ref: f5cc8f6eeb677435da24372f738055728c9acb93
parent: 88281a76b99c430f41f651baaa6b53eef27fc07e
author: Roberto E. Vargas Caballero <[email protected]>
date: Sun Nov 21 13:27:11 EST 2021
libc: Do some stilistic changes to realloc() and malloc()
--- a/src/libc/stdlib/malloc.c
+++ b/src/libc/stdlib/malloc.c
@@ -7,6 +7,7 @@
#include "../libc.h"
#undef malloc
+#undef free
#define MAXADDR ((char *)-1)
#define ERRADDR ((char *)-1)
@@ -43,7 +44,7 @@
void
free(void *mem)
{- Header *hp, *prev;
+ Header *hp, *prev, *next;
if (!mem)
return;
@@ -50,13 +51,14 @@
hp = (Header *) mem - 1;
prev = _prevchunk(hp);
+ next = prev->h.next;
/* join to next */
- if (hp + hp->h.size == prev->h.next) {- hp->h.size += prev->h.next->h.size;
- hp->h.next = prev->h.next->h.next;
+ if (hp + hp->h.size == next) {+ hp->h.size += next->h.size;
+ hp->h.next = next->h.next;
} else {- hp->h.next = prev->h.next;
+ hp->h.next = next;
}
/* join to previous */
@@ -94,7 +96,7 @@
static Header *
morecore(size_t nunits)
{- char *rawmem;
+ void *rawmem;
Header *hp;
if (nunits < NALLOC)
@@ -104,7 +106,7 @@
if (rawmem == ERRADDR)
return NULL;
- hp = (Header*)rawmem;
+ hp = (Header *) rawmem;
hp->h.size = nunits;
/* integrate new memory into the list */
@@ -135,7 +137,7 @@
size_t nunits;
/* 1 unit for header plus enough units to fit nbytes */
- nunits = (nbytes+sizeof(Header)-1) / sizeof(Header)+1;
+ nunits = (nbytes+sizeof(Header)-1)/sizeof(Header) + 1;
for (prev = freep; ; prev = cur) {cur = prev->h.next;
@@ -147,7 +149,10 @@
cur += cur->h.size;
cur->h.size = nunits;
}
+
+ cur->h.next = NULL;
freep = prev;
+
return cur + 1;
}
--- a/src/libc/stdlib/realloc.c
+++ b/src/libc/stdlib/realloc.c
@@ -16,8 +16,8 @@
if (!ptr)
return malloc(nbytes);
- nunits = (nbytes + sizeof(Header) - 1) / sizeof(Header) + 1;
- oh = (Header*) ptr - 1;
+ nunits = (nbytes+sizeof(Header)-1)/sizeof(Header) + 1;
+ oh = (Header *) ptr - 1;
if (oh->h.size == nunits)
return ptr;
@@ -24,43 +24,44 @@
new = oh + nunits;
- if (nunits < oh->h.size - 1) {+ if (nunits < oh->h.size) {new->h.size = oh->h.size - nunits;
oh->h.size = nunits;
free(new + 1);
- return oh + 1;
+ return ptr;
}
prev = _prevchunk(oh);
+ next = prev->h.next;
- if (oh + oh->h.size == prev->h.next) {+ if (oh + oh->h.size == next) {/*
* if there is free space adjacent
* to the current memory
*/
- next = prev->h.next;
avail = oh->h.size + next->h.size;
if (avail == nunits) {oh->h.size = nunits;
prev->h.next = next->h.next;
- return oh + 1;
+ return ptr;
}
- if (avail > nunits) {+ if (nunits < avail) {oh->h.size = nunits;
prev->h.next = new;
new->h.next = next->h.next;
new->h.size = avail - nunits;
- return oh + 1;
+ return ptr;
}
}
- onbytes = (oh->h.size - 1) * sizeof(Header);
if ((new = malloc(nbytes)) == NULL)
return NULL;
- n = (onbytes > nbytes) ? nbytes : onbytes;
+ n = (oh->h.size - 1) * sizeof(Header);
+ if (n > nbytes)
+ n = nbytes;
memcpy(new, ptr, n);
free(ptr);