diff options
Diffstat (limited to 'malloc')
| -rw-r--r-- | malloc/malloc-internal.h | 53 | ||||
| -rw-r--r-- | malloc/malloc.c | 63 |
2 files changed, 53 insertions, 63 deletions
diff --git a/malloc/malloc-internal.h b/malloc/malloc-internal.h index 98afd14040..a3df8c30ba 100644 --- a/malloc/malloc-internal.h +++ b/malloc/malloc-internal.h @@ -19,6 +19,59 @@ #ifndef _MALLOC_INTERNAL_H #define _MALLOC_INTERNAL_H +#include <malloc-machine.h> +#include <malloc-sysdep.h> + +/* INTERNAL_SIZE_T is the word-size used for internal bookkeeping of + chunk sizes. + + The default version is the same as size_t. + + While not strictly necessary, it is best to define this as an + unsigned type, even if size_t is a signed type. This may avoid some + artificial size limitations on some systems. + + On a 64-bit machine, you may be able to reduce malloc overhead by + defining INTERNAL_SIZE_T to be a 32 bit `unsigned int' at the + expense of not being able to handle more than 2^32 of malloced + space. If this limitation is acceptable, you are encouraged to set + this unless you are on a platform requiring 16byte alignments. In + this case the alignment requirements turn out to negate any + potential advantages of decreasing size_t word size. + + Implementors: Beware of the possible combinations of: + - INTERNAL_SIZE_T might be signed or unsigned, might be 32 or 64 bits, + and might be the same width as int or as long + - size_t might have different width and signedness as INTERNAL_SIZE_T + - int and long might be 32 or 64 bits, and might be the same width + + To deal with this, most comparisons and difference computations + among INTERNAL_SIZE_Ts should cast them to unsigned long, being + aware of the fact that casting an unsigned int to a wider long does + not sign-extend. (This also makes checking for negative numbers + awkward.) Some of these casts result in harmless compiler warnings + on some systems. */ +#ifndef INTERNAL_SIZE_T +# define INTERNAL_SIZE_T size_t +#endif + +/* The corresponding word size. */ +#define SIZE_SZ (sizeof (INTERNAL_SIZE_T)) + +/* MALLOC_ALIGNMENT is the minimum alignment for malloc'ed chunks. It + must be a power of two at least 2 * SIZE_SZ, 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. */ +#ifndef MALLOC_ALIGNMENT +# define MALLOC_ALIGNMENT (2 * SIZE_SZ < __alignof__ (long double) \ + ? __alignof__ (long double) : 2 * SIZE_SZ) +#endif + +/* The corresponding bit mask value. */ +#define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1) + + /* Called in the parent process before a fork. */ void __malloc_fork_lock_parent (void) internal_function attribute_hidden; diff --git a/malloc/malloc.c b/malloc/malloc.c index 1f5f166ea2..bb52b3e177 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -173,8 +173,6 @@ Changing default word sizes: INTERNAL_SIZE_T size_t - MALLOC_ALIGNMENT MAX (2 * sizeof(INTERNAL_SIZE_T), - __alignof__ (long double)) Configuration and functionality options: @@ -216,9 +214,6 @@ #include <stdlib.h> /* for getenv(), abort() */ #include <unistd.h> /* for __libc_enable_secure */ -#include <malloc-machine.h> -#include <malloc-sysdep.h> - #include <atomic.h> #include <_itoa.h> #include <bits/wordsize.h> @@ -304,64 +299,6 @@ __malloc_assert (const char *assertion, const char *file, unsigned int line, /* - INTERNAL_SIZE_T is the word-size used for internal bookkeeping - of chunk sizes. - - The default version is the same as size_t. - - While not strictly necessary, it is best to define this as an - unsigned type, even if size_t is a signed type. This may avoid some - artificial size limitations on some systems. - - On a 64-bit machine, you may be able to reduce malloc overhead by - defining INTERNAL_SIZE_T to be a 32 bit `unsigned int' at the - expense of not being able to handle more than 2^32 of malloced - space. If this limitation is acceptable, you are encouraged to set - this unless you are on a platform requiring 16byte alignments. In - this case the alignment requirements turn out to negate any - potential advantages of decreasing size_t word size. - - Implementors: Beware of the possible combinations of: - - INTERNAL_SIZE_T might be signed or unsigned, might be 32 or 64 bits, - and might be the same width as int or as long - - size_t might have different width and signedness as INTERNAL_SIZE_T - - int and long might be 32 or 64 bits, and might be the same width - To deal with this, most comparisons and difference computations - among INTERNAL_SIZE_Ts should cast them to unsigned long, being - aware of the fact that casting an unsigned int to a wider long does - not sign-extend. (This also makes checking for negative numbers - awkward.) Some of these casts result in harmless compiler warnings - on some systems. -*/ - -#ifndef INTERNAL_SIZE_T -#define INTERNAL_SIZE_T size_t -#endif - -/* The corresponding word size */ -#define SIZE_SZ (sizeof(INTERNAL_SIZE_T)) - - -/* - MALLOC_ALIGNMENT is the minimum alignment for malloc'ed chunks. - It must be a power of two at least 2 * SIZE_SZ, 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. -*/ - - -#ifndef MALLOC_ALIGNMENT -# define MALLOC_ALIGNMENT (2 * SIZE_SZ < __alignof__ (long double) \ - ? __alignof__ (long double) : 2 * SIZE_SZ) -#endif - -/* The corresponding bit mask value */ -#define MALLOC_ALIGN_MASK (MALLOC_ALIGNMENT - 1) - - - -/* REALLOC_ZERO_BYTES_FREES should be set if a call to realloc with zero bytes should be the same as a call to free. This is required by the C standard. Otherwise, since this malloc |