfix) with SMTP id 553711632A7 for ; Sun, 23 Jul 2017 20:39:11 +0200 (CEST) Received: (qmail 98647 invoked by uid 500); 23 Jul 2017 18:39:10 -0000 Mailing-List: contact commits-help@arrow.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@arrow.apache.org Delivered-To: mailing list commits@arrow.apache.org Received: (qmail 98596 invoked by uid 99); 23 Jul 2017 18:39:10 -0000 Received: from git1-us-west.apache.org (HELO git1-us-west.apache.org) (140.211.11.23) by apache.org (qpsmtpd/0.29) with ESMTP; Sun, 23 Jul 2017 18:39:10 +0000 Received: by git1-us-west.apache.org (ASF Mail Server at git1-us-west.apache.org, from userid 33) id 441CAF32B4; Sun, 23 Jul 2017 18:39:08 +0000 (UTC) Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: wesm@apache.org To: commits@arrow.apache.org Date: Sun, 23 Jul 2017 18:39:09 -0000 Message-Id: In-Reply-To: <5d460483a2694b698acf02f5571638aa@git.apache.org> References: <5d460483a2694b698acf02f5571638aa@git.apache.org> X-Mailer: ASF-Git Admin Mailer Subject: [02/14] arrow git commit: [C++] Remove Plasma source tree for 0.5.0 release pending IP Clearance archived-at: Sun, 23 Jul 2017 18:39:13 -0000 http://git-wip-us.apache.org/repos/asf/arrow/blob/62ef2cd8/cpp/src/plasma/thirdparty/dlmalloc.c ---------------------------------------------------------------------- diff --git a/cpp/src/plasma/thirdparty/dlmalloc.c b/cpp/src/plasma/thirdparty/dlmalloc.c deleted file mode 100644 index 84ccbd2..0000000 --- a/cpp/src/plasma/thirdparty/dlmalloc.c +++ /dev/null @@ -1,6281 +0,0 @@ -/* - This is a version (aka dlmalloc) of malloc/free/realloc written by - Doug Lea and released to the public domain, as explained at - http://creativecommons.org/publicdomain/zero/1.0/ Send questions, - comments, complaints, performance data, etc to dl@cs.oswego.edu - -* Version 2.8.6 Wed Aug 29 06:57:58 2012 Doug Lea - Note: There may be an updated version of this malloc obtainable at - ftp://gee.cs.oswego.edu/pub/misc/malloc.c - Check before installing! - -* Quickstart - - This library is all in one file to simplify the most common usage: - ftp it, compile it (-O3), and link it into another program. All of - the compile-time options default to reasonable values for use on - most platforms. You might later want to step through various - compile-time and dynamic tuning options. - - For convenience, an include file for code using this malloc is at: - ftp://gee.cs.oswego.edu/pub/misc/malloc-2.8.6.h - You don't really need this .h file unless you call functions not - defined in your system include files. The .h file contains only the - excerpts from this file needed for using this malloc on ANSI C/C++ - systems, so long as you haven't changed compile-time options about - naming and tuning parameters. If you do, then you can create your - own malloc.h that does include all settings by cutting at the point - indicated below. Note that you may already by default be using a C - library containing a malloc that is based on some version of this - malloc (for example in linux). You might still want to use the one - in this file to customize settings or to avoid overheads associated - with library versions. - -* Vital statistics: - - Supported pointer/size_t representation: 4 or 8 bytes - size_t MUST be an unsigned type of the same width as - pointers. (If you are using an ancient system that declares - size_t as a signed type, or need it to be a different width - than pointers, you can use a previous release of this malloc - (e.g. 2.7.2) supporting these.) - - Alignment: 8 bytes (minimum) - This suffices for nearly all current machines and C compilers. - However, you can define MALLOC_ALIGNMENT to be wider than this - if necessary (up to 128bytes), at the expense of using more space. - - Minimum overhead per allocated chunk: 4 or 8 bytes (if 4byte sizes) - 8 or 16 bytes (if 8byte sizes) - Each malloced chunk has a hidden word of overhead holding size - and status information, and additional cross-check word - if FOOTERS is defined. - - Minimum allocated size: 4-byte ptrs: 16 bytes (including overhead) - 8-byte ptrs: 32 bytes (including overhead) - - Even a request for zero bytes (i.e., malloc(0)) returns a - pointer to something of the minimum allocatable size. - The maximum overhead wastage (i.e., number of extra bytes - allocated than were requested in malloc) is less than or equal - to the minimum size, except for requests >= mmap_threshold that - are serviced via mmap(), where the worst case wastage is about - 32 bytes plus the remainder from a system page (the minimal - mmap unit); typically 4096 or 8192 bytes. - - Security: static-safe; optionally more or less - The "security" of malloc refers to the ability of malicious - code to accentuate the effects of errors (for example, freeing - space that is not currently malloc'ed or overwriting past the - ends of chunks) in code that calls malloc. This malloc - guarantees not to modify any memory locations below the base of - heap, i.e., static variables, even in the presence of usage - errors. The routines additionally detect most improper frees - and reallocs. All this holds as long as the static bookkeeping - for malloc itself is not corrupted by some other means. This - is only one aspect of security -- these checks do not, and - cannot, detect all possible programming errors. - - If FOOTERS is defined nonzero, then each allocated chunk - carries an additional check word to verify that it was malloced - from its space. These check words are the same within each - execution of a program using malloc, but differ across - executions, so externally crafted fake chunks cannot be - freed. This improves security by rejecting frees/reallocs that - could corrupt heap memory, in addition to the checks preventing - writes to statics that are always on. This may further improve - security at the expense of time and space overhead. (Note that - FOOTERS may also be worth using with MSPACES.) - - By default detected errors cause the program to abort (calling - "abort()"). You can override this to instead proceed past - errors by defining PROCEED_ON_ERROR. In this case, a bad free - has no effect, and a malloc that encounters a bad address - caused by user overwrites will ignore the bad address by - dropping pointers and indices to all known memory. This may - be appropriate for programs that should continue if at all - possible in the face of programming errors, although they may - run out of memory because dropped memory is never reclaimed. - - If you don't like either of these options, you can define - CORRUPTION_ERROR_ACTION and USAGE_ERROR_ACTION to do anything - else. And if if you are sure that your program using malloc has - no errors or vulnerabilities, you can define INSECURE to 1, - which might (or might not) provide a small performance improvement. - - It is also possible to limit the maximum total allocatable - space, using malloc_set_footprint_limit. This is not - designed as a security feature in itself (calls to set limits - are not screened or privileged), but may be useful as one - aspect of a secure implementation. - - Thread-safety: NOT thread-safe unless USE_LOCKS defined non-zero - When USE_LOCKS is defined, each public call to malloc, free, - etc is surrounded with a lock. By default, this uses a plain - pthread mutex, win32 critical section, or a spin-lock if if - available for the platform and not disabled by setting - USE_SPIN_LOCKS=0. However, if USE_RECURSIVE_LOCKS is defined, - recursive versions are used instead (which are not required for - base functionality but may be needed in layered extensions). - Using a global lock is not especially fast, and can be a major - bottleneck. It is designed only to provide minimal protection - in concurrent environments, and to provide a basis for - extensions. If you are using malloc in a concurrent program, - consider instead using nedmalloc - (http://www.nedprod.com/programs/portable/nedmalloc/) or - ptmalloc (See http://www.malloc.de), which are derived from - versions of this malloc. - - System requirements: Any combination of MORECORE and/or MMAP/MUNMAP - This malloc can use unix sbrk or any emulation (invoked using - the CALL_MORECORE macro) and/or mmap/munmap or any emulation - (invoked using CALL_MMAP/CALL_MUNMAP) to get and release system - memory. On most unix systems, it tends to work best if both - MORECORE and MMAP are enabled. On Win32, it uses emulations - based on VirtualAlloc. It also uses common C library functions - like memset. - - Compliance: I believe it is compliant with the Single Unix Specification - (See http://www.unix.org). Also SVID/XPG, ANSI C, and probably - others as well. - -* Overview of algorithms - - 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 malloc-intensive programs. - - In most ways, this malloc is a best-fit allocator. Generally, it - chooses the best-fitting existing chunk for a request, with ties - broken in approximately least-recently-used order. (This strategy - normally maintains low fragmentation.) However, for requests less - than 256bytes, it deviates from best-fit when there is not an - exactly fitting available chunk by preferring to use space adjacent - to that used for the previous small request, as well as by breaking - ties in approximately most-recently-used order. (These enhance - locality of series of small allocations.) And for very large requests - (>= 256Kb by default), it relies on system memory mapping - facilities, if supported. (This helps avoid carrying around and - possibly fragmenting memory used only for large chunks.) - - All operations (except malloc_stats and mallinfo) have execution - times that are bounded by a constant factor of the number of bits in - a size_t, not counting any clearing in calloc or copying in realloc, - or actions surrounding MORECORE and MMAP that have times - proportional to the number of non-contiguous regions returned by - system allocation routines, which is often just 1. In real-time - applications, you can optionally suppress segment traversals using - NO_SEGMENT_TRAVERSAL, which assures bounded execution even when - system allocators return non-contiguous spaces, at the typical - expense of carrying around more memory and increased fragmentation. - - The implementation is not very modular and seriously overuses - macros. Perhaps someday all C compilers will do as good a job - inlining modular code as can now be done by brute-force expansion, - but now, enough of them seem not to. - - Some compilers issue a lot of warnings about code that is - dead/unreachable only on some platforms, and also about intentional - uses of negation on unsigned types. All known cases of each can be - ignored. - - For a longer but out of date high-level description, see - http://gee.cs.oswego.edu/dl/html/malloc.html - -* MSPACES - If MSPACES is defined, then in addition to malloc, free, etc., - this file also defines mspace_malloc, mspace_free, etc. These - are versions of malloc routines that take an "mspace" argument - obtained using create_mspace, to control all internal bookkeeping. - If ONLY_MSPACES is defined, only these versions are compiled. - So if you would like to use this allocator for only some allocations, - and your system malloc for others, you can compile with - ONLY_MSPACES and then do something like... - static mspace mymspace = create_mspace(0,0); // for example - #define mymalloc(bytes) mspace_malloc(mymspace, bytes) - - (Note: If you only need one instance of an mspace, you can instead - use "USE_DL_PREFIX" to relabel the global malloc.) - - You can similarly create thread-local allocators by storing - mspaces as thread-locals. For example: - static __thread mspace tlms = 0; - void* tlmalloc(size_t bytes) { - if (tlms == 0) tlms = create_mspace(0, 0); - return mspace_malloc(tlms, bytes); - } - void tlfree(void* mem) { mspace_free(tlms, mem); } - - Unless FOOTERS is defined, each mspace is completely independent. - You cannot allocate from one and free to another (although - conformance is only weakly checked, so usage errors are not always - caught). If FOOTERS is defined, then each chunk carries around a tag - indicating its originating mspace, and frees are directed to their - originating spaces. Normally, this requires use of locks. - - ------------------------- Compile-time options --------------------------- - -Be careful in setting #define values for numerical constants of type -size_t. On some systems, literal values are not automatically extended -to size_t precision unless they are explicitly casted. You can also -use the symbolic values MAX_SIZE_T, SIZE_T_ONE, etc below. - -WIN32 default: defined if _WIN32 defined - Defining WIN32 sets up defaults for MS environment and compilers. - Otherwise defaults are for unix. Beware that there seem to be some - cases where this malloc might not be a pure drop-in replacement for - Win32 malloc: Random-looking failures from Win32 GDI API's (eg; - SetDIBits()) may be due to bugs in some video driver implementations - when pixel buffers are malloc()ed, and the region spans more than - one VirtualAlloc()ed region. Because dlmalloc uses a small (64Kb) - default granularity, pixel buffers may straddle virtual allocation - regions more often than when using the Microsoft allocator. You can - avoid this by using VirtualAlloc() and VirtualFree() for all pixel - buffers rather than using malloc(). If this is not possible, - recompile this malloc with a larger DEFAULT_GRANULARITY. Note: - in cases where MSC and gcc (cygwin) are known to differ on WIN32, - conditions use _MSC_VER to distinguish them. - -DLMALLOC_EXPORT default: extern - Defines how public APIs are declared. If you want to export via a - Windows DLL, you might define this as - #define DLMALLOC_EXPORT extern __declspec(dllexport) - If you want a POSIX ELF shared object, you might use - #define DLMALLOC_EXPORT extern __attribute__((visibility("default"))) - -MALLOC_ALIGNMENT default: (size_t)(2 * sizeof(void *)) - Controls the minimum alignment for malloc'ed chunks. It must be a - power of two and at least 8, even on machines for which smaller - alignments would suffice. It may be defined as larger than this - though. Note however that code and data structures are optimized for - the case of 8-byte alignment. - -MSPACES default: 0 (false) - If true, compile in support for independent allocation spaces. - This is only supported if HAVE_MMAP is true. - -ONLY_MSPACES default: 0 (false) - If true, only compile in mspace versions, not regular versions. - -USE_LOCKS default: 0 (false) - Causes each call to each public routine to be surrounded with - pthread or WIN32 mutex lock/unlock. (If set true, this can be - overridden on a per-mspace basis for mspace versions.) If set to a - non-zero value other than 1, locks are used, but their - implementation is left out, so lock functions must be supplied manually, - as described below. - -USE_SPIN_LOCKS default: 1 iff USE_LOCKS and spin locks available - If true, uses custom spin locks for locking. This is currently - supported only gcc >= 4.1, older gccs on x86 platforms, and recent - MS compilers. Otherwise, posix locks or win32 critical sections are - used. - -USE_RECURSIVE_LOCKS default: not defined - If defined nonzero, uses recursive (aka reentrant) locks, otherwise - uses plain mutexes. This is not required for malloc proper, but may - be needed for layered allocators such as nedmalloc. - -LOCK_AT_FORK default: not defined - If defined nonzero, performs pthread_atfork upon initialization - to initialize child lock while holding parent lock. The implementation - assumes that pthread locks (not custom locks) are being used. In other - cases, you may need to customize the implementation. - -FOOTERS default: 0 - If true, provide extra checking and dispatching by placing - information in the footers of allocated chunks. This adds - space and time overhead. - -INSECURE default: 0 - If true, omit checks for usage errors and heap space overwrites. - -USE_DL_PREFIX default: NOT defined - Causes compiler to prefix all public routines with the string 'dl'. - This can be useful when you only want to use this malloc in one part - of a program, using your regular system malloc elsewhere. - -MALLOC_INSPECT_ALL default: NOT defined - If defined, compiles malloc_inspect_all and mspace_inspect_all, that - perform traversal of all heap space. Unless access to these - functions is otherwise restricted, you probably do not want to - include them in secure implementations. - -ABORT default: defined as abort() - Defines how to abort on failed checks. On most systems, a failed - check cannot die with an "assert" or even print an informative - message, because the underlying print routines in turn call malloc, - which will fail again. Generally, the best policy is to simply call - abort(). It's not very useful to do more than this because many - errors due to overwriting will show up as address faults (null, odd - addresses etc) rather than malloc-triggered checks, so will also - abort. Also, most compilers know that abort() does not return, so - can better optimize code conditionally calling it. - -PROCEED_ON_ERROR default: defined as 0 (false) - Controls whether detected bad addresses cause them to bypassed - rather than aborting. If set, detected bad arguments to free and - realloc are ignored. And all bookkeeping information is zeroed out - upon a detected overwrite of freed heap space, thus losing the - ability to ever return it from malloc again, but enabling the - application to proceed. If PROCEED_ON_ERROR is defined, the - static variable malloc_corruption_error_count is compiled in - and can be examined to see if errors have occurred. This option - generates slower code than the default abort policy. - -DEBUG default: NOT defined - The DEBUG setting is mainly intended for people trying to modify - this code or diagnose problems when porting to new platforms. - However, it may also be able to better isolate user errors than just - using runtime checks. The assertions in the check routines spell - out in more detail the assumptions and invariants underlying the - algorithms. The checking is fairly extensive, and will slow down - execution noticeably. Calling malloc_stats or mallinfo with DEBUG - set will attempt to check every non-mmapped allocated and free chunk - in the course of computing the summaries. - -ABORT_ON_ASSERT_FAILURE default: defined as 1 (true) - Debugging assertion failures can be nearly impossible if your - version of the assert macro causes malloc to be called, which will - lead to a cascade of further failures, blowing the runtime stack. - ABORT_ON_ASSERT_FAILURE cause assertions failures to call abort(), - which will usually make debugging easier. - -MALLOC_FAILURE_ACTION default: sets errno to ENOMEM, or no-op on win32 - The action to take before "return 0" when malloc fails to be able to - return memory because there is none available. - -HAVE_MORECORE default: 1 (true) unless win32 or ONLY_MSPACES - True if this system supports sbrk or an emulation of it. - -MORECORE default: sbrk - The name of the sbrk-style system routine to call to obtain more - memory. See below for guidance on writing custom MORECORE - functions. The type of the argument to sbrk/MORECORE varies across - systems. It cannot be size_t, because it supports negative - arguments, so it is normally the signed type of the same width as - size_t (sometimes declared as "intptr_t"). It doesn't much matter - though. Internally, we only call it with arguments less than half - the max value of a size_t, which should work across all reasonable - possibilities, although sometimes generating compiler warnings. - -MORECORE_CONTIGUOUS default: 1 (true) if HAVE_MORECORE - If true, take advantage of fact that consecutive calls to MORECORE - with positive arguments always return contiguous increasing - addresses. This is true of unix sbrk. It does not hurt too much to - set it true anyway, since malloc copes with non-contiguities. - Setting it false when definitely non-contiguous saves time - and possibly wasted space it would take to discover this though. - -MORECORE_CANNOT_TRIM default: NOT defined - True if MORECORE cannot release space back to the system when given - negative arguments. This is generally necessary only if you are - using a hand-crafted MORECORE function that cannot handle negative - arguments. - -NO_SEGMENT_TRAVERSAL default: 0 - If non-zero, suppresses traversals of memory segments - returned by either MORECORE or CALL_MMAP. This disables - merging of segments that are contiguous, and selectively - releasing them to the OS if unused, but bounds execution times. - -HAVE_MMAP default: 1 (true) - True if this system supports mmap or an emulation of it. If so, and - HAVE_MORECORE is not true, MMAP is used for all system - allocation. If set and HAVE_MORECORE is true as well, MMAP is - primarily used to directly allocate very large blocks. It is also - used as a backup strategy in cases where MORECORE fails to provide - space from system. Note: A single call to MUNMAP is assumed to be - able to unmap memory that may have be allocated using multiple calls - to MMAP, so long as they are adjacent. - -HAVE_MREMAP default: 1 on linux, else 0 - If true realloc() uses mremap() to re-allocate large blocks and - extend or shrink allocation spaces. - -MMAP_CLEARS default: 1 except on WINCE. - True if mmap clears memory so calloc doesn't need to. This is true - for standard unix mmap using /dev/zero and on WIN32 except for WINCE. - -USE_BUILTIN_FFS default: 0 (i.e., not used) - Causes malloc to use the builtin ffs() function to compute indices. - Some compilers may recognize and intrinsify ffs to be faster than the - supplied C version. Also, the case of x86 using gcc is special-cased - to an asm instruction, so is already as fast as it can be, and so - this setting has no effect. Similarly for Win32 under recent MS compilers. - (On most x86s, the asm version is only slightly faster than the C version.) - -malloc_getpagesize default: derive from system includes, or 4096. - The system page size. To the extent possible, this malloc manages - memory from the system in page-size units. This may be (and - usually is) a function rather than a constant. This is ignored - if WIN32, where page size is determined using getSystemInfo during - initialization. - -USE_DEV_RANDOM default: 0 (i.e., not used) - Causes malloc to use /dev/random to initialize secure magic seed for - stamping footers. Otherwise, the current time is used. - -NO_MALLINFO default: 0 - If defined, don't compile "mallinfo". This can be a simple way - of dealing with mismatches between system declarations and - those in this file. - -MALLINFO_FIELD_TYPE default: size_t - The type of the fields in the mallinfo struct. This was originally - defined as "int" in SVID etc, but is more usefully defined as - size_t. The value is used only if HAVE_USR_INCLUDE_MALLOC_H is not set - -NO_MALLOC_STATS default: 0 - If defined, don't compile "malloc_stats". This avoids calls to - fprintf and bringing in stdio dependencies you might not want. - -REALLOC_ZERO_BYTES_FREES default: not defined - This should be set if a call to realloc with zero bytes should - be the same as a call to free. Some people think it should. Otherwise, - since this malloc returns a unique pointer for malloc(0), so does - realloc(p, 0). - -LACKS_UNISTD_H, LACKS_FCNTL_H, LACKS_SYS_PARAM_H, LACKS_SYS_MMAN_H -LACKS_STRINGS_H, LACKS_STRING_H, LACKS_SYS_TYPES_H, LACKS_ERRNO_H -LACKS_STDLIB_H LACKS_SCHED_H LACKS_TIME_H default: NOT defined unless on WIN32 - Define these if your system does not have these header files. - You might need to manually insert some of the declarations they provide. - -DEFAULT_GRANULARITY default: page size if MORECORE_CONTIGUOUS, - system_info.dwAllocationGranularity in WIN32, - otherwise 64K. - Also settable using mallopt(M_GRANULARITY, x) - The unit for allocating and deallocating memory from the system. On - most systems with contiguous MORECORE, there is no reason to - make this more than a page. However, systems with MMAP tend to - either require or encourage larger granularities. You can increase - this value to prevent system allocation functions to be called so - often, especially if they are slow. The value must be at least one - page and must be a power of two. Setting to 0 causes initialization - to either page size or win32 region size. (Note: In previous - versions of malloc, the equivalent of this option was called - "TOP_PAD") - -DEFAULT_TRIM_THRESHOLD default: 2MB - Also settable using mallopt(M_TRIM_THRESHOLD, x) - The maximum amount of unused top-most memory to keep before - releasing via malloc_trim in free(). Automatic trimming is mainly - useful in long-lived programs using contiguous MORECORE. Because - trimming via sbrk can be slow on some systems, and can sometimes be - wasteful (in cases where programs immediately afterward allocate - more large chunks) the value should be high enough so that your - overall system performance would improve by releasing this much - memory. As a rough guide, you might set to a value close to the - average size of a process (program) running on your system. - Releasing this much memory would allow such a process to run in - memory. Generally, it is worth tuning trim thresholds when a - program undergoes phases where several large chunks are allocated - and released in ways that can reuse each other's storage, perhaps - mixed with phases where there are no such chunks at all. The trim - value must be greater than page size to have any useful effect. To - disable trimming completely, you can set to MAX_SIZE_T. Note that the trick - some people use of mallocing a huge space and then freeing it at - program startup, in an attempt to reserve system memory, doesn't - have the intended effect under automatic trimming, since that memory - will immediately be returned to the system. - -DEFAULT_MMAP_THRESHOLD default: 256K - Also settable using mallopt(M_MMAP_THRESHOLD, x) - The request size threshold for using MMAP to directly service a - request. Requests of at least this size that cannot be allocated - using already-existing space will be serviced via mmap. (If enough - normal freed space already exists it is used instead.) Using mmap - segregates relatively large chunks of memory so that they can be - individually obtained and released from the host system. A request - serviced through mmap is never reused by any other request (at least - not directly; the system may just so happen to remap successive - requests to the same locations). Segregating space in this way has - the benefits that: Mmapped space can always be individually released - back to the system, which helps keep the system level memory demands - of a long-lived program low. Also, mapped memory doesn't become - `locked' between other chunks, as can happen with normally allocated - chunks, which means that even trimming via malloc_trim would not - release them. However, it has the disadvantage that the space - cannot be reclaimed, consolidated, and then used to service later - requests, as happens with normal chunks. The advantages of mmap - nearly always outweigh disadvantages for "large" chunks, but the - value of "large" may vary across systems. The default is an - empirically derived value that works well in most systems. You can - disable mmap by setting to MAX_SIZE_T. - -MAX_RELEASE_CHECK_RATE default: 4095 unless not HAVE_MMAP - The number of consolidated frees between checks to release - unused segments when freeing. When using non-contiguous segments, - especially with multiple mspaces, checking only for topmost space - doesn't always suffice to trigger trimming. To compensate for this, - free() will, with a period of MAX_RELEASE_CHECK_RATE (or the - current number of segments, if greater) try to release unused - segments to the OS when freeing chunks that result in - consolidation. The best value for this parameter is a compromise - between slowing down frees with relatively costly checks that - rarely trigger versus holding on to unused memory. To effectively - disable, set to MAX_SIZE_T. This may lead to a very slight speed - improvement at the expense of carrying around more memory. -*/ - -/* Version identifier to allow people to support multiple versions */ -#ifndef DLMALLOC_VERSION -#define DLMALLOC_VERSION 20806 -#endif /* DLMALLOC_VERSION */ - -#ifndef DLMALLOC_EXPORT -#define DLMALLOC_EXPORT extern -#endif - -#ifndef WIN32 -#ifdef _WIN32 -#define WIN32 1 -#endif /* _WIN32 */ -#ifdef _WIN32_WCE -#define LACKS_FCNTL_H -#define WIN32 1 -#endif /* _WIN32_WCE */ -#endif /* WIN32 */ -#ifdef WIN32 -#define WIN32_LEAN_AND_MEAN -#include -#include -#define HAVE_MMAP 1 -#define HAVE_MORECORE 0 -#define LACKS_UNISTD_H -#define LACKS_SYS_PARAM_H -#define LACKS_SYS_MMAN_H -#define LACKS_STRING_H -#define LACKS_STRINGS_H -#define LACKS_SYS_TYPES_H -#define LACKS_ERRNO_H -#define LACKS_SCHED_H -#ifndef MALLOC_FAILURE_ACTION -#define MALLOC_FAILURE_ACTION -#endif /* MALLOC_FAILURE_ACTION */ -#ifndef MMAP_CLEARS -#ifdef _WIN32_WCE /* WINCE reportedly does not clear */ -#define MMAP_CLEARS 0 -#else -#define MMAP_CLEARS 1 -#endif /* _WIN32_WCE */ -#endif /*MMAP_CLEARS */ -#endif /* WIN32 */ - -#if defined(DARWIN) || defined(_DARWIN) -/* Mac OSX docs advise not to use sbrk; it seems better to use mmap */ -#ifndef HAVE_MORECORE -#define HAVE_MORECORE 0 -#define HAVE_MMAP 1 -/* OSX allocators provide 16 byte alignment */ -#ifndef MALLOC_ALIGNMENT -#define MALLOC_ALIGNMENT ((size_t)16U) -#endif -#endif /* HAVE_MORECORE */ -#endif /* DARWIN */ - -#ifndef LACKS_SYS_TYPES_H -#include /* For size_t */ -#endif /* LACKS_SYS_TYPES_H */ - -/* The maximum possible size_t value has all bits set */ -#define MAX_SIZE_T (~(size_t)0) - -#ifndef USE_LOCKS /* ensure true if spin or recursive locks set */ -#define USE_LOCKS ((defined(USE_SPIN_LOCKS) && USE_SPIN_LOCKS != 0) || \ - (defined(USE_RECURSIVE_LOCKS) && USE_RECURSIVE_LOCKS != 0)) -#endif /* USE_LOCKS */ - -#if USE_LOCKS /* Spin locks for gcc >= 4.1, older gcc on x86, MSC >= 1310 */ -#if ((defined(__GNUC__) && \ - ((__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)) || \ - defined(__i386__) || defined(__x86_64__))) || \ - (defined(_MSC_VER) && _MSC_VER>=1310)) -#ifndef USE_SPIN_LOCKS -#define USE_SPIN_LOCKS 1 -#endif /* USE_SPIN_LOCKS */ -#elif USE_SPIN_LOCKS -#error "USE_SPIN_LOCKS defined without implementation" -#endif /* ... locks available... */ -#elif !defined(USE_SPIN_LOCKS) -#define USE_SPIN_LOCKS 0 -#endif /* USE_LOCKS */ - -#ifndef ONLY_MSPACES -#define ONLY_MSPACES 0 -#endif /* ONLY_MSPACES */ -#ifndef MSPACES -#if ONLY_MSPACES -#define MSPACES 1 -#else /* ONLY_MSPACES */ -#define MSPACES 0 -#endif /* ONLY_MSPACES */ -#endif /* MSPACES */ -#ifndef MALLOC_ALIGNMENT -#define MALLOC_ALIGNMENT ((size_t)(2 * sizeof(void *))) -#endif /* MALLOC_ALIGNMENT */ -#ifndef FOOTERS -#define FOOTERS 0 -#endif /* FOOTERS */ -#ifndef ABORT -#define ABORT abort() -#endif /* ABORT */ -#ifndef ABORT_ON_ASSERT_FAILURE -#define ABORT_ON_ASSERT_FAILURE 1 -#endif /* ABORT_ON_ASSERT_FAILURE */ -#ifndef PROCEED_ON_ERROR -#define PROCEED_ON_ERROR 0 -#endif /* PROCEED_ON_ERROR */ - -#ifndef INSECURE -#define INSECURE 0 -#endif /* INSECURE */ -#ifndef MALLOC_INSPECT_ALL -#define MALLOC_INSPECT_ALL 0 -#endif /* MALLOC_INSPECT_ALL */ -#ifndef HAVE_MMAP -#define HAVE_MMAP 1 -#endif /* HAVE_MMAP */ -#ifndef MMAP_CLEARS -#define MMAP_CLEARS 1 -#endif /* MMAP_CLEARS */ -#ifndef HAVE_MREMAP -#ifdef linux -#define HAVE_MREMAP 1 -#define _GNU_SOURCE /* Turns on mremap() definition */ -#else /* linux */ -#define HAVE_MREMAP 0 -#endif /* linux */ -#endif /* HAVE_MREMAP */ -#ifndef MALLOC_FAILURE_ACTION -#define MALLOC_FAILURE_ACTION errno = ENOMEM; -#endif /* MALLOC_FAILURE_ACTION */ -#ifndef HAVE_MORECORE -#if ONLY_MSPACES -#define HAVE_MORECORE 0 -#else /* ONLY_MSPACES */ -#define HAVE_MORECORE 1 -#endif /* ONLY_MSPACES */ -#endif /* HAVE_MORECORE */ -#if !HAVE_MORECORE -#define MORECORE_CONTIGUOUS 0 -#else /* !HAVE_MORECORE */ -#define MORECORE_DEFAULT sbrk -#ifndef MORECORE_CONTIGUOUS -#define MORECORE_CONTIGUOUS 1 -#endif /* MORECORE_CONTIGUOUS */ -#endif /* HAVE_MORECORE */ -#ifndef DEFAULT_GRANULARITY -#if (MORECORE_CONTIGUOUS || defined(WIN32)) -#define DEFAULT_GRANULARITY (0) /* 0 means to compute in init_mparams */ -#else /* MORECORE_CONTIGUOUS */ -#define DEFAULT_GRANULARITY ((size_t)64U * (size_t)1024U) -#endif /* MORECORE_CONTIGUOUS */ -#endif /* DEFAULT_GRANULARITY */ -#ifndef DEFAULT_TRIM_THRESHOLD -#ifndef MORECORE_CANNOT_TRIM -#define DEFAULT_TRIM_THRESHOLD ((size_t)2U * (size_t)1024U * (size_t)1024U) -#else /* MORECORE_CANNOT_TRIM */ -#define DEFAULT_TRIM_THRESHOLD MAX_SIZE_T -#endif /* MORECORE_CANNOT_TRIM */ -#endif /* DEFAULT_TRIM_THRESHOLD */ -#ifndef DEFAULT_MMAP_THRESHOLD -#if HAVE_MMAP -#define DEFAULT_MMAP_THRESHOLD ((size_t)256U * (size_t)1024U) -#else /* HAVE_MMAP */ -#define DEFAULT_MMAP_THRESHOLD MAX_SIZE_T -#endif /* HAVE_MMAP */ -#endif /* DEFAULT_MMAP_THRESHOLD */ -#ifndef MAX_RELEASE_CHECK_RATE -#if HAVE_MMAP -#define MAX_RELEASE_CHECK_RATE 4095 -#else -#define MAX_RELEASE_CHECK_RATE MAX_SIZE_T -#endif /* HAVE_MMAP */ -#endif /* MAX_RELEASE_CHECK_RATE */ -#ifndef USE_BUILTIN_FFS -#define USE_BUILTIN_FFS 0 -#endif /* USE_BUILTIN_FFS */ -#ifndef USE_DEV_RANDOM -#define USE_DEV_RANDOM 0 -#endif /* USE_DEV_RANDOM */ -#ifndef NO_MALLINFO -#define NO_MALLINFO 0 -#endif /* NO_MALLINFO */ -#ifndef MALLINFO_FIELD_TYPE -#define MALLINFO_FIELD_TYPE size_t -#endif /* MALLINFO_FIELD_TYPE */ -#ifndef NO_MALLOC_STATS -#define NO_MALLOC_STATS 0 -#endif /* NO_MALLOC_STATS */ -#ifndef NO_SEGMENT_TRAVERSAL -#define NO_SEGMENT_TRAVERSAL 0 -#endif /* NO_SEGMENT_TRAVERSAL */ - -/* - mallopt tuning options. SVID/XPG defines four standard parameter - numbers for mallopt, normally defined in malloc.h. None of these - are used in this malloc, so setting them has no effect. But this - malloc does support the following options. -*/ - -#define M_TRIM_THRESHOLD (-1) -#define M_GRANULARITY (-2) -#define M_MMAP_THRESHOLD (-3) - -/* ------------------------ Mallinfo declarations ------------------------ */ - -#if !NO_MALLINFO -/* - This version of malloc supports the standard SVID/XPG mallinfo - routine that returns a struct containing usage properties and - statistics. It should work on any system that has a - /usr/include/malloc.h defining struct mallinfo. The main - declaration needed is the mallinfo struct that is returned (by-copy) - by mallinfo(). The malloinfo struct contains a bunch of fields that - are not even meaningful in this version of malloc. These fields are - are instead filled by mallinfo() with other numbers that might be of - interest. - - HAVE_USR_INCLUDE_MALLOC_H should be set if you have a - /usr/include/malloc.h file that includes a declaration of struct - mallinfo. If so, it is included; else a compliant version is - declared below. These must be precisely the same for mallinfo() to - work. The original SVID version of this struct, defined on most - systems with mallinfo, declares all fields as ints. But some others - define as unsigned long. If your system defines the fields using a - type of different width than listed here, you MUST #include your - system version and #define HAVE_USR_INCLUDE_MALLOC_H. -*/ - -/* #define HAVE_USR_INCLUDE_MALLOC_H */ - -#ifdef HAVE_USR_INCLUDE_MALLOC_H -#include "/usr/include/malloc.h" -#else /* HAVE_USR_INCLUDE_MALLOC_H */ -#ifndef STRUCT_MALLINFO_DECLARED -/* HP-UX (and others?) redefines mallinfo unless _STRUCT_MALLINFO is defined */ -#define _STRUCT_MALLINFO -#define STRUCT_MALLINFO_DECLARED 1 -struct mallinfo { - MALLINFO_FIELD_TYPE arena; /* non-mmapped space allocated from system */ - MALLINFO_FIELD_TYPE ordblks; /* number of free chunks */ - MALLINFO_FIELD_TYPE smblks; /* always 0 */ - MALLINFO_FIELD_TYPE hblks; /* always 0 */ - MALLINFO_FIELD_TYPE hblkhd; /* space in mmapped regions */ - MALLINFO_FIELD_TYPE usmblks; /* maximum total allocated space */ - MALLINFO_FIELD_TYPE fsmblks; /* always 0 */ - MALLINFO_FIELD_TYPE uordblks; /* total allocated space */ - MALLINFO_FIELD_TYPE fordblks; /* total free space */ - MALLINFO_FIELD_TYPE keepcost; /* releasable (via malloc_trim) space */ -}; -#endif /* STRUCT_MALLINFO_DECLARED */ -#endif /* HAVE_USR_INCLUDE_MALLOC_H */ -#endif /* NO_MALLINFO */ - -/* - Try to persuade compilers to inline. The most critical functions for - inlining are defined as macros, so these aren't used for them. -*/ - -#ifndef FORCEINLINE - #if defined(__GNUC__) -#define FORCEINLINE __inline __attribute__ ((always_inline)) - #elif defined(_MSC_VER) - #define FORCEINLINE __forceinline - #endif -#endif -#ifndef NOINLINE - #if defined(__GNUC__) - #define NOINLINE __attribute__ ((noinline)) - #elif defined(_MSC_VER) - #define NOINLINE __declspec(noinline) - #else - #define NOINLINE - #endif -#endif - -#ifdef __cplusplus -extern "C" { -#ifndef FORCEINLINE - #define FORCEINLINE inline -#endif -#endif /* __cplusplus */ -#ifndef FORCEINLINE - #define FORCEINLINE -#endif - -#if !ONLY_MSPACES - -/* ------------------- Declarations of public routines ------------------- */ - -#ifndef USE_DL_PREFIX -#define dlcalloc calloc -#define dlfree free -#define dlmalloc malloc -#define dlmemalign memalign -#define dlposix_memalign posix_memalign -#define dlrealloc realloc -#define dlrealloc_in_place realloc_in_place -#define dlvalloc valloc -#define dlpvalloc pvalloc -#define dlmallinfo mallinfo -#define dlmallopt mallopt -#define dlmalloc_trim malloc_trim -#define dlmalloc_stats malloc_stats -#define dlmalloc_usable_size malloc_usable_size -#define dlmalloc_footprint malloc_footprint -#define dlmalloc_max_footprint malloc_max_footprint -#define dlmalloc_footprint_limit malloc_footprint_limit -#define dlmalloc_set_footprint_limit malloc_set_footprint_limit -#define dlmalloc_inspect_all malloc_inspect_all -#define dlindependent_calloc independent_calloc -#define dlindependent_comalloc independent_comalloc -#define dlbulk_free bulk_free -#endif /* USE_DL_PREFIX */ - -/* - malloc(size_t n) - Returns a pointer to a newly allocated chunk of at least n bytes, or - null if no space is available, in which case errno is set to ENOMEM - on ANSI C systems. - - If n is zero, malloc returns a minimum-sized chunk. (The minimum - size is 16 bytes on most 32bit systems, and 32 bytes on 64bit - systems.) Note that size_t is an unsigned type, so calls with - arguments that would be negative if signed are interpreted as - requests for huge amounts of space, which will often fail. The - maximum supported value of n differs across systems, but is in all - cases less than the maximum representable value of a size_t. -*/ -DLMALLOC_EXPORT void* dlmalloc(size_t); - -/* - free(void* p) - Releases the chunk of memory pointed to by p, that had been previously - allocated using malloc or a related routine such as realloc. - It has no effect if p is null. If p was not malloced or already - freed, free(p) will by default cause the current program to abort. -*/ -DLMALLOC_EXPORT void dlfree(void*); - -/* - calloc(size_t n_elements, size_t element_size); - Returns a pointer to n_elements * element_size bytes, with all locations - set to zero. -*/ -DLMALLOC_EXPORT void* dlcalloc(size_t, size_t); - -/* - realloc(void* p, size_t n) - Returns 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. The algorithm - prefers extending p in most cases when possible, otherwise it - employs the equivalent of a malloc-copy-free sequence. - - If p is null, realloc is equivalent to malloc. - - If space is not available, realloc returns null, errno is set (if on - ANSI) and p is NOT freed. - - if n is for fewer bytes than already held by p, the newly unused - space is lopped off and freed if possible. realloc with a size - argument of zero (re)allocates a minimum-sized chunk. - - The old unix realloc convention of allowing the last-free'd chunk - to be used as an argument to realloc is not supported. -*/ -DLMALLOC_EXPORT void* dlrealloc(void*, size_t); - -/* - realloc_in_place(void* p, size_t n) - Resizes the space allocated for p to size n, only if this can be - done without moving p (i.e., only if there is adjacent space - available if n is greater than p's current allocated size, or n is - less than or equal to p's size). This may be used instead of plain - realloc if an alternative allocation strategy is needed upon failure - to expand space; for example, reallocation of a buffer that must be - memory-aligned or cleared. You can use realloc_in_place to trigger - these alternatives only when needed. - - Returns p if successful; otherwise null. -*/ -DLMALLOC_EXPORT void* dlrealloc_in_place(void*, size_t); - -/* - memalign(size_t alignment, size_t n); - Returns a pointer to a newly allocated chunk of n bytes, aligned - in accord with the alignment argument. - - The alignment argument should be a power of two. If the argument is - not a power of two, the nearest greater power is used. - 8-byte alignment is guaranteed by normal malloc calls, so don't - bother calling memalign with an argument of 8 or less. - - Overreliance on memalign is a sure way to fragment space. -*/ -DLMALLOC_EXPORT void* dlmemalign(size_t, size_t); - -/* - int posix_memalign(void** pp, size_t alignment, size_t n); - Allocates a chunk of n bytes, aligned in accord with the alignment - argument. Differs from memalign only in that it (1) assigns the - allocated memory to *pp rather than returning it, (2) fails and - returns EINVAL if the alignment is not a power of two (3) fails and - returns ENOMEM if memory cannot be allocated. -*/ -DLMALLOC_EXPORT int dlposix_memalign(void**, size_t, size_t); - -/* - valloc(size_t n); - Equivalent to memalign(pagesize, n), where pagesize is the page - size of the system. If the pagesize is unknown, 4096 is used. -*/ -DLMALLOC_EXPORT void* dlvalloc(size_t); - -/* - mallopt(int parameter_number, int parameter_value) - Sets tunable parameters The format is to provide a - (parameter-number, parameter-value) pair. mallopt then sets the - corresponding parameter to the argument value if it can (i.e., so - long as the value is meaningful), and returns 1 if successful else - 0. To workaround the fact that mallopt is specified to use int, - not size_t parameters, the value -1 is specially treated as the - maximum unsigned size_t value. - - SVID/XPG/ANSI defines four standard param numbers for mallopt, - normally defined in malloc.h. None of these are use in this malloc, - so setting them has no effect. But this malloc also supports other - options in mallopt. See below for details. Briefly, supported - parameters are as follows (listed defaults are for "typical" - configurations). - - Symbol param # default allowed param values - M_TRIM_THRESHOLD -1 2*1024*1024 any (-1 disables) - M_GRANULARITY -2 page size any power of 2 >= page size - M_MMAP_THRESHOLD -3 256*1024 any (or 0 if no MMAP support) -*/ -DLMALLOC_EXPORT int dlmallopt(int, int); - -/* - malloc_footprint(); - Returns the number of bytes obtained from the system. The total - number of bytes allocated by malloc, realloc etc., is less than this - value. Unlike mallinfo, this function returns only a precomputed - result, so can be called frequently to monitor memory consumption. - Even if locks are otherwise defined, this function does not use them, - so results might not be up to date. -*/ -DLMALLOC_EXPORT size_t dlmalloc_footprint(void); - -/* - malloc_max_footprint(); - Returns the maximum number of bytes obtained from the system. This - value will be greater than current footprint if deallocated space - has been reclaimed by the system. The peak number of bytes allocated - by malloc, realloc etc., is less than this value. Unlike mallinfo, - this function returns only a precomputed result, so can be called - frequently to monitor memory consumption. Even if locks are - otherwise defined, this function does not use them, so results might - not be up to date. -*/ -DLMALLOC_EXPORT size_t dlmalloc_max_footprint(void); - -/* - malloc_footprint_limit(); - Returns the number of bytes that the heap is allowed to obtain from - the system, returning the last value returned by - malloc_set_footprint_limit, or the maximum size_t value if - never set. The returned value reflects a permission. There is no - guarantee that this number of bytes can actually be obtained from - the system. -*/ -DLMALLOC_EXPORT size_t dlmalloc_footprint_limit(); - -/* - malloc_set_footprint_limit(); - Sets the maximum number of bytes to obtain from the system, causing - failure returns from malloc and related functions upon attempts to - exceed this value. The argument value may be subject to page - rounding to an enforceable limit; this actual value is returned. - Using an argument of the maximum possible size_t effectively - disables checks. If the argument is less than or equal to the - current malloc_footprint, then all future allocations that require - additional system memory will fail. However, invocation cannot - retroactively deallocate existing used memory. -*/ -DLMALLOC_EXPORT size_t dlmalloc_set_footprint_limit(size_t bytes); - -#if MALLOC_INSPECT_ALL -/* - malloc_inspect_all(void(*handler)(void *start, - void *end, - size_t used_bytes, - void* callback_arg), - void* arg); - Traverses the heap and calls the given handler for each managed - region, skipping all bytes that are (or may be) used for bookkeeping - purposes. Traversal does not include include chunks that have been - directly memory mapped. Each reported region begins at the start - address, and continues up to but not including the end address. The - first used_bytes of the region contain allocated data. If - used_bytes is zero, the region is unallocated. The handler is - invoked with the given callback argument. If locks are defined, they - are held during the entire traversal. It is a bad idea to invoke - other malloc functions from within the handler. - - For example, to count the number of in-use chunks with size greater - than 1000, you could write: - static int count = 0; - void count_chunks(void* start, void* end, size_t used, void* arg) { - if (used >= 1000) ++count; - } - then: - malloc_inspect_all(count_chunks, NULL); - - malloc_inspect_all is compiled only if MALLOC_INSPECT_ALL is defined. -*/ -DLMALLOC_EXPORT void dlmalloc_inspect_all(void(*handler)(void*, void *, size_t, void*), - void* arg); - -#endif /* MALLOC_INSPECT_ALL */ - -#if !NO_MALLINFO -/* - mallinfo() - Returns (by copy) a struct containing various summary statistics: - - arena: current total non-mmapped bytes allocated from system - ordblks: the number of free chunks - smblks: always zero. - hblks: current number of mmapped regions - hblkhd: total bytes held in mmapped regions - usmblks: the maximum total allocated space. This will be greater - than current total if trimming has occurred. - fsmblks: always zero - uordblks: current total allocated space (normal or mmapped) - fordblks: total free space - keepcost: the maximum number of bytes that could ideally be released - back to system via malloc_trim. ("ideally" means that - it ignores page restrictions etc.) - - Because these fields are ints, but internal bookkeeping may - be kept as longs, the reported values may wrap around zero and - thus be inaccurate. -*/ -DLMALLOC_EXPORT struct mallinfo dlmallinfo(void); -#endif /* NO_MALLINFO */ - -/* - independent_calloc(size_t n_elements, size_t element_size, void* chunks[]); - - independent_calloc is similar to calloc, but instead of returning a - single cleared space, it returns an array of pointers to n_elements - independent elements that can hold contents of size elem_size, each - of which starts out cleared, and can be independently freed, - realloc'ed etc. The elements are guaranteed to be adjacently - allocated (this is not guaranteed to occur with multiple callocs or - mallocs), which may also improve cache locality in some - applications. - - The "chunks" argument is optional (i.e., may be null, which is - probably the most typical usage). If it is null, the returned array - is itself dynamically allocated and should also be freed when it is - no longer needed. Otherwise, the chunks array must be of at least - n_elements in length. It is filled in with the pointers to the - chunks. - - In either case, independent_calloc returns this pointer array, or - null if the allocation failed. If n_elements is zero and "chunks" - is null, it returns a chunk representing an array with zero elements - (which should be freed if not wanted). - - Each element must be freed when it is no longer needed. This can be - done all at once using bulk_free. - - independent_calloc simplifies and speeds up implementations of many - kinds of pools. It may also be useful when constructing large data - structures that initially have a fixed number of fixed-sized nodes, - but the number is not known at compile time, and some of the nodes - may later need to be freed. For example: - - struct Node { int item; struct Node* next; }; - - struct Node* build_list() { - struct Node** pool; - int n = read_number_of_nodes_needed(); - if (n <= 0) return 0; - pool = (struct Node**)(independent_calloc(n, sizeof(struct Node), 0); - if (pool == 0) die(); - // organize into a linked list... - struct Node* first = pool[0]; - for (i = 0; i < n-1; ++i) - pool[i]->next = pool[i+1]; - free(pool); // Can now free the array (or not, if it is needed later) - return first; - } -*/ -DLMALLOC_EXPORT void** dlindependent_calloc(size_t, size_t, void**); - -/* - independent_comalloc(size_t n_elements, size_t sizes[], void* chunks[]); - - independent_comalloc allocates, all at once, a set of n_elements - chunks with sizes indicated in the "sizes" array. It returns - an array of pointers to these elements, each of which can be - independently freed, realloc'ed etc. The elements are guaranteed to - be adjacently allocated (this is not guaranteed to occur with - multiple callocs or mallocs), which may also improve cache locality - in some applications. - - The "chunks" argument is optional (i.e., may be null). If it is null - the returned array is itself dynamically allocated and should also - be freed when it is no longer needed. Otherwise, the chunks array - must be of at least n_elements in length. It is filled in with the - pointers to the chunks. - - In either case, independent_comalloc returns this pointer array, or - null if the allocation failed. If n_elements is zero and chunks is - null, it returns a chunk representing an array with zero elements - (which should be freed if not wanted). - - Each element must be freed when it is no longer needed. This can be - done all at once using bulk_free. - - independent_comallac differs from independent_calloc in that each - element may have a different size, and also that it does not - automatically clear elements. - - independent_comalloc can be used to speed up allocation in cases - where several structs or objects must always be allocated at the - same time. For example: - - struct Head { ... } - struct Foot { ... } - - void send_message(char* msg) { - int msglen = strlen(msg); - size_t sizes[3] = { sizeof(struct Head), msglen, sizeof(struct Foot) }; - void* chunks[3]; - if (independent_comalloc(3, sizes, chunks) == 0) - die(); - struct Head* head = (struct Head*)(chunks[0]); - char* body = (char*)(chunks[1]); - struct Foot* foot = (struct Foot*)(chunks[2]); - // ... - } - - In general though, independent_comalloc is worth using only for - larger values of n_elements. For small values, you probably won't - detect enough difference from series of malloc calls to bother. - - Overuse of independent_comalloc can increase overall memory usage, - since it cannot reuse existing noncontiguous small chunks that - might be available for some of the elements. -*/ -DLMALLOC_EXPORT void** dlindependent_comalloc(size_t, size_t*, void**); - -/* - bulk_free(void* array[], size_t n_elements) - Frees and clears (sets to null) each non-null pointer in the given - array. This is likely to be faster than freeing them one-by-one. - If footers are used, pointers that have been allocated in different - mspaces are not freed or cleared, and the count of all such pointers - is returned. For large arrays of pointers with poor locality, it - may be worthwhile to sort this array before calling bulk_free. -*/ -DLMALLOC_EXPORT size_t dlbulk_free(void**, size_t n_elements); - -/* - pvalloc(size_t n); - Equivalent to valloc(minimum-page-that-holds(n)), that is, - round up n to nearest pagesize. - */ -DLMALLOC_EXPORT void* dlpvalloc(size_t); - -/* - malloc_trim(size_t pad); - - If possible, gives memory back to the system (via negative arguments - to sbrk) if there is unused memory at the `high' end of the malloc - pool or in unused MMAP segments. You can call this after freeing - large blocks of memory to potentially reduce the system-level memory - requirements of a program. However, it cannot guarantee to reduce - memory. Under some allocation patterns, some large free blocks of - memory will be locked between two used chunks, so they cannot be - given back to the system. - - The `pad' argument to malloc_trim represents the amount of free - trailing space to leave untrimmed. If this argument is zero, only - the minimum amount of memory to maintain internal data structures - will be left. Non-zero arguments can be supplied to maintain enough - trailing space to service future expected allocations without having - to re-obtain memory from the system. - - Malloc_trim returns 1 if it actually released any memory, else 0. -*/ -DLMALLOC_EXPORT int dlmalloc_trim(size_t); - -/* - malloc_stats(); - Prints on stderr the amount of space obtained from the system (both - via sbrk and mmap), the maximum amount (which may be more than - current if malloc_trim and/or munmap got called), and the current - number of bytes allocated via malloc (or realloc, etc) but not yet - freed. Note that this is the number of bytes allocated, not the - number requested. It will be larger than the number requested - because of alignment and bookkeeping overhead. Because it includes - alignment wastage as being in use, this figure may be greater than - zero even when no user-level chunks are allocated. - - The reported current and maximum system memory can be inaccurate if - a program makes other calls to system memory allocation functions - (normally sbrk) outside of malloc. - - malloc_stats prints only the most commonly interesting statistics. - More information can be obtained by calling mallinfo. -*/ -DLMALLOC_EXPORT void dlmalloc_stats(void); - -/* - malloc_usable_size(void* p); - - Returns the number of bytes you can actually use in - an allocated chunk, which may be more than you requested (although - often not) due to alignment and minimum size constraints. - You can use this many bytes without worrying about - overwriting other allocated objects. This is not a particularly great - programming practice. malloc_usable_size can be more useful in - debugging and assertions, for example: - - p = malloc(n); - assert(malloc_usable_size(p) >= 256); -*/ -size_t dlmalloc_usable_size(void*); - -#endif /* ONLY_MSPACES */ - -#if MSPACES - -/* - mspace is an opaque type representing an independent - region of space that supports mspace_malloc, etc. -*/ -typedef void* mspace; - -/* - create_mspace creates and returns a new independent space with the - given initial capacity, or, if 0, the default granularity size. It - returns null if there is no system memory available to create the - space. If argument locked is non-zero, the space uses a separate - lock to control access. The capacity of the space will grow - dynamically as needed to service mspace_malloc requests. You can - control the sizes of incremental increases of this space by - compiling with a different DEFAULT_GRANULARITY or dynamically - setting with mallopt(M_GRANULARITY, value). -*/ -DLMALLOC_EXPORT mspace create_mspace(size_t capacity, int locked); - -/* - destroy_mspace destroys the given space, and attempts to return all - of its memory back to the system, returning the total number of - bytes freed. After destruction, the results of access to all memory - used by the space become undefined. -*/ -DLMALLOC_EXPORT size_t destroy_mspace(mspace msp); - -/* - create_mspace_with_base uses the memory supplied as the initial base - of a new mspace. Part (less than 128*sizeof(size_t) bytes) of this - space is used for bookkeeping, so the capacity must be at least this - large. (Otherwise 0 is returned.) When this initial space is - exhausted, additional memory will be obtained from the system. - Destroying this space will deallocate all additionally allocated - space (if possible) but not the initial base. -*/ -DLMALLOC_EXPORT mspace create_mspace_with_base(void* base, size_t capacity, int locked); - -/* - mspace_track_large_chunks controls whether requests for large chunks - are allocated in their own untracked mmapped regions, separate from - others in this mspace. By default large chunks are not tracked, - which reduces fragmentation. However, such chunks are not - necessarily released to the system upon destroy_mspace. Enabling - tracking by setting to true may increase fragmentation, but avoids - leakage when relying on destroy_mspace to release all memory - allocated using this space. The function returns the previous - setting. -*/ -DLMALLOC_EXPORT int mspace_track_large_chunks(mspace msp, int enable); - - -/* - mspace_malloc behaves as malloc, but operates within - the given space. -*/ -DLMALLOC_EXPORT void* mspace_malloc(mspace msp, size_t bytes); - -/* - mspace_free behaves as free, but operates within - the given space. - - If compiled with FOOTERS==1, mspace_free is not actually needed. - free may be called instead of mspace_free because freed chunks from - any space are handled by their originating spaces. -*/ -DLMALLOC_EXPORT void mspace_free(mspace msp, void* mem); - -/* - mspace_realloc behaves as realloc, but operates within - the given space. - - If compiled with FOOTERS==1, mspace_realloc is not actually - needed. realloc may be called instead of mspace_realloc because - realloced chunks from any space are handled by their originating - spaces. -*/ -DLMALLOC_EXPORT void* mspace_realloc(mspace msp, void* mem, size_t newsize); - -/* - mspace_calloc behaves as calloc, but operates within - the given space. -*/ -DLMALLOC_EXPORT void* mspace_calloc(mspace msp, size_t n_elements, size_t elem_size); - -/* - mspace_memalign behaves as memalign, but operates within - the given space. -*/ -DLMALLOC_EXPORT void* mspace_memalign(mspace msp, size_t alignment, size_t bytes); - -/* - mspace_independent_calloc behaves as independent_calloc, but - operates within the given space. -*/ -DLMALLOC_EXPORT void** mspace_independent_calloc(mspace msp, size_t n_elements, - size_t elem_size, void* chunks[]); - -/* - mspace_independent_comalloc behaves as independent_comalloc, but - operates within the given space. -*/ -DLMALLOC_EXPORT void** mspace_independent_comalloc(mspace msp, size_t n_elements, - size_t sizes[], void* chunks[]); - -/* - mspace_footprint() returns the number of bytes obtained from the - system for this space. -*/ -DLMALLOC_EXPORT size_t mspace_footprint(mspace msp); - -/* - mspace_max_footprint() returns the peak number of bytes obtained from the - system for this space. -*/ -DLMALLOC_EXPORT size_t mspace_max_footprint(mspace msp); - - -#if !NO_MALLINFO -/* - mspace_mallinfo behaves as mallinfo, but reports properties of - the given space. -*/ -DLMALLOC_EXPORT struct mallinfo mspace_mallinfo(mspace msp); -#endif /* NO_MALLINFO */ - -/* - malloc_usable_size(void* p) behaves the same as malloc_usable_size; -*/ -DLMALLOC_EXPORT size_t mspace_usable_size(const void* mem); - -/* - mspace_malloc_stats behaves as malloc_stats, but reports - properties of the given space. -*/ -DLMALLOC_EXPORT void mspace_malloc_stats(mspace msp); - -/* - mspace_trim behaves as malloc_trim, but - operates within the given space. -*/ -DLMALLOC_EXPORT int mspace_trim(mspace msp, size_t pad); - -/* - An alias for mallopt. -*/ -DLMALLOC_EXPORT int mspace_mallopt(int, int); - -#endif /* MSPACES */ - -#ifdef __cplusplus -} /* end of extern "C" */ -#endif /* __cplusplus */ - -/* - ======================================================================== - To make a fully customizable malloc.h header file, cut everything - above this line, put into file malloc.h, edit to suit, and #include it - on the next line, as well as in programs that use this malloc. - ======================================================================== -*/ - -/* #include "malloc.h" */ - -/*------------------------------ internal #includes ---------------------- */ - -#ifdef _MSC_VER -#pragma warning( disable : 4146 ) /* no "unsigned" warnings */ -#endif /* _MSC_VER */ -#if !NO_MALLOC_STATS -#include /* for printing in malloc_stats */ -#endif /* NO_MALLOC_STATS */ -#ifndef LACKS_ERRNO_H -#include /* for MALLOC_FAILURE_ACTION */ -#endif /* LACKS_ERRNO_H */ -#ifdef DEBUG -#if ABORT_ON_ASSERT_FAILURE -#undef assert -#define assert(x) if(!(x)) ABORT -#else /* ABORT_ON_ASSERT_FAILURE */ -#include -#endif /* ABORT_ON_ASSERT_FAILURE */ -#else /* DEBUG */ -#ifndef assert -#define assert(x) -#endif -#define DEBUG 0 -#endif /* DEBUG */ -#if !defined(WIN32) && !defined(LACKS_TIME_H) -#include /* for magic initialization */ -#endif /* WIN32 */ -#ifndef LACKS_STDLIB_H -#include /* for abort() */ -#endif /* LACKS_STDLIB_H */ -#ifndef LACKS_STRING_H -#include /* for memset etc */ -#endif /* LACKS_STRING_H */ -#if USE_BUILTIN_FFS -#ifndef LACKS_STRINGS_H -#include /* for ffs */ -#endif /* LACKS_STRINGS_H */ -#endif /* USE_BUILTIN_FFS */ -#if HAVE_MMAP -#ifndef LACKS_SYS_MMAN_H -/* On some versions of linux, mremap decl in mman.h needs __USE_GNU set */ -#if (defined(linux) && !defined(__USE_GNU)) -#define __USE_GNU 1 -#include /* for mmap */ -#undef __USE_GNU -#else -#include /* for mmap */ -#endif /* linux */ -#endif /* LACKS_SYS_MMAN_H */ -#ifndef LACKS_FCNTL_H -#include -#endif /* LACKS_FCNTL_H */ -#endif /* HAVE_MMAP */ -#ifndef LACKS_UNISTD_H -#include /* for sbrk, sysconf */ -#else /* LACKS_UNISTD_H */ -#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) -extern void* sbrk(ptrdiff_t); -#endif /* FreeBSD etc */ -#endif /* LACKS_UNISTD_H */ - -/* Declarations for locking */ -#if USE_LOCKS -#ifndef WIN32 -#if defined (__SVR4) && defined (__sun) /* solaris */ -#include -#elif !defined(LACKS_SCHED_H) -#include -#endif /* solaris or LACKS_SCHED_H */ -#if (defined(USE_RECURSIVE_LOCKS) && USE_RECURSIVE_LOCKS != 0) || !USE_SPIN_LOCKS -#include -#endif /* USE_RECURSIVE_LOCKS ... */ -#elif defined(_MSC_VER) -#ifndef _M_AMD64 -/* These are already defined on AMD64 builds */ -#ifdef __cplusplus -extern "C" { -#endif /* __cplusplus */ -LONG __cdecl _InterlockedCompareExchange(LONG volatile *Dest, LONG Exchange, LONG Comp); -LONG __cdecl _InterlockedExchange(LONG volatile *Target, LONG Value); -#ifdef __cplusplus -} -#endif /* __cplusplus */ -#endif /* _M_AMD64 */ -#pragma intrinsic (_InterlockedCompareExchange) -#pragma intrinsic (_InterlockedExchange) -#define interlockedcompareexchange _InterlockedCompareExchange -#define interlockedexchange _InterlockedExchange -#elif defined(WIN32) && defined(__GNUC__) -#define interlockedcompareexchange(a, b, c) __sync_val_compare_and_swap(a, c, b) -#define interlockedexchange __sync_lock_test_and_set -#endif /* Win32 */ -#else /* USE_LOCKS */ -#endif /* USE_LOCKS */ - -#ifndef LOCK_AT_FORK -#define LOCK_AT_FORK 0 -#endif - -/* Declarations for bit scanning on win32 */ -#if defined(_MSC_VER) && _MSC_VER>=1300 -#ifndef BitScanForward /* Try to avoid pulling in WinNT.h */ -#ifdef __cplusplus -extern "C" { -#endif /* __cplusplus */ -unsigned char _BitScanForward(unsigned long *index, unsigned long mask); -unsigned char _BitScanReverse(unsigned long *index, unsigned long mask); -#ifdef __cplusplus -} -#endif /* __cplusplus */ - -#define BitScanForward _BitScanForward -#define BitScanReverse _BitScanReverse -#pragma intrinsic(_BitScanForward) -#pragma intrinsic(_BitScanReverse) -#endif /* BitScanForward */ -#endif /* defined(_MSC_VER) && _MSC_VER>=1300 */ - -#ifndef WIN32 -#ifndef malloc_getpagesize -# ifdef _SC_PAGESIZE /* some SVR4 systems omit an underscore */ -# ifndef _SC_PAGE_SIZE -# define _SC_PAGE_SIZE _SC_PAGESIZE -# endif -# endif -# ifdef _SC_PAGE_SIZE -# define malloc_getpagesize sysconf(_SC_PAGE_SIZE) -# else -# if defined(BSD) || defined(DGUX) || defined(HAVE_GETPAGESIZE) - extern size_t getpagesize(); -# define malloc_getpagesize getpagesize() -# else -# ifdef WIN32 /* use supplied emulation of getpagesize */ -# define malloc_getpagesize getpagesize() -# else -# ifndef LACKS_SYS_PARAM_H -# include -# endif -# ifdef EXEC_PAGESIZE -# define malloc_getpagesize EXEC_PAGESIZE -# else -# ifdef NBPG -# ifndef CLSIZE -# define malloc_getpagesize NBPG -# else -# define malloc_getpagesize (NBPG * CLSIZE) -# endif -# else -# ifdef NBPC -# define malloc_getpagesize NBPC -# else -# ifdef PAGESIZE -# define malloc_getpagesize PAGESIZE -# else /* just guess */ -# define malloc_getpagesize ((size_t)4096U) -# endif -# endif -# endif -# endif -# endif -# endif -# endif -#endif -#endif - -/* ------------------- size_t and alignment properties -------------------- */ - -/* The byte and bit size of a size_t */ -#define SIZE_T_SIZE (sizeof(size_t)) -#define SIZE_T_BITSIZE (sizeof(size_t) << 3) - -/* Some constants coerced to size_t */ -/* Annoying but necessary to avoid errors on some platforms */ -#define SIZE_T_ZERO ((size_t)0) -#define SIZE_T_ONE ((size_t)1) -#define SIZE_T_TWO ((size_t)2) -#define SIZE_T_FOUR ((size_t)4) -#define TWO_SIZE_T_SIZES (SIZE_T_SIZE<<1) -#define FOUR_SIZE_T_SIZES (SIZE_T_SIZE<<2) -#define SIX_SIZE_T_SIZES (FOUR_SIZE_T_SIZES+TWO_SIZE_T_SIZES) -#define HALF_MAX_SIZE_T (MAX_SIZE_T / 2U) - -/* The bit mask value corresponding to MALLOC_ALIGNMENT */ -#define CHUNK_ALIGN_MASK (MALLOC_ALIGNMENT - SIZE_T_ONE) - -/* True if address a has acceptable alignment */ -#define is_aligned(A) (((size_t)((A)) & (CHUNK_ALIGN_MASK)) == 0) - -/* the number of bytes to offset an address to align it */ -#define align_offset(A)\ - ((((size_t)(A) & CHUNK_ALIGN_MASK) == 0)? 0 :\ - ((MALLOC_ALIGNMENT - ((size_t)(A) & CHUNK_ALIGN_MASK)) & CHUNK_ALIGN_MASK)) - -/* -------------------------- MMAP preliminaries ------------------------- */ - -/* - If HAVE_MORECORE or HAVE_MMAP are false, we just define calls and - checks to fail so compiler optimizer can delete code rather than - using so many "#if"s. -*/ - - -/* MORECORE and MMAP must return MFAIL on failure */ -#define MFAIL ((void*)(MAX_SIZE_T)) -#define CMFAIL ((char*)(MFAIL)) /* defined for convenience */ - -#if HAVE_MMAP - -#ifndef WIN32 -#define MUNMAP_DEFAULT(a, s) munmap((a), (s)) -#define MMAP_PROT (PROT_READ|PROT_WRITE) -#if !defined(MAP_ANONYMOUS) && defined(MAP_ANON) -#define MAP_ANONYMOUS MAP_ANON -#endif /* MAP_ANON */ -#ifdef MAP_ANONYMOUS -#define MMAP_FLAGS (MAP_PRIVATE|MAP_ANONYMOUS) -#define MMAP_DEFAULT(s) mmap(0, (s), MMAP_PROT, MMAP_FLAGS, -1, 0) -#else /* MAP_ANONYMOUS */ -/* - Nearly all versions of mmap support MAP_ANONYMOUS, so the following - is unlikely to be needed, but is supplied just in case. -*/ -#define MMAP_FLAGS (MAP_PRIVATE) -static int dev_zero_fd = -1; /* Cached file descriptor for /dev/zero. */ -#define MMAP_DEFAULT(s) ((dev_zero_fd < 0) ? \ - (dev_zero_fd = open("/dev/zero", O_RDWR), \ - mmap(0, (s), MMAP_PROT, MMAP_FLAGS, dev_zero_fd, 0)) : \ - mmap(0, (s), MMAP_PROT, MMAP_FLAGS, dev_zero_fd, 0)) -#endif /* MAP_ANONYMOUS */ - -#define DIRECT_MMAP_DEFAULT(s) MMAP_DEFAULT(s) - -#else /* WIN32 */ - -/* Win32 MMAP via VirtualAlloc */ -static FORCEINLINE void* win32mmap(size_t size) { - void* ptr = VirtualAlloc(0, size, MEM_RESERVE|MEM_COMMIT, PAGE_READWRITE); - return (ptr != 0)? ptr: MFAIL; -} - -/* For direct MMAP, use MEM_TOP_DOWN to minimize interference */ -static FORCEINLINE void* win32direct_mmap(size_t size) { - void* ptr = VirtualAlloc(0, size, MEM_RESERVE|MEM_COMMIT|MEM_TOP_DOWN, - PAGE_READWRITE); - return (ptr != 0)? ptr: MFAIL; -} - -/* This function supports releasing coalesed segments */ -static FORCEINLINE int win32munmap(void* ptr, size_t size) { - MEMORY_BASIC_INFORMATION minfo; - char* cptr = (char*)ptr; - while (size) { - if (VirtualQuery(cptr, &minfo, sizeof(minfo)) == 0) - return -1; - if (minfo.BaseAddress != cptr || minfo.AllocationBase != cptr || - minfo.State != MEM_COMMIT || minfo.RegionSize > size) - return -1; - if (VirtualFree(cptr, 0, MEM_RELEASE) == 0) - return -1; - cptr += minfo.RegionSize; - size -= minfo.RegionSize; - } - return 0; -} - -#define MMAP_DEFAULT(s) win32mmap(s) -#define MUNMAP_DEFAULT(a, s) win32munmap((a), (s)) -#define DIRECT_MMAP_DEFAULT(s) win32direct_mmap(s) -#endif /* WIN32 */ -#endif /* HAVE_MMAP */ - -#if HAVE_MREMAP -#ifndef WIN32 -#define MREMAP_DEFAULT(addr, osz, nsz, mv) mremap((addr), (osz), (nsz), (mv)) -#endif /* WIN32 */ -#endif /* HAVE_MREMAP */ - -/** - * Define CALL_MORECORE - */ -#if HAVE_MORECORE - #ifdef MORECORE - #define CALL_MORECORE(S) MORECORE(S) - #else /* MORECORE */ - #define CALL_MORECORE(S) MORECORE_DEFAULT(S) - #endif /* MORECORE */ -#else /* HAVE_MORECORE */ - #define CALL_MORECORE(S) MFAIL -#endif /* HAVE_MORECORE */ - -/** - * Define CALL_MMAP/CALL_MUNMAP/CALL_DIRECT_MMAP - */ -#if HAVE_MMAP - #define USE_MMAP_BIT (SIZE_T_ONE) - - #ifdef MMAP - #define CALL_MMAP(s) MMAP(s) - #else /* MMAP */ - #define CALL_MMAP(s) MMAP_DEFAULT(s) - #endif /* MMAP */ - #ifdef MUNMAP - #define CALL_MUNMAP(a, s) MUNMAP((a), (s)) - #else /* MUNMAP */ - #define CALL_MUNMAP(a, s) MUNMAP_DEFAULT((a), (s)) - #endif /* MUNMAP */ - #ifdef DIRECT_MMAP - #define CALL_DIRECT_MMAP(s) DIRECT_MMAP(s) - #else /* DIRECT_MMAP */ - #define CALL_DIRECT_MMAP(s) DIRECT_MMAP_DEFAULT(s) - #endif /* DIRECT_MMAP */ -#else /* HAVE_MMAP */ - #define USE_MMAP_BIT (SIZE_T_ZERO) - - #define MMAP(s) MFAIL - #define MUNMAP(a, s) (-1) - #define DIRECT_MMAP(s) MFAIL - #define CALL_DIRECT_MMAP(s) DIRECT_MMAP(s) - #define CALL_MMAP(s) MMAP(s) - #define CALL_MUNMAP(a, s) MUNMAP((a), (s)) -#endif /* HAVE_MMAP */ - -/** - * Define CALL_MREMAP - */ -#if HAVE_MMAP && HAVE_MREMAP - #ifdef MREMAP - #define CALL_MREMAP(addr, osz, nsz, mv) MREMAP((addr), (osz), (nsz), (mv)) - #else /* MREMAP */ - #define CALL_MREMAP(addr, osz, nsz, mv) MREMAP_DEFAULT((addr), (osz), (nsz), (mv)) - #endif /* MREMAP */ -#else /* HAVE_MMAP && HAVE_MREMAP */ - #define CALL_MREMAP(addr, osz, nsz, mv) MFAIL -#endif /* HAVE_MMAP && HAVE_MREMAP */ - -/* mstate bit set if continguous morecore disabled or failed */ -#define USE_NONCONTIGUOUS_BIT (4U) - -/* segment bit set in create_mspace_with_base */ -#define EXTERN_BIT (8U) - - -/* --------------------------- Lock preliminaries ------------------------ */ - -/* - When locks are defined, there is one global lock, plus - one per-mspace lock. - - The global lock_ensures that mparams.magic and other unique - mparams values are initialized only once. It also protects - sequences of calls to MORECORE. In many cases sys_alloc requires - two calls, that should not be interleaved with calls by other - threads. This does not protect against direct calls to MORECORE - by other threads not using this lock, so there is still code to - cope the best we can on interference. - - Per-mspace locks surround calls to malloc, free, etc. - By default, locks are simple non-reentrant mutexes. - - Because lock-protected regions generally have bounded times, it is - OK to use the supplied simple spinlocks. Spinlocks are likely to - improve performance for lightly contended applications, but worsen - performance under heavy contention. - - If USE_LOCKS is > 1, the definitions of lock routines here are - bypassed, in which case you will need to define the type MLOCK_T, - and at least INITIAL_LOCK, DESTROY_LOCK, ACQUIRE_LOCK, RELEASE_LOCK - and TRY_LOCK. You must also declare a - static MLOCK_T malloc_global_mutex = { initialization values };. - -*/ - -#if !USE_LOCKS -#define USE_LOCK_BIT (0U) -#define INITIAL_LOCK(l) (0) -#define DESTROY_LOCK(l) (0) -#define ACQUIRE_MALLOC_GLOBAL_LOCK() -#define RELEASE_MALLOC_GLOBAL_LOCK() - -#else -#if USE_LOCKS > 1 -/* ----------------------- User-defined locks ------------------------ */ -/* Define your own lock implementation here */ -/* #define INITIAL_LOCK(lk) ... */ -/* #define DESTROY_LOCK(lk) ... */ -/* #define ACQUIRE_LOCK(lk) ... */ -/* #define RELEASE_LOCK(lk) ... */ -/* #define TRY_LOCK(lk) ... */ -/* static MLOCK_T malloc_global_mutex = ... */ - -#elif USE_SPIN_LOCKS - -/* First, define CAS_LOCK and CLEAR_LOCK on ints */ -/* Note CAS_LOCK defined to return 0 on success */ - -#if defined(__GNUC__)&& (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 1)) -#define CAS_LOCK(sl) __sync_lock_test_and_set(sl, 1) -#define CLEAR_LOCK(sl) __sync_lock_release(sl) - -#elif (defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))) -/* Custom spin locks for older gcc on x86 */ -static FORCEINLINE int x86_cas_lock(int *sl) { - int ret; - int val = 1; - int cmp = 0; - __asm__ __volatile__ ("lock; cmpxchgl %1, %2" - : "=a" (ret) - : "r" (val), "m" (*(sl)), "0"(cmp) - : "memory", "cc"); - return ret; -} - -static FORCEINLINE void x86_clear_lock(int* sl) { - assert(*sl != 0); - int prev = 0; - int ret; - __asm__ __volatile__ ("lock; xchgl %0, %1" - : "=r" (ret) - : "m" (*(sl)), "0"(prev) - : "memory"); -} - -#define CAS_LOCK(sl) x86_cas_lock(sl) -#define CLEAR_LOCK(sl) x86_clear_lock(sl) - -#else /* Win32 MSC */ -#define CAS_LOCK(sl) interlockedexchange(sl, (LONG)1) -#define CLEAR_LOCK(sl) interlockedexchange (sl, (LONG)0) - -#endif /* ... gcc spins locks ... */ - -/* How to yield for a spin lock */ -#define SPINS_PER_YIELD 63 -#if defined(_MSC_VER) -#define SLEEP_EX_DURATION 50 /* delay for yield/sleep */ -#define SPIN_LOCK_YIELD SleepEx(SLEEP_EX_DURATION, FALSE) -#elif defined (__SVR4) && defined (__sun) /* solaris */ -#define SPIN_LOCK_YIELD thr_yield(); -#elif !defined(LACKS_SCHED_H) -#define SPIN_LOCK_YIELD sched_yield(); -#else -#define SPIN_LOCK_YIELD -#endif /* ... yield ... */ - -#if !defined(USE_RECURSIVE_LOCKS) || USE_RECURSIVE_LOCKS == 0 -/* Plain spin locks use single word (embedded in malloc_states) */ -static int spin_acquire_lock(int *sl) { - int spins = 0; - while (*(volatile int *)sl != 0 || CAS_LOCK(sl)) { - if ((++spins & SPINS_PER_YIELD) == 0) { - SPIN_LOCK_YIELD; - } - } - return 0; -} - -#define MLOCK_T int -#define TRY_LOCK(sl) !CAS_LOCK(sl) -#define RELEASE_LOCK(sl) CLEAR_LOCK(sl) -#define ACQUIRE_LOCK(sl) (CAS_LOCK(sl)? spin_acquire_lock(sl) : 0) -#define INITIAL_LOCK(sl) (*sl = 0) -#define DESTROY_LOCK(sl) (0) -static MLOCK_T malloc_global_mutex = 0; - -#else /* USE_RECURSIVE_LOCKS */ -/* types for lock owners */ -#ifdef WIN32 -#define THREAD_ID_T DWORD -#define CURRENT_THREAD GetCurrentThreadId() -#define EQ_OWNER(X,Y) ((X) == (Y)) -#else -/* - Note: the following assume that pthread_t is a type that can be - initialized to (casted) zero. If this is not the case, you will need to - somehow redefine these or not use spin locks. -*/ -#define THREAD_ID_T pthread_t -#define CURRENT_THREAD pthread_self() -#define EQ_OWNER(X,Y) pthread_equal(X, Y) -#endif - -struct malloc_recursive_lock { - int sl; - unsigned int c; - THREAD_ID_T threadid; -}; - -#define MLOCK_T struct malloc_recursive_lock -static MLOCK_T malloc_global_mutex = { 0, 0, (THREAD_ID_T)0}; - -static FORCEINLINE void recursive_release_lock(MLOCK_T *lk) { - assert(lk->sl != 0); - if (--lk->c == 0) { - CLEAR_LOCK(&lk->sl); - } -} - -static FORCEINLINE int recursive_acquire_lock(MLOCK_T *lk) { - THREAD_ID_T mythreadid = CURRENT_THREAD; - int spins = 0; - for (;;) { - if (*((volatile int *)(&lk->sl)) == 0) { - if (!CAS_LOCK(&lk->sl)) { - lk->threadid = mythreadid; - lk->c = 1; - return 0; - } - } - else if (EQ_OWNER(lk->threadid, mythreadid)) { - ++lk->c; - return 0; - } - if ((++spins & SPINS_PER_YIELD) == 0) { - SPIN_LOCK_YIELD; - } - } -} - -static FORCEINLINE int recursive_try_lock(MLOCK_T *lk) { - THREAD_ID_T mythreadid = CURRENT_THREAD; - if (*((volatile int *)(&lk->sl)) == 0) { - if (!CAS_LOCK(&lk->sl)) { - lk->threadid = mythreadid; - lk->c = 1; - return 1; - } - } - else if (EQ_OWNER(lk->threadid, mythreadid)) { - ++lk->c; - return 1; - } - return 0; -} - -#define RELEASE_LOCK(lk) recursive_release_lock(lk) -#define TRY_LOCK(lk) recursive_try_lock(lk) -#define ACQUIRE_LOCK(lk) recursive_acquire_lock(lk) -#define INITIAL_LOCK(lk) ((lk)->threadid = (THREAD_ID_T)0, (lk)->sl = 0, (lk)->c = 0) -#define DESTROY_LOCK(lk) (0) -#endif /* USE_RECURSIVE_LOCKS */ - -#elif defined(WIN32) /* Win32 critical sections */ -#define MLOCK_T CRITICAL_SECTION -#define ACQUIRE_LOCK(lk) (EnterCriticalSection(lk), 0) -#define RELEASE_LOCK(lk) LeaveCriticalSection(lk) -#define TRY_LOCK(lk) TryEnterCriticalSection(lk) -#define INITIAL_LOCK(lk) (!InitializeCriticalSectionAndSpinCount((lk), 0x80000000|4000)) -#define DESTROY_LOCK(lk) (DeleteCriticalSection(lk), 0) -#define NEED_GLOBAL_LOCK_INIT - -static MLOCK_T malloc_global_mutex; -static volatile LONG malloc_global_mutex_status; - -/* Use spin loop to initialize global lock */ -static void init_malloc_global_mutex() { - for (;;) { - long stat = malloc_global_mutex_status; - if (stat > 0) - return; - /* transition to < 0 while initializing, then to > 0) */ - if (stat == 0 && - interlockedcompareexchange(&malloc_global_mutex_status, (LONG)-1, (LONG)0) == 0) { - InitializeCriticalSection(&malloc_global_mutex); - interlockedexchange(&malloc_global_mutex_status, (LONG)1); - return; - } - SleepEx(0, FALSE); - } -} - -#else /* pthreads-based locks */ -#define MLOCK_T pthread_mutex_t -#define ACQUIRE_LOCK(lk) pthread_mutex_lock(lk) -#define RELEASE_LOCK(lk) pthread_mutex_unlock(lk) -#define TRY_LOCK(lk) (!pthread_mutex_trylock(lk)) -#define INITIAL_LOCK(lk) pthread_init_lock(lk) -#define DESTROY_LOCK(lk) pthread_mutex_destroy(lk) - -#if defined(USE_RECURSIVE_LOCKS) && USE_RECURSIVE_LOCKS != 0 && defined(linux) && !defined(PTHREAD_MUTEX_RECURSIVE) -/* Cope with old-style linux recursive lock initialization by adding */ -/* skipped internal declaration from pthread.h */ -extern int pthread_mutexattr_setkind_np __P ((pthread_mutexattr_t *__attr, - int __kind)); -#define PTHREAD_MUTEX_RECURSIVE PTHREAD_MUTEX_RECURSIVE_NP -#define pthread_mutexattr_settype(x,y) pthread_mutexattr_setkind_np(x,y) -#endif /* USE_RECURSIVE_LOCKS ... */ - -static MLOCK_T malloc_global_mutex = PTHREAD_MUTEX_INITIALIZER; - -static int pthread_init_lock (MLOCK_T *lk) { - pthread_mutexattr_t attr; - if (pthread_mutexattr_init(&attr)) return 1; -#if defined(USE_RECURSIVE_LOCKS) && USE_RECURSIVE_LOCKS != 0 - if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) return 1; -#endif - if (pthread_mutex_init(lk, &attr)) return 1; - if (pthread_mutexattr_destroy(&attr)) return 1; - return 0; -} - -#endif /* ... lock types ... */ - -/* Common code for all lock types */ -#define USE_LOCK_BIT (2U) - -#ifndef ACQUIRE_MALLOC_GLOBAL_LOCK -#define ACQUIRE_MALLOC_GLOBAL_LOCK() ACQUIRE_LOCK(&malloc_global_mutex); -#endif - -#ifndef RELEASE_MALLOC_GLOBAL_LOCK -#define RELEASE_MALLOC_GLOBAL_LOCK() RELEASE_LOCK(&malloc_global_mutex); -#endif - -#endif /* USE_LOCKS */ - -/* ----------------------- Chunk representations ------------------------ */ - -/* - (The following includes lightly edited explanations by Colin Plumb.) - - The malloc_chunk declaration below is misleading (but accurate and - necessary). It declares a "view" into memory allowing access to - necessary fields at known offsets from a given base. - - Chunks of memory are maintained using a `boundary tag' method as - originally described by Knuth. (See the paper by Paul Wilson - ftp://ftp.cs.utexas.edu/pub/garbage/allocsrv.ps for a survey of such - techniques.) Sizes of free chunks are stored both in the front of - each chunk and at the end. This makes consolidating fragmented - chunks into bigger chunks fast. The head fields also hold bits - representing whether chunks are free or in use. - - Here are some pictures to make it clearer. They are "exploded" to - show that the state of a chunk can be thought of as extending from - the high 31 bits of the head field of its header through the - prev_foot and PINUSE_BIT bit of the following chunk header. - - A chunk that's in use looks like: - - chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Size of previous chunk (if P = 0) | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| - | Size of this chunk 1| +-+ - mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | | - +- -+ - | | - +- -+ - | : - +- size - sizeof(size_t) available payload bytes -+ - : | - chunk-> +- -+ - | | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |1| - | Size of next chunk (may or may not be in use) | +-+ - mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - - And if it's free, it looks like this: - - chunk-> +- -+ - | User payload (must be in use, or we would have merged!) | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |P| - | Size of this chunk 0| +-+ - mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Next pointer | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Prev pointer | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | : - +- size - sizeof(struct chunk) unused bytes -+ - : | - chunk-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | Size of this chunk | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |0| - | Size of next chunk (must be in use, or we would have merged)| +-+ - mem-> +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - | : - +- User payload -+ - : | - +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - |0| - +-+ - Note that since we always merge adjacent free chunks, the chunks - adjacent to a free chunk must be in use. - - Given a pointer to a chunk (which can be derived trivially from the - payload pointer) we can, in O(1) time, find out whether the adjacent - chunks are free, and if so, unlink them from the lists that they - are on and merge them with the current chunk. - - Chunks always begin on even word boundaries, so the mem portion - (which is returned to the user) is also on an even word boundary, and - thus at least double-word aligned. - - The P (PINUSE_BIT) bit, stored in the unused low-order bit of the - chunk size (which is always a multiple of two words), is an in-use - bit for the *previous* chunk. If that bit is *clear*, then the - word before the current chunk size contains the previous chunk - size, and can be used to find the front of the previous chunk. - The very first chunk allocated always has this bit set, preventing - access to non-existent (or non-owned) memory. If pinuse is set for - any given chunk, then you CANNOT determine the size of the - previous chunk, and might even get a memory addressing fault when - trying to do so. - - The C (CINUSE_BIT) bit, stored in the unused second-lowest bit of - the chunk size redundantly records whether the current chunk is - inuse (unless the chunk is mmapped). This redundancy enables usage - checks within free and realloc, and reduces indirection when freeing - and consolidating chunks. - - Each freshly allocated chunk must have both cinuse and pinuse set. - That is, each allocated chunk borders either a previously allocated - and still in-use chunk, or the base of its memory arena. This is - ensured by making all alloc