summaryrefslogtreecommitdiff
path: root/src/user/lib/libc/include/_dlmalloc.h
diff options
context:
space:
mode:
Diffstat (limited to 'src/user/lib/libc/include/_dlmalloc.h')
-rw-r--r--src/user/lib/libc/include/_dlmalloc.h865
1 files changed, 865 insertions, 0 deletions
diff --git a/src/user/lib/libc/include/_dlmalloc.h b/src/user/lib/libc/include/_dlmalloc.h
new file mode 100644
index 0000000..d896e22
--- /dev/null
+++ b/src/user/lib/libc/include/_dlmalloc.h
@@ -0,0 +1,865 @@
+#ifndef DEF_DLMALLOC_H
+#define DEF_DLMALLOC_H
+
+#include <stdlib.h>
+#include <string.h>
+
+#define NO_MALLOC_STATS 1
+#define LACKS_TIME_H
+#define LACKS_UNISTD_H
+#define LACKS_SYS_PARAM_H
+
+#define USE_LOCKS 2
+
+
+/* Version identifier to allow people to support multiple versions */
+#ifndef DLMALLOC_VERSION
+#define DLMALLOC_VERSION 20805
+#endif /* DLMALLOC_VERSION */
+
+#ifndef DLMALLOC_EXPORT
+#define DLMALLOC_EXPORT extern
+#endif
+
+
+/* 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)8U)
+#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 0
+#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);
+
+#endif /* ONLY_MSPACES */
+
+/*
+ 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*);
+
+#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(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 */
+
+
+
+#endif
+
+