partially split malloc.c

Signed-off-by: Mattias Andrée <maandree@member.fsf.org>

1 files changed, 51 insertions, 0 deletions

diff --git a/src/malloc/posix_memalign.c b/src/malloc/posix_memalign.c
new file mode 100644
index 0000000..80d27c8
--- /dev/null
+++ b/src/malloc/posix_memalign.c
@@ -0,0 +1,51 @@
+/**
+ * slibc — Yet another C library
+ * Copyright © 2015, 2016  Mattias Andrée (maandree@member.fsf.org)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <stdlib.h>
+#include <errno.h>
+
+
+
+/**
+ * `posix_memalign(p, b, n)` is equivalent to
+ * `(*p = memalign(b, n), *p ? 0 : errno)`, except
+ * `boundary` must also be a multiple of `sizeof(void*)`,
+ * and `errno` is unspecified.
+ * 
+ * As a GNU-compliant slibc extension, memory allocated
+ * with this function can be freed with `free`.
+ * 
+ * @etymology  (POSIX)-extension: (mem)ory alignment.
+ * 
+ * @param   ptrptr    Output parameter for the allocated memory.
+ * @param   boundary  The alignment.
+ * @param   size      The number of bytes to allocated.
+ * @return            Zero on success, a value for `errno` on error.
+ * 
+ * @throws  ENOMEM  The process cannot allocate more memory.
+ * @throws  EINVAL  If `boundary` is not a power-of-two multiple of `sizeof(void*)`.
+ * 
+ * @since  Always.
+ */
+int posix_memalign(void** ptrptr, size_t boundary, size_t size)
+{
+  if (boundary < sizeof(void*))
+    return EINVAL;
+  *ptrptr = memalign(boundary, size);
+  return *ptrptr ? 0 : errno;
+}
+