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-rw-r--r--libc/stdlib/malloc-simple/alloc.c189
1 files changed, 189 insertions, 0 deletions
diff --git a/libc/stdlib/malloc-simple/alloc.c b/libc/stdlib/malloc-simple/alloc.c
new file mode 100644
index 000000000..ee0135581
--- /dev/null
+++ b/libc/stdlib/malloc-simple/alloc.c
@@ -0,0 +1,189 @@
+/* alloc.c
+ *
+ * Written by Erik Andersen <andersee@debian.org>
+ * LGPLv2
+ *
+ * Parts of the memalign code were stolen from malloc-930716.
+ */
+
+#include <features.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+
+
+#ifdef L_malloc
+void *malloc(size_t size)
+{
+ void *result;
+
+ if (unlikely(size == 0)) {
+#if defined(__MALLOC_GLIBC_COMPAT__)
+ size++;
+#else
+ /* Some programs will call malloc (0). Lets be strict and return NULL */
+ return 0;
+#endif
+ }
+
+#ifdef __UCLIBC_HAS_MMU__
+ result = mmap((void *) 0, size + sizeof(size_t), PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
+ if (result == MAP_FAILED)
+ return 0;
+ * (size_t *) result = size;
+ return(result + sizeof(size_t));
+#else
+ result = mmap((void *) 0, size, PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_ANONYMOUS, 0, 0);
+ if (result == MAP_FAILED)
+ return 0;
+ return(result);
+#endif
+}
+#endif
+
+#ifdef L_calloc
+void *calloc(size_t num, size_t size)
+{
+ void *ptr = malloc(num * size);
+ if (ptr)
+ memset(ptr, 0, num * size);
+ return ptr;
+}
+#endif
+
+#ifdef L_realloc
+void *realloc(void *ptr, size_t size)
+{
+ void *newptr = NULL;
+
+ if (!ptr)
+ return malloc(size);
+ if (!size) {
+ free(ptr);
+ return malloc(0);
+ }
+
+ newptr = malloc(size);
+ if (newptr) {
+ memcpy(newptr, ptr,
+#ifdef __UCLIBC_HAS_MMU__
+ *((size_t *) (ptr - sizeof(size_t)))
+#else
+ size
+#endif
+ );
+ free(ptr);
+ }
+ return newptr;
+}
+#endif
+
+#ifdef L_free
+extern int weak_function __libc_free_aligned(void *ptr);
+void free(void *ptr)
+{
+ if (ptr == NULL)
+ return;
+ if (unlikely(__libc_free_aligned!=NULL)) {
+ if (__libc_free_aligned(ptr)) {
+ return;
+ }
+ }
+#ifdef __UCLIBC_HAS_MMU__
+ ptr -= sizeof(size_t);
+ munmap(ptr, * (size_t *) ptr + sizeof(size_t));
+#else
+ munmap(ptr, 0);
+#endif
+}
+#endif
+
+#ifdef L_memalign
+#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
+
+/* List of blocks allocated with memalign or valloc */
+struct alignlist
+{
+ struct alignlist *next;
+ __ptr_t aligned; /* The address that memaligned returned. */
+ __ptr_t exact; /* The address that malloc returned. */
+};
+struct alignlist *_aligned_blocks;
+
+/* Return memory to the heap. */
+int __libc_free_aligned(void *ptr)
+{
+ struct alignlist *l;
+
+ if (ptr == NULL)
+ return 0;
+
+ LOCK;
+ for (l = _aligned_blocks; l != NULL; l = l->next) {
+ if (l->aligned == ptr) {
+ /* Mark the block as free */
+ l->aligned = NULL;
+ ptr = l->exact;
+#ifdef __UCLIBC_HAS_MMU__
+ ptr -= sizeof(size_t);
+ munmap(ptr, * (size_t *) ptr + sizeof(size_t));
+#else
+ munmap(ptr, 0);
+#endif
+ return 1;
+ }
+ }
+ UNLOCK;
+ return 0;
+}
+void * memalign (size_t alignment, size_t size)
+{
+ void * 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(result);
+ UNLOCK;
+ return NULL;
+ }
+ l->next = _aligned_blocks;
+ _aligned_blocks = l;
+ }
+ l->exact = result;
+ result = l->aligned = (char *) result + alignment - adj;
+ UNLOCK;
+ }
+
+ return result;
+}
+#endif
+