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Diffstat (limited to 'libc/stdlib/malloc-930716/memalign.c')
-rw-r--r-- | libc/stdlib/malloc-930716/memalign.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/libc/stdlib/malloc-930716/memalign.c b/libc/stdlib/malloc-930716/memalign.c new file mode 100644 index 000000000..eea460aad --- /dev/null +++ b/libc/stdlib/malloc-930716/memalign.c @@ -0,0 +1,67 @@ +/* malloc.c - C standard library routine. + Copyright (c) 1989, 1993 Michael J. Haertel + You may redistribute this library under the terms of the + GNU Library General Public License (version 2 or any later + version) as published by the Free Software Foundation. + THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY EXPRESS OR IMPLIED + WARRANTY. IN PARTICULAR, THE AUTHOR MAKES NO REPRESENTATION OR + WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY OF THIS + SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. */ + +#define _GNU_SOURCE +#include <features.h> +#include <limits.h> +#include <stddef.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include "malloc.h" + +#ifdef __UCLIBC_HAS_THREADS__ +#include <pthread.h> +extern pthread_mutex_t __malloclock; +# define LOCK pthread_mutex_lock(&__malloclock) +# define UNLOCK pthread_mutex_unlock(&__malloclock); +#else +# define LOCK +# define UNLOCK +#endif + + +__ptr_t memalign (size_t alignment, size_t size) +{ + __ptr_t result; + unsigned long int adj; + + result = malloc (size + alignment - 1); + if (result == NULL) + return NULL; + adj = (unsigned long int) ((unsigned long int) ((char *) result - + (char *) NULL)) % alignment; + if (adj != 0) + { + struct alignlist *l; + LOCK; + for (l = _aligned_blocks; l != NULL; l = l->next) + if (l->aligned == NULL) + /* This slot is free. Use it. */ + break; + if (l == NULL) + { + l = (struct alignlist *) malloc (sizeof (struct alignlist)); + if (l == NULL) { + __free_unlocked (result); + UNLOCK; + return NULL; + } + l->next = _aligned_blocks; + _aligned_blocks = l; + } + l->exact = result; + result = l->aligned = (char *) result + alignment - adj; + UNLOCK; + } + + return result; +} + |