From 0b44a0315b47dd8eced9f3b7f31580cf14bbfc01 Mon Sep 17 00:00:00 2001
From: Rich Felker <dalias@aerifal.cx>
Date: Sat, 12 Feb 2011 00:22:29 -0500
Subject: initial check-in, version 0.5.0

---
 src/malloc/__simple_malloc.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)
 create mode 100644 src/malloc/__simple_malloc.c

(limited to 'src/malloc/__simple_malloc.c')

diff --git a/src/malloc/__simple_malloc.c b/src/malloc/__simple_malloc.c
new file mode 100644
index 00000000..49b74c8e
--- /dev/null
+++ b/src/malloc/__simple_malloc.c
@@ -0,0 +1,44 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <limits.h>
+#include <errno.h>
+#include "libc.h"
+
+uintptr_t __brk(uintptr_t);
+
+#define ALIGN 16
+
+void *__simple_malloc(size_t n)
+{
+	static uintptr_t cur, brk;
+	uintptr_t base, new;
+	static int lock;
+	size_t align=1;
+
+	if (n < SIZE_MAX - ALIGN)
+		while (align<n && align<ALIGN)
+			align += align;
+	n = n + align - 1 & -align;
+
+	LOCK(&lock);
+	if (!cur) cur = brk = __brk(0)+16;
+	if (n > SIZE_MAX - brk) goto fail;
+
+	base = cur + align-1 & -align;
+	if (base+n > brk) {
+		new = base+n + PAGE_SIZE-1 & -PAGE_SIZE;
+		if (__brk(new) != new) goto fail;
+		brk = new;
+	}
+	cur = base+n;
+	UNLOCK(&lock);
+
+	return (void *)base;
+
+fail:
+	UNLOCK(&lock);
+	errno = ENOMEM;
+	return 0;
+}
+
+weak_alias(__simple_malloc, malloc);
-- 
cgit v1.2.1