commit 0a930b465cf2e90229135b2be22573a4997fc6f4
Author: gearsix <gearsix@tuta.io>
Date: Mon, 6 Sep 2021 22:11:52 +0100
init work; did most of it this afternoon - needs testing.
Diffstat:
| A | stdlibw.c | | | 76 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | stdlibw.h | | | 44 | ++++++++++++++++++++++++++++++++++++++++++++ |
2 files changed, 120 insertions(+), 0 deletions(-)
diff --git a/stdlibw.c b/stdlibw.c
@@ -0,0 +1,76 @@
+#include "stdlibw.h"
+
+static size_t _heap(char op, size_t n)
+{
+ static size_t siz = 0, lim = 0;
+ switch (op) {
+ case 0: break;
+ case '!': return (lim = n);
+ case '?': return lim;
+ case '+':
+ if (lim > 0) assert(siz + n <= lim);
+ siz += n;
+ break;
+ case '-':
+ if (lim > 0) assert(siz - n >= lim);
+ siz -= n;
+ break;
+ default: /* invalid op */
+ assert(1);
+ }
+ return siz;
+}
+
+size_t heapsiz()
+{
+ return _heap(0, 0);
+}
+
+size_t heaplim()
+{
+ return _heap('?', 0);
+}
+
+size_t limheap(size_t n)
+{
+ return _heap('!', 0);
+}
+
+size_t sizeofw(void *ptr)
+{
+ return ((size_t *)ptr)[-1];
+}
+
+void *mallocw(size_t siz)
+{
+ size_t *ptr;
+ assert(siz);
+ ptr = (size_t *)malloc(siz += sizeof(size_t));
+ _heap('+', siz);
+ ptr[0] = siz;
+ return &ptr[1];
+}
+
+void *callocw(size_t num, size_t siz)
+{
+ size_t *ptr;
+ assert(siz && (size_t)-1/num);
+ ptr = (size_t *)mallocw(num * siz);
+ return ptr;
+}
+
+void *realloc(void *ptr, size_t siz)
+{
+ size_t *ret, psiz = sizeofw(ptr);
+ assert(siz > psiz);
+ ret = mallocw(siz);
+ while (--psiz > 0) ret[psiz] = ((size_t *)ptr)[psiz];
+ freew(ptr);
+ return ret;
+}
+
+void freew(void *ptr)
+{
+ _heap('-', ((size_t *)ptr)[-1]);
+ free((size_t *)ptr-1);
+}
diff --git a/stdlibw.h b/stdlibw.h
@@ -0,0 +1,44 @@
+#ifndef STDLIBW
+#define STDLIBW
+
+#include <stdlib.h>
+#include <assert.h>
+
+/** heapsiz - heap size?
+ * returns the currently tracked `heapsiz`
+**/
+size_t heapsiz();
+
+/** heaplim - heapsiz limit?
+ * returns the current limit set on `heapsiz`.
+ * if 0 is returned, there is no limit.
+**/
+size_t heaplim();
+
+/** limheap - limit heapsiz
+ * set the limit on `heapsiz` to `siz`, returns the set limit.
+ * if the returned value is not `n`, then the call failed.
+**/
+size_t limheap(size_t n);
+
+/**
+ * sizeofw - sizeof wrapper
+ * returns the number of allocated bytes for `ptr`.
+ * will fail if called on a pointer not allocated by stdlibw.
+**/
+size_t sizeofw(void *ptr);
+
+/** mallocw - malloc wrapper
+ * malloc (sizeof(size_t) + siz) bytes and return that pointer from [1]
+ * [0] is used to store `siz`.
+ * `(siz + sizeof(size_t))` will be added to `heapsiz`
+**/
+void *mallocw(size_t siz);
+
+void *callocw(size_t num, size_t siz);
+
+void *reallocw(void *ptr, size_t siz);
+
+void freew(void *ptr);
+
+#endif
