Changeset 7ad3c2f in mainline for libc/generic/mmap.c

Timestamp:

2006-03-14T16:34:17Z (19 years ago)

Author:

Ondrej Palkovsky <ondrap@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

00c4994

Parents:

79522a7

Message:

Added malloc implementation.

File:

• libc/generic/mmap.c (modified) (1 diff)

libc/generic/mmap.c

@@ -30 +30 @@
 #include <unistd.h>
 
+/** Mremap syscall */
 void *mremap(void *address, size_t size, unsigned long flags)
 {
         return (void *) __SYSCALL3(SYS_MREMAP, (sysarg_t ) address, (sysarg_t) size, (sysarg_t) flags);
 }
+
+
+static size_t heapsize = 0;
+/* Start of heap linker symbol */
+extern char _heap;
+
+/** Sbrk emulation 
+ *
+ * @param size New area that should be allocated or negative, 
+               if it should be shrinked
+ * @return Pointer to newly allocated area
+ */
+void *sbrk(ssize_t incr)
+{
+        void *res;
+        /* Check for invalid values */
+        if (incr < 0 && -incr > heapsize)
+                return NULL;
+        /* Check for too large value */
+        if (incr > 0 && incr+heapsize < heapsize)
+                return NULL;
+        /* Check for too small values */
+        if (incr < 0 && incr+heapsize > heapsize)
+                return NULL;
+
+        res = mremap(&_heap, heapsize + incr,0);
+        if (!res)
+                return NULL;
+        res = (void *)&_heap + incr;
+        heapsize += incr;
+        return res;
+}