Use dmalloc instead of EFence when available (dmalloc has lot of improvements

over EFence and also hopefully smaller memory overhead, but sadly it's non-free
for commercial use).

If the DMALLOC_OPTIONS environment variable is not set, switch on `reasonable'
checks by default.

Also introduced mb_allocz() for cleared mb_alloc().

lib/resource.c

@@ -8,6 +8,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "nest/bird.h"
 #include "lib/resource.h"
@@ -156,6 +157,14 @@ mb_alloc(pool *p, unsigned size)
   return b->data;
 }
 
+void *
+mb_allocz(pool *p, unsigned size)
+{
+  void *x = mb_alloc(p, size);
+  bzero(x, size);
+  return x;
+}
+
 void
 mb_free(void *m)
 {

lib/resource.h

@@ -43,6 +43,7 @@ extern pool root_pool;
 /* Normal memory blocks */
 
 void *mb_alloc(pool *, unsigned size);
+void *mb_allocz(pool *, unsigned size);
 void mb_free(void *);
 
 /* Memory pools with linear allocation */
@@ -62,9 +63,24 @@ slab *sl_new(pool *, unsigned size);
 void *sl_alloc(slab *);
 void sl_free(slab *, void *);
 
-/* Low-level memory allocation functions, please don't use */
+/*
+ * Low-level memory allocation functions, please don't use
+ * outside resource manager and possibly sysdep code.
+ */
 
+#ifdef HAVE_LIBDMALLOC
+/*
+ * The standard dmalloc macros tend to produce lots of namespace
+ * conflicts and we use only xmalloc and xfree, so we can define
+ * the stubs ourselves.
+ */
+#define DMALLOC_DISABLE
+#include <dmalloc.h>
+#define xmalloc(size) _xmalloc_leap(__FILE__, __LINE__, size)
+#define xfree(ptr) _xfree_leap(__FILE__, __LINE__, ptr)
+#else
 void *xmalloc(unsigned);
 #define xfree(x) free(x)
+#endif
 
 #endif

lib/xmalloc.c

@@ -1,7 +1,7 @@
 /*
  *	BIRD Library -- malloc() With Checking
  *
- *	(c) 1998 Martin Mares <mj@ucw.cz>
+ *	(c) 1998--1999 Martin Mares <mj@ucw.cz>
  *
  *	Can be freely distributed and used under the terms of the GNU GPL.
  */
@@ -11,6 +11,8 @@
 #include "nest/bird.h"
 #include "lib/resource.h"
 
+#ifndef HAVE_LIBDMALLOC
+
 void *
 xmalloc(unsigned size)
 {
@@ -19,3 +21,5 @@ xmalloc(unsigned size)
     return p;
   die("Unable to allocate %d bytes of memory", size);
 }
+
+#endif